Mobile and Wireless Networks
ITTC © James P.G. Sterbenz Communication Networks The University of Kansas EECS 780 MAC; Mobile and Wireless Networks
James P.G. Sterbenz
Department of Electrical Engineering & Computer Science Information Technology & Telecommunications Research Center The University of Kansas
http://www.ittc.ku.edu/~jpgs/courses/nets
19 November 2018 rev. 18.1 © 2004–2018 James P.G. Sterbenz ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks Outline
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-2 ITTC © James P.G. Sterbenz Wireless Networks Classification of Types
• Geographic scope – distance over which links operate – area of layer 2 subnetwork (not IP subnet) • Mobility – mobility of wireless nodes • Coördination – centralised vs. distributed control
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-3 ITTC © James P.G. Sterbenz Wireless Networks Classification of Types: Scope
• Geographic scope – WBAN: wireless body area network – WPAN: wireless personal area network – WLAN: wireless local area network – WMAN: wireless metropolitan network – WWAN: wireless wide area network • Mobility • Coördination
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-4 ITTC © James P.G. Sterbenz Wireless Networks Classification of Types: Mobility
• Geographic scope – WBAN, WPAN, WLAN, WMAN, WWAN • Mobility – fixed: nodes are stationary • WMN: wireless mesh network – mobile: nodes are mobile • some nodes may be fixed (e.g. base stations) • nodes mobile and self-organizing: MANET (mobile ad hoc net) – nomadic: nodes are highly and routinely mobile may be frequently out of range of one-another • DTN: disruption-tolerant network • Coördination 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-5 ITTC © James P.G. Sterbenz Wireless Networks Classification of Types: Coördination
• Geographic scope – WBAN, WPAN, WLAN, WMAN, WWAN • Mobility – fixed, mobile, nomadic – WMN, MANET, DTN • Coördination – infrastructure: base station controls and transit traffic – ad hoc or peer-to-peer: mobile nodes directly communicate • WMN (wireless mesh network) • MANET (mobile ad hoc network)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-6 ITTC © James P.G. Sterbenz Wireless Networks Characteristics
• Wireless LANs very different from wired why?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-7 ITTC © James P.G. Sterbenz Wireless Networks Characteristics
• Wireless LANs very different from wired – always use shared medium; MAC is required • Wireless characteristics – significant attenuation 1/r 2 • multipath reflections increases attenuation to ≈ 1/r 4 – noise and interference • from one-another • from other devices • from environment • jamming (physical DoS) – open channel • subject to eavesdropping
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-8 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Base Station
• Base station (BS) or cell Access point (AP)
– fixed wireless node BS • one or more antennæ • may be small (e.g. home gateway) • may have huge tower Internet – range may be called a cell • particularly in context of mobile telephony – typically connected to Internet via wired link • in which case it is an intermediate system
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-9 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Base Station
• Base station (BS) or cell Access point (AP) – fixed wireless node BS BS • one or more antennæ • may be small (e.g. home gateway) • may have huge tower Internet – range is frequently called a cell – typically connected to Internet via wired link – or wireless multihop to Internet access • wireless backhaul through other BSs • peer-to-peer multihop between wireless nodes
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-10 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Wireless Node
• Base station or access point cell • Wireless node (WN)
– also called untethered node BS BS – no wired network connection – fixed or stationary node doesn’t move Internet • wireless does not imply mobility WN • typical example: laptop personal computer – mobile node later WN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-11 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Wireless Link
• Base station or access point cell • Wireless node
• Wireless link BS BS – formed when 2 nodes in range associate Internet – MAC needed to arbitrate medium access WN
WN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-12 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Wireless Link
• Base station or access point cell • Wireless node
• Wireless link BS BS – nodes associate; MAC arbitrates
– interconnects BSs Internet • for backhaul to Internet WN • as mesh network infrastructure WN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-13 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Wireless Link
• Base station or access point cell • Wireless node
• Wireless link BS BS – nodes associate; MAC arbitrates
– interconnects BSs Internet – interconnects WNs to BSs for access WN
WN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-14 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Wireless Link
• Base station or access point cell • Wireless node
• Wireless link BS BS – nodes associate; MAC arbitrates
– interconnects BSs for backhaul Internet – interconnects WNs to BSs WN – interconnects WNs WN • for multihop access to BS • peer-to-peer in ad hoc net • multihop WNs are both ES and IS
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-15 ITTC © James P.G. Sterbenz Wireless Networks Network Elements: Wireless / Mobile
• Base station or access point cell • Wireless node
• Wireless link BS BS – nodes associate; MAC arbitrates
– interconnects BSs for backhaul Internet – interconnects WNs to BSs WN – interconnects WNs WN • for multihop access to BS • peer-to-peer in ad hoc net • multihop WNs are both ES and IS • Wireless does not imply mobile 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-16 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.2 MAC Functions and Services
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-17 ITTC © James P.G. Sterbenz Medium Access Layer Hybrid Layer/Plane Cube
management plane MAC layer: data plane control plane arbitration to shared L8 social medium in L7 application control plane L5 session L4 transport L3 network L2.5 virtual link L2 link L1.5 MAC L1 physical 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-18 ITTC © James P.G. Sterbenz Medium Access Layer MAC Definition
network CPU CPU
M app M app station station
• Medium access control (MAC) arbitrates a channel in shared medium (free space, guided wire, or fiber) among stations (end systems, hosts)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-19 ITTC © James P.G. Sterbenz Link and MAC Layer MAC Protocol application application session session transport transport network network network network link/MAC link/MAC link/MAC link/MAC end system intermediate intermediate end system network (station) system system (station) link/MAC network intermediate system • MAC protocol (or algorithm) – responsible for determining when node can transmit frame – may fully distributed or coördinated
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-20 ITTC © James P.G. Sterbenz MAC Layer Service and Interfaces
• MAC is in between physical layer 1 and link layer 2 – lower link sublayer in IEEE 802 model • MAC layer in control plane – control over when to transmit a L2 frame – but may have its own encapsulation (e.g. IEEE 802 legacy) • layer 2 addresses needed for shared medium • MAC layer service to link layer (L2) – MAC layer encapsulate/decapsulate if appropriate – initiate transfer of frame into the medium
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-21 ITTC © James P.G. Sterbenz MAC Layer Service and Interfaces
• MAC layer frame may encapsulate link layer frame – done for link layer / MAC protocol independence • IEEE 802: 802.2 LLC (logical link control) over 802.N MAC
link layer link layer
H NPDU T frame H NPDU T MAC layer MAC layer
H H NPDU T frame H H NPDU T …10111001010… physical layer physical layer
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-22 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.3 MAC Algorithms
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.3.1 Channel partitioning MW.3.2 Coördinated access MW.3.3 Random access MW.3.4 Spread spectrum MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-23 ITTC © James P.G. Sterbenz Link Sharing Multiplexing vs. Multiple Access
• Multiplexing vs. multiple access • Link multiplexing Lecture LL – single transmitter – dedicated point-to-point link • Multiple access: – multiple transmitters – shared medium – essentially physical layer multiplexing – MAC algorithm needed to arbitrate
free space RF
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-24 ITTC © James P.G. Sterbenz MAC Algorithms MW.3.1 Channel Partitioning
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.3.1 Channel partitioning MW.3.2 Coördinated access MW.3.3 Random access MW.3.4 Spread spectrum MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-25 ITTC © James P.G. Sterbenz Channel Partitioning MAC Introduction and Assumptions
• Channel has sufficient capacity – individual inter-station date rates less than channel capacity • Multiple stations share a channel
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-26 ITTC © James P.G. Sterbenz Channel Partitioning MAC Introduction and Assumptions
• Channel has sufficient capacity – individual inter-station date rates less than channel capacity • Multiple stations share a channel • Channel partitioned into pieces – pieces assigned to individual inter-station communication – MAC arbitrates assignment
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-27 ITTC © James P.G. Sterbenz Channel Partitioning MAC Introduction and Assumptions
• Channel has sufficient capacity – individual inter-station date rates less than channel capacity • Multiple stations share a channel • Channel partitioned into pieces – pieces assigned to individual inter-station communication – MAC arbitrates assignment • Contention-free MAC – partitioning ensures no contention in medium • subject to engineering and design, e.g. sufficient guard bands
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-28 ITTC © James P.G. Sterbenz Channel Partitioning MAC Alternatives
• TDMA: time division multiple access • FDMA: frequency division multiple access – typically refers to RF – WDMA: wavelength division multiple access (light) • CDMA: code-division multiple access – spread spectrum (later) • SDMA: space-division multiple access – directional antennæ • Note similarity to multiplexing schemes – TDMA ~ TDM, WDMA ~ WDM – essentially distributed physical layer versions of link muxing 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-29 ITTC © James P.G. Sterbenz Channel Partitioning MAC TDMA
• TDMA: time division multiple access
• Channel divided into n time slots ti – served cyclically
– generally equal size 1 –
– within a frequency band f n
channel 0 channel
channel channel 1 channel
channel 0 channel t f
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-30 ITTC © James P.G. Sterbenz Channel Partitioning MAC TDMA
• TDMA: time division multiple access • Channel divided into n time slots – served cyclically – generally equal size – within a frequency band f • MAC arbitrates how nodes assigned to slots – static TDMA: slots reserved for particular stations (nodes) – dynamic TDMA: slots scheduled based on traffic demand
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-31 ITTC © James P.G. Sterbenz Channel Partitioning MAC FDMA
• FDMA: frequency division multiple access
• Channel divided into n frequency bands fj – generally of equal bandwidth
– over period of time t
1
–
n
channel 0 channel channel 2 channel
channel 1 channel t channel f
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-32 ITTC © James P.G. Sterbenz Channel Partitioning MAC FDMA
• FDMA: frequency division multiple access
• Channel divided into n frequency bands fj – generally of equal bandwidth – over period of time t • MAC arbitrates how nodes assigned to frequencies – static – dynamic
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-33 ITTC © James P.G. Sterbenz Channel Partitioning MAC WDMA
• Medium: fiber optic cable • Channel divided into wavelengths • MAC arbitrates how stations assigned to wavelengths – example: multiple transmitters attached to star coupler • Distinction from WDM – WDM multiplexing determined by higher layers • e.g. network layer assignment of flows to wavelengths – distinction between WDM and WDMA subtle
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-34 ITTC © James P.G. Sterbenz Channel Partitioning MAC OFDMA
• OFDMA: orthogonal freq. div. multiple access – based on OFDM using multiple carriers • Channel consists of frequency band – divided into closely spaced carriers – adjacent carriers non-interfering: orthogonal • Each link assigned subset of carriers • MAC arbitrates how stations carrier subset
todo: fig
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-35 ITTC © James P.G. Sterbenz Channel Partitioning MAC Link Duplexing
• Link types – half duplex: unidirectional hop-by-hop transfer – full duplex: bidirectional hop-by-hop transfer • Most communication requires full duplex link – even unidirectional data transfer why?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-36 ITTC © James P.G. Sterbenz Channel Partitioning MAC Link Duplexing
• Link types – half duplex: unidirectional hop-by-hop transfer – full duplex: bidirectional hop-by-hop transfer • Most communication requires full duplex link – even unidirectional data transfer – control messages such as ACKs for ARQ – may be highly asymmetric
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-37 ITTC © James P.G. Sterbenz Channel Partitioning MAC Link Duplexing
• Link types – half duplex: unidirectional hop-by-hop transfer – full duplex: bidirectional hop-by-hop transfer • Most communication requires full duplex link – even unidirectional data transfer – control messages such as ACKs for ARQ – may be highly asymmetric – Alternative strategies for full duplex – separate end-to-end paths problem?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-38 ITTC © James P.G. Sterbenz Channel Partitioning MAC Link Duplexing
• Link types – half duplex: unidirectional hop-by-hop transfer – full duplex: bidirectional hop-by-hop transfer • Most communication requires full duplex link – even unidirectional data transfer – control messages such as ACKs for ARQ – may be highly asymmetric – Alternative strategies for full duplex – separate distinct end-to-end paths through network – may have different loss & delay properties – may be necessary in some cases (e.g. satellite)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-39 ITTC © James P.G. Sterbenz Channel Partitioning MAC Link Duplexing
• Link types – half duplex: unidirectional hop-by-hop transfer – full duplex: bidirectional hop-by-hop transfer • Most communication requires full duplex link – even unidirectional data transfer – control messages such as ACKs for ARQ – may be highly asymmetric – Alternative strategies for full duplex – separate distinct end-to-end paths through network – paired unidirectional links in same guided media – e.g. 2twisted-pair, 2fiber
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-40 ITTC © James P.G. Sterbenz Channel Partitioning MAC Link Duplexing
• Link types – half duplex: unidirectional hop-by-hop transfer – full duplex: bidirectional hop-by-hop transfer • Most communication requires full duplex link – even unidirectional data transfer – control messages such as ACKs for ARQ – may be highly asymmetric – Alternative strategies for full duplex – separate distinct end-to-end paths through network – paired unidirectional links in same guided media – sharing same media (e.g. fiber or free space) 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-41 ITTC © James P.G. Sterbenz Channel Partitioning MAC Frequency Division Duplexing
• Duplexing : bidirectional transmission sharing media • FDD: frequency division duplexing – forward and reverse traffic assigned to different freq. bands advantages and disadvantages?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-42 ITTC © James P.G. Sterbenz Channel Partitioning MAC Frequency Division Duplexing
• Duplexing : bidirectional transmission sharing media • FDD: frequency division duplexing – forward and reverse traffic assigned to different freq. bands – simple scheme – no collisions between forward and reverse packets – less efficient use of spectrum under light load
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-43 ITTC © James P.G. Sterbenz Channel Partitioning MAC Frequency Division Duplexing
• Duplexing : bidirectional transmission sharing media • FDD: frequency division duplexing – FDD can be used within FDMA or TDMA
FDD in FDMA FDD in TDMA
1
–
n
1
–
channel 0 channel
n channel
forward / reverse / 1 channel
channel 0 channel
channel 0 channel channel 2 channel
channel 1 channel t uplink downlink t channel f f 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-44 ITTC © James P.G. Sterbenz Channel Partitioning MAC Time Division Duplexing
• Multiplexing in time and space for full duplex – bidirectional data transmission • FDD: frequency division duplexing • TDD: time division duplexing – forward and reverse traffic assigned to same freq. bands advantages and disadvantages?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-45 ITTC © James P.G. Sterbenz Channel Partitioning MAC Time Division Duplexing
• Multiplexing in time and space for full duplex – bidirectional data transmission • FDD: frequency division duplexing • TDD: time division duplexing – forward and reverse traffic assigned to same freq. bands – slots divided between upstream and downstream traffic – asymmetric traffic needs dynamic bandwidth adjustment – operates in conjunction with various channel multiplexing • eg. TDD within FDMA
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-46 ITTC © James P.G. Sterbenz Channel Partitioning MAC Time Division Duplexing
• Duplexing : bidirectional transmission sharing media • TDD: time division duplexing – TDD in FDMA allows each pair to separately determine ratio
TDD in FDMA TDD in TDMA
1
– n
rev / 1
– dwnlink channel 0 channel n fwd /
uplink channel
channel 1 channel
channel 0 channel
channel 0 channel channel 2 channel
channel 1 channel t t channel f f 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-47 ITTC © James P.G. Sterbenz Channel Partitioning MAC Advantages and Disadvantages
• Channel partitioning advantages and disadvantages?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-48 ITTC © James P.G. Sterbenz Channel Partitioning MAC Advantages and Disadvantages
• Channel partitioning advantages – simple mechanism (if static) – inherently fair with respect to station sharing – best under high uniform and deterministic load
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-49 ITTC © James P.G. Sterbenz Channel Partitioning MAC Advantages and Disadvantages
• Channel partitioning advantages – simple mechanism – inherently fair with respect to station sharing – best under high uniform and deterministic load • Channel partitioning disadvantages – per flow fairness more difficult – inefficient under low load • 1/n of channel bandwidth unless multiple partitions/station – inefficient under high-nondeterministic load • distributed partition assignment difficult; controller assigns • multiple or variable partition sizes difficult to manage
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-50 ITTC © James P.G. Sterbenz Channel Partitioning MAC SDMA and Directional Antennæ
• Assumption so far – omnidirectional antennæ radiate in all directions problem?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-51 ITTC © James P.G. Sterbenz Channel Partitioning MAC SDMA and Directional Antennæ
• Assumption so far – omnidirectional antennæ radiate in all directions – radiate even where not needed – reduce channel capacity • Directional antennæ – radiate focused beam toward receiver – reduce power use – reduce interference: spatial reuse • SDMA: space division multiple access MAC – complexity of beam steering and station tracking
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-52 ITTC © James P.G. Sterbenz Channel Partitioning MAC Characteristics Channel Cöordinated Random Spread Characteristic Partitioning Access Access Spectrum TDMA Types (O)FDMA SDMA low Complexity (static) high Load Tolerance (uniform det.) Consequence of – Contention poor Resilience (central ctl)
Examples 802.16 mesh
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-53 ITTC © James P.G. Sterbenz MAC Algorithms MW.3.2 Coördinated Access MAC
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.3.1 Channel partitioning MW.3.2 Coördinated access MW.3.3 Random access MW.3.4 Spread spectrum MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-54 ITTC © James P.G. Sterbenz Coördinated Access MAC Introduction and Assumptions
• Channel has sufficient capacity – individual inter-station date rates less than channel capacity • Multiple stations share a channel
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-55 ITTC © James P.G. Sterbenz Coördinated Access MAC Introduction and Assumptions
• Channel has sufficient capacity – individual inter-station date rates less than channel capacity • Multiple stations share a channel • Stations use channel for a period of time – in a fully highly coördinated manner • central controller (e.g. polling) • algorithmic turn taking (e.g. token passing) – MAC arbitrates
[Kurose & Ross] call this taking turns MAC
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-56 ITTC © James P.G. Sterbenz Coördinated Access MAC Polling
• Controller grants channel access to station – each station polled to determine if it needs to transmit
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-57 ITTC © James P.G. Sterbenz Coördinated Access MAC Token Passing
• Token grants channel access to station – token passed between stations – generally round robin • Topologies – bus • IEEE 802.4 never successful – natural ring interconnection • IEEE 802.5
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-58 ITTC © James P.G. Sterbenz Coördinated Access MAC Token Passing Resilience
• Token ring interface – inserted in the ring what happens when station turned off?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-59 ITTC © James P.G. Sterbenz Coördinated Access MAC Token Passing Resilience
• Token ring interface – inserted in the ring – relay required to close circuit
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-60 ITTC © James P.G. Sterbenz Coördinated Access MAC Token Passing Resilience
• Token ring interface – inserted in the ring – relay required to close circuit • Resilience to ring cuts problems?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-61 ITTC © James P.G. Sterbenz Coördinated Access MAC Token Passing Resilience
• Token ring interface – inserted in the ring – relay required to close circuit • Resilience to ring cuts – user unplugging station cuts ring
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-62 ITTC © James P.G. Sterbenz Coördinated Access MAC Token Passing Resilience
• Token ring interface – inserted in the ring – relay required to close circuit • Resilience to ring cuts – user unplugging station cuts ring – dual ring resilient to single cut • stations wrap to second ring
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-63 ITTC © James P.G. Sterbenz Coördinated Access MAC Advantages and Disadvantages
• Channel partitioning – simple mechanism, best for high uniform load • Coördinated access advantages and disadvantages?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-64 ITTC © James P.G. Sterbenz Coördinated Access MAC Advantages and Disadvantages
• Channel partitioning – simple mechanism, best for high uniform load – needs controller to assign time slots or frequency bands • Coördinated access advantages – nondeterministic algorithm good for nonuniform loads – balances benefits of partitioning and random access – good for relatively high load
