Lecture #4
Wireless Network Convergence and Fixe d Mo bile Convergence
Dr. Kun Yang University of Essex, Colchester, UK
Thursday 19th March 2009
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Agenda
Network Convergence among Wireless Networks Network Convergence between Fixed and Mobile Networks Summary, Q&A
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1 Wireless Access Networks There are many different types of wireless access networks. There will be no perfect wireless system in terms various factors such as mobility, capacity, coverage, and cost. Instead, these networks, each with its unique features, will co- exist. IEEE802.11a/b/g/n IEEE802.15.1 IEEE802.15.3a (Wireless LAN) (Bluetooth) (UWB) IEEE802.15.4 RF-tag (ZigBee) DVB-H IEEE802.15.4a (low-rate UWB) DVB-T Wireless Access Networks IEEE802.16-2004 Satellite (Fixed Wireless MAN) 3G Cellular (UMTS, CDMA2000, IEEE802.16e TD-SCDMA) (Mobile Wireless MAN) 2.5G (GPRS) 2G Cellular IEEE802.21 IEEE802.20 2.75G (EDGE) (GSM, etc) (MIH) (Mobile BWA)
Technologies that enable users to seamlessly and easily use these networks are needed.
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Wireless Mobile Internet – driven from mobile devices
2B cell phones vs. 500M Internet-connected PC in 2005 400M cell phones with Internet capability, rising rapidly Wireless devices will be more portable, more intelligent, more functional and with multi-radio access capacity.
There is a historic shift from PC’ s to mobile devices for Internet access.
Mobile applications get more complicated.
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2 Wireless Convergence: Loosely Coupled
www.vysoo.com/images 5
Heterogeneous Wireless for e-Health @ UEssex “Always-on” lifeline using media-independent handover (MIH) across heterogeneous wireless networks (standardised within IEEE802.21) Video conferencing/VoIP to patient from home (also while mobile, but less practil!)tical!) GPS Sensors WiMAX Fall detector Storage Heart Monitor WiFi Router Blood Oxygen MIH GPRS Blood Glucose (802.21) Bluetooth (100m range) (100m Bluetooth HSDPA (3G) Processo Mobile r Linux low version LCD Monitor VoIP/Video power Ethernet (fixed broadband connection) Conference Camera, mic, speaker miniPC Media Independent Gateway (MIG)
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3 By A. Bontozoglou MIG Software Implementation 7
UEssex Research Network Testbed
Application and Service Manager Policy & Service Level Network Manager Agreement (SLA) Management Routing and Dynamic Network Resource Bandwidth Allocation Management Quality of Experience anagement (QoE) Monitoring Quality of Service (QoS) Monitoring Signalling ervice Layer ervice vice Resource vice r M S
Application Layer Signalling Network Layer Signalling Se
Campus Perimeter Campus Central (<10km) Outskirts Campus Voice Betrand Russell IP DPI DPI Wireless Video Backhaul (IPTV/VoD) 3G WiMAX WiMAX
Storage Quays South Courts Ethernet WiFi cess Node cess Node
2-10Mbit/s Isolated WiFi Sports Car c c Future Broadband hot-spots Grounds Parks Access Traffic Fibre GPON Generator NG-SDH Optical Splitters Campus Fibre Network ONU Traffic Generator
Ethernet A Multi-Service A Multi-Service WDM Internet Access Network Emulator Public IP Heterogeneous Access Technologies Multi-Layer Switching Nodes 8 address (Wired and Wireless) (Circuit and Packet-Switched)
4 iDorm – Digital Lifestyle Environments
iDorm1 (development environment)
Single student bed-sit (work, sleep etc) iSpace ( evaluation environment) • Test‐bed for ambient intelligent and pervasive computing in a domestic setting (Full sized 2 bedroom apartment) • Sensor, actuator, computer and network rich environment to enable open‐ended R&D • £250,000 in IT related aspects (+£100,000 energy equipment) • Capable of supporting evaluations with long‐term occupants
9 For further information, contact Prof Vic Callaghan ([email protected])
A Closely-coupled HWN: Motivation
Current cellular systems are As a result, some cells limited in flexibilities in that could be congested cellular architectures are fixed because of temporary and bandwidth allocation events, such as traffic cannot dynamically adapt to accidents and sports instant network change. events.
Proposal: introduce MANET over cellular networks to divert traffic.
