QoS guaranteed Technology in Ubiquitous Digital Home Networks

2004. 8. 31

김 재 현

e-mail: [email protected], home: http://ajou.ac.kr/~jkim School of Electrical Engineering Ajou University

Talk Outline

IEEE 802.11 Wireless LAN IEEE 802.15 Wireless PAN Fast Ethernet IEEE 1394 QoS guaranteed technology in Home Networks

KJH 2 IEEE 802.11 Wireless LAN IEEE 802.15 Wireless PAN Fast Ethernet IEEE 1394 QoS guaranteed technology in Home networks

KJH 3

IEEE 802.11 Overview (PHY & Data Rates)

802.11a 802.11b 802.11g Frequency 5.2 GHz 2.4GHz Data Rate PHY Modulation Scheme Carrier (Mbps) Mandatory Optional Mandatory Optional Mandatory Optional 1 Single DS/SS DS/SS 2 Single DS/SS DS/SS 5.5 Single CCK PBCC CCK PBCC 6 Multi OFDM OFDM CC-OFDM 9 Multi OFDM OFDM, CCK-OFDM 11 Single CCK PBCC CCK PBCC 12 Multi OFDM OFDM CC-OFDM 18 Multi OFDM OFDM, CCK-OFDM 22 Single PBCC 24 Multi OFDM OFDM CC-OFDM 33 Multi PBCC 36 Multi OFDM OFDM, CCK-OFDM 48 Multi OFDM OFDM, CCK-OFDM 54 Multi OFDM OFDM, CCK-OFDM

– CCK : Complementary Code Keying – PBCC: Packet Binary Convolutional Code

KJH 4 802.11a/g PHY

OFDM Subcarrier Frequency Allocation

Total 52 subcarriers (-26 ~ 26) using 64 FFT ‰ 48 subcarriers for data ‰ 4 subcarriers for pilot (-21, -7, 7, 21) ‰ 20MHz channel Runs in 5GHz U-NII bands (in case of US) ‰ 300MHz from 5.15-5.35(8 Ch.) & 5.725-5.825GHz (4 Ch.) ‰ Total 12 channels available

KJH 5

IEEE 802.11b PHY

Runs in 2.4GHz ISM bands (US : 2.412 – 2.462 GHz) ‰ 11 22MHz channel

Channel 1 Channel 6 Channel 11 Power

Frequency

3 different transmission rates: ‰ Complementary Code Keying (CCK) for 5.5 & 11 Mbps ‰ Direct-Sequence Spread Spectrum (DSSS) for 1 & 2 Mbps ‰ Packet Binary Convolutional Code (PBCC) for 5.5, 11, 22, 33 Mbps

KJH 6 Major Task Groups in 802.11 standard

Task Group Objectives 802.11 a PHY & MAC for 5 GHz 802.11 b PHY & MAC for 2.4 GHz 802.11 e MAC Enhancements for Quality of Service 802.11 f Inter Access Point Protocol 802.11 g Higher Rate (20+ Mbps) in the 2.4GHz 802.11 h Spectrum Managed 802.11a 802.11 i MAC Enhancements for Enhanced Security 802.11 k Radio Resource Measurement Enhancements 802.11 n High Throughput

KJH 7

Wireless LAN Architecture

Ad hoc WLAN Mode ‰ Peer-to-peer communication only ‰ Independent Basic Service Set Æ IBSS Infrastructure WLAN Mode ‰ No peer to peer communication, always through AP ‰ Distribution system : Connect two or more BSS

Distribution System

AP-A AP-B BSS-A BSS-B

Ad hoc network Infrastructure network

KJH Service Types and Coordination Functions

Asynchronous Service : Data service, FTP, Web, etc. ‰ Contention Traffic ‰ DCF (Distributed Coordination Function) ‰ Distributed controlled by STA Isochronous Service : Delay sensitive traffic, voice, etc ‰ Contention-Free Traffic ‰ PCF (Point Coordination Function) ‰ Centralized controlled by AP (Access Point) Super Frame Concept

Superframe

Contention-Free Contention Burst Traffic

KJH 9

Distributed Coordination Function (DCF)