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-65 ITTC © James P.G. Sterbenz Coördinated Access MAC Advantages and Disadvantages
• Channel partitioning – simple mechanism, best for high uniform load – needs controller to assign time slots or frequency bands • Coördinated access advantages – nondeterministic algorithm good for nonuniform loads – balances benefits of partitioning and random access – good for relatively high load • Coördinated access disadvantages – relatively complex network interface
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-66 ITTC © James P.G. Sterbenz Coördinated Access MAC Characteristics Channel Cöordinated Random Spread Characteristic Partitioning Access Access Spectrum TDMA token ring Types (O)FDMA polling SDMA low Complexity high (static) high Load Tolerance high (uniform det.) Consequence of – degradation Contention poor wired: moderate Resilience (central ctl) wireless: poor
Examples 802.16 mesh 802.5 TR
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-67 ITTC © James P.G. Sterbenz MAC Algorithms MW.3.3 Random Access MAC
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.3.1 Channel partitioning MW.3.2 Coördinated access MW.3.3 Random access MW.3.4 Spread spectrum MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-68 ITTC © James P.G. Sterbenz Random Access MAC Introduction and Assumptions
• Multiple stations share a channel f • Stations use channel for a period of time t – given a frequency channel (baseband access) – in a fully distributed (random ) manner – MAC arbitrates t f
What is simplest possible random access technique?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-69 ITTC © James P.G. Sterbenz Random Access MAC ALOHA
• ALOHA: 1970s radio network among Hawaiian islands • Senders transmit whenever they have data (no MAC)
A B C
t • Performance metrics – channel efficiency • what fraction of transmission attempts are successful – channel throughput • what is the maximum carried load of the channel?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-70 ITTC © James P.G. Sterbenz Random Access MAC ALOHA
• ALOHA: 1970s radio network among Hawaiian islands • Senders transmit whenever they have data (no MAC)
A B C
t • Problem – collisions : transmissions interfere with one another
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-71 ITTC © James P.G. Sterbenz Random Access MAC ALOHA
• ALOHA: 1970s radio network among Hawaiian islands • Senders transmit whenever they have data (no MAC)
A B C
t • Problem – collisions : transmissions interfere with one another – even if only very small overlap
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-72 ITTC © James P.G. Sterbenz Random Access MAC ALOHA
• ALOHA: 1970s radio network among Hawaiian islands • Senders transmit whenever they have data (no MAC)
A B C
t • Problem – collisions : transmissions interfere with one another – even if only very small overlap can we do better?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-73 ITTC © James P.G. Sterbenz Random Access MAC Slotted ALOHA
• ALOHA: 1970s radio network among Hawaiian islands • Senders transmit whenever they have data in slot
A B C
t • Problem – collisions : transmissions interfere with one another – improvement: divide time into slots
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-74 ITTC © James P.G. Sterbenz Random Access MAC Slotted ALOHA
• ALOHA: 1970s radio network among Hawaiian islands • Senders transmit whenever they have data in slot
A B C
t • Problem – collisions : transmissions interfere with one another – improvement: divide time into slots – delay transmissions to next slot time
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-75 ITTC © James P.G. Sterbenz Random Access MAC Slotted ALOHA
• ALOHA: 1970s radio network among Hawaiian islands • Senders transmit whenever they have data in slot
A B C
t • Problem – collisions : transmissions interfere with one another – improvement: divide time into slots – delay transmissions to next slot time – slotted time reduces probability of collisions
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-76 ITTC © James P.G. Sterbenz Random Access MAC Unslotted vs. Slotted Performance
0.40 [adapted from Tannenbaum]
0.30 slotted 0.20
0.10 unslotted [throughput [throughput / packet time] 0.0 0.5 1.0 1.5 2.0 2.5 3.0
G [attempts / packet time]
• Slotting approximately doubles performance – slotted: Throughput = GeG – unslotted: Throughput = Ge2G
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-77 ITTC © James P.G. Sterbenz Random Access MAC Challenges
• Multiple nodes must be able to share channel • When 2 or more nodes simultaneously transmit – signals garbled in a collision : none of them are successful • How to arbitrate among them? – MAC algorithm
How can we do better than random transmission?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-78 ITTC © James P.G. Sterbenz Random Access MAC Contention
• Contention-based or random-access MAC – nodes transmit when they have data – subject to MAC • per frame decision • analogue to connectionless service – collisions possible – efficient channel utilisation • in the absence of collisions • Note: – partitioned MAC is sometimes referred to as contention-free
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-79 ITTC © James P.G. Sterbenz Random Access MAC Contention and Collisions
What is the simplest way to reduce collisions?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-80 ITTC © James P.G. Sterbenz Random Access MAC CSMA (1-persistant)
• CSMA – carrier sense multiple access – nodes can sense if channel is in use by another station – wait to transmit to avoid collision – human analogy: don’t interrupt others already speaking • 1-persistant CSMA – wait until channel free, then transmit (transmit with probability 1) Problem? How can we do better?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-81 ITTC © James P.G. Sterbenz Random Access MAC CSMA (non- and p -persistent)
• Problem: synchronisation of collisions – waiting nodes will all transmit as soon as channel free • Non-persistent CSMA – if carrier sensed wait random period before trying again (rather than continuously sensing until channel free) – better utilisation, but delayed even when unnecessary • p -persistent CSMA (for slotted time) – continuously sense carrier until channel is available – but with only with probability p transmit on next slot
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-82 ITTC © James P.G. Sterbenz CSMA Collisions
• Collisions occur even with carrier sense – due to propagation delay – sender may not know channel already in use
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-83 ITTC © James P.G. Sterbenz CSMA Collisions
• Collisions still occur A B C D – due to propagation delay – sender may not know channel already in use • Pr[collision] incr. w/ length – B & D don’t know other xmit
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-84 ITTC © James P.G. Sterbenz CSMA Collisions
• Collisions still occur A B C D – due to propagation delay – sender may not know channel already in use • Pr[collision] incr. w/ length – B & D don’t know other xmit – until signals meet near C – and return • Inefficient – channel used by garbage Can we do better? 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-85 ITTC © James P.G. Sterbenz CSMA/CD Collision Detection
• CSMA/CD: CSMA with collision detection – station detecting a collision immediately ceases transmission – human analogy: polite conservationist • Worst case CD takes twice media propagation delay – A transmits packet
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-86 ITTC © James P.G. Sterbenz CSMA/CD Collision Detection
• CSMA/CD: CSMA with collision detection – station detecting a collision immediately ceases transmission – human analogy: polite conservationist • Worst case CD takes twice media propagation delay – A transmits packet
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-87 ITTC © James P.G. Sterbenz CSMA/CD Collision Detection
• CSMA/CD: CSMA with collision detection – station detecting a collision immediately ceases transmission – human analogy: polite conservationist • Worst case CD takes twice media propagation delay – A transmits packet – B transmits packet just before A reaches B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-88 ITTC © James P.G. Sterbenz CSMA/CD Collision Detection
• CSMA/CD: CSMA with collision detection – station detecting a collision immediately ceases transmission – human analogy: polite conservationist • Worst case CD takes twice media propagation delay – A transmits packet – B transmits packet just before A reaches B – A+B interference travels back to A
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-89 ITTC © James P.G. Sterbenz CSMA/CD Collision Detection Efficiency
• CD frees channel earlier A B C D
= 1 / [1+5tprop/ttrans] tprop max prop between nodes ttrans time to transmit max frame • Efficiency
1 as tprop 0
1 as ttrans ∞
reclaimed capacity
CD and abort
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-90 ITTC © James P.G. Sterbenz CSMA/CD Collision Detection Efficiency
• CD frees channel earlier A B C D
= 1 / [1+5tprop/ttrans] tprop max prop between nodes ttrans time to transmit max frame • Efficiency
1 as tprop 0
1 as ttrans ∞ • Much better than CSMA – still decentralized, reclaimed simple, and cheap capacity problem? CD and abort
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-91 ITTC © James P.G. Sterbenz CSMA/CD Backoff
• If stations all transmit after backoff, same problem – need some way of un-synchronising retransmissions How?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-92 ITTC © James P.G. Sterbenz CSMA/CD Exponential Backoff
• If stations all transmit after backoff, same problem – need some way of un-synchronising transmissions • Exponential backoff: – stations wait a random number of slot times before retrying – binary exponential distribution: nth collision wait randomly among {0…2n–1} slots 1st collision: wait 0 or 1 slots 2nd collision: wait 0, 1, 2, or 3 slots … – low load: minimise delay moderate load: spread retries
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-93 ITTC © James P.G. Sterbenz CSMA/CD Problems
Problems?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-94 ITTC © James P.G. Sterbenz CSMA/CD Problems: Collision Detection and Carrier Sense
Problem with collision detection?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-95 ITTC © James P.G. Sterbenz CSMA/CD Problem with Collision Detection
• Problems with collision detection – station must be able to simultaneously transmit and receive • requires full duplex – not possible for single wireless tranceiver at given frequency • CSMA/CD not appropriate for wireless networks – Ethernet evolution eliminated vast majority of CSMA/CD
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-96 ITTC © James P.G. Sterbenz CSMA Problem with Carrier Sense
• CSMA/CD not appropriate for wireless networks Problem with carrier sense?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-97 ITTC © James P.G. Sterbenz CSMA Problem with Carrier Sense
• CSMA/CD not appropriate for wireless networks • Problem with carrier sense – only appropriate when all nodes within range – typically not the case for wireless networks problem?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-98 ITTC © James P.G. Sterbenz CSMA Problem with Carrier Sense
• CSMA/CD not appropriate for wireless networks • Problem with carrier sense – only appropriate when all nodes within range – typically not the case for wireless networks – problem: hidden nodes
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-99 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden nodes (terminals) – some nodes are hidden from one another – out of transmission range or obstruction – unaware that they are causing collisions with hidden node
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-100 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden node problem
C
B A
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-101 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden node problem – A can communicate with B
C
B A
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-102 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden node problem – A can communicate with B
– C can communicate with B C
B A
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-103 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden node problem – A can communicate with B
– C can communicate with B C – A can not communicate with C B A
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-104 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden node problem – A can communicate with B
– C can communicate with B C – A can not communicate with C B • unaware of interference at B A
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-105 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden node problem – A can communicate with B
– C can communicate with B C – A can not communicate with C B • unaware of interference at B A • Causes of hidden nodes – line-of-sight obstructions
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-106 ITTC © James P.G. Sterbenz CSMA Hidden Nodes
• Hidden node problem – A can communicate with B
– C can communicate with B C – A can not communicate with C B • unaware of interference at B A • Causes of hidden nodes – line-of-sight obstructions – signal attenuation • limited transmission range A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-107 ITTC © James P.G. Sterbenz CSMA Exposed Nodes
• Exposed nodes (terminals) problem?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-108 ITTC © James P.G. Sterbenz CSMA Exposed Nodes
• Exposed nodes (terminals) – some nodes are in range of one another – prevent transmission because collision assumed
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-109 ITTC © James P.G. Sterbenz CSMA Exposed Nodes
• Exposed nodes (terminals) – some nodes are in range of one another – prevent transmission because collision assumed • Example: – B transmitting to C
B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-110 ITTC © James P.G. Sterbenz CSMA Exposed Nodes
• Exposed nodes (terminals) – some nodes are in range of one another – prevent transmission because collision assumed • Example: – B transmitting to C – but A hears B: won’t transmit due to carrier sense
A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-111 ITTC © James P.G. Sterbenz CSMA Exposed Nodes
• Exposed nodes (terminals) – some nodes are in range of one another – prevent transmission because collision assumed • Example: – B transmitting to C – but A hears B: won’t transmit due to CA – even though it could to D without jamming BC
D A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-112 ITTC © James P.G. Sterbenz CSMA Exposed Nodes
• Exposed nodes (terminals) – some nodes are in range of one another – prevent transmission because collision assumed Solution?
D A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-113 ITTC © James P.G. Sterbenz CSMA Exposed Nodes
• Exposed nodes (terminals) – some nodes are in range of one another – prevent transmission because collision assumed • Spatial reuse necessary (SDMA) – directional antennæ one strategy EECS 882
D A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-114 ITTC © James P.G. Sterbenz CSMA Alternative Improvement to CD
• CSMA/CD not practical for wireless networks – full duplex problem – hidden terminal problem Alternatives that are still better than (pure ) CSMA?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-115 ITTC © James P.G. Sterbenz CSMA Collision Avoidance
• Collision avoidance (CA) – attempt to avoid collision (but don’t detect once occurs)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-116 ITTC © James P.G. Sterbenz CSMA Collision Avoidance: Floor Acquisition
• Floor acquisition (FAMA: floor access multiple access) – efficient negation to determine which node transmits – may be in-band or out-of band (e.g. signalling frequency) – similar to audio conference floor acquisition protocols
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-117 ITTC © James P.G. Sterbenz CSMA/CA MACA
• MACA: multiple access with collision avoidance – in-band floor acquisition How?
A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-118 ITTC © James P.G. Sterbenz CSMA/CA MACA
• MACA: multiple access with collision avoidance – in-band floor acquisition • MACA operation (analogy: teleconference “may I”) – sender transmits RTS (request to send) if no carrier sense
RTS
A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-119 ITTC © James P.G. Sterbenz CSMA/CA MACA
• MACA: multiple access with collision avoidance – in-band floor acquisition • MACA operation – sender transmits RTS (request to send) – intended receiver replies with CTS (clear to send) – all nodes in range of both will detect at least 1 of RTS/CTS
CTS CTS
A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-120 ITTC © James P.G. Sterbenz CSMA/CA MACA
• MACA: multiple access with collision avoidance – in-band floor acquisition • MACA operation – sender transmits RTS (request to send) – intended receiver replies with CTS (clear to send) – all nodes in range of both will detect at least 1 of RTS/CTS – if sender receives clear CTS it can transmit
A B C
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-121 ITTC © James P.G. Sterbenz CSMA/CA MACAW
• MACAW: MACA for wireless – CSMA/CA – data frames acknowledged – exponential backoff per send/receive pair – modified backoff algorithm
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-122 ITTC © James P.G. Sterbenz Random Access MAC Characteristics Channel Cöordinated Random Spread Characteristic Partitioning Access Access Spectrum TDMA ALOHA, slot token ring Types (O)FDMA polling CSMA SDMA CD, CA low Complexity high low (static) high Load Tolerance higher lower (uniform det.) Consequence of – degradation collisions Contention poor wired: moderate Resilience good (central ctl) wireless: poor 802.11 old Ethernet Examples 802.5 TR 802.16 mesh 802.11 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-123 ITTC © James P.G. Sterbenz MAC Algorithms MW.3.4 Spread Spectrum MAC
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.3.1 Channel partitioning MW.3.2 Coördinated access MW.3.3 Random access MW.3.4 Spread spectrum MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-124 ITTC © James P.G. Sterbenz Spread Spectrum MAC Introduction and Assumptions
• Multiple stations share a channel • Stations use channel for a period of time
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-125 ITTC © James P.G. Sterbenz Spread Spectrum MAC Introduction and Assumptions
• Multiple stations share a channel • Stations use channel for a period of time • Transmission spread in frequency spectrum – coding techniques avoid interference • CDMA: code division multiple access
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-126 ITTC © James P.G. Sterbenz Spread Spectrum MAC CDMA
• CDMA: code division multiple access • Channel use different codes – in a given frequency band – over period of time code n –1 • Analogy: speaking c – English, German, code 1 t Chinese, Hindi code 0 – in the same room f at the same time – easier to converse in a given language (code) if interference is in different languages (codes)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-127 ITTC © James P.G. Sterbenz Spread Spectrum MAC CDMA Types
• Frequency hopping (FH) – transmissions rapidly hop among different frequency carriers • pseudorandom sequence negotiated between transceiver • interference limited to small periods of time under limited load • Direct sequence (DS)
code n –1 c code 1 t t code 0 f f 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-128 ITTC © James P.G. Sterbenz Spread Spectrum MAC CDMA Types
• Frequency hopping (FH) – transmissions rapidly hop among different frequency carriers • pseudorandom sequence negotiated between tranceivers • Direct sequence (DS) – symbols multiplied by higher frequency chipping sequence
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-129 ITTC © James P.G. Sterbenz Spread Spectrum MAC DS CDMA Concepts
• All stations share same frequency band f – unique code assigned to each station • Each station has its own chipping sequence in time t – unique code at higher chipping rate – encoded signal = (original data) (chipping sequence) – decoding: inner-product of encoded signal and chipping seq. • Multiple stations transmit simultaneously – minimal interference if codes are orthogonal analogy : conversations at the same time in different languages
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-130 ITTC © James P.G. Sterbenz Spread Spectrum MAC DS CDMA Encode/Decode Example
d = 01 +1 +1+1+1+1+1+1 +1 d0=+1 d =-1 -1-1-1 -1 -1 -1-1-1 1 encode cs = 11101000 coded in channel +1+1+1 +1 +1+1+1 +1
-1 -1-1-1 -1 -1-1-1
+1+1+1 +1 +1+1+1 +1
-1 -1-1-1 -1 -1-1-1
decode d = 01 +1 +1+1+1+1+1+1 +1 d0=+1 -1-1-1 -1 -1 -1-1-1 d1=-1 [Kurose & Ross 7.2.1] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-131 ITTC © James P.G. Sterbenz Spread Spectrum MAC DS CDMA Encode/Decode with Interference d = 01 0 d01=+1 +1 +1+1+1+1+1+1 +1 d00=-1 encode -1-1-1 -1 coded -1 -1-1-1 cs0 = 11101000 +1+1+1 +1 +1+1+1 +1 -1 -1-1-1 -1 -1-1-1 coded d1 = 11 d10=+1 d11=+1 +1 +1+1+1 +1+1+1 +1+1+1 +1+1 -1 -1 -1 -1 cs1 = 10111011 encode +1 +1+1+1 +1+1+1 +1+1+1 +1+1 -1 -1 -1 -1
+2 +2+2+2 +2 +2 0 0 0 0 0 0 0 -2 -2 -2
+1+1+1 +1 +1+1+1 +1 mixed in channel
-1 -1-1-1 -1 -1-1-1 +2 +2+2+2 +2 +2 d =+1 0 0 0 0 0 0 0 01 d00=-1 -2 decode -2 -2 [Kurose & Ross 7.2.1] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-132 ITTC © James P.G. Sterbenz Spread Spectrum MAC Characteristics Channel Cöordinated Random Spread Characteristic Partitioning Access Access Spectrum TDMA ALOHA, slot token ring CDMA Types FDMA WDMA polling CSMA FH, DS SDMA CD, CA low Complexity high low high (static) high Load Tolerance higher lower degrades (uniform det.) Consequence of – degradation collisions degradation Contention poor wired: moderate resistant to Resilience good (central ctl) wireless: poor interference 802.11 old Ethernet Examples 802.5 TR 802.11 802.16 802.11 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-133 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.4 Wireless Networks
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.4.1 802.11 WLAN MW.4.2 802.16 WMAN and WiMAX MW.4.3 802.15 WPAN and Bluetooth MW.4.4 Sensor networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-134 ITTC © James P.G. Sterbenz Wireless Networks Relationship by Geographical Scope
WMAN
WLAN
WPAN
• WPAN: wireless personal area network • WLAN: wireless local area network (802.11) • WMAN: wireless metropolitan area network (802.16)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-135 ITTC © James P.G. Sterbenz Wireless Networks MW.4.1 802.11 WLAN
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.4.1 802.11 WLAN MW.4.2 802.16 WMAN and WiMAX MW.4.3 802.15 WPAN and Bluetooth MW.4.4 Sensor networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-136 ITTC © James P.G. Sterbenz Wireless Networks: WLAN 802.11 Overview
• IEEE 802.11 – wireless links based loosely on Ethernet framing • 6B MAC addresses, 4B FCS • 802.2 SNAP/LLC subheader – enables simple cheap 802.3+802.11 hubs and switches • Unlicensed ISM/U-NII bands: 900 MHz, 2.4, 5.8 GHz – significant interference from FHSS 2.4 GHz cordless phones • Additional licensed bands: 3.7 GHz
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-137 ITTC © James P.G. Sterbenz Wireless Networks: WLAN 802.11 Relation to other 802 Wireless Protocols
802.16 WMAN
802.11 WLAN
802.15 WPAN 50 m • IEEE 802.11 – first of the 802 wireless protocols – design motivated by Ethernet • was sometimes called “wireless Ethernet”
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-138 ITTC © James P.G. Sterbenz Wireless Networks: WLAN Wi-Fi Overview
• Wi-Fi – Wi-Fi alliance: www.wi-fi.org • note capitalisation and hyphen: Wi-Fi not WiFi nor Wifi – 802.11 standards compliance and interoperability testing – commonly (but incorrectly) used as synonym for 802.11 Wi-Fi ≠ 802.11!