Existing work: iCAR: diversion station has only cellular interface UCAN: high-date rate, within a cell 10
5 Physical Characteristics of the HWN system
MH2
Traffic Diversion Station #1
Mobile Host #1 TDS3 TDS2 Base Station #1 BS2 MH4 MH3 MH5
Cellular Interface Ad Hoc Interface BS: no change from the current UMTS BS TDS: with both cellular and ad hoc interfaces, deployed close to the borders of a cell MH: with only A-interface, C-interface, or both interfaces. 11
QoS: QoS Mapping Heterogeneous Wireless Network Home WLAN BS TDS IP Internet aDSL (RSVP/DiffServ/ Router AP Egress MPLS) Router
Home Server (video) C-interface C-to-A A-to-C A-interface mapping mapping Wired HWN QoS Routing Internet QoS Routing interface
EndtoendQoSEnd-to-end QoS K. Yang, et. al. “QoS-Aware Routing in Emerging Heterogeneous Wireless Networks”, IEEE Communications Magazine, Feb. 2007. Page(s): 74-80.
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6 Adaptive Routing
Start End
Not needed in normal routing MHs initiates a request Transmit data from MHs but blocked using route r
YES MHj releases channel; Is there a TDS next MH’ uses the channel; Source Selection to MHs? NO NO Destination Selection YES Is MH’ empty? Source Selection Procedure: Route discovery & find a MHj in the same cell as MHs selection Route Selection YES Procedure: r=r Is MHj empty? failure k
NO NO
MH’=MHs; YES MHs=MHj; Is R empty?
Route Discovery Destination Selection Procedure: Procedure discover route 13
R={rk|k=1,..,|R|}
Evaluation
D D D D
D C C C D
D C B B C D
D C B A B C D
D C B B C D
D C C C D The structure of a single cell D D D D
The whole network enviroment
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7 Further Integration with DVB Focus is on the DVB-H: Digital Video Broadcast-Handheld DVB Base Station network architecture and its service-driven • Three types of nets • Unicast+broadcast adaptation and mngt. • Uplink for DVB via cellular net. MH9 MH2 Cellular MH5 Cell
DVB MH1 Cell MH4 Base Station #1 BS2 MH8 MH6 MH3 MH7
Cellular Interface DVB-H Downlik Ad Hoc Interface It utilizes a policy-based mngt (PBM) approach in combination with fuzzy control theory, aiming to maximize the 15 overall effectiveness, flexibility, and robustness of the network.
Overall architecture U W D Service Gateway D Service
WLAN overlays UMTS. UMTS and DVB-H networks operate separately but connected via a pair of signalling gateways. UWD Service Gateway monitors the UWD network status and conducts network selection and configuration to satisfy user-perceived services. K. Yang, et al. “A Flexible QoS-aware Service Gateway for Heterogeneous Wireless Networks”, IEEE Networks, March 2007. Page(s): 6-12. 16
8 Operations
MH UMTS BS UWD Service Gateway WLAN DVB-H BS
(1) Service request (2) QoS not satisfied, invoke service gateway (2) QoS satisfied, request served by UMTS (3) Decision making
(4a) Configure (4b) Configure WLAN (5a) service UMTS execution via UMTS (4c) Configure DVB-H (()5b) service execution via WLAN (5c) service execution via DVB-H
How the three types of networks collaborate to fulfill a service as coordinated by the USG.
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Network Environment
D D D D DVB-H Base Station D C C C D
D C B B C D
D C B A B C D
D C B B C D
D C C C D The structure of a single cellular cell D D D D
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9 Agenda
Network Convergence among Wireless Networks Network Convergence between Fixed and Mobile Networks: EPON+WiMAX Summary, Q&A
K. Yang, et al. “The Convergence of Ethernet PON and IEEE 802.16 Broadband Access Networks and its QoS-aware Dynamic Bandwidth Allocation Scheme”, to appear in IEEE JSAC
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Background
IEEE 802.16 provides wireless broadband access with high bandwidth capacity, large network coverage, strong QoS support. But how to backhaul its traffic? -> EPON (Ethernet Passive Optical Network), a point-to-multipoint optical access network technology. The most popular EPON topology is tree-based architecture where transmission occurs between an optical line terminal (OLT) and multiple optical network units (ONUs). The OLT is usually connected to the core networks whereas each ONU locates at either curb (thus the so called fiber-to-the curb or FTTC), within a residential building (i.e., fiber-to-the-building or FTTB), or even to the home (i.e., fiber-to-the- home or FTTH). Of course, an ONU can be connected to an IEEE 802.16 base station (BS).