CSMA/CA protocol Use different Inter Frame Space (IFS) to differentiate traffic ‰ SIFS (Short Inter Frame Space) : High Priority ‰ PIFS (PCF Inter Frame Space) : Medium Priority ‰ DIFS (DCF Inter Frame Space) : Low Priority

DIFS Sense channel during DIFS Contention Window DIFS PIFS SIFS Busy Medium Backoff-Window Next Frame Slot time

Defer Access Backoff slot reduced when channel is idle

KJH 10 Distributed Coordination Function (DCF)

Baseline 802.11 MAC includes a virtual carrier sensing scheme to address the Hidden Terminal Problem

STA2 STA1 STA5 SIFS SIFS SIFS STA 1 Random CTS ACK ACK Random backoff=6 backoff=10 SIFS SIFS

STA 2 DIFS RTS DATA DATA DIFS 전송 지연 SIFS Random Random ACK STA 3 backoff=8 backoff=2

STA 2 패킷 전송 감지로 전송 시도 지연 Backoff slot=2 DIFS STA 4 DIFS DATA RTS수신후 NAV Set

Time STA 2로부터hidden terminal STA 5 STA 1으로 부터 CTS받은 후 NAV Set KJH

Exponential Backoff Algorithm

CW : Contention Window ( 0 to CW_min ~ CW_max ) : Backoff delay = INT( CW ×× Random() ) Slot Time

‰ CW is doubled when transmission is failed ‰ CW_min : 11.a = 15, 11.b = 7, 11.b HR = 31, CW_max = 1023 Slot time : Receiver turn on time + propagation delay + media busy detection time

Example

300 CWmax=255 255 250 200 127 150 63 100 CWmin 31 50 =7 0 123456

KJH 12 Point Coordination Function (PCF)

Send Request in Contention Period AP poll STA by the polling list

Dynamic Polling List Polling List Polling List Delete from list when idle too long Delete from list when idle too long Add to list when activity

Async Traffic

CF-B CF-B CF-B CF-B CF-B SFP

KJH 13

ContentionContention FreeFree OperationOperation

Two consecutive frames are separated by SIFS CFP lengths depend on traffic amount ‰ Maximum length announced by AP; used for NAV set

Contention Free Period Repetition Interval (CFPRI) or Superframe Contentio Free Period (CFP) for PCF SIFS SIFS SIFS Contention Period (CP) Downlink Beacon D1+Poll D2+Ack+Poll CF-End for DCF Uplink U1+Ack U2+Ack Reset NAV PIFS SIFS SIFS

NAV Dx - downlink frame to STA x CF_MAX_Duration Ux - uplink frame from STA x

KJH 14 QoS Support in 802.11e

HCF (Hybrid Coordination Function) ‰ Two channel access mechanism : ¾Contention based channel access ¾Controlled based channel access ‰ EDCA (Enhanced Distributed Channel Access) ¾Using Arbitration IFS, differentiate QoS ‰ HCCA (HCF Controlled Channel Access) ¾Channel access for parameterized QoS

Transmission Opportunity (TXOP) ‰ Multiple frames can be transmitted during a TXOP with certain rules ‰ EDCA TXOP – acquired by beacon ‰ Polled TXOP – acquired by QoS CF poll

KJH 15

EDCA (Enhanced Distributed Channel Access) Access category (AC) as a virtual DCF 4 ACs implemented to support 8 user priorities EDCA Parameters ‰ AIFS ¾ AIFS[AC]=SIFS+AIFSN[AC]*aSlotTime ‰ Contention Window Parameters ‰ Max. TXOP duration(TXOP Limit)

3 4 7 12 0 56 Priority Access Destination (Same as Category(AC) (Informative) 802.1D) AC_BK AC_BE AC_VI AC_VO 1 AC_BK Background 2 AC_BK Background 0 AC_BE Best Effort 3 AC_VI Video Probe 4 AC_VI Video Backoff Backoff Backoff Backoff AIFSN[0] AIFSN[1] AIFSN[2] AIFSN[3] 5 AC_VI Video BO[0] BO[1] BO[2] BO[3] 6 AC_VO Voice Virtual Collision Handler 7 AC_VO Voice KJH Transmission Attempt 16 Typical TXOP