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-139 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
Motivation for deploying WLANs?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-140 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
• Motivation for WLAN deployment – cheaper than running Ethernet cables for desktops – allows untethered access for laptops and smart phones
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-141 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
• Motivation for WLAN deployment – cheaper than running Ethernet cables for desktops – allows untethered access for laptops and smart phones • Deployment scenarios – home networks • frequently the only network infrastructure why?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-142 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
• Motivation for WLAN deployment – cheaper than running Ethernet cables for desktops – allows untethered access for laptops and smart phones • Deployment scenarios – home networks • frequently the only network infrastructure • most homes not wired for networking
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-143 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
• Motivation for WLAN deployment – cheaper than running Ethernet cables for desktops – allows untethered access for laptops and smart phones • Deployment scenarios – home networks – office buildings • generally supplements wired LANs why?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-144 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
• Motivation for WLAN deployment – cheaper than running Ethernet cables for desktops – allows untethered access for laptops and smart phones • Deployment scenarios – home networks – office buildings – hotel lobbies, meeting rooms, classrooms, outdoor areas • large spaces impractical to wire
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-145 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
• Motivation for WLAN deployment – cheaper than running Ethernet cables for desktops – allows untethered access for laptops and smart phones • Deployment scenarios – home networks – office buildings – hotel lobbies, meeting rooms, classrooms, outdoor area – wireless hotspots • free service to draw customers (e.g. Starbucks, McDonald’s) • free public service (e.g. MCI airport) • for-profit service (e.g. T-Mobile)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-146 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Scenarios
• Motivation for WLAN deployment – cheaper than running Ethernet cables for desktops – allows untethered access for laptops and smart phones • Deployment scenarios – home networks – office buildings – hotel lobbies, meeting rooms, classrooms, outdoor area – wireless hotspots – public Internet service • free public service (e.g. Lancaster University) • fee-based service (e.g. Lawrence Freenet)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-147 ITTC © James P.G. Sterbenz 802.11 WLAN
Standards Overview1 • 802.11-1997: original standard • 802.11-2007: 802.11-1997 + – 802.11a: 5.8 GHz high rate – 802.11b: 2.4 GHz higher rate – 802.11d: additional regulatory domains – 802.11e: QoS enhancements – 802.11g: 2.4 GHz further higher rate – 802.11h: Europe power management extensions – 802.11i: security enhancements – 802.11j: operation in Japan
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-148 ITTC © James P.G. Sterbenz 802.11 WLAN
Standards Overview2
• 802.11-2012: 802.11-2007 + – 802.11k: radio resource management – 802.11n: higher throughput – 802.11p: vehicular environments – 802.11r: fast handoffs between BSs – 802.11s: mesh networking – 802.11u: interworking with external networks – 802.11v: wireless network management – 802.11w: protected management frames – 802.11y: 3.7 GHz 20W licensed – 802.11z: direct link setup extensions
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-149 ITTC © James P.G. Sterbenz 802.11 WLAN
Standards Overview3
• 802.11-2016: 802.11-2012 + – 802.11aa: MAC enhancements for robust A/V streaming – 802.11ac: very high throughput < 6 GHz – 802.11ad: very high throughput in 60 GHz – 802.11ae: management frame prioritisation – 802.11af: television white spaces
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-150 ITTC © James P.G. Sterbenz 802.11 WLAN
Standards Overview4 • additional not yet rolled into base standard – 802.11ax: draft higher throughput, outdoor, heavy load – 802.11ay: higher data rates in 60 GHz – 802.11az: positioning and directionality – 802.11ba: low-power wake-up radio – 802.11bb: light communication
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-151 ITTC © James P.G. Sterbenz 802.11 WLAN Generic Frame Format
frame control • MAC Header [30B] duration / ID address 1 – frame control [2B] address 2 MAC – duration/ID [2B] header 30B – address 1 [6B] address 3 – address 2 [6B] sequence control address 4 – address 3 [6B] – sequence control [6B] – address 4 [6B] frame body 0 – 2312 B • Frame body [0–2312B]
trailer • Trailer: FCS [4B] FCS 4B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-152 ITTC © James P.G. Sterbenz 802.11 WLAN Header Format: Frame Control Type
frame control • Frame control [2B] duration / ID address 1 – protocol version [2b] = 00 address 2 MAC – type [2b] header 30B 00 = management address 3 01 = control sequence control 10 = data address 4 11 = reserved – [4b] subtype frame body • dependent on type 0 – 2312 B
trailer FCS 4B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-153 ITTC © James P.G. Sterbenz 802.11 WLAN Header Format: Frame Control Addresses
frame control • Address n [6B] duration / ID address 1 – IEEE 802-1990 MAC address address 2 MAC – types: header 30B • individual station address address 3 • multicast group 01-XX-XX-XX-XX-XX sequence control • broadcast address FF-FF-FF-FF-FF-FF address 4 – fields dependent on frame control type
• BSSID: BSS AP address frame body • DA: destination address (final recipient) 0 – 2312 B • SA: source address of frame (individual)
• RA: (immediate) receiver address trailer FCS 4B • TA: transmitter address
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-154 ITTC © James P.G. Sterbenz 802.11 WLAN Body Format
frame control • Frame body [0-2312B] duration / ID address 1 – variable length address 2 MAC – not present in control frames header 30B address 3
sequence control
address 4
frame body 0 – 2312 B
trailer FCS 4B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-155 ITTC © James P.G. Sterbenz 802.11 WLAN Trailer Format: CRC
frame control • FCS [4B] duration / ID address 1 – frame check sequence address 2 MAC – CRC-32 header 30B address 3
sequence control
address 4
frame body 0 – 2312 B
trailer FCS 4B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-156 ITTC © James P.G. Sterbenz 802.11 WLAN Management Frame
frame ctl type=10 • Management frame duration destination address (type=01 subtype [4b]): source address MAC – beacon header 24B – (re)association BSSID • request sequence control • response – probe frame body 0 – 2312 B • request • response trailer FCS – disassociation 4B – (de)authentication
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-157 ITTC © James P.G. Sterbenz 802.11 WLAN Control Frame
frame ctl type=01 • Control frame (type=01 subtype [4b]): duration / ID address 1 – collision avoidance address 2 MAC • 1011 RTS header • 1100 CTS 30B address 3
– data transfer sequence control
• 1101 ACK address 4 • 1000 BlockAckReq (802.11n) • 1001 BlockAck (802.11n) – contention free operation frame body • 1110 CF-end 0 – 2312 B • 1111 CF-end+CF-ACK trailer FCS – power save 4B • 1010 PS-poll 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-158 ITTC © James P.G. Sterbenz 802.11 WLAN Data Frame
frame ctl type=10 • Data frame (type=10) duration (s) destination address – duration (μs) source address MAC – SA: source address header 30B – DA: destination address basic service set id – BSSID of access point sequence control – sequence control address 4 LLC LLC/SNAP – frame body subheader SNAP • LLC/SNAP 8B
payload • payload payload 0 – 2304 B – FCS trailer FCS – CRC-32 4B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-159 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types
• Link types (PHY and MAC) – 802.11: original 802.11 links at 1–2 Mb/s – 802.11b, 802.11a: second set of link standards – 802.11g: third link standard; common in late 2000s – 802.11y: licensed 3.7 GHz – 802.11n: 100 Mb/s link rate common in early 2010s – 802.11ac: 500 Mb/s link rate (current) – 802.11ax: ~ 2 Gb/s link rate (under development) • Typically referred to by temporary standard number – even after folded into 802.11 revision – a,b,g in 802.11-2007; n in 802.11-2012; ac in 802.11-2016
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-160 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11b
• IEEE 802.11b – 2.4 GHz ISM/U-NII band – formerly widest deployment – 11 Mb/s maximum MAC rate • actual performance highly dependent on environment • 5 Mb/s goodput typical over 60m range with few obstructions • adequate for most home, SOHO, and hotspot use • exceeds rate of HFC and DSL access links – DSSS coding; all stations use same chipping sequences • what does this mean?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-161 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11a
• IEEE 802.11a – 5.8 GHz ISM/U-NII band • higher rate alternative to 802.11b but more expensive • simultaneously available with 802.11b – a and b were IEEE 802.11 working group numbers – 54 Mb/s maximum MAC rate • actual performance highly dependent on environment • 24 Mb/s goodput over 35m range typical – deployment limited to users that needed higher rate • high rate LAN applications • users and campuses with higher rate Internet access links – e.g. T3, 100M/1G Ethernet, SONET
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-162 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11g
• IEEE 802.11g – 2.4 GHz ISM/U-NII band • backward compatible with 802.11b • higher rate successor to 802.11b using OFDM – 54 Mb/s maximum MAC rate • actual performance highly dependent on environment – was most common deployment in mid 2000s
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-163 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11y
• IEEE 802.11y – 3 GHz licensed band – FCC “lite” licensing • nationwide license with non-interference requirements – 20mW • higher power for backhaul • e.g. hotspot meshing for city-wide 802.11 service
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-164 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11n
• IEEE 802.11n – MAC rate of ~ 100 Mb/s – MIMO (multiple-input multiple-output) antenna technology – became most common deployment in 2010s
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-165 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11n Enhancements
• 802.11n physical layer – MIMO (multiple-in multiple-output) antennæ – spatial multiplexing and beamforming – new coding techniques • 802.11n MAC – frame aggregation – block acknowledgements • 802.11n link layer framing – new header fields – longer payload: up to 7955B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-166 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11ac
• IEEE 802.11ac – MAC rate of ~ 500 Mb/s – common on new equipment in mid-late 2010s • Enhancements – 802.11ac physical layer • higher-order MIMO 8 • new standard beamforming • support for SDMA (directional antennæ) • higher layer coding: 256-QAM • binding of multiple OFDMA channels in single link
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-167 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11ad and ay
• 802.11ad – 61.25 GHz (61.0–61.5) commonly called 60 GHz – 7 Gb/s MAC rate over 10 m (shorter range than 802.11n) • 802.11ay – enhancement to 802.11ad – 20–40 Gb/s over 300–500 m expected
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-168 ITTC © James P.G. Sterbenz 802.11 WLAN Link Types: 802.11ax
• IEEE 802.11ax – MAC rate of ~ 2–10 Gb/s – currently under standardisation • Enhancements (likely) – 802.11ax physical layer • OFDMA • MIMO uplink • spatial reuse – 802.11ax MAC • smaller guard interval • dynamic fragmentation • TWT (target wakeup time) and dual NAV 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-169 ITTC © James P.G. Sterbenz 802.11 WLAN IEEE Standards Availability
• IEEE Standards charges hundreds of dollars each – IEEE Standards supplement to IEEE Explore gets access – KU paid $150 000 to IEEE in 2018 • IEEE 802.11ax – currently draft standard – outside of scope of KU IEEE Explore+standards subscription – IEEE Standards want $329 for a PDF of the draft • IEEE – is legally a non-profit – standards are supposed to be open – engages in bad behavior inconsistent with their mission 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-170 ITTC © James P.G. Sterbenz 802.11 WLAN Link Characteristics
Link band channel channels typical typical year coding MAC rate payload type (US) bw (US) us/eu/jp/* range goodput Wavelan 1991 915 MHz 26 MHz DSSS 1 – 2 Mb/s DSSS 802.11 1997 2.4 GHz 83.5 MHz 11|13|14|3 1 – 2 Mb/s 0–2304 B FHSS DSSS 802.11b 1999 2.4 GHz 83.5 MHz 11|13|14|3 1 – 11 Mb/s 60 m 0–2304 B 5 Mb/s FHSS
802.11a 1999 5.8 GHz 300 MHz 12|19|4 OFDM 6 – 54 Mb/s 35 m 0–2304 B 24 Mb/s
OFDM 6 – 54 Mb/s 802.11g 2003 2.4 GHz 83.5 MHz 8 0–2304 B 24 Mb/s DSSS 1 – 11 Mb/s 3.7 GHz 802.11y 2008 50 MHz 0–2304 B 24 Mb/s licensed 2.4 GHz 83.5 MHz OFDM 802.11n 2010 < 248 Mb/s 75 m 0–7955 B 75 Mb/s 5.8 GHz 300 MHz MIMO 433 Mb/s 802.11ac 2013 5.8 GHz 6.93 Gb/s)
2.4 GHz *number non- 802.11ax 2019 500 MHz ~2 Gb/s 5.8 GHz overlapping 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-171 ITTC © James P.G. Sterbenz 802.11 WLAN Subnetwork Modes and Terminology
• Modes – infrastructure mode: STAtions communicate through APs (access points) – ad hoc mode: STAtions communicate directly • BSS: basic service set – 802.11 subnetwork covered by a single AP (access point) – typical mode of operation for home networks • ESS: extended service set – 802.11 subnetwork covered by multiple APs sharing SSID – distribution system (DS) connects multiple BSSs
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-172 ITTC © James P.G. Sterbenz 802.11 WLAN
Infrastructure Mode: BSS1 • Infrastructure mode: BSS (basic service set) – STAtions communicate through single AP – common 802.11 configuration • home networks • small businesses and SOHOs (small office / home office) • single hotspots (e.g. coffee shop)
BSS 1 Internet
STA IP STA STA AP
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-173 ITTC © James P.G. Sterbenz 802.11 WLAN
Infrastructure Mode: BSS2 • Infrastructure mode: BSS (extended service set) – multiple APs with different SSIDs connected by Ethernet – example configuration BSS 2 • multiple users in shared office space SSID2
STA BSS 1 STA SSID1 Internet AP STA IP STA STA L2 AP
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-174 ITTC © James P.G. Sterbenz 802.11 WLAN Infrastructure Mode: ESS
• Infrastructure mode: ESS (extended service set) – multiple APs with shared SSIDs connected by Ethernet – common 802.11 configuration SSID • enterprise networks 1 • campus networks – e.g. KU wireless network
STA SSID1 ESS 1 STA Internet AP STA IP STA STA L2 AP
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-175 ITTC © James P.G. Sterbenz 802.11 WLAN Ad Hoc Mode
• Ad hoc mode – STAtions communicate directly with one another – access point infrastructure not needed – rarely used • occasionally used for inter-PC file transfer • generally sign of misconfigured PC • can be used as SSID DoS attack against AP
BSS Internet
3 STA STA
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-176 ITTC © James P.G. Sterbenz 802.11 WLAN 802.11 Channels and Association
• Spectrum divided into channels at different freq. – 802.11g has 8 channels – AP administrator chooses frequency for AP – interference possible • channel can be same as that chosen by neighboring AP • Wireless node must associate with an AP – scans channels – listens for beacon frames containing APs SSID and MAC addr – selects AP to associate with – should perform authentication – typically run DHCP to get IP address in AP subnet
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-177 ITTC © James P.G. Sterbenz 802.11 WLAN MAC Options
• DCF: distributed coördination function – random access MAC: CSMA/CA – mandatory function – most common 802.11 WLAN deployment • PCF: point coördination function EECS 882 – contention-free MAC with polling and ACKs – optional function; not compliance tested by Wi-Fi – generally not used – not needed for small home networks • HCF: hybrid coördination function EECS 882 – enhancements for QoS in 802.11e 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-178 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Characteristics
• Typical deployment – infrastructure mode: AP + STAs in a BSS or ESS • sensible to have some infrastructure for many LANs • scalability and administrative issues for ad hoc mode • IEEE 802.11 didn’t originally specify routing – DCF: CSMA • with or without CA: RTS/CTS when CA should be used?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-179 ITTC © James P.G. Sterbenz 802.11 WLAN Deployment Characteristics
• Typical deployment – infrastructure mode: AP + STAs in a BSS or ESS • sensible to have some infrastructure for many LANs • scalability and administrative issues for ad hoc mode • IEEE 802.11 didn’t originally specify routing – DCF: CSMA • with or without CA: RTS/CTS • turn off CA for single laptop at home and no close neighbours • turn on CA for moderate to heavy load • check administrative options in access point
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-180 ITTC © James P.G. Sterbenz 802.11 WLAN Medium Access Control
• IEEE 802.11 is typically CSMA and CDMA hybrid • Variety of coding schemes… – DSSS: direct sequence spread spectrum – FHSS: frequency hopping spread spectrum (rarely used) – OFDM: orthogonal frequency division multiplexing (newer) • …Over which CSMA/CA MAC is typically run – CSMA with optional RTS/CTS • …Within FDMA – one of a set of channels
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-181 ITTC © James P.G. Sterbenz 802.11 WLAN Medium Access Control
• IEEE 802.11 is typically CSMA and CDMA hybrid • Interframe spacing – guard times between transmissions – relative length determines priority why?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-182 ITTC © James P.G. Sterbenz 802.11 WLAN Medium Access Control
• IEEE 802.11 is typically CSMA and CDMA hybrid • Inter-frame spacing (IFS) – guard times between transmissions – relative length determines priority – shorter IFS will transmit first; longer will sense channel busy • IFS types – SIFS: short for control messages – PIFS: PCF packet transmission – DIFS: DCF frame transmission – EIFS: extended for resynchronisation
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-183 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense and wait for DIFS interval
1 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-184 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense and wait for DIFS interval RTS – if channel free send RTS
2 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-185 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense and wait for DIFS interval RTS – if channel free send RTS SIFS • Receiver – wait for SIFS interval
3 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-186 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense and wait for DIFS interval RTS – if channel free send RTS CTS SIFS • Receiver – wait for SIFS interval – return CTS if channel idle • receiver hears nodes hidden from sender
4 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-187 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense and wait for DIFS interval RTS – if channel free send RTS CTS SIFS • Receiver SIFS – wait for SIFS interval – return CTS if channel idle • Sender – wait for SIFS interval why not DIFS? 5 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-188 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense and wait for DIFS interval RTS – if channel free send RTS CTS SIFS • Receiver SIFS – wait for SIFS interval – return CTS if channel idle • Sender – wait for SIFS interval • DIFS already used to seize channel 5 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-189 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense and wait for DIFS interval RTS – if channel free send RTS CTS SIFS • Receiver SIFS – wait for SIFS interval frame – return CTS if channel idle • Sender – wait for SIFS interval – transmit frame 6 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-190 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense, wait for DIFS, send RTS RTS • Receiver CTS SIFS – wait for SIFS, return CTS SIFS • Sender frame – wait for SIFS, transmit frame ACK SIFS • Receiver – wait for SIFS interval and return ACK
7 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-191 ITTC © James P.G. Sterbenz 802.11 WLAN CSMA/CA MAC
• CSMA/CA: collision avoidance – RTS/CTS to reduce Pr[collision] sense • Sender DIFS – sense, wait for DIFS, send RTS RTS • Receiver CTS SIFS – wait for SIFS, return CTS SIFS • Sender frame – wait for SIFS, transmit frame ACK SIFS
• Receiver DIFS – wait for SIFS interval and return ACK • Sender frame – must wait DIFS before next frame 8 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-192 ITTC © James P.G. Sterbenz 802.11 WLAN 802.11 – 802.3 Switching and Bridging
frame ctl type=10 • Ethernet frequently duration (s) destination address used to interconnect preamble + SFD source address MAC 802.11 APs header 30B 14B • Similar frame format basic service set id destination address sequence control makes bridging trivial source address address 4 – map addresses length/type LLC LLC/SNAP LLC – copy LLC/SNAP subheader SNAP 8B SNAP – copy payload – copy FCS payload payload payload
trailer FCS FCS 4B
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-193 ITTC © James P.G. Sterbenz 802.11 WLAN Handoff
• Within BSS: no handoff • Inter-BSS within ESS or IP subnet – learning bridge in Ethernet switch – not fast enough for real-time traffic with authentication • IAPP inter-access point protocol – 802.11F trial standard no longer in force – unique association throughout ESS – not fast enough for real-time traffic • 802.11r: fast BSS transition EECS 882 – overlaps association and authentication using cached keys
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-194 ITTC © James P.G. Sterbenz 802.11 WLAN Mesh Networking
• 802.11 specified ESS capability – 802.11s mesh standard • Mesh points : relay APs or STAs BSS 2 STA
BSS 1 STA STA MP Internet AP STA MP 3 STA STA AP AP MP STA 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-195 ITTC © James P.G. Sterbenz 802.11 WLAN 802.11s Mesh Networking
• MAC enhancements – segregation mesh traffic / BSS using contention free period – RTS/CTX (request/clear to switch) to negotiate frequencies • Multihop routing – layer 2 routing within LAN under Internet routing – HWMP (hybrid wireless mesh protocol) mandatory • based on AODV and tree-based routing – RA-OLSR (radio-aware optimised link state routing) optional • based on OLSR – other optional protocols allowed
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-196 ITTC © James P.G. Sterbenz Wireless Networks MW.4.1 802.16 WMAN and WiMAX
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.4.1 802.11 WLAN MW.4.2 802.16 WMAN and WiMAX MW.4.3 802.15 WPAN and Bluetooth MW.4.4 Sensor networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-197 ITTC © James P.G. Sterbenz Wireless Networks: WMAN 802.16 Overview
• WirelessMAN: Wireless MANs – IEEE 802.16 grouper.ieee.org/groups/802/16 • Metropolitan wireless networks – originally intended for fixed wireless access – standardisation and replacement for MMDS in 10 – 66 GHz – 802.16a additional operation in licensed bands 2 – 11 GHz – 802.16b additional operation in unlicensed 5.8 GHz band • Later support for mobility – 802.16e – overlaps with now-defunct IEEE 802.20 MBWA charter
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-198 ITTC © James P.G. Sterbenz Wireless Networks: WMAN 802.16 Relation to other 802 Wireless Protocols
802.16 WMAN
802.11 WLAN
802.15 WPAN 10 km • IEEE 802.16 – part of 2nd set of 802 wireless protocols (802.15 & 802.16) – design motivated by MMDS – no similarity to 802.11/Ethernet framing or operation
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-199 ITTC © James P.G. Sterbenz Wireless Networks: WMAN WiMAX Overview
• WiMAX – Worldwide Interoperability for Microwave Access – www.wimaxforum.org – note capitalisation: WiMAX not WiMax • 802.16 standards compliance & interoperability tests – similar in concept to Wi-Fi for 802.11 • 802.16 deployment scenarios & service architecture – recall that 802 mission is L1 and L2 only WiMAX ≠ 802.16!