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10 Illustration of an EPON Network Backhauling IEEE 802.16 Access Networks
OLT ONU BS SS
ONU 802.16 BS ... VOD Client SS Core 1:n ONU 802.16 BS OLT splitter ... SS
SS VOD Server ONU Residential Building
We assume that an EPON ONU is integrated with an 802.16 BS into a converged box called Virtual ONU-BS (VOB). We call it “virtual” because there is not such an integrated box physically. 21
Why this Convergence?
Firstly, most 802.16 BSs are equipped with Ethernet interface as such can be easily connected to EPON. Secondly, both technologies share many similarities in terms of bandwidth request/allocation and QoS supporting mechanisms. Thirdly, EPON and 802.16 also complement each other in that the convergence of two has the potential to combine the bandwidth advantage of optical networks with the mobility feature of wireless communications. Furthermore, this integration enables the design of joint bandwidth allocation/reservation, connection admission control and transmission scheduling schemes. These collaborative schemes are more likely to provide a close-to-optimal solution to system’s overall resource management, including both wired optical resources and wireless radio resources. In return, a better support of end-to-end QoS guarantee and improvement of overall system performances such as throughput and delay can be expected. But how to design such schemes is still an open and challenging issue! We endeavor to make a first-step attempt towards this challenge by focusing on 22 bandwidth allocation.
11 A bit of state-of-the-art on FMC
Application Layer: IMS (IP Multimedia Sub-system)/SIP (Session Initiation Protocol) -> loads of work Physical Layer: Radio over Fibre (RoF) -> tons of work MAC Layer C. Qiao. et al. appears to consider FMC in a layer other than physical layer or application layer. However, this seminal work does not reflect too much the flavor of 802.16 networks. IEEE OFC March 2006 – seminal work Shen et al. recently summarize the architecture issues arising in the integration of EPON and 802.16. but not concrete algorithm details presented. Re f. IEEE CMComMag, Aug. 2007 –work at roughly hl the same timeline as ours. Our work endeavors to design a QoS-aware dynamic bandwidth allocation (DBA) scheme at the MAC layer for a converged network of EPON and 802.16.
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Technical Focus
Firstly, to propose converged network architecture of EPON and 802.16 (especially the concept of VOB) and identify the unique research issues as a result of this convergence. Secondly, to investigate a DBA scheme that is specifically designed for the WEN networks. This DBA scheme takes into consideration the specific features of the converged network to enable: (1) a smooth data transmission across optical and wireless networks, (2) an end-to-end differentiated service to user traffics of diverse CoS (Class of Service) requirements. Here the end-to-end means from a connection originated from an 802.16 SS to the OLT. • This QoS-aware DBA scheme shall ensure certain fairness under network traffic saturation condition along both station dimension and CoS dimension. • CoS fairness specifically means that the low-priority traffic (such as best effort traffic) shall not be significantly disadvantaged under network saturation condition. The proposed DBA scheme, called WE-DBA for WiMAX-EPON DBA 24
12 A bit practical work first …
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Feasibility Study: Experiments Ref.: S. Ou, K. Yang, M. P. Farrera, C. Okonkwo, and K. M. Guild, "A Control Bridge to Automate the Convergence of Passive Optical Networks and IEEE 802.16 (WiMAX) Wireless Networks," Proc. of BROADNETS 2008, London, UK, Sept. 8-11, 2008.