Once a STA has gained the medium for transmission, there are limits on how long it can transmit or burst EDCA TXOP Defaults AC TXOP Limit(802.11b) TXOP Limit (802.11a/g) AC_VO(Voice) 3.3ms 1.5ms AC_VI(Video) 6.0ms 3.0ms AC_BE(Best 1Mbps = 12.3ms 6Mbps = 2.1ms effort) 2Mbps = 6.2ms 24Mbps = 0.5ms 11Mbps = 1.2ms 54Mbps = 0.2ms AC_BK(Backg 1Mbps = 12.3ms 6Mbps = 2.1ms round) 2Mbps = 6.2ms 24Mbps = 0.5ms 11Mbps = 1.2ms 54Mbps = 0.2ms TXOP limit value of 0 indicates that a single packet may be transmitted at any rate for each TXOP

KJH 17

EDCA (Enhanced Distributed Channel Access)

AIFS[AC] CW=rand[1,CWi+1]

AIFS[AC] low priority AC backoff AIFS[AC] =DIFS PIFS medium priority AC backoff

SIFS ACK SIFS high priority AC RTS

Contention Windows CTS defer access (counted in slots, 9us SIFS count down as long as medium is idle, Back off when medium gets bust again

AC CWmin CWmax AIFSN With 802.11a AC_BK CWmin CWmax 3 aSlotTime: 9us SIFS: 16us AC_BE CWmin CWmax 7 PIFS: 25us AC_VO (CWmin+1)/2-1 CWmin 2 DIFS: 34us AC_VI (CWmin+1)/4-1 (CWmin+1)/2-1 2 AIFS: >=34 us

CWi+1 [AC]=min[ ( ( CWi[AC] + 1 )*PF[AC] ) - 1, CWmax] PF : Persistent Factor KJH 18 HCCA (HCF Controlled Channel Access)

Additional polling based controlled contention scheme for HC to learn the TXOPs needed by the stations

Contention Free Period, CFP(polling through HCF) Contention Period, CP (listen before talk and polling through HCF)

CF-end Beacon QoS CF-Poll QoS CF-Poll

Transmitted by HC

Transmitted by (Q)STAs

TBTT Time TBTT TXOP TXOP TXOP TXOP

RTS/CTS RTS/CTS Fragmented RTS/CTS/DATA/ACK Fragmented DATA/ACK (after DIFS+backoff) DATA/ACK (polled by HC ) (polled by HC )

KJH 19

IEEE 802.11 Wireless LAN IEEE 802.15 Wireless PAN Fast Ethernet IEEE 1394 QoS guaranteed technology in Home networks

KJH 20 IEEE 802.15 Overview

802.15.1 802.15.3 802.15.3a 802.15.4 Objectives Bluetooth High Rate UWB Low Rate/Zigbee 868/915MHz Frequency 2.4~2.4835Ghz 2.4GHz 3.1GHz~10.6GHz band 2.4GHz CSMA/CA, FH/TDD CSMA/CA S-Aloha, MAC 79 Ch, TDMA 1600hop/sec TDMA Piconet, Piconet, Star, Child piconet, Topology Scatternet Peer2peer Neighbor piconet 100Mbps at 10m < 1Mbps(sync.) < 55Mbps 200Mbps at 4m 20k~250kbps Data Rate < 723Kbps(Async.) path to 400Mbps QPSK, DQPSK, QAM BPSK(868/915M 16/32/64-QAM Hz) Modulation GFSK (11,22,33,44,55 (if Multi-band Mbps) OFDM) O-QPSK(2.4GHz) 10m(1mW) 5~10m 10~20m Range 100m(100mW) Nokia, Major Sony, Xtreme spectrum, Timedomain Philips, Motorola Vender Ericsson

KJH 21

IEEE 802.15.1 Overview

Concept ‰ Short Range : 0.01m - 10m (100m) ‰ Low Power : 1mW, 2.5 mW, 100 mW ‰ Low Cost : < $5 Can be used for ‰ Data (max 753 kbps) / Voice(3 64kbps) Access ‰ Appliance Cable replacement ‰ Personal Ad-Hoc Connectivity Standard (Bluetooth SIG and IEEE802.15.1) ‰ 1999 : Version 1.0b ‰ 2001 : Version 1.1 (1Mbps) ‰ Current : on going for Version 2.0 (2-11Mbps) Topology ‰ Piconet, Scatternet