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-200 ITTC © James P.G. Sterbenz Wireless Networks: WMAN 802.16 Physical and Link Characteristics
• 802.16 (original) – 10-66 GHz licensed spectrum; LOS (line of sight) – 2 – 5 km transmission radius – 32 – 134 Mb/s • 802.16a and 802.16b – 2 – 11 GHz; non-LOS – 7 – 10 km typical; 50 km max transmission radius – 75 Mb/s
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-201 ITTC © James P.G. Sterbenz Wireless Networks: WMAN 802.16 Physical and Link Characteristics
• 802.16e: mobile – 2 – 6 GHz; non-LOS – 2 – 5 km transmission radius – 15 Mb/s • 802.16m: advanced interface – 100 Mb/s mobile; 1 Gb/s fixed – intended for LTE-advanced 4G mobile cellular telephony • but abandoned by most carriers
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-202 ITTC © James P.G. Sterbenz Wireless Networks: WMAN 802.16 Link Characteristics
Link channel MAC typical typical year band topology duplex coding payload type BW rate range goodput
MMDS
10–66 GHz point-to TDD & 34–134 802.16 2001 SC 2–5 km licensed multipoint FDD MB/s 2–11 GHz point-to- 802.16a 2002 non-LOS OFDM OFDMA licensed multipoint 5.8 GHz 0–2304 802.16b non-LOS UNII B 1.25–20 0–2304 802.16e 2006 2–6 GHz non-LOS MIMO 2–5 km 5 Mb/s MHz B 100 Mb/s 802.16m 2011 >20Mhz 1 Gb/s
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-203 ITTC © James P.G. Sterbenz 802.16 WMAN Components
• BS: base station – directly connected to Internet infrastructure – arranged as mesh with other base stations • SS: subscriber station – fixed SS • 802.16 communication with base station • connected to LAN infrastructure, e.g. Ethernet, 802.11 – mobile SS • mobile node such as PDA using 802.16e
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-204 ITTC © James P.G. Sterbenz 802.16 WMAN Subnetwork Topologies
• PMP: point-to-multipoint topology – BS: base station communicates with multiple SSs • Mesh mode – arbitrary mesh of BSs and SSs
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-205 ITTC © James P.G. Sterbenz 802.16 WMAN PMP Mode
• PMP: point-to-multipoint topology – BS: base station • communicates with multiple SSs • typically sectorised cell using multiple directional antennæ – SS subscriber stations • communicate through BSs
802.11 SS BSS 802.16 MT Internet
STA 3 STA STA 2 SS 802.11 AP BS 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-206 ITTC © James P.G. Sterbenz 802.16 WMAN Mesh Mode
• Mesh mode – BS – SS (as in PMP) – BS – BS multihop relay to SS SS – BS – BS mesh network (e.g for backhaul) 802.16 MT – SS – SS ad hoc mode SS 802.16 MT
802.11 BSS Internet
STA BS 3 STA STA 2 SS 802.11 AP BS 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-207 ITTC © James P.G. Sterbenz 802.16 WMAN MAC and Link Layer Functions
• Link layer functions (called MAC layer in spec) – error control • ARQ • hybrid ARQ with OFDMA – scheduling and link adaptation for QoS • Medium access control – SC (single carrier) with FDD or TDD – OFDMA (orthogonal frequency division multiple access)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-208 ITTC © James P.G. Sterbenz 802.16 WMAN MAC and Link Layer: Duplexing
• 802.16 link duplexing options – FDD: frequency division duplexing • uplink and downlink assigned different frequencies • accommodates full-duplex SSs with multiple tranceivers • half-duplex SSs must retune between up-and downlink • permitted only for 802.16 licensed spectrum – TDD: time division duplexing • slots divided between upstream and downstream traffic • dynamic bandwidth adjustment • permitted for both 802.16 licensed and unlicensed bands
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-209 ITTC © James P.G. Sterbenz 802.16 WMAN TDD Physical Framing
pre T T DL UL downlink uplink am T T map map ble subframe G subframe G j th physical frame • 802.16 TDD physical framing – preamble – broadcast control • DL map: map of downlink transmissions for this frame • UL map: map up uplink transmissions for next frame – data transmission bursts – TTG: transmit/receive transmission gap • allows transceivers to retune – variable boundary between down- and uplink subframes • dynamic bandwidth adjustment 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-210 ITTC © James P.G. Sterbenz 802.16 WMAN Generic Frame Format
0 0 type • Generic Header [6B] CI EKS LEN MAC – HT=0 header type [1b] header CID 6B – EC=0 encryption control [2B] HCS – type [6b] – CI: CRC indicator [1b] – EKS: encryption key seq. [2B] payload – LEN: length [11b] 0 – 2042 B – CID: connection id [6B] – HCS: header check seq. [1B]
• Payload [0–2312B] trailer CRC 4B • Trailer: CRC [4B] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-211 ITTC © James P.G. Sterbenz 802.16 WMAN MAC Traffic Classes
• Traffic Classes – constant bit rate service – real-time polling: rt-VBR – non-real-time polling: nrt-VBR – best effort – unsolicited grant service: connectionless
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-212 ITTC © James P.G. Sterbenz WiMAX WMAN Reference Architecture
• 802.16 only specifies air interface – PHY, MAC, and link layers – insufficient for service deployment architecture (ala 3G) • Need for implementation agreements for – equipment manufacturers – service providers
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-213 ITTC © James P.G. Sterbenz WiMAX WMAN Reference Architecture
• 802.16 only specifies air interface • Need for implementation agreements • WiMAX forum reference architecture – specifies components, subnetworks, and their roles – specifies service architecture • including AAA, … – specifies reference points • physical interfaces • conceptual links (protocol and service relationships)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-214 ITTC © James P.G. Sterbenz WiMAX WMAN Selected Reference Points
R1 • ASN R8 – access service network SS – WiMAX Forum ref points BS GW R3 • Intra-ASN RPs R6 R1 – R1: BS–SS SS – R6: GW–BS BS – R4: GW–GW R4 • Inter-ASN RPs – R3: GW GW
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-215 ITTC © James P.G. Sterbenz 802.16 and WiMAX Future Outlook
• 802.16 as a MAN technology – never widely deployed – could be used for large campuses, e.g. KU – but 802.16 devices not widely available • 802.16 as a mobile telephony – 802.16e was deployed Sprint and falsely called 4G – 802.16m certified for real 4G IMT-Advanced – 802.16 largely abandoned switching to LTE • Will probably not be in important future technology
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-216 ITTC © James P.G. Sterbenz Wireless Networks MW.4.3 802.15 WPAN and Bluetooth
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.4.1 802.11 WLAN MW.4.2 802.16 WMAN and WiMAX MW.4.3 802.15 WPAN and Bluetooth MW.4.4 Sensor networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-217 ITTC © James P.G. Sterbenz Wireless Personal Networks Introduction and Definitions
• PAN: local area network – links or subnetwork of shorter reach than LAN – replacement for interconnect cables • computer peripherals • mobile phone headsets – private intimate group of personal devices [IEEE 802] • in personal operating space (POS) – several meters: O (10 m) • Examples – wired: USB, IEEE 1394 Firewire – wireless: IrDA, 802.15.1/Bluetooth, 802.15.3, Wireless USB
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-218 ITTC © James P.G. Sterbenz Wireless Networks: WPAN Bluetooth History
• Initial work done at Ericsson in Sweden – Bluetooth named after Harald I • Bluetooth SIG (special interest group) – industry consortium formed in 1998 – mobile telephone vendors: Ericsson, Nokia – other electronics vendors: IBM, Intel, Toshiba • Proprietary specification development – membership was required to see draft specifications – specifications now freely available (5 is current) • www.bluetooth.com/Bluetooth/Learn/Technology/Specifications • 1000+ page behemoth
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-219 ITTC © James P.G. Sterbenz Bluetooth WPAN Network Topology
• Piconet – collection of devices in transmission range of master – master dictates timing; transmits in odd-numbered slots – up to 7 active slaves use even-numbered slots – up to 247 parked (inactive) devices – all slave–slave communication through master • Scatternet – collection of piconets that share devices
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-220 ITTC © James P.G. Sterbenz Bluetooth WPAN Architecture
• Stovepipe protocol stack for very specialised domain – driven by mobile telephone manufacturers – physical through application layer • Application profiles define vertical protocol slices, e.g.: • generic access • telephony • printing • data transfer • Not compatible with other protocol stacks – OSI, Internet, or IEEE 802 – IEEE reworked as 802.15.1
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-221 ITTC © James P.G. Sterbenz Bluetooth WPAN Protocol Stack
audio Phone apps Internet vCard mgmt
applications TCP c S o AT TCS IP OBEX D n modem PPP P t RFCOMM r software o L2CAP: LLC and adaptation protocol l audio HCI link manager baseband layer hardware radio layer • HCI: host controller interface • RFCCOMM: emulates serial port • TCS: telephony control protocol specification • SDP: service discovery protocol 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-222 ITTC © James P.G. Sterbenz Bluetooth WPAN Deployment Status
• Deployment status – widely deployed in mobile telephones • most commonly used for wireless headsets – widely deployed in PDAs and laptop computers Problems?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-223 ITTC © James P.G. Sterbenz Bluetooth WPAN Deployment Issues
• Problems and issues – closed development process driven by mobile telephony – incompatible with Internet and 802 architecture • rectified by IEEE 802.15.1 (future?) – interference not considered • interference with 802.11 • poor scalability in dense deployments (e.g. 2001 CeBIT debacle) – numerous security flaws – competition looming from wireless USB – architectural limitations …
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-224 ITTC © James P.G. Sterbenz Bluetooth WPAN Architectural Limitations
• Significant architectural restrictions – 3-bit address space only 8 active devices / piconet • appalling lack of foresight – evidently driven mobile telephone marketing folk • personal networks easily far exceed 8 devices • computer manufacturers (IBM, Intel) deny responsibility – master/slave configuration – scatternets consisting of multiple piconets – problems largely rectified by IEEE 802.15.3 • future uncertain
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-225 ITTC © James P.G. Sterbenz Wireless Networks: WPAN 802.15 Relation to other 802 Wireless Protocols
802.16 WMAN
802.11 WLAN
802.15 WPAN 10 m • IEEE 802.15 – part of 2nd set of 802 wireless protocols (802.15 & 802.16) – design motivated by Bluetooth – no similarity to 802.11/Ethernet framing or operation
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-226 ITTC © James P.G. Sterbenz 802.15 WPAN WPAN Overview
• WPAN: Wireless Personal Area Networks – IEEE 802.15 grouper.ieee.org/groups/802/15 • Personal and short-reach wireless network – shorter range than 802.11 – initially motivated by Bluetooth & compatibility with 802.11
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-227 ITTC © James P.G. Sterbenz 802.15 WPAN Standards Overview: Links
• IEEE 802.15 – wireless personal area networks • Personal and short-reach wireless network – 802.15.1: standardisation of Bluetooth physical/MAC layers – 802.15.2: co-existence of 802.11 and 802.15 in 2.4 GHz • original goal of 802.15.1 was to interoperate with 802.11 – 802.15.3: high rate and larger addresses – 802.15.4: low energy for sensor networks – 802.15.5: mesh networking (work in progress) – 802.15.6: BAN body area networks (work in progress) – 802.15.7: short range visible-light optical (work in progress)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-228 ITTC © James P.G. Sterbenz 802.15 WPAN Standards Overview: Networking
• IEEE 802.15 – wireless personal area networks • Personal and short-reach wireless network – 802.15.1: standardisation of Bluetooth physical/MAC layers – 802.15.2: co-existence of 802.11 and 802.15 in 2.4 GHz • original goal of 802.15.1 was to interoperate with 802.11 – 802.15.3: high rate and larger addresses – 802.15.4: low energy for sensor networks – 802.15.5: mesh networking – 802.15.6: BAN body area networks – 802.15.7: short range visible-light optical
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-229 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Physical Layer Characteristics
• 2.4 GHz unlicensed ISM band implications?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-230 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Physical Layer Characteristics
• 2.4 GHz unlicensed ISM band – interference issues with 802.11b/g and cordless phones
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-231 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Physical Layer Characteristics
• 2.4 GHz unlicensed ISM band • Three power classes – class 1: 1–100 mW with power control in 2–8 dB steps – class 2: 0.25–2.5 mW with optional power control – class 3: max 1 mW with optional power control • Three line coding options – GFSK (Gaussian FSK) line coding: 1b/symbol = 1Mb/s – /4-DQPSK: 2b/symbol = 2Mb/s – 8-DQPSK: 3b/symbol = 3Mb/s • Low sensitivity receivers for low cost – –70dBm for 0.1%BER at 1Mb/s, 0.01%BER at 2, 3 Mb/s 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-232 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Medium Access Control
• TDD (time division duplexing) – simple to achieve over very short distances • independent clocks are frequently synchronised – 625μs / slot (27-bit slot number k) – transmissions use 1, 3, or 5 slots – masters begin transmission in even slot
k k+1 k+2 k+3 k+4 k+5 k+6 . . . master slave
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-233 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Medium Access Control
• TDD (time division duplexing) – simple to achieve over very short distances • independent clocks are frequently synchronised – 625μs / slot (27-bit slot number k) – transmissions use 1, 3, or 5 slots – masters begin transmission in even slot; slaves in odd slot
k k+1 k+2 k+3 k+4 k+5 k+6 . . . master slave
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-234 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Medium Access Control
• TDD • FHSS (frequency hopping spread spectrum) – FHSS robust to narrow-band interference – 79 1MHz bands between 2.402 and 2.4835 GHz (US) – pseudorandom hopping sequence determined by master – 1600 | 3200 hop/s in connection for data transfer| control – significant interference with 802.11 DSSS f(k) f(k+1) f(k+2) f(k+3) f(k+4) f(k+5) f(k+6) . . . master slave
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-235 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Piconet
• Piconet : up to 256 devices – transmission range of master
M
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-236 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Piconet
• Piconet : up to 256 devices – transmission range of master
• Master dictates timing M – transmits in odd-numbered slots
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-237 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Piconet
• Piconet : up to 256 devices – transmission range of master S
• Master dictates timing M
– transmits in even-numbered slots S • Slaves S – max of only 7 active at a time – use odd-numbered slots
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-238 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Piconet
• Piconet : up to 256 devices – transmission range of master S
• Master dictates timing M
– transmits in odd-numbered slots S • Slaves S – max of only 7 active at a time – use even-numbered slots – all slave–slave communication through master
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-239 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Piconet
• Piconet : up to 256 devices – transmission range of master P S
• Master dictates timing M
– transmits in odd-numbered slots S • Slaves S P – max of only 7 active at a time P P – use even-numbered slots – all slave–slave communication through master • Parked (inactive) devices – max 247
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-240 ITTC © James P.G. Sterbenz 802.15.1 and Bluetooth WPAN Scatternet
• Scatternet – collection of piconets that share devices • Barely mentioned in the Bluetooth specs – theoretical construct to deflect criticism on architectural limits of Bluetooth?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-241 ITTC © James P.G. Sterbenz Wireless Networks: WPAN 802.15.3 Overview
• 802.15 Task Group 3: High Rate PANs – higher data rates: 11 – 55 Mb/s – multimedia and QoS – ad-hoc and peer-to-peer networking – better co-existence with 802.11
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-242 ITTC © James P.G. Sterbenz 802.15.3 WPAN Piconets
• Piconets how to improve over Bluetooth/802.15.1?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-243 ITTC © James P.G. Sterbenz 802.15.3 WPAN Piconets
• Piconets: 64K devices – 16 b DEV address – peer-to-peer data PNC • doesn’t need to go via PNC why do we need a controller?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-244 ITTC © James P.G. Sterbenz 802.15.3 WPAN Piconets
• Piconets: 64K devices – 16 b DEV address – peer-to-peer data PNC • doesn’t need to go via PNC – PNC: piconet coördinator • beacons to all DEVs in piconet • distributes timing
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-245 ITTC © James P.G. Sterbenz 802.15.1/3 and Bluetooth Future Outlook
• Bluetooth widely deployed in spite of flaws – substitute for a few wired peripherals – mobile phone headset – computer keyboard and mouse – Bluetooth SIG has taken back development from 802.15.1 • 802.15.3 not widely deployed – may wait until needed – more than 8 peripherals – high-bandwidth multimedia
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-246 ITTC © James P.G. Sterbenz Bluetooth Releases
• Bluetooth SIG industry consortium www.bluetooth.com – has taken over standards; 802.15.1 dormant – only organisational membership • Bluetooth releases – a confusing succession of technologies Release Capability 802.15 1 802.15.1 721 kb/s max rate 2 Classic 3 Mb/s max rate 3 High Speed 802.11 data channel 4 Low Energy larger address space 5 IoT enhancements 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-247 ITTC © James P.G. Sterbenz Wireless Networks MW.4.4 Sensor Networks
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.4.1 802.11 WLAN MW.4.2 802.16 WMAN and WiMAX MW.4.3 802.15 WPAN and Bluetooth MW.4.4 Sensor networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-248 ITTC © James P.G. Sterbenz Wireless Networks Sensor Network Overview
• Wireless sensor network (WSN) motivation – remote sensing of environmental conditions • e.g. temperature, chemical/radiological conditions – perhaps remote actuation of control systems • Sensor network characteristics – network of sensors (and perhaps actuators) – may be deployed in large numbers in remote areas – low-power operation frequently essential – in-network data-fusion
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-249 ITTC © James P.G. Sterbenz WSN Architecture Components
• Sensor – device that senses information from environment • Actuator – device that controls environment • Sink S – destination of sensor data for processing or storage • Gateway – interworking between WSN and data network • typically the Internet
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-250 ITTC © James P.G. Sterbenz WSN Characteristics Introduction
Defining characteristics of WSNs?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-251 ITTC © James P.G. Sterbenz WSN Characteristics Introduction
• Defining characteristics of WSNs – wireless nodes – energy efficiency critical • difficult or impossible to replace battery – large scale • sensor fields may have thousand or millions of nodes • ad hoc: manual configuration impractical
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-252 ITTC © James P.G. Sterbenz WSN Characteristics Differences from WPANs
• WPAN: wireless personal network • Energy concerns – WPAN nodes have rechargeable or replaceable batteries – WSN energy management more critical • Limited mobility – many sensors are stationary – initial self-organisation more important • dynamic reoptimisation less critical • network must react to failed nodes that have no energy left
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-253 ITTC © James P.G. Sterbenz WSN Characteristics Differences from MANETs
• MANET: mobile ad hoc network • Energy concerns – WPAN nodes have rechargeable or replaceable batteries – WSN energy management more critical – low duty cycle of sensors helps • Limited mobility – many sensors are stationary
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-254 ITTC © James P.G. Sterbenz WSN Characteristics Differences from other Networks
• WSNs are data centric – information important – not necessarily related to particular nodes • Examples – min / max / average temperature of a region – mapping of a storm or wildfire – location of an animal Consequence?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-255 ITTC © James P.G. Sterbenz WSN Characteristics In-Network Processing
• WSNs frequently manipulate data in the network – sensor nodes not only relay multihop traffic… – but also process it on the way • More energy efficient – processing generally cheaper then transmission – e.g. nodes compute average, max, or min value • significantly reduces communication cost – referred to as sensor fusion
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-256 ITTC © James P.G. Sterbenz WSN Characteristics In-Network Processing Types
• Aggregation – compute statistical functions on the way to the sink – average, min, max, etc. • Edge detection – compute and convey boundaries between values – e.g isotherms, isobars, storm edges, wildfire boundaries • Trajectory tracking – e.g. animal movement • Other variants possible…
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-257 ITTC © James P.G. Sterbenz Wireless Sensor Networks Application Examples