Control Bridge
Bandwidth Allocation Control Control API Interface to higher level management QoS Mapping entities, such as service managers
OLT Control Module BS Control Module
Interface to GPON OLT Interface to 802.16 BS The GPON equipment used: one Ericsson EDA 1500 (OLT) and three T050G ONUs. IEEE 802.16: one Airspan MicroMAXB BS (AS.MAX MicroMAX- SOC) and three SSs (AS.MAX ProST). 26
13 GPON and 802.16 Upstream Packet Classification and QoS Mapping
Control Bridge
GPON 802.16 ONU T-CONT Buffer SS Queues UGS T-CONT 1 To ertPS User T-CONT 2 ONU ONU SS SS SDUs ONU Classifier BS Scheduler rtPS Classifier OLT Scheduler T-CONT 3 nrtPS
T-CONT 4 BE ONU SS BW Request BW Request
Control Flow Data Flow a. QoS Mapping 802.1Q/p User Priority Lowest-Cost-First Mapping Algorithm 7 802.16 6 Services 5 UGS 4 ertPS 3 2 rtPS ONU T-CONT nrtPS 802.16 1 Buffer BE Services 0 T-CONT 1 UGS DSCP T-CONT 2 ertPS EF Classified by other parameters rtPS T-CONT 3 AF4x (such as source/destination nrtPS AF3x MAC address, VLAN ID, IP BE AF2x T-CONT 4 AF1x protocol, etc.) BE b. An Example of Packet Classification in c. An Example of Packet Classification in 27 SS Classifier ONU Classifier
Dynamic Bandwidth Control
VOD Service Control GPON 802.16 VOD Client Server Manager Bridge OLT BS (SS)
1. VOD service request a. VOD service web page 2. servi ce gran td/jted/rejec tdted
3. Invoke Control API to provide just-enough BW 4. Resize the CIR of the service flow 5. Resize the max. BW 6. Inform VOD b. service manager allocated for the T-CONT server to provide service to the client
7. VOD service begins
8. VOD service ends 9. Invoke Control API to release BW
10. Release allocated BW
11. Release allocated BW
c. control bridge daemon 28
14 1 Without Control Bridge (Maximum) 0.9 Without Control Bridge (Average) With Control Bridge Some results 0.8 0.7
6 0.6 Channel utilization 5.5 Without Control Bridge 0.5 With Control Bridge, U=5MB 5 With Control Bridge, U=50MB 0.4 With Control Bridge, U=100MB Channel Utilization (%) Utilization Channel t (per MB)
s 003.3 454.5 0.2 4 Delivery cost 0.1 3.5 0 0 25 50 75 100 125 150 3 Traffic Load (%)
2.5 Average Packet DeliveryCo 1 2 0.95 1.5 0 20 40 60 80 100 120 0.9 Traffic Load (%)
atio 0.85 R Without Control Bridge 0.8 With Control Bridge, U=50MB 0.75 Delivery ratio 0.7
0.65 Average PacketDelivery 0.6
0.55
0.5 29 0 25 50 75 100 125 150 Traffic Load (%)
A bit theoretical work …
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15 Virtual ONU-BS (VOB) Box
logical architecture
hardware layout
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Bandwidth Request & Grant
• The VOB queues are presented as virtual queues by dashed lines because these qqpueues represent the bandwidth requested instead of the real data. • EPON: Multi-Point Control Protocol (MPCP); IEEE 802.16 has similar mechanism and procedure. • These standardised mechanisms have defined the precise format for bandwidth request and grant messages as well as their processing. However, no DBA algorithm is specified. • Note that VOBs employ MPCP for bandwidth request and the 802.16 mechanism for bandwidth grant. 32
16 Illustration of Bandwidth Request and Allocation
Grant per CoS
Refer to the attached paper for technical details and discussion. 33
DBA at OLT
( EPON ) ××− RTnT n: # of VOBs; Tg: guard time Bavg = cycle g VOB 8 × n R Mbps: EPON trans. rate
3 req req i: VOB; j: CoS i = ∑BB , ji j=1
n excess avg req avg req B ∑ VOB −= i (|)( VOB > BBBB i ) i=1
g avg excess req i = min( VOB + BBBB ii ),
len g Written in the MPCP GRANT message i i ×= /)8( RBt 34
17 DBA at VOB
min avg BBE = α × BBE
avg B rBE +1, = Traffic ,rBE
avg avg rBE +1, (BB rBE −1, += Traffic ,rBE 2/)
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Evaluation Design
Benchmarks: DBA1: both the OLT and VOBs statically allocate bandwidth (equal share) to its client stations. DBA2: EPON static whereas 802.16 dynamic (the other way round is less common) Test design: To evaluate against benchmark to show the benefit of dynamic • in terms of throughput and delay To evaluate itself under different conditions. • In terms of throughput and delay under different serving cycles, types of services, channel utilization, and BE windows
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18 Overall Throughput of WEN under different DBA schemes
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Average Delayof WEN under different DBA schemes
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19 Thoughput under different Serving Cycles
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Delay under different Serving Cycles
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20 Average Delay for Types of Services
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Channel Utilization
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21 Effect of minimum bw allocated to BE
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Conclusions
PON+802.16 at MAC appears to be beneficial though jjypygust some very limited preliminary work being carried out. However, this is a massive research topic and much more effort is needed. Other topics such as scheduling and admission control, a comparative study on the performance differences between a centralized control mechanism (carried out by the OLT) and a cascading decision making strategy. Investigation into the effect of mobility on network performance. Long-term work includes research into a fully unified hardware VOB.
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22 Contact，Q&A
Dr Kun Yang School of Computer Science & Elec. Eng. (CSEE), University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK Email: [email protected] http://privatewww.essex.ac.uk/~kunyang/
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