KJH 22 Channel Allocation

TDD/Single slot

Multi-slot allocation

KJH 23

Service Profile and Protocol Stack

Appropriate protocol stack for service profiles Example : DialHeadset Up Networking profile vCard/vCal WAE FAX Profile OBEX WAP

UDP TCP AT- TCS SDP IP Commands BIN

PPP RFCOMM Audio L2CAP Stream LMP

ACL BaseBand SCO

Radio

- LMP : Link Manager Protocol - HCI :Host Control Interface - SDP : Service Discovery Protocol - L2CAP : Logical Link Control and Adaptation Protocol - TCS : Telephony Control protocol Spec. - SCO Synchronous Connection Oriented Link - ACL: Asynchronous Connectionless Link - OBEX OBject EXchange protocol - WAE : WAP Application Environment

KJH 24 IEEE 802.15.3 (High Rate) Overview

Objective ‰ Low complexity, Low cost, Low power, Short Range, QoS Capable, Peer to peer communication, High data rate (> 20Mbps) PHY ‰ 2.4GHz 5 Channel MAC Functionality ‰ Fast Connection Time ‰ Ad hoc Network ‰ QoS support ‰ Security ‰ Dynamic Membership ‰ Efficient data transfer Topology ‰ Piconet, Child piconet, Neighbor piconet ‰ Piconet Coordinator (PNC), Device (DEV)

KJH 25

MAC Frame Format

Easy Connection and Disconnection ‰ Authentication ‰ Addressing ‰ Security-Key setting ‰ Bootstrap Any DEV can be PNC Power save mode MAC frame is in Superframe

Non Secure

MAC Header MAC frameMAC bodyframe body

Stream Fragmentation Src Dest PN Frame IntegrityFrame Security FCSFCS SFC SECID index control ID ID ID control CodepayloadPayload

1 3 1 1 2 2 0 ~0 4 ~ 4 8 Ln Ln 2 2

- SFC : Secure Frame Count - SEC ID : Security ID KJH 26 Superframe Structure

Super frame #m-1 Super frame #m Super frame #m+1

Beacon CFP (Contention Free Period) CAP #m Asynchronous Isochronous Asynchronous Isochronous

CFP (Contention Free Period) Beacon Contention Access CTA CTA CTM CTA #m MCTA1 MCTA2 … Period 1 2 n-1 n

1,000 ~ 65,535μs

CSMA/CA S-ALOHA TDMA Data/Control Data/Control Data

- MCTA : Management Channel Time Allocation KJH 27

Piconet Independent piconet: PNC and DEV Dependent piconet ‰ Child piconet : # DEV > 255, extended area, Communication with PNC or DEV in parent piconet ‰ Neighbor piconet : when no available channel in parent piconet, communication only with PNC or DEV in neighbor piconet

Contention CFP Beacon Access Beacon Period CTA 1 CTA 2 … CTA n CFP Bea CAP Reserved time con CTA CTA … CTA Reserved time 1 2 n

DEV 1 C- DEV DE 2 V 1

P- C- C- PNC PNC DEV 2

KJH 28 IEEE 802.15.3a (UWB) Overview

UWB (Ultra-Wide Band) : Bandwidth > 500 MHz

Narrow Band: (fH –fL) < 0.01*FC

UWB: (fH –fL) > 0.25*FC density (dB) Power spectral

fL fC fH Frequency (Hz) Characteristics ‰ Frequency : 3.1GHz~10.6GHz ¾ERIP Emission level should be less than -41.3dBm/MHz ‰ Data rate : 110 ~ 480 Mbps, Range : < 10m ‰ Use IEEE802.15.3 MAC

KJH 29

IEEE 803.15.3a PHY layer (Proposed) Single Band vs. Multi-Band OFDM(MBOA) Single Band Multi Band OFDM

Bandwidth BW: 2GHz, 4.8GHz, 1 or 2 13-17 band (528 MHz)

Modulation FDM+CDM+TDM (PSK) OFDM/ QPSK Data rate 28.5 Mbps – 1.2Gbps 55 – 480 Mbps Simple HW Easy to implement Advantage Low cost, low power robust to interference Time to Market (’03 4Q) Time to Market (’05 1Q) UWB Antenna Peak to average ratio Prob. Difficulty Complex to Sync. Not verified yet Intel, TimeDomain, DTC, WisAir, Vendors XSI, SONY GA, Femto Devices