• IoT: Internet of things • Environmental monitoring – long term, e.g. climate change – short term, e.g. wildfire mapping • Medical and health – vital signs and ongoing biochemical monitoring – automated drug dosing • Intelligent buildings – fine-grained monitoring and control of temperature • Military and homeland security – situational awareness 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-258 ITTC © James P.G. Sterbenz Wireless Sensor Networks Architectures
• Multihop – communication with limited transmission power – may conserve energy • but may not: S energy use for transit traffic
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-259 ITTC © James P.G. Sterbenz Wireless Networks: WPAN 802.15.4 Overview
• 802.15.4 – 20 – 250 kb/s with multi-month to -year battery life target – peer-to-peer networking – extended addresses: 16 and 64 bit • Generally intended for wireless sensor networks
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-260 ITTC © James P.G. Sterbenz Wireless Networks: WPAN ZigBee Overview
• ZigBee protocol specification – upper level protocols for WSNs – uses 802.15.4 MAC and PHY • ZigBee Alliance – industry consortium that maintains standard – similar to Bluetooth, but not a L1–7 stovepipe
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-261 ITTC © James P.G. Sterbenz 802.15.4 and ZigBee Future Outlook
• Limited deployments until recently • Becoming an important technology for IoT – Internet of Things – e.g. Osram Lightify smart bulbs • base station connects to 802.11 • bulbs form multihop network
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-262 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.5 Mobile Networks
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.5 Mobile networks MW.5.1 DHCP and Mobile IP MW.5.2 Mobile ad hoc networks and MANET protocols MW.5.3 Mobile cellular telephony MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-263 ITTC © James P.G. Sterbenz Mobility Overview
• So far, we’ve been assuming fixed nodes – end systems and intermediate systems (switches/routers) • Mobility – ability to move a device through the network • Spectrum of mobility – fixed: no movement (may still be wireless!) – mobile: changes point of attachment to network • requiring reconnection, e.g. DHCP • allowing handoff, e.g. mobile IP, cellular telephony – nomadic: frequent high-mobility, possible disconnected ops
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-264 ITTC © James P.G. Sterbenz Mobile Wireless Networks Characteristics
• Mobile networks – wireless needed to enable mobility • Dynamicity as nodes move – layer 1 and 2 effects: link characteristics change • e.g. signal strength, bandwidth, delay – layer 3 effects: topologies change • induces route changes – layer 4 effects: end-to-end path characteristics change • e.g. throughput, goodput, delay
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-265 ITTC © James P.G. Sterbenz Mobile Wireless Networks Network Elements: Mobile Node
• Base station (BS) cell • Mobile node (MN)
– wireless node that moves BS BS
Internet MN
MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-266 ITTC © James P.G. Sterbenz Mobile Wireless Networks Network Elements: Mobile Node
• Base station (BS) cell • Mobile node (MN)
– wireless node that moves BS – roams among base stations – handoff between cells Internet – e.g. mobile telephone MN
MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-267 ITTC © James P.G. Sterbenz Mobile Wireless Networks Network Elements: Mobile Node
• Base station (BS) cell • Mobile node (MN)
– wireless node that moves BS – roams among base stations – handoff between cells MN Internet – e.g. mobile telephone
MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-268 ITTC © James P.G. Sterbenz Mobile Wireless Networks Network Elements: Mobile Node
• Base station (BS) cell • Mobile node (MN)
– wireless node that moves BS – roams among base stations – move with respect to one-another Internet – ad hoc network MN
MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-269 ITTC © James P.G. Sterbenz Mobile Wireless Networks Network Elements: Mobile Node
• Base station (BS) cell • Mobile node (MN)
– wireless node that moves BS – roams among base stations – move with respect to one-another Internet – ad hoc network
MN MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-270 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.5.1 DHCP and Mobile IP
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.5 Mobile networks MW.5.1 DHCP and Mobile IP MW.5.2 Mobile ad hoc networks and MANET protocols MW.5.3 Mobile cellular telephony MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-271 ITTC © James P.G. Sterbenz IP Mobility Overview
• Problem: node mobility between IP prefixes – need to revisit IP-address/node bindings
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-272 ITTC © James P.G. Sterbenz DHCP Overview
• DHCP: dynamic host configuration protocol [RFC 2131] • Allows node to dynamically obtain IP address – as well as other configuration parameters, e.g. DNS server • Benefits – reduces manual configuration – allows mobile nodes to easily move attachment point Problems?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-273 ITTC © James P.G. Sterbenz DHCP Overview
• DHCP: dynamic host configuration protocol [RFC 2131] • Allows node to dynamically obtain IP address – as well as other configuration parameters, e.g. DNS server • Benefits – reduces manual configuration – allows mobile nodes to easily move attachment point • Problems – no handoff capabilities – flows and sessions interrupted during move
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-274 ITTC © James P.G. Sterbenz Mobile IP Overview
• Mobile IP [RFC 3220] (designed by C.E. Perkins) – designed to enable untethered Internet access – with limited mobility – without disrupting higher level protocol flows
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-275 ITTC © James P.G. Sterbenz Mobile IP Overview
• Mobile IP [RFC 3220] (designed by C.E. Perkins) – designed to enable untethered Internet access – with limited mobility – without disrupting higher level protocol flows • Simple way of forwarding IP packets to mobile nodes
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-276 ITTC © James P.G. Sterbenz Mobile IP Architecture Home Network Home Net
IP IP IP IP AP AP MN IP 128.119.40.86
128.119.40/24 IP
• Home network: permanent (normal) home of MN – MN: mobile node – permanent address assigned from home network block • e.g. 128.119.40.186 assigned from 128.119.40/24
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-277 ITTC © James P.G. Sterbenz Mobile IP Architecture Visited Network
Home Net Visited Net
IP IP IP IP AP AP MN IP
128.119.40/24 IP 79.129.13/24
CN • Home network: permanent (normal) home of MN • Visited Network: temporary location of MN – e.g. 79.129.13/24
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-278 ITTC © James P.G. Sterbenz Mobile IP Architecture Visited Network
Home Net Visited Net
IP IP IP IP AP AP MN IP MN
128.119.40/24 IP 79.129.13/24
CN • Home network: permanent (normal) home of MN • Visited Network: temporary location of MN – e.g. 79.129.13/24 problem?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-279 ITTC © James P.G. Sterbenz Mobile IP Architecture Visited Network
Home Net Visited Net
IP IP IP IP AP AP MN IP MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home network: permanent (normal) home of MN • Visited Network: temporary location of MN – home IP addr not in visited block: packets fwd to wrong net • e.g. 128.119.40.186 ∉ 79.129.13/24
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-280 ITTC © James P.G. Sterbenz Mobile IP Architecture Visited Network
Home Net Visited Net
IP IP IP IP AP AP MN IP MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home network: permanent (normal) home of MN • Visited Network: temporary location of MN – home IP addr not in visited block: packets fwd to wrong net solution?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-281 ITTC © James P.G. Sterbenz Mobile IP Architecture Visited Network
Home Net Visited Net
IP IP IP IP AP AP MN IP MN 79.129.13.101
128.119.40/24 IP 79.129.13/24
CN • Home network: permanent (normal) home of MN • Visited Network: temporary location of MN – home IP addr not in visited block: packets fwd to wrong net – use DHCP to get address in visiting net: all flows interrupted
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-282 ITTC © James P.G. Sterbenz Mobile IP Architecture Visited Network
Home Net Visited Net
IP IP IP IP AP AP MN IP MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home network: permanent (normal) home of MN • Visited Network: temporary location of MN – home IP addr not in visited block: packets fwd to wrong net solution?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-283 ITTC © James P.G. Sterbenz Mobile IP Architecture Visited Network
Home Net Visited Net
IP IP IP IP AP AP MN IP MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home network: permanent (normal) home of MN • Visited Network: temporary location of MN – home IP addr not in visited block: packets fwd to wrong net – mobile IP agents forward on behalf of MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-284 ITTC © James P.G. Sterbenz Mobile IP Architecture Home Agent
Home Net Visited Net
IP IP IP IP AP AP MN IP MN HA 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home network receives traffic destined for MN – home agent (HA) receives traffic destined for MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-285 ITTC © James P.G. Sterbenz Mobile IP Architecture Foreign Agent
Home Net Visited Net
IP IP IP IP AP AP IP MN HA FA MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home agent (HA) forwards on behalf of MN to visited • Foreign agent (FA) intercepts and relays to MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-286 ITTC © James P.G. Sterbenz Mobile IP Architecture Foreign Agent
Home Net Visited Net
IP IP IP IP AP AP IP MN HA FA MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home agent (HA) forwards on behalf of MN to visited • Foreign agent (FA) intercepts and relays to MN
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-287 ITTC © James P.G. Sterbenz Mobile IP Architecture Reverse Path
Home Net Visited Net
IP IP IP IP AP AP IP MN HA FA MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home agent (HA) forwards on behalf of MN to visited • Foreign agent (FA) intercepts and relays to MN Does MN need to use agents to send to CN?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-288 ITTC © James P.G. Sterbenz Mobile IP Architecture Reverse Path
Home Net Visited Net
IP IP IP IP AP AP IP MN HA FA MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home agent (HA) forwards on behalf of MN to visited • Foreign agent (FA) intercepts and relays to MN • MN can address datagrams directly to CN issues? 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-289 ITTC © James P.G. Sterbenz Mobile IP Architecture Triangle Routing
Home Net Visited Net
IP IP IP IP AP AP IP MN HA FA MN 128.119.40.86
128.119.40/24 IP 79.129.13/24
CN • Home agent (HA) forwards on behalf of MN to visited • Foreign agent (FA) intercepts and relays to MN • MN can address datagrams directly to CN – triangle routing : forward path ≠ reverse path 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-290 ITTC © James P.G. Sterbenz Mobile IP Architecture Direct Routing
• Direct routing – overcomes triangle routing problem • Correspondent requests care-of address – home agent replies – correspondent sends packets directly to COA • Problem – additional signalling complexity and handoff latency
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-291 ITTC © James P.G. Sterbenz Mobile IP Protocol Overview
What steps must be taken?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-292 ITTC © James P.G. Sterbenz Mobile IP Protocol Overview
• Agent discovery • Registration • Tunneling • Handoff
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-293 ITTC © James P.G. Sterbenz Mobile IP Protocol Agent Discovery
• Agent discovery process – home and foreign agents advertise their service – mobile nodes solicit the existence of an agent • ICMP message – router advertisement: type = 9 – mobility agent advertisement extension: code = 16
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-294 ITTC © James P.G. Sterbenz Mobile IP Protocol Registration
• Registration process for mobile nodes – request forwarding services from foreign agent – registers care-of address with home agent • directly • via foreign agent – renew binding about to expire – deregister from foreign agent • UDP messages – mobile IP message header
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-295 ITTC © James P.G. Sterbenz Mobile IP Protocol Tunneling
• Tunneling – home agent tunnels datagrams to care-of address • Methods – IP-in-IP encapsulation – minimal encapsulation [RFC 2004] • eliminates redundant fields from IP-in-IP – GRE (generic routing encapsulation) [RFC 1701, 1702]
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-296 ITTC © James P.G. Sterbenz Mobile IP Protocol Handoff
• Handoff: mobile node moves to new visited network • Procedure – mobile node deregisters with old foreign agent – mobile node registers with new foreign agent – new foreign agent registers with home agent – home agent updates care-of-address for mobile – packets continue to be forwarded to mobile • new care-of-address
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-297 ITTC © James P.G. Sterbenz Mobile IP Protocol Handoff
• Handoff: mobile node moves to new visited network • Procedure – mobile node deregisters with old foreign agent – mobile node registers with new foreign agent – new foreign agent registers with home agent – home agent updates care-of-address for mobile – packets continue to be forwarded to mobile • new care-of-address Problem?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-298 ITTC © James P.G. Sterbenz Mobile IP Protocol Handoff
• Handoff: mobile node moves to new visited network • Procedure – mobile node deregisters with old foreign agent – mobile node registers with new foreign agent – new foreign agent registers with home agent – home agent updates care-of-address for mobile – packets continue to be forwarded to mobile • new care-of-address • Problem – hand-off delay – packet loss during handoff 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-299 ITTC © James P.G. Sterbenz Mobile IP Protocol Advantages and Disadvantages
Advantages?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-300 ITTC © James P.G. Sterbenz Mobile IP Protocol Advantages and Disadvantages
• Advantages – very simple mechanism
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-301 ITTC © James P.G. Sterbenz Mobile IP Advantages and Disadvantages
• Advantages – very simple mechanism • Disadvantages – hand-off latency may be seconds • registration • authentication • many optimisations proposed – triangle routing • different forward and reverse paths – security issues • ingress and firewall address filtering of address mismatches
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-302 ITTC © James P.G. Sterbenz Mobile IP Reality
• IP routers – most supported mobile IP for a long time • Service providers – some deployment within cellular telephony service providers • Users – very little actual use why?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-303 ITTC © James P.G. Sterbenz Mobile IP Reality
• IP routers – most supported mobile IP for a long time • Service providers – some deployment within cellular telephony service providers • Users – very little actual use – DHCP reattachment sufficient for many applications • email and Web transactions – not yet much continuous wireless coverage • very few users roam among 802.11 hot spots • mobile telephony has won this niche
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-304 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.5.2 MANETs
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.5 Mobile networks MW.5.1 DHCP and Mobile IP MW.5.2 Mobile ad hoc networks and MANET protocols MW.5.3 Mobile cellular telephony MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-305 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Overview
• Mobile ad hoc networks – MANETs in IETF jargon (pronounced ma-net not ma-nay) • Mobile – nodes are untethered • Ad hoc – no pre-existing infrastructure is assumed – auto-configuration of nodes – self-organisation of networks – example: group of users meets in cave and forms a network Details in EECS 882
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-306 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Multihop Networking
• Multihop – nodes act as both end and intermediate systems – users carry transit traffic • security and performance implications • energy and power considerations
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-307 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Protocol Overview
• Neighbour discovery • Link formation • Self-organisation • Topology optimisation and maintenance
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-308 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Neighbour Discovery
• Nodes emit beacons to announce their presence – known frequencies and codes used for announcements • Establishes set of directly reachable nodes
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-309 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Link Formation
• Pairwise negotiation of link formation – interested nodes answer beacons – exchange identification, node and link characteristics – layer 2 connectivity structure • Maintain link adjacencies – e.g. keepalive messages 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-310 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Self-Organisation and Federation leaderless cluster abstraction or peer group leader
• Communicating nodes self-organise into federations – address acquisition – hierarchical cluster formation and leader election • based on administrative concerns, security, role/task based – bootstrap routing topology 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-311 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Topology Optimisation and Maintenance
• Topology maintenance of federations – merge/split • group mobility, dynamic coalitions – heal partition
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-312 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Topology Optimisation and Maintenance
leave then join
• Topology maintenance of nodes – node mobility – leave/join from/to federation – resolution to identifier vs. topological address reassignment
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-313 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Impact of Mobility
• Dynamic nodes and topologies – changing links, clustering, and federation topology – difficult to achieve routing convergence • Control loop delay – mobility may exceed ability of control loops to react • Impacts QOS
1 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-314 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Impact of Mobility
• Dynamic nodes and topologies – changing links, clustering, and federation topology – difficult to achieve routing convergence • Control loop delay – mobility may exceed ability of control loops to react • Impacts QOS – changes in inter-node distance • requires power adaptation • changes density and impacts degree of connectivity – latency issues (routing optimisations temporary)
2 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-315 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Impact of Mobility
• Dynamic nodes and topologies – changing links, clustering, and federation topology – difficult to achieve routing convergence • Control loop delay – mobility may exceed ability of control loops to react • Impacts QOS – changes in inter-node distance • requires power adaptation • changes density and impacts degree of connectivity – latency issues (routing optimisations temporary)
3 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-316 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Routing Algorithms
• Types – proactive or table driven • compute routes that may be needed • low communication startup latency • overhead of continuous route maintenance – reactive or on-demand • compute routes only when needed • higher startup latency • lower overall overhead
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-317 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Routing Algorithm Examples
• Many proposals – many within the IETF MANET working group – specilaised domains: e.g. supersonic military aircraft • VANETs: vehicular ad-hoc networks • Examples: – DSDV: destination-sequenced distance vector – AODV: ad hoc on-demand distance vector – DSR: dynamic source routing – OLSR: optimized link state routing protocol • No one protocol can possibly be right for all scenarios – adaptive framework needed to negotiate protocols 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-318 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Routing Algorithms: AODV
• AODV: ad hoc on-demand distance vector – distance vector algorithm – acquires and maintains routes only on demand • routes cached while in use • routes purged after use
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-319 ITTC © James P.G. Sterbenz Mobile Ad Hoc Networking Routing Algorithms: DSR
• DSR: dynamic source routing – source routing: packets carry source routes – source routes constructed on-demand
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-320 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.5.3 Mobile Cellular Telephony
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.5 Mobile networks MW.5.1 DHCP and Mobile IP MW.5.2 Mobile ad hoc networks and MANET protocols MW.5.3 Mobile cellular telephony MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-321 ITTC © James P.G. Sterbenz Mobile Wireless Telephony Motivation
• Untethered replacement for wired phones scenarios?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-322 ITTC © James P.G. Sterbenz Mobile Wireless Telephony Motivation
• Untethered replacement for wired phones – cordless phone replacement within premises
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-323 ITTC © James P.G. Sterbenz Mobile Wireless Telephony Motivation
• Untethered replacement for wired phones – cordless phone replacement within premises – mobile telephones for use anywhere • including while moving: driving, riding train or bus
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-324 ITTC © James P.G. Sterbenz Mobile Wireless Telephony Motivation
• Untethered replacement for wired phones – cordless phone replacement within premises – mobile telephones for use anywhere • including while moving: driving, riding train or bus • Design goals – seamless mobility is prime requirement
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-325 ITTC © James P.G. Sterbenz Mobile Wireless Telephony Motivation
• Untethered replacement for wired phones – cordless phone replacement within premises – mobile telephones for use anywhere • including while moving: driving, riding train or bus • Design goals – seamless mobility is prime requirement how is this different from mobile IP?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-326 ITTC © James P.G. Sterbenz Mobile Wireless Telephony Motivation
• Untethered replacement for wired phones – cordless phone replacement within premises – mobile telephones for use anywhere • including while moving: driving, riding train or bus • Design goals – seamless mobility is prime requirement: handoff – more aggressive requirement than for mobile IP
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-327 ITTC © James P.G. Sterbenz Wireless Telephony Early History
• 1947–1977 (0G) – 1946: FCC allocates 33 FM channels in 35,150,450 MHz band – 1947: operator relay begins to US passenger trains – 1960s: direct dialing from automobiles in home area • extremely limited channel capacity – 1977: Bell Labs begins first AMPS 1G cellular trial in Chicago
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-328 ITTC © James P.G. Sterbenz Cellular Network Topology Motivation
• Goal: wireless telephony everywhere Problem: how to place base stations?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-329 ITTC © James P.G. Sterbenz Cellular Network Topology Motivation
• How to place base stations randomly?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-330 ITTC © James P.G. Sterbenz Cellular Network Topology Motivation
• How to place base stations – random: difficult for network traffic engineering
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-331 ITTC © James P.G. Sterbenz Cellular Network Topology dead zones Motivation
• How to place base stations – random: difficult for network traffic engineering alternative?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-332 ITTC © James P.G. Sterbenz Cellular Network Topology Motivation
• How to place base stations – regular tessellation in cellular structure what shape?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-333 ITTC © James P.G. Sterbenz Cellular Network Topology Motivation
• How to place base stations – regular tessellation in cellular structure square grid?
cell
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-334 ITTC © James P.G. Sterbenz Cellular Network Topology Motivation
• How to place base stations – regular tessellation in cellular structure – square grid: very non-uniform distance between transmitters • range of 1 to 1.414 units results?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-335 ITTC © James P.G. Sterbenz Cellular Network Topology Motivation
• How to place base stations – regular tessellation in cellular structure – square grid: very non-uniform distance between transmitters • range of 1 to 1.414 units – results in • significant overlap or • dead zones alternative?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-336 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• How to place base stations – hexagonal tessellation is most efficient packing of circles • e.g. beehive results?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-337 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• How to place base stations – hexagonal tessellation is most efficient packing of circles – still results in • some overlap
cell
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-338 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• How to place base stations – hexagonal tessellation is most efficient packing of circles – still results in some overlap – circle is idealisation of coverage why?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-339 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• How to place base stations – hexagonal tessellation is most efficient packing of circles – still results in some overlap – circle is idealisation of coverage • assumes perfect omnidirectionality • assumes abrupt attenuation practical?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-340 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• How to place base stations – hexagonal tessellation is most efficient packing of circles – still results in some overlap – circle is idealisation of coverage – reality: exact location constrained by • economics • regulation and zoning • topography • location of existing towers
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-341 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• Hexagonal cell plan Problem?
cell
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-342 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• Hexagonal cell plan • Problem: interference between adjacent cells solution?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-343 ITTC © James P.G. Sterbenz Cellular Network Topology Hexagonal Cell Structure
• Hexagonal cell plan • Adjacent cells need to use different frequencies – avoid inter-cell interference – signal-strength sensing for handoff how to allocate?
cell
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-344 ITTC © James P.G. Sterbenz Cellular Network Topology Frequency Reuse
• Hexagonal cell plan • Frequency reuse – plan to assign differing frequencies to adjacent cells – 3, 4, or 7 cluster sizes among the choices
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-345 ITTC © James P.G. Sterbenz Cellular Network Topology Frequency Reuse
• Hexagonal cell plan • Frequency reuse – plan to assign differing frequencies to adjacent cells – 3 frequency plan most efficient
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-346 ITTC © James P.G. Sterbenz Cellular Network Topology Frequency Reuse
• Hexagonal cell plan • Frequency reuse – plan to assign differing frequencies to adjacent cells – 7 frequency plan allows later subdivision
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-347 ITTC © James P.G. Sterbenz Cellular Network Topology Increasing Capacity
• Cell plan designed for a given traffic load what happens when traffic increases?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-348 ITTC © James P.G. Sterbenz Cellular Network Topology Increasing Capacity: Add Spectrum
• Add channels – constrained by available spectrum – e.g. channels added to US 700 MHz cellular b • taken from UHF television in 2009
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-349 ITTC © James P.G. Sterbenz Cellular Network Topology Increasing Capacity: Dynamic Assignment
• Add channels • Frequency borrowing – adjust long-term allocation between cells • limited applicability – dynamically load balance channels among cells • complexity
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-350 ITTC © James P.G. Sterbenz Cellular Network Topology Increasing Capacity: Sectorisation
• Add channels • Frequency borrowing What else?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-351 ITTC © James P.G. Sterbenz Cellular Network Topology Increasing Capacity: Sectorisation
• Add channels • Frequency borrowing • Sectorisation (SDMA) – replace omnidirectional antenna with directional antennæ – 3, 4, and 6 sector designs common
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-352 ITTC © James P.G. Sterbenz Cellular Network Topology Increasing Capacity: Cell Splitting
• Add channels • Frequency borrowing • Sectorisation • Cell splitting – overlay microcells
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-353 ITTC © James P.G. Sterbenz Cellular Network Topology Increasing Capacity: Cell Splitting
• Add channels • Frequency borrowing • Sectorisation • Cell splitting • Combination of techniques
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-354 ITTC © James P.G. Sterbenz Cellular Network Mobility Problem
How to support mobility between cells?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-355 ITTC © James P.G. Sterbenz Cellular Network Mobility Handoffs
• Handoffs (handovers) for mobility between cells – without call/connection termination
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-356 ITTC © James P.G. Sterbenz Cellular Network Mobility Handoffs
• Handoffs (handovers) for mobility between cells – without call/connection termination • Handoff types – hard handoff: break-before-make – soft handoff: make-before-break Metrics?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-357 ITTC © James P.G. Sterbenz Cellular Network Mobility Handoff Metrics
• Handoff metrics – call dropping probability – handoff delay (due to signalling) – interruption duration (time MT not connected to either BS) • results in silence for voice and packet loss for data – probability of unnecessary handoff
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-358 ITTC © James P.G. Sterbenz Cellular Network Mobility Handoff Strategies
• Handoff strategies: relative signal strength – handoff to BS with stronger signal problem?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-359 ITTC © James P.G. Sterbenz Cellular Network Mobility Handoff Strategies
• Handoff strategies: relative signal strength – handoff to BS with stronger signal – ping-pong oscillations between adjacent base stations alternatives?
todo: figure
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-360 ITTC © James P.G. Sterbenz Cellular Network Mobility Handoff Strategies
• Handoff strategies: relative signal strength – handoff to BS with stronger signal – ping-pong oscillations between adjacent base stations
• Handoff optimisations cell assignment – thresholds – hysteresis – predictive HO B HO A • future signal strength – combinations relative signal strength
based on [Stallings 2005] fig. 10.7b 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-361 ITTC © James P.G. Sterbenz Mobile Telephone Network Roaming
• Roaming between service providers – handoff – service and billing agreements
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-362 ITTC © James P.G. Sterbenz Mobile Telephone Network Architecture Overview
cell wireless base station backhaul mobile terminal
Internet IP 3G+ backhaul PSTN 4 MSC MSC mobile switching center (wired) • Network divided in cells each covered by base station – adjacent cells use different frequencies (spatial reuse ) • Mobile terminals move among cells • Cells interconnected by mobile switching centers – backhaul from base stations to MSCs (may be wireless ) 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-363 ITTC © James P.G. Sterbenz Mobile Telephone Network Generations
• 1G: analog voice • 2G: digital voice – 2.5G: 2nd generation with added data services – emerged with delay of 3G past planned deployment in 2000 • 3G: moderate-rate data access • 4G: high-rate data access – ITU req: 1 Gb/s stationary / 100 Mb/s moving data rate • 5G: under development – higher data rate at current power levels – large dense M2M (machine-to-machine) deployments
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-364 ITTC © James P.G. Sterbenz Mobile Cellular Telephony Prehistory: Mobile Radio Telephone
• Mobile radio telephone (0G) – all calls required operator assistance – not scalable Solution?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-365 ITTC © James P.G. Sterbenz Mobile Cellular Telephony Prehistory: Mobile Radio Telephone
• Mobile radio telephone (0G) – all calls required operator assistance – expensive service restricted to selected metro areas • no ability to roam – not scalable for mass deployment • Solution: cellular mobile telephone network
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-366 ITTC © James P.G. Sterbenz Mobile Telephone Network
Recent History1 • 1978–2000: analog to digital and early data services – 1977: Bell Labs begins first AMPS cellular trial in Chicago • 2000 car phones manufactured by OKI, E.F. Johnson, Motorola – 1979: first AMPS deployment in Tokyo by NTT – 1984: first commercial US AMPS deployment – 1991: first digital deployment – 2G GSM in Germany – 1994: CDPD (cellular digital packet data) in US • 14.4 kb/s – 2000: GPRS general packet radio service) for GSM • up to 64kb/s • begins to replace CDPD in US
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-367 ITTC © James P.G. Sterbenz Mobile Telephone Network
Recent History2 • 2000–2008: 3G data services – 2001: first 3G deployments • cdma2000 in Korea • UMTS in Europe – 2002: first SMS sent over Vodafone in UK – 2003: FCC requires number portability for wireless service – 2003: UMTS deployment in Germany – 2005: UMTS deployment in US by AT&T – 2006: HSDPA 3 Mb/s deployment in Germany – 2008: HSPPA 7.1 Mb/s down 1.4 Mb/s up in Germany
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-368 ITTC © James P.G. Sterbenz Mobile Telephone Network
Recent History3 • 2010–preaent: LTE and early 4G deployments – 2010: Sprint announces end of 802.16e in favour of LTE • 802.16 dead as a mobile telephony technology – 2011: US LTE deployments begin • at&t Sep. 2011 • Sprint Jul. 2012 • T-Mobile Mar. 2013 • Verizon Dec. 2010 – 2013: LTE-A 4G services begin in Russia and Korea
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-369 ITTC © James P.G. Sterbenz Mobile Cellular Telephony First Generation: Analog Voice
• 1G: analog voice • 2G: digital voice • 3G: digital voice with moderate-rate data access • 4G: high-rate data access • 5G: dense ubiquitous very-high-rate data with M2M
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-370 ITTC © James P.G. Sterbenz Mobile Cellular Telephony First Generation: Analog Voice
• 1G (first generation) mobile telephony – voice: analog modulation of analog signal – control: analog modulation of digital signal – data: no support • Development – trials in 1970s – first commercial services in 1980s – ubiquitous in 1990s • most cities & along freeways, motorways, autobahnen
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-371 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony Characteristics
• First generation: analog cellular telephony • Handsets – large and bulky – similar in size to wired phones with lead-acid batteries • e.g. “bag phone” – later more compact with NiCd batteries with poor life • e.g. 1989 Motorola MicroTAC (total area coverage) flip phone • Call characteristics – attenuation and noise resulted in variable quality – quality degraded significantly when handoff between cells
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-372 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony Deployed Systems
• 1G deployments: multiple incompatible systems – AMPS (advanced mobile phone system) • US, South America, Australia, China, Japan – NMT (Nordic mobile telephone) • Nordic countries, Switzerland, Eastern Europe, Soviet Union – TACS (total access communications system) • United Kingdom, Ireland, Japan (JTAC) – B-Netz, C-Netz West Germany, Austria, Portugal, South Africa – RTM (radio telephone mobile) Italy – Radiocom 2000 France Consequence to user?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-373 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony Deployed Systems
• 1G deployments: multiple incompatible systems – AMPS (advanced mobile phone system) • US, South America, Australia, China, Japan – NMT (Nordic mobile telephone) • Nordic countries, Switzerland, Eastern Europe, Soviet Union – TACS (total access communications system) • United Kingdom, Ireland, Japan (JTAC) – B-Netz, C-Netz West Germany, Austria, Portugal, South Africa – RTM (radio telephone mobile) Italy – Radiocom 2000 France • No ability to roam between systems and countries
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-374 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony AMPS History
• AMPS (advanced mobile phone system) – US, South America, Australia, China – 1977: Bell Labs begins first AMPS cellular trial in Chicago • 2000 car phones manufactured by OKI, E.F. Johnson, Motorola – 1979: first AMPS deployment in Tokyo by NTT – 1984: first commercial US AMPS deployment – late 1990s: AMPS superceded by 2G digital in major markets – 2008: FCC ends AMPS service requirement
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-375 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony AMPS US Deployment
• FCC granted two licenses for each market – A: second service provider (e.g. Cellular One) – B: incumbent wireline provider (e.g. RBOC) – each allocated 333 voice + 21 control channels – later expanded to 416 voice channels • FCC reclaimed UHF TV channels 70 – 83 • Initially A/B network manually provisioned in phone – phone identified by EIN – no automatic roaming between carriers – special roaming codes needed to receive calls
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-376 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony AMPS Link Characteristics
• AMPS (advanced mobile phone system) – US, South America, Australia, China • Frequency bands: 2 25 MHz – base station: 869 – 894 MHz – handset: 824 – 849 MHz, 3W max • Channels: 30 kHz bandwidth – 790 full-duplex analog voice channels • FM with no encryption – 2 (rev & fwd) 42 full-duplex digital control channels • 10 kb/s FSK framed with BCH error coding
• Cells: 2 – 20 km diameter based on [Stallings 2005] Table10.4 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-377 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony AMPS Operation
• Handset has NAM (numeric assignment module) in ROM – telephone number + serial number • NAM transmitted to MSC – phone number used for billing – stolen phones locked out • User dials optional PIN and phone number – NAM and PIN transmitted in clear • NAM cloning became common theft-of-service • MSC – replies to handset with voice channel assignment – completes call to destination through basedPSTN on [Stallings 2005] Table10.4 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-378 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony Problems
Problems with 1G cellular telephony?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-379 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony Problems
• Problems with 1G cellular telephony – analog voice transmission subject to noise and interference – developed reputation for poor quality Solution?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-380 ITTC © James P.G. Sterbenz 1G Mobile Cellular Telephony Problems
• Problems with 1G cellular telephony – analog voice transmission subject to noise and interference – developed reputation for poor quality • Solution – digital coding of voice channels
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-381 ITTC © James P.G. Sterbenz Mobile Cellular Telephony Second Generation: Digital Voice
• 1G: analog voice • 2G: digital voice – 2.5G: 2nd generation with data over voice channels – 2.75G: 2.5 generation with enhanced data rates • 3G: digital voice with moderate-rate data access • 4G: high-rate data access • 5G: dense ubiquitous very-high-rate data with M2M
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-382 ITTC © James P.G. Sterbenz 2G Mobile Cellular Telephony Characteristics
• Second generation: digital cellular telephony • Handsets – smaller than analog sets • driven by more compact digital components and Moore’s law – later premium phones very small • e.g. 1996 Motorola StarTAC: 1st small clamshell • Call characteristics – marketing claim: clear voice with no dropped calls – reality: • better quality when signal strong • worse quality when signal very weak, especially during handoff
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-383 ITTC © James P.G. Sterbenz 2G Mobile Cellular Telephony Voice Network Overview PSTN
Radio Network Subsystem circuit-switched 4 voice
Core Network
MS
• Radio network subsystem (RNS) – connected to circuit switched mobile core network – core network MSCs connected to traditional PSTN 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-384 ITTC © James P.G. Sterbenz 2G Mobile Cellular Telephony Deployed Systems: TDMA
• 2G TDMA deployments – GSM (Groupe Spécial Mobile) (global system for mobile communications) • Europe and most of the world – iDEN (integrated digital enhanced network) • developed by Motorola • US (Nextel), Canada (Telus Mobility) – D-AMPS (digital AMPS) IS-136 using AMPS channels • US (US Cellular former AT&T Wireless), Canada (Rogers) – PDC (personal digital cellular) • Japan (NTT DoCoMo), South Korea • 2G CDMA deployments 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-385 ITTC © James P.G. Sterbenz 2G Mobile Cellular Telephony Deployed Systems: CDMA
• 2G TDMA deployments • 2G CDMA deployments – IS-95 cdmaOne • developed by Qualcomm • US (many carriers including Sprint and Verizon), Canada, Mexico, Australia, Korea, China, India, Israel, Sri Lanka, Venezuela, Brasil • became dominant system in the US • lost US market share to GSM (T-Mobile, at&t/Cingular)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-386 ITTC © James P.G. Sterbenz 2G Mobile Cellular Telephony Link Characteristics
AMPS D-AMPS GSM cdmaOne Introduced 1979/1984 1991 1990 1993 Type analog digital digital digital Coding FM TDMA TDMA CDMA band MHz BS 869 – 894 869 – 894 935 – 960 869 – 894 MT 824 – 849 824 – 849 890 – 915 824 – 849 Channel BW 30 kHz 30 kHz 200 kHz 1.25 MHz Duplex channels 790 + 42 832 125 20 Mux. degree 1 3 8 35 Max. xmit. power 3 W 3 W 20 W 200 mW Modulation FM + FSK /4 DQPSK GMSK QPSK
based on [Stallings 2005] Table10.5 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-387 ITTC © James P.G. Sterbenz 2G GSM TDMA Overview