802.15.3 - EIRP (Equivalent Isotropic Radiated Power) EIRP Emission Level (-41.3 dBm/MHz) -41.3 dBm/MHz

Low High Band Band

KJH 2.4 35 7 10 GHz 3 10GHz 30 IEEE 802.15.4 (Zigbee) Overview

Low Rate (20, 40, 250Kbps), Low Cost, Low Power Short Range (< 10m) Dynamic device addressing Support for low latency devices Reliable by fully handshake protocol CSMA-CA channel access. Low power consumption Apply to ‰ u-Digital Network : Energy save, Consumer Electronics, Toy, Security ‰ Health care check and monitoring System Topology ‰ Star or peer-to-peer topology

KJH 31

Comparison of Zigbee and Bluetooth

Zigbee Bluetooth FHSS DSSS Air interface 62.4k symbol/s 1M symbol/s 128kbps 720kbps

2+ year from ‘normal’ Power model as a mobile batteries phone Power Designed to optimize slave (regular charging) Consideration power Designed to maximize ad-hoc functionality Minimum software and Take advantage of host processing(80C51) processor power (ARM7…) Cost Standpoint System design for eventual 802.11 functionality but with single-chip antenna-to- simplified RF specifications application realization

KJH 32 IEEE 802.15.4 PHY (Frequency)

868MHz 902MHz 928MHz 2.4GHz 2.4835GHz

Frequency 868MHz 915MHz 2.4GHz Data Rate 20kbps 40kbps 250kbps Modulation BPSK BPSK O-QPSK

# of Channel 1 10 (2MHz) 16 (5MHz)

Packet period 53.2ms 26.6ms 4.25ms Receiver < -92dBm < -92dBm < -85dBm sensitivity Range 10~20m(1mW) 10~20m(1mW) 10~20m(1mW)

KJH 33

802.15.4 MAC/PHY Frame Format

octet 2 1 4-20 n ≤ 102 2

Sequence Frame Address Payload FCS control number info MAC octet 2 11 MHR MSDU MAF

Preamble SFD FL MAC Protocol Data Unit (MPDU)

SHR PHR Physical Service Data Unit (PSDU) PHY

Physical Protocol Data Unit (PSDU)

PPDU size : 11 + ( 4 to 20) + n (≤ 133 Octet)

- FCS : Frame Check Sequence - MHR : MAC Header - MSDU : MAC Service Data Unit - MAF : MAC Footer - FL : Frame Length - SFD : Start Frame Delimiter - SHR : Synchronization Header - PHR : Physical Header - PPDU : Physical Protocol Data Unit

KJH 34 MAC Overview

The features of the MAC sub-layer ‰ Beacon management ‰ Channel access ‰ Guaranteed time slot management ‰ Frame validation ‰ Acknowledged frame delivery ‰ Association and disassociation ‰ Security mechanisms FFD (Full Function Device) ‰ A device capable of operating as a coordinator or device, implementing the complete protocol set. RFD (Reduced Function Device) ‰ A device operating with a minimal implementation of the IEEE 802.15.4 protocol.

KJH 35

Star / Pear-to-Pear Topology

Star topology PAN coordinator

Cluster Head (CLH)

Full Function Device (FFD)

Pear to Pear topology Reduced Function Device (RFD) ex) Cluster Tree Network

KJH 36 Superframe

The LR-WPAN standard allows the Contention access period (CAP) optional use of a superframe ‰ a slotted CSMA-CA mechanism structure. ‰ transactions shall be completed bounded by network beacons by the time of the next network divided into 16 equally sized slots. beacon. Channel access mechanism Contention free period (CFP) ‰ Beacon enabled network ‰ Included The guaranteed time ¾ slotted CSMA-CA slots (GTSs) ‰ A non beacon enabled network ‰ The PAN coordinator may ¾ Un-slotted CSMA-CA allocate up to seven of these GTSs ¾ TDD

Frame Becon

Contention Access Period Contention Free Period

KJH 37

IEEE 802.11 Wireless LAN IEEE 802.15 Wireless PAN Fast Ethernet IEEE 1394 QoS guaranteed technology in Home networks

KJH 38 Fast Ethernet(100BASE-T) Std.

IEEE 802.3 WG History IEEE Title Year Feature 802.3 10Mbps MAC, PLS, AUI 1983.6.24 10Base5, 50ΩCoax Cable (thick), Bus 802.3a 10Mbps Cheapernet MAU 1985.6.13 10Base2, 50ΩCoax Cable (thick), Bus 802.3b 10Mbps Broadband MAU 1985.9.19 10Base36, 75Ω Coax Cable, Bus 802.3c Broadband repeater 1986.3.13 802.3d 10Mbps FOIRL MAU 1987.12.1 Fiber Inter-Repeater Link 1Base5, UTP cable, Manchester code, 802.3e 1Mbps "starLAN" MAU 1987.6.11 Star-LAN, 100m/2.5km 802.3h Layer Management for 10Mbps DTEs 1990.9.28 10Base-T, UTP cable, Hub usb, NIC- 802.3i 10Mbps UTP MAUs 1990.9.28 Hub : 100m, star 10Base-FP, FB&FL, Fiber Cable, Point- 802.3j 10Mbps Fiber Optic MAUs 1993.9.15 to-Point Connection (2km) 802.3k Layer management for 10Mbpsrepeater 1992.9.17 802.3l PICS perform for 10Mbps UTP MAU 1992.9.27 802.3p Management for 10Mbps Integrated MAUs 1993.6.17 GDMO formating of Layer Management for 802.3q 1993.6.17 10Mbps DTEs Informative Annex to 10Base-T for 120Ω 802.3t 1995.6.14 cabling 100Base-TX : UTP cable, NIC-Hub : 802.3u 100Mbps Standard, MII, PHY and MAUs 1995.6.14 100m , star 100Base-FX : Fiber optic cable, star 802.311 100Base-VG 1995 UTP cable, NIC-HUB: 100m, star KJH 39

Ethernet Overview

IEEE 802.3x(100BaseX) ‰ No QoS support 100BaseX Feature ‰ Physical Topology : STAR ‰ Logical Topology : Linear BUS ‰ Access Method : CSMA/CD ‰ Date Rate : 100Mbps ‰ Signal Transmission mode : Baseband 100VG-AnyLAN ‰ IEEE 802.12 Std. : proposed HP, AT&T ‰ QoS support 100BaseVG Feature ‰ Physical Topology : Star ‰ Logicak Topology : Star/Bus ‰ Access Method : Demand Priority mode ‰ Support Ethernet and Token-Ring ‰ Date Rate : 100Mbps ‰ Signal Transmission mode : Baseband

KJH 40 Ethernet MAC Frame

Max Frame Lengh 1518bytes, Min Frame Length 64bytes LLC

Preamble SFD Destination Source Length Information pad FCS (4) (7) (1) Address(6) Address(6)

LLC Header LLC information field LSB 0 Individual Address

1 0 local Address Multicast Address 1 1 Global Address DSAP SSAP CTRL IP/X.25/….

1111….1111: broadcast Address SNAP

DSAP SSAP CTRL OUI PID IP/X.25/…

DSAP=Destination Service Access Point SSAP=Source Service Access Point CTRL=Control field SNAP=Sub Network Access Protocol OUI=Organizationally Unique Identifier PID=Protocol Identifier LLC=Logical Link Control SFD=Starting Frame Delimiter FCS=Frame Check Sequence

KJH 41

IEEE 802.1p and IEEE 802.1Q

802.1D (the spanning tree standard) ‰ Traffic forwarding(bridge), multicast frames(port) ‰ No mechanism for the switch to determine(multicast) 802.1p ‰ Extension from 802.1D to allow for more intelligent handling of multicast frames. ‰ Directly attached or further downsteam that needs to receive the multicast frame(dynamic) ‰ Safety, speedly time-critical information forwarding 802.1Q ‰ exentended 802.1p ‰ Definition and management of vLAN(set)

KJH 42 IEEE 802.1p/ IEEE 802.1Q Priority Level IEEE 802.1p establishes 8 levels of priority. ‰ Network managers must determine actual mappings ‰ The highest priority is seven, which might go to network-critical traffic ¾Routing Information Protocol (RIP), Open Shortest Path First (OSPF) table updates. ‰ Values five and six might be for delay-sensitive applications ¾interactive video, voice. ‰ Data classes four through one range from controlled-load applications ¾Streaming multimedia, business-critical traffic - carrying SAP data ‰ The zero value is used as a best-effort default

KJH 43

IEEE 802.1p: LAN Layer 2 QoS/CoS Protocol for Traffic Prioritization Prioritize traffic ‰ The prioritization specification works at the MAC framing layer Perform dynamic multicast filtering. ‰ Filter multicast traffic to ensure it does not proliferate over layer 2-switched networks. Defined as best-effort QoS or CoS (Class of Service) at Layer 2 ‰ Implemented in network adapters and switches without involving any reservation setup. No bandwidth reservations are established. ‰ 802.1p traffic is simply classified and sent to the destination

KJH 44 IEEE 802.1p/ IEEE 802.1Q MAC Frame Format Tag Protocol ID(TPID) ‰ defined value of 8100 in hex. When a frame has the EtherType equal to 8100, this frame carries the tag IEEE 802.1Q / 802.1P. Tag Control Information (TCI) ‰ User Priority ¾ eight priority levels. ‰ Canonical Format Indicator (CFI) ¾ used for compatibility reason between Ethernet type network and Token Ring type network. ‰ VLAN ID (VID) ¾ VLAN ID is the identification of the VLAN, which is basically used by the standard 802.1Q. ¾ maximum possible VLAN configurations are 4,094. 9 VID of 0 – used to identify priority frames 9 VID of 4095 – reserved value

Preamble SFD TPID TCI Type Data FCS DA (6) SA (6) Length (7) (1) (2) (2) (2) (42-1496) (4)

User Priority CFI Bits of VLAN ID to identify possible VLANs (3bits) (1bit) (12bits)

KJH 45

IEEE 802.11 Wireless LAN IEEE 802.15 Wireless PAN Fast Ethernet IEEE 1394 QoS guaranteed technology in Home networks

KJH 46 IEEE 1394 Standards

IEEE 1394 : 1995 ‰ Supports up to 400Mbps links and PHYs ‰ 6 pin cables ‰ Range : 4.3m IEEE 1394a : 2000 ‰ Supports up to 400Mbps links and PHYs ‰ Power management clean up ‰ Cable power specification in flux IEEE 1394 OHCI(Open Host Controller Interface) IEEE 1394b : 2002 ‰ Supports up to 3.2Gbps ‰ Range : 100m IEEE 1394.1(Bridging) IEEE 1394.3(Peer-to-Peer Printing) IEEE 1394 over wireless

KJH 47

IEEE 1394 Overview

Logical bus model Peer-to-peer operation User friendly Ease of Use - Plug and Play Transaction and addressing models Asynchronous and Isochronous operation models (QOS) Power management (with one new mode) “Daisy chaining” of devices

KJH 48 IEEE 1394 Network Architecture

IEEE 1394 network architecture(bus and bridge)

Bus Bus B Bus B

B :Bridge(max 1023) :Cable(4.5m) :Node(max 63/bus)

KJH 49

IEEE 1394 Topology

The 1394 protocol is a peer-to-peer network with a point-to-point

signalingCPU MemoryenvironmentI/O CPU ‰ A specific host isn’t required Nodes Nodes on the bus may have several ports on them Serial bus(backplane environment) Bridge Ports

Desktop Laser Digital Set-top Digital camera printer TV box VTR

IEEE 1394 serial bus (cable environment) Nodes

KJH 50 IEEE 1394 Protocol Stacks

Serial Soft API

Configuration & Error control Read,Write,Lock Isochronous Transaction Layer channel (Read/write asynchronous data)

Bus mgr Packets

Link Layer Synchronous (Cycle control, Packet function) Resource mgr Channel assignments Symbols for media flows Node controller Physical Layer (Bus initialization and arbitration, synchronization, coding and signaling)

IEEE 1394 physical interface

KJH 51

IEEE 1394 Protocol Model

Packets created at the link level of arbitrary size Transaction-level protocol ‰ Handles writings and reading of asynchronous data Link-level protocol ‰ Distributes a timing and synchronization “cycle control” signal Synchronous resource manager ‰ Allocates time slots to devices with periodic data to send Bus manager ‰ power management and bus optimization Contention for management roles occurs during initialization with selections made according to device numbering or random selection criteria

KJH 52 IEEE 1394 Physical Layer

The Physical layer provides initialization and arbitration services ‰ It assures that only one node is sending data at a time

The physical layer of the 1394 protocol includes: ‰ The electrical signaling ‰ The mechanical connectors and cabling ‰ The arbitration mechanisms ‰ The serial coding and decoding of the data being transferred or received ‰ Transfer speed detection

KJH 53

IEEE 1394 Link Layer

Gets data packets on and off the wire Error detection and correction Retransmission Handles provision of cycle control for isochronous channels The link layer supplies an acknowledged datagram to the transaction layer ‰ A datagram is a one-way data transfer with request confirmation

KJH 54 IEEE 1394 Transaction Layer

Implements the request-response protocol Read ‰ Data is transferred back to a responder Write ‰ Data is transferred from a requester to an address within one or more responders Lock ‰ Data is transferred from a requester to a responder, processed with data at a particular address within the responder, and then transferred back to the requester

KJH 55

Isochronous Transmission

Isochronous transfers ‰ Isochronous transfers are always broadcast ‰ No error correction and retransmission ‰ Up to 80% of the available bus bandwidth can be used ‰ The delegation of bandwidth is tracked by a node on the bus ‰ Isochronous channel IDs are transmitted followed by the packet data ‰ The receiver monitors the incoming data's channel ID and accepts only data with the specified ID

KJH 56 Asynchronous Transmission

Asynchronous transfers ‰ Asynchronous transfers are targeted to a specific node with an explicit address ‰ Not guaranteed a specific amount of bandwidth on the bus ‰ They are guaranteed a fair shot at gaining access to the bus when asynchronous transfers are permitted ‰ Asynchronous transfers are acknowledged and responded to ¾ This allows error-checking and retransmission mechanisms to take place

KJH 57

Arbitration

Sources of isochronous flows send requests for channel number and time slots to the synchronous resource manager Each 125 μsec cycle : one-byte time slots ‰ E.g. 6250 slots at 400Mbps First-come first-served Asynchronous traffic : 20% of time slots Isochronous traffic : 80% of time slots

KJH 58 IEEE 1394 Time Slot Assignments

Assigned channel numbers and allocated time slots

Cycle n Cycle n+1 Delay Delay Isochronous (short) gaps Isochronous (short) gaps

Packet ACK Cycle Cycle Packet ACK Cycle Ch B Ch C Ch D Ch E Ch B Ch C Ch D Ch D Ch B B Start Start B Start

Nominal cycle period = 125 us Nominal cycle period = 125 us

Subaction (long) Gaps Subaction (long) Gaps SubactionCycle Sync (long) Gaps Cycle Sync Cycle Sync

One byte time slots

: Isochronous Transactions : Asynchronous Transactions

: Cycle starts Packets

KJH 59

Bridging IEEE 1394 networks

1394 device 1394 bridge device

1394 application 1394 mngmnt & internal fabric 1394 Tr. 1394 Tr. 1394 Tr.

Asynch. Isoch. Asynch. Isoch. Isoch. Asynch.

1394 Link 1394 Link 1394 Link 1394 PHY 1394 PHY 1394 PHY

KJH 60 IEEE 1394 to a wireless air interface

Wireless 1394 device Wireless 1394 bridge device

1394 application 1394 mngmnt & internal fabric 1394 Tr. 1394 Tr. 1394 Tr.

Asynch. Isoch. Asynch. Isoch. Isoch. Asynch.

1394.1 CL 1394.1 CL 1394 Link Wireless DLC Wireless DLC 1394 PHY Wireless PHY Wireless PHY

‰CL : Convergence layer, DLC : Data Link Control

KJH 61

Protocol stack for the HDNI serial bus

Isochronous Asynchronous

DVCR : Digital Video Cassette recorder Application Data Channel HTML, OSD : On-Screen Application, JavaScript, Display OSD AV/C,etc DVCR MPEG Other Etc. AV/C : Audio Video (61883) (61883) (61883) Control MPEG : Motion Picture Experts Group UDP or CIP : Common TCP FCP FCP Isochronous Packet 61883 – CIP FCP : (Function Control IP Protocol

1394 Transaction

1394 Link

1394 Physical

ƒReference [8] “Engineering Committee, Digital