• Groupe Spécial Mobile (GSM) – formed in 1987 by CEPT Conférence européenne des administrations des postes et des télécommunications European conference of Postal and Telecommunication Administrations – 1987: MOA signed toward common European deployment – 1990: ETSI standard published European Telecommunications Standards Institute • Renamed Global System for Mobile communication – recent standards freely available from www.etsi.org • Most widely deployed system worldwide – except North America, Japan, Korea
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-388 ITTC © James P.G. Sterbenz 2G GSM TDMA Link Characteristics
• Symmetric forward / reverse links
Band 400/450 MHz 850 MHz 900 MHz 1800 MHz 1900 MHz Use 1G reuse N. America original N. America Forward 935 – 960 Reverse 890 – 915
• TDMA within FDMA with slow FHSS (1hop /4.615 ms) – 125 full-duplex channels – 8 logical channels (slots) /frame – 1 hop / 4.615 ms to improve multipath resistance
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-389 ITTC © James P.G. Sterbenz 2G GSM TDMA Multiple Access
• TDMA in FDMA/FDD slow FHSS – FDMA • set of full-duplex channels (FDMA)
• 124 in original GSM-900 down up – FDD links links • symmetric down/uplink channels 200 4.615 – TDMA kHz ms
• 1 burst with 2 data fields / slot
1
n –
• 8 slots / frame n frame 4 frame
• frame hierarchy 3 frame
framel 1 framel
frame 0 frame
channel 0 channel channel – FHSS 1 channel
channel t • 1 hop / 4.615 ms frame f 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-390 ITTC © James P.G. Sterbenz 2G GSM TDMA Channels
• TCH: traffic channels – voice: full rate (28.8 kb/s) and half rate (11.4 kb/s) – data: 4.8, 9.6, and 14.4 kb/s – data to 57.6 kb/s with HSCSD channel group enhancement • CCH: control channels for signalling – BCCH: broadcast CCH • broadcast of information to all MSs – CCCH: common CCH • connection management – DCCH: dedicated CCH • bidirectional signalling channels
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-391 ITTC © James P.G. Sterbenz 2.5 and 2.75G GSM TDMA GPRS and EDGE Motivation
• 3G deployments for mobile data significantly delayed – consumers wanted promised data capabilities • Solution: add data to existing GSM infrastructure – GPRS (2.5G): very-low-rate data in existing voice channels – EDGE (2.75G): low-rate data channels added to 2G • Note: data in 2G CDMA not widely deployed
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-392 ITTC © James P.G. Sterbenz 2.5G GSM TDMA GPRS Overview
• GPRS: General Packet Radio Service – data packet transport over GSM • Data rate varies – based on multi-slot allocation • various combinations of downlink/uplink – based on adaptive coding: 8 – 20 kb/s per slot – theoretical maximum of 107 kb/s per 5 slots • not a normal service offering • Displayed as ‘G’ or ‘2G’ on many Android phones
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-393 ITTC © James P.G. Sterbenz 2.75G GSM TDMA EDGE Overview
• EDGE: Enhanced Data Rates for GSM Evolution – enhanced data packet transport over GSM – meets technical definition of 3G • but slower than current 3G technologies UMTS and EV-DO • Data rate varies – 236.8 kb/s per 4 slots • Displayed as ‘E’ on many Android phones
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-394 ITTC © James P.G. Sterbenz 2G IS-95 CDMA Overview
• Developed by Qualcomm in 1990 • Standardised as TIA/EIA IS-95 (interim standard 95) [Telecommunications Industry Association] [Electronic Industries Alliance] in 1993 • Branded by CDG [CDMA Development Group] as cdmaOne
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-395 ITTC © James P.G. Sterbenz 2G CDMA vs. TDMA Advantages and Disadvantages
• CDMA advantages – resistance to interference and fading – resistance to multipath interference • orthogonal chipping sequences – physical layer confidentiality • but not impossible to crack! – graceful degradation as load increases
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-396 ITTC © James P.G. Sterbenz 2G CDMA vs. TDMA Advantages and Disadvantages
• CDMA advantages – resistance to interference and fading – resistance to multipath interference • orthogonal chipping sequences – physical layer confidentiality (but not impossible to crack!) – graceful degradation as load increases • CDMA disadvantages – self-jamming from non-synchronised users • no equivalent of TDMA guard bands – power management more important – soft handoff required (why? ) • more complex
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-397 ITTC © James P.G. Sterbenz 2G IS-95 CDMA 2G Voice Network Architecture PSTN
BSC HLR VLR
MS BSC MSC 5
BTS • BTS: base transceiver station – cell tower and transceivers • BSC: base station controller MS – intelligence for multiple BTSs • MSC: mobile switching center • HLR/VLR: home/visitor location registry BTS 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-398 ITTC © James P.G. Sterbenz 2G IS-95 CDMA Link Characteristics
• Asymmetric forward / reverse links • Forward link – 824 – 849 MHz (same frequency band as AMPS) – 1.228 MHz carriers, each with: – 64 CDMA DSSS logical channels • pilot (0): timing, phase, signal strength for handoff • paging (1–7): signalling messages for mobile terminals • synch. (32): 1200 b/s for identification of cellular system • traffic (8–31, 33–63) 9600 b/s
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-399 ITTC © James P.G. Sterbenz 2G IS-95 CDMA Link Characteristics
• Asymmetric forward / reverse links • Reverse link – 869 – 894 MHz (same frequency band as AMPS) – 1.228 MHz carriers, each with: – up to 94 CDMA DSSS logical channels • ≤ 32 for signalling • ≤ 62 traffic unique ESN-based code per user
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-400 ITTC © James P.G. Sterbenz Mobile Cellular Telephony Third Generation: Moderate Rate Data
• 1G: analog voice • 2G: digital voice • 3G: digital voice with moderate-rate data access • 4G: high-rate data access • 5G: dense ubiquitous very-high-rate data with M2M
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-401 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Motivation and Characteristics
Problems with 2G cellular telephony?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-402 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Motivation and Characteristics
• Problems with 2G cellular telephony – nothing really, for voice…
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-403 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Motivation and Characteristics
• Problems with 2G cellular telephony – nothing really, for voice… – but not engineered for data and Internet access
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-404 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Motivation and Characteristics
• Problems with 2G cellular telephony – nothing really, for voice… – but not engineered for data and Internet access • but is this really the right device to access the Internet?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-405 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Motivation and Characteristics
• Problems with 2G cellular telephony – nothing really, for voice… – but not engineered for data and Internet access • but is this really the right device to access the Internet? Response?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-406 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Motivation and Characteristics
• Problems with 2G cellular telephony – nothing really, for voice… – but not engineered for data and Internet access • but is this really the right device to access the Internet? • Response of mobile service providers – hack data services into and onto cellular infrastructure
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-407 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Motivation and Characteristics
• Problems with 2G cellular telephony – nothing really, for voice… – but not engineered for data and Internet access • but is this really the right device to access the Internet? • Response of mobile service providers – hack data services into and onto cellular infrastructure • Market advantage – widely deployed wireless infrastructure – way ahead of 802.11 – predates 802.16
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-408 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Standards Evolution from 2G
• GSM family: UMTS – 2G GSM 2.75G EDGE 3G UMTS – UMTS: universal mobile telecommunication service – most of the world (US at&t and T-Mobile) • CDMA family – 2G IS-95 cdmaONE 3G CDMA2000 – US (Sprint and Verizon) and a few other world markets
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-409 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Standards and Interfaces
• IMT-2000: – International Mobile Telecommunications 2000 – ITU-R standard M.1457 for 3G networking – six submitted interfaces certified by ITU as IMT-200 3G
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-410 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking
IMT-2000 Standards and Interfaces1 • Widely deployed – IMT-DS: direct sequence • W-CDMA (wideband CDMA) in UMTS • standardised by 3GPP (3G Partnership Project) – IMT-MC: multicarrier • CDMA2000 • standardised by 3GPP2 (3G Partnership Project 2) • Limited deployment – OFDMA TDD WMAN in 2007 • based on 802.16e standards standardised by IEEE • based on implementation agreements from WiMAX forum • Sprint/Clearwire offered as “4G” ~2010 – 2015
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-411 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking
IMT-2000 Standards and Interfaces2 • Other standards – IMT-TD: time division • TD-CDMA standardised by 3GPP – IMT-SC: single carrier • EDGE 2.75G technically qualified as 3G – IMT-FT: frequency time • DECT: ETSI standard digital enhanced cordless telephone
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-412 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Link Characteristics
GSM UMTS cdmaOne cdma2000 Introduced 1990 ~ 2002 1993 ~ 2002 Type digital digital digital digital Coding TDMA DS-CDMA CDMA CDMA band MHz BS 935 – 960 869 – 894 MT 890 – 915 824 – 849 Channel BW 200 kHz 5 MHz 1.25 MHz 1.25 MHz Duplex channels 125 20 Mux. degree 8 35 Max. xmit. power 20 W 200 mW Modulation GMSK QPSK Generation 2G 3G 2G 3G based in part on [Stallings 2005] Table10.5 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-413 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Voice and Data Network Overview PSTN
Radio Network Subsystem circuit-switched 4 voice
Core Network Internet
MS
packet-switched IP data • RNS access split into two: – circuit switched voice (as in 2G) – packet switched data (new with 3G) 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-414 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking UMTS Network Architecture
VLR BSS BTS Abis Iu
BSC MSC GMSC PSTN NodeBTS B IuCS AuC EIR HLR GR Node B Iub Node B RNC SGSN GGSN G Gn i Node B I PS RNS u CN [Schiller 2003 Fig. 4.31] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-415 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking EV-DO Network Architecture RNC Internet 802.16 backhaul AAA
AT aggr RNC PDSN IP DOM
BTS
• BTS: base transceiver station T1 – DOM: data-only module AT backhaul • RNC: radio network controller DOM – AAA: authentication, auth., & acct. BTS • PDSN: packet data serving node 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-416 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Evolution to 3.5 and 3.75G
• 3G technologies evolved to higher data rates – and briefly included 802.16 WiMAX – 3.5 / 3.75 / 3.9G designations unofficial • commonly used, but not always in agreement – US carriers piled on to compete as “4G” • Alternatives – GSM: 3G UMTS 3.5G HSPA 3.75G HSPA+ – CDMA: 3G CDMA2000 3.5G EV-DO – 802.16 WiMAX: 802.16e 3G – UMTS 3.9G LTE
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-417 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Evolution to 3.5 and 3.75G
• GSM family: UMTS – 3G UMTS HSPA(+) (high-speed packet access) – HSPA: 14/5.76 Mb/s down/up (3.5G) • widely deployed worldwide – HSPA+: 14/5.76 Mb/s down/up (3.75G) • widely deployed worldwide; being phased out to LTE • incorrectly branded in the US by T-Mobile as 4G • CDMA family – 3G CDMA2000 EV-DO (evolution data optimized) • 802.16 family – 802.16e 3G 802.16m 4G 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-418 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Evolution to 3.5 and 3.75G
• GSM family: UMTS – 3G UMTS HSPA(+) (high-speed packet access) • CDMA family – 3G CDMA2000 EV-DO (evolution data optimized) – EV-DO Rev. A: 3.1 Mb/s downlink (3.5G) • widely deployed in the US by Sprint – EV-DO Rev. B: 14.7 Mb/s downlink • plans in US and most others abandoned for LTE – EV-DO Rev. C: 4G Qualcomm development abandoned • 802.16 family – 802.16e 3G 802.16m 4G 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-419 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking Evolution to 3.5 and 3.75G
• GSM family: UMTS – 3G UMTS 3.75G HSPA(+) (high-speed packet access) • CDMA family – 3G CDMA2000 3.5G EV-DO (evolution data optimized) • 802.16 family – 802.16e 3.5G 802.16m 4G – 802.16e mobile WiMAX 3.5G • adopted by Sprint/Clearwire in US; incorrectly branded as 4G • deployed as WiBro in South Korea • abandoned in favour of LTE (by Sprint in 2011) – 802.16m 4G compliant air interface; LTE won
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-420 ITTC © James P.G. Sterbenz 3G Mobile Cellular Networking LTE Evolution toward 4G
• LTE: long term evolution – 3GPP successor to UMTS • Appears to finally be worldwide converged standards – air interfaces and link protocols – deployment architecture and interfaces – frequency bands • but many complicate universal handset deployment • e.g. China and India bands 39/40/41 – 3.9G (unofficially) • doesn’t meet ITU 4G requirements • but the same architecture as 4G LTE-A
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-421 ITTC © James P.G. Sterbenz 3.9G/4G Mobile Networking LTE History
• 2004: initiated by NTT DoCoMo as E-UTRA – E-UTRA enhancement of UTRA – performance targets 100 M b/s downlink; 50 Mb/s uplink; < 10 ms RTT • 2007: first approved 3GPP technical specifications • 2008: stable for commercial implementation • 2009: first public LTE service in Stockholm and Oslo • 2010: LTE service in Germany • 2015: LTE deployment and substitution in US • 2019: Verizon decommissioning 3.5G EV-DO network
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-422 ITTC © James P.G. Sterbenz 3.9G/4G Mobile Networking LTE Data Network Overview PSTN
Radio Network Subsystem circuit-switched voice
Core Network Internet
MS
packet-switched IP data • RNS access – only packet switched data and VoIP – legacy circuit-switched network gone 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-423 ITTC © James P.G. Sterbenz 3.9G/4G Mobile Networking LTE Architectural Features
• Simplified network architecture vs. 3G – flat IP-based network replacing the GPRS core – optimised for the IP-Multimedia Subsystem (IMS) • circuit switching gone – network partly self-organising • Scheme for soft frequency reuse between cells – inner part uses all sub-bands with less power – outer part uses pre-served sub-bands with higher power • Transition from 3G networks – but with completely different radios and air interfaces
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-424 ITTC © James P.G. Sterbenz 3.9G/4G Mobile Networking LTE Performance
• Enhanced performance over 3G – higher data throughput using MIMO • only incremental improvement over HSPA+ rates – if that; depends on deployment, range, load – lower RTT for interactive and gaming applications • Greater flexibility – spectrum, bandwidth, rates • Step towards 4G – architecturally compatible – but insufficient data rate: not 100 Mb/s / 1 Gb/s
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-425 ITTC © James P.G. Sterbenz 3.9G/4G Mobile Networking LTE Physical Layer Characteristics
• E-UTRA (Evolved Universal Terrestrial Radio Access) – Operating bands: 700-2700MHz – Channel bandwidth 1.4, 3, 5, 10, 15, or 20 MHz – TDD and FDD • Modulation: QPSK, 16QAM, 64QAM • Multiple Access – OFDMA (DL), SC-FDMA (UL) • Peak data rates – 300 Mbit/s DL; 75 Mbit/s UL – Depends on UE category • Cell radius: <1 km to 100 km 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-426 ITTC © James P.G. Sterbenz 3G Mobile Networking LTE Architecture
Mobility Management Entity Serving Gateway U Packet-data network Gateway Home UE2 u Subscriber Server Policy andMME Charging Rules Function GPRS eNode B S10 S3
X2-U/- MME HSS eNode B X2-U/-C S1-MME S6 C
UE1 S1-MME S11 X2-U/- eNode B S4 U PCRF u C S1-U X2-U/- S7 eNode B S-GW Rx+ C S1-U S5 S8 (roaming) Internet, eNode B Operators… P-GW SGi E- EPC (Evolved Packet Core) UTRAN [Schiller 2011] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-427 ITTC © James P.G. Sterbenz Mobile Cellular Telephony Fourth Generation: High Rate Data
• 1G: analog voice • 2G: digital voice • 3G: digital voice with moderate-rate data access • 4G: high-rate data access • 5G: dense ubiquitous very-high-rate data with M2M
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-428 ITTC © James P.G. Sterbenz 4G Mobile Networking Deployment Status
• Who here has 4G?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-429 ITTC © James P.G. Sterbenz 4G Mobile Networking Deployment Status
• Who here has 4G? Really? Run a speedtest and lets see who’s the fastest
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-430 ITTC © James P.G. Sterbenz 4G Mobile Networking Deployment Status
• Who here has 4G? – results: – I routinely get 30–60 Mb/s in KC/Lawrence from T-Mobile • not much better than HSPA+ – I occasionally get 60–90 Mb/s – I once got 138 Mb/s in downtown Kansas City – I once got 161 Mb/s in St. Louis • Unless you got 1 Gb/s , you don’t really have 4G – if you got > 100 Mb/s , we’ll talk… More later
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-431 ITTC © James P.G. Sterbenz 4G Mobile Networking Overview
• High data rates for modern smart phones – mobile PSTN has become de facto mobile Internet access • IMT-advanced (international mobile telecommunications) – ITU-R M.2133, M.2134 – 100 Mb/s mobile – 1 Gb/s stationary • Service offerings – many claimed based on 802.16, HSPA, and LTE – not actually 4G • are being spun as 4G by service providers
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-432 ITTC © James P.G. Sterbenz 4G Mobile Networking LTE and LTE-A Mobile Telephony Generations
• LTE is next architectural generation in GSM family – GSM UMTS LTE E-UTRAN • evolved UMTS terrestrial radio access • ITU defines generations by capabilities – 3G = ITU-R M.1457 IMT-2000 – 4G = ITU-R M.1645 IMT-Advanced • Relationship – provider marketing folk want to sell you new & improved – but doesn’t reflect reality of ITR-R standards – LTE = IMT2000 = 3G (referred to here as 3.9G) – LTE-A = IMT-Advanced = 4G unless ITU redefines 4G 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-433 ITTC © James P.G. Sterbenz 4G Mobile Networking IMT-Advanced Overview
• IMT-advanced – ITU-R M. series specification – worldwide compatibility – flexibility to efficiently support wide range of services – interworking with other technologies – requirement for 4G certification • Desired features – high data rates for mobile broadband services and apps • 1 Gb/s stationary to 100 Mb/s high mobility – worldwide roaming
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-434 ITTC © James P.G. Sterbenz 4G Mobile Networking 3GPP LTE-Advanced Overview
• 3GPP LTE-advanced – successor to LTE • 3GPP releases 10–12 – theoretical data rates sufficient for IMT-A / 4G certification • sometimes called “real 4G” or “true 4G” • Major architectural thrusts – new scenarios – densification – multi-antennæ techniques – spectrum flexibility – device enhancements
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-435 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria: Marketing
• Criteria for 4G – service providers advertising 4G? • Nope! They lie about net neutrality as well
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-436 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria: Standards
• Criteria for 4G – compliant with ITU-R IMT-Advanced M.2134 • Downlink: 1 Gb/s stationary | 100 Mb/s moving – 3GPP standards • LTE releases 8 and 9 not compliant • LTE-A releases 10–12 are compliant – other compliant standards • 802.16m (mostly dead after Sprint abandoned) • 3GPP2 UMB (cdma2000 EV-DO successor) dead
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-437 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria: Device Support
• Criteria for 4G: LTE-A: 3GPP rel. 10–12 does your phone support?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-438 ITTC © James P.G. Sterbenz 4G Mobile Networking
Criteria: Device Support [gsmarena.com] Phone G Protocol Max rate Year Sams Apl Rel Cat Dnlink Uplink 4 (4s) HSPA cl10 7.2 Mb/s 5.76 Mb/s 2010 2Q SII LTE 21.1? 5.76? 2011 2Q SIII 5 (5s) 3G LTE 3 100 Mb/s 50 Mb/s 2012 3Q S4 3G LTE 3 100 Mb/s 50 Mb/s 2013 2Q S4 Act 4G LTE-A 4 150 Mb/s 50 Mb/s 2013 4Q S5 6 4G LTE-A 4 150 Mb/s 50 Mb/s 14 3Q 15 2Q S6 4G LTE-A 6 300 Mb/s 50 Mb/s 2015 2Q S7 7 4G LTE-A 3CA 9 450 Mb/s 50 Mb/s 2016 2Q 3Q 8 X 4G LTE-A 3CA 12 600 Mb/s 150 Mb/s 2017 3Q 4Q S8 / N8 XS 4G LTE-A 5CA 16 1.0 Gb/s 150 Mb/s 17 1Q 18 4Q S9 4G LTE-A 6CA 18 1.2 Gb/s 200 Mb/s 2018 1Q
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-439 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria: Device Support
• Criteria for 4G: LTE-A: 3GPP rel. 10–12 – phone support (2014–2017) • LTE-A in recent high-end phones • but not at real 4G data rates for any iPhone does your service provider support?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-440 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria: Provider Support
• Criteria for 4G: LTE-A: 3GPP rel. 10–12 – phone support (2014–2017) • LTE-A in recent high-end phones • but not at real 4G data rates for any iPhone except 8 XS – service provider support (~2016) • some providers announce markets (e.g. T-Mobile Lawrence) • difficult to tell (LTE Discovery rooted?) – unless you get > 150 Mb/s measured downlink … … which you don’t do you have an actual 4G-rate downlink?
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-441 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria: Provider Support
• Criteria for 4G: LTE-A: 3GPP rel. 10–12 – phone support (2014–2017) • LTE-A in recent high-end phones • but not at real 4G data rates for any iPhone – service provider support (~2016) • some providers announce markets (e.g. T-Mobile Lawrence) • difficult to tell (LTE Discovery rooted?) – unless you get > 150 Mb/s measured downlink … … which you don’t – channel capabilities and throughput (not yet) • ≥ cat 6 @ 300 Mb/s 50 Mb/s – being very loose with what is 4G
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-442 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria
• Criteria for 4G: LTE-A: 3GPP rel. 10–12 – phone support (2014–2017) – service provider support (~2016) – channel capabilities and throughput (not yet) • But this doesn’t matter, you say – it’s all pedantry
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-443 ITTC © James P.G. Sterbenz 4G Mobile Networking Criteria
• Criteria for 4G: LTE-A: 3GPP rel. 10–12 – phone support (2014–2017) – service provider support (~2016) – channel capabilities and throughput (not yet) • But this doesn’t matter, you say – I’m a scientist: I do pedantry – you’re OK buying a “1 Gb/s Ethernet switch” … … and only getting 20 Mb/s throughput? • “4G” is now meaningless – LTE-Advanced & 3GPP releases not advertised to consumers
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-444 ITTC © James P.G. Sterbenz 4G Mobile Networking 3GPP 4G LTE-A Releases
• Pre-LTE 3GPP UMTS releases 4–7 • 3GPP 4G LTE releases 8–9 • 3GPP 4G LTE-Advanced releases stable – 3GPP release 10 Jun 2011 – 3GPP release 11 Mar 2013 – 3GPP release 12 Mar 2015 • 3GPP 4.5G LTE-Advanced Pro releases 13–14 • 3GPP 5G releases 15–16
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-445 ITTC © James P.G. Sterbenz 4G Mobile Networking
3GPP 4G LTE-A Release Features1 • LTE-A release 10 (stable Mar 2009) – carrier aggregation (channel bonding) – enhanced downlink MIMO; uplink MIMO – enhanced ICIC (inter-cell interference coordination) – relays • LTE-A release 11 (stable Mar 2013) • LTE-A release 12 (stable Mar 2013)
[DPS2016] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-446 ITTC © James P.G. Sterbenz 4G Mobile Networking
3GPP 4G LTE-A Release Features2 • LTE-A release 10 (stable Mar 2009) • LTE-A release 11 (stable Mar 2013) – interprovider service layer interconnection (check this) – carrier aggregation enhancements – enhanced HetNet (heterogeneous networks) – CoMP (coördinated multipoint) • LTE-A release 12 (stable Mar 2013)
[DPS2016] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-447 ITTC © James P.G. Sterbenz 4G Mobile Networking
3GPP 4G LTE-A Release Features3 • LTE-A release 10 (stable Mar 2009) • LTE-A release 11 (stable Mar 2013) • LTE-A release 12 (stable Mar 2013) – small cell enhancements – lean carrier – multi-antennæ enhancements – D2D (device-to-device communication) – FDD/TDD carrier aggregation
[DPS2016] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-448 ITTC © James P.G. Sterbenz 4G Mobile Networking 3GPP LTE-Advanced Pro Overview
• 3GPP LTE-advanced pro – further enhancement to LTE-A • 3GPP releases 13–14 – sometimes referred to as 4.5G • Continued architectural thrusts – new scenarios – densification – multi-antennæ techniques – spectrum flexibility – device enhancements
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-449 ITTC © James P.G. Sterbenz 4G Mobile Networking 3GPP 4.5G LTE-AP Releases Stable
• Pre-LTE 3GPP UMTS releases 4–7 • 3GPP 4G LTE releases 8–9 • 3GPP 4G LTE-Advanced releases 10–12 • 3GPP 4.5G LTE-Advanced Pro releases – 3GPP release 13 Mar 2016 – 3GPP release 14 Jun 2017 • 3GPP 5G releases 15–16
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-450 ITTC © James P.G. Sterbenz 4G Mobile Networking
3GPP 4.5G LTE-AP Release Features1 • LTE-AP release 13 (stable Mar 2016) – MTC enhancements – LAA (license assisted access) – narrowband IoT – FD-MIMO – dual connectivity • LTE-AP release 14 (stable Jun 2017)
[DPS2016] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-451 ITTC © James P.G. Sterbenz 4G Mobile Networking
3GPP 4.5G LTE-AP Release Features2 • LTE-AP release 13 (stable Mar 2016) • LTE-AP release 14 (stable Jun 2017) (check all) – energy efficiency – LCS location services – mission-critical data and video – FMSS (flexible mobile service steering) – MBSP (multimedia broadcast supplement public warning sys) – enhancements for television – massive IoT – CBS (cell broadcast service) [DPS2016] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-452 ITTC © James P.G. Sterbenz Mobile Cellular Telephony Fifth Generation: Dense Ubiquitous Deployment
• 1G: analog voice • 2G: digital voice • 3G: digital voice with moderate-rate data access • 4G: high-rate data access • 5G: dense ubiquitous very-high-rate data with M2M
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-453 ITTC © James P.G. Sterbenz Fifth Generation Mobile Networking 5G Overview
• Very high data rates – for evolving smart phones and other mobile devices – aggregate capacity for many more devices – P2P communications for efficiency • Large number of devices – continued increase in mobile device adoption – M2M (machine-to-machine) communication for the IoT • IMT-advanced (international mobile telecommunications)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-454 ITTC © James P.G. Sterbenz 5G Mobile Networking Projected Traffic Demand
• 5G traffic predictions – 1 ZB = 1k EB = 1M PB = 1G TB – 1 ZB/month = 4 PB/s traffic/month
6000 5000
EB 4000 3000 2000 1000 0 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
Non-Video Video M2M ITU-R M.2370] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-455 ITTC © James P.G. Sterbenz 5G Mobile Networking IMT-2020 Overview
• IMT-2020 – vision and framework: ITU-R M.2083 – timeline • vision: 2012 • development: 2016 • deployment: 2020 – usage scenarios • enhanced mobile broadband • ultra-reliable low-latency communications • massive machine-type communications
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-456 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G vs. 4G Requirements peak rate user rate • ITU-T Kiviat [Gb/s] [Mb/s] 4G vs. 5G 20 100 IMT-2020 capacity 10 spectrum [Mb/s/m2] 1 efficiency 10 1 3 .1 1 350 IMT-adv energy100 500 5 mobility efficiency 10 10 [km/h]
106 1 density latency 2 [dev/km ] [ms] [ITU-R M.2083] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-457 ITTC © James P.G. Sterbenz 5G Mobile Networking 3GPP 5G Overview
• 3GPP 5G – massive IoT – critical communications: latency, reliability, availability – enhanced mobile broadband – enhanced network operation and security
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-458 ITTC © James P.G. Sterbenz 5G Mobile Networking 3GPP 5G Releases Stable
• Pre-LTE 3GPP UMTS releases 4–7 • 3GPP 4G LTE releases 8–9 • 3GPP 4G LTE-Advanced releases 10–12 • 3GPP 4.5G LTE-Advanced Pro releases 13–14 • 3GPP 5G releases 15–16 – 3GPP release 15 Sep 2018 planned – 3GPP release 16 Dec 2020 planned
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-459 ITTC © James P.G. Sterbenz 5G Mobile Networking 3GPP 5G Release Features
• 5G release 15 (planned stable Sep 2018) (check all) – initial 5G-NR (new radio) release • not full 5G; no other 5G network capabilities – support for vehicular communications – IMS (IP multimedia core-network susbsystem) • 5G release 16 (stable Dec 2020) – more likely to be real 5G
[DPS2016] 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-460 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G Carrier Claims
• “5G” deployments – carriers already announcing “5G” network service • late 2018 – early 2019 – initial 5G-NR (new radio) release 15 subset • not full 5G; no other 5G network capabilities • won’t even use mm-wave spectrum!
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-461 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G Carrier Claims
• “5G” NR deployment US announcements – • – • – • – Verizon: 4Q2018 first and only 5G ultra wideband network [https://www.youtube.com/watch?v=6Mppg32to_g] • Houston, Indianapolis, LA, Sacramento (bad URL to release) • sign up for ‘5G Home now’! (with photo of hot spot puck)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-462 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G Carrier Claims
• “5G” NR deployment US announcements – at&t: late 2018 • 12 cities (possibly Dallas, Waco TX, Atlanta) – Sprint: 1H2019 • Atlanta, Chicago, Dallas, Houston, KC, LA, NYC, Phoenix, DC – T-Mobile with Ericsson: 2018 • 30 cities in 2018 with mmWave spectrum beginning – Verizon: 4Q2018 first and only 5G ultra wideband network [https://www.youtube.com/watch?v=6Mppg32to_g] • Houston, Indianapolis, LA, Sacramento (bad URL to release) • sign up for ‘5G Home now’! (with photo of hot spot puck)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-463 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G Handset Vendor Claims
• “5G” NR deployment US announcements – Motorola • 5G moto mod (when available) for moto z – currently moto z only LTA-A cat 9 450 Mb/s • “Be the first to try 5G. Only on Verizon. Coming Soon.” • “Download a 4K movie in just seconds” – and watch on a teeny-tiny screen!
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-464 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G Carrier Quotes
• Fun quotes – at&t • “… we’ve taken a different approach to transforming our network. AT&T 5G services will be based on industry standars for 5G.” – T-Mobile • “While other guys make promises we’re putting our money where our mouth is.” • “Dumb and dumber are in a meaningless race to be first. Their so-called 5G isn’t mobile, and it’s not even on a smartphone.” – Verizon • “There’s 5G, then there’s Verizon 5G Ultra Wideband”
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-465 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G Deployment Realities
• Real 5G density requires massive infrastructure – 4 increased in cell towers over urban LTE • very expensive to deploy • significant time for regulatory approval – ubiquitious roadway deployment for vehicles • 5G is just as meaningless as 4G – appallingly, IEEE already talking about 6G
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-466 ITTC © James P.G. Sterbenz 5G Mobile Networking 5G Deployment Realities
• What really is 5G? – a set of functionalities and features being added to LTE • on an all-IP network core • higher rates, denser, more energy efficient • Will you see it in your lifetime? – possibly: it depends (will likely be marketed as 9G) • how old you are • where you live (Shropshire still waiting for 3G)
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-467 ITTC © James P.G. Sterbenz Mobile Telephony and Networking Major Generation Summary
Gen Standard A/D Type Access Core Rate 1 AMPS analog voice AMPS PSTN 0 2 GSM | IS-95 TDMA | CDMA 10 kb/s digital voice PSTN 2.75 EDGE 100 kb/s 3 UMTS | cdma2000 voice W-CDMA | CDMA PSTN 1 Mb/s 3.5 HSPA(+) digital +data 10 Mb/s 3.9 LTE data OFDMA IP 100 Mb/s 4 LTE-A digital data OFDMA IP 1 Gb/s 5 5G digital data IP 10 Gb/s
• order of magnitude theoretical max fixed
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-468 ITTC © James P.G. Sterbenz Mobile Telephony and Networking Generation Characteristics Gen Standard A/D Type Access Rate GSM CDMA GSM CDMA [b/s] 1 AMPS, … analogue voice – 2 GSM IS-95 voice 14.4 k 2.5 GPRS digital + TDMA CDMA 170 k 2.75 EDGE data 270 k 3 UMTS EV-DO A data 384 k 3.5 HSPA EV-DO B + W-CDMA CDMA 14.4 M digital 3.75 HSPA+ EV-DO C voice 28 M 3.9 LTE rel 08–09 300 M data OFDMA 4 LTE-A rel 10–12 4 G digital (VoIP) TDD | FDD 4.5 LTE-AP rel 13–14 8 G 5 5G rel 15–16 digital data 20 G
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-469 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks MW.6 Internet of Things
MW.1 Wireless and mobile networking concepts MW.2 MAC functions and services MW.3 MAC algorithms MW.4 Wireless networks MW.5 Mobile networks MW.6 Internet of Things
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-470 ITTC © James P.G. Sterbenz Internet of Things Introduction
• Just because you can…
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-471 ITTC © James P.G. Sterbenz Internet of Things Introduction
• Just because you can… …doesn’t mean you should
#internetofshit
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-472 ITTC © James P.G. Sterbenz Internet of Things Introduction
• IoT: Internet everywhere – whether or not we want it – whether or not it should be
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-473 ITTC © James P.G. Sterbenz Internet of Things Introduction
• IoT: decades-old idea with a new name – pervasive computing [Weiser 1991] – ubiquitous and ambient computing – smart spaces – wearable computing • Supported by old networking technologies – MANETs [PRNET 1972, SURAN ~1980] – body area networks – home automation – cloud computing [timesharing 1960s; file servers 1980s] – SDN [TINA-C IN Q.1219 1992, DARPA/EUActive Nets ~1995]
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-474 ITTC © James P.G. Sterbenz Internet of Things Network and Operations Complexity
• IoT incredibly and inherently complex system – “… is big. Really big. You just won’t believe how vastly mindboggling big it is.” —Douglas Adams, HHGTTG • Internet complex now – IoT and smart cities orders of magnitude more so – vehicular networks simpler, but must be part of this system
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-475 ITTC © James P.G. Sterbenz Internet of Things Smart Home Model Complexity
LoRa
Z15.4 Z-W
LTE/4G/5G PC 802.11
Bluetooth ZigBee LT Z15.4 Wi-Fi Z-W Z-WAVE ISP LoRa NID LTE/4G/5G 802.11 802.11 DSL/Cable 19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-476 ITTC © James P.G. Sterbenz IoT and Smart Home/City Complexity Smart City Complexity
IP IP IP IP IP IP IP IP IP IP IP IP IP IP IP IP IP
S S MSC M S M N
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-477 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks Further Reading
• Murthy and Manoj, Ad Hoc Wireless Networks: Architectures and Protocols, Prentice-Hall Pearson, 2004 • Stallings, Wireless Communications & Networks, 2nd edition, Prentice-Hall Pearson, 2005 • Walke, Mangold, & Berlemann, IEEE 802 Wireless Systems: Protocols, Multi-Hop Mesh/Relaying, Performance and Spectrum Coexistence, Wiley, 2006
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-478 ITTC © James P.G. Sterbenz MAC; Mobile and Wireless Networks Acknowledgements
Some material in these foils comes from the textbook supplementary materials: • Tannenbaum, Computer Networks • Kurose & Ross, Computer Networking: A Top-Down Approach Featuring the Internet • Sterbenz & Touch, High-Speed Networking: A Systematic Approach to High-Bandwidth Low-Latency Communication http://hsn-book.sterbenz.org
19 November 2018 KU EECS 780 – Comm Nets – MAC Mobile Wireless NET-MW-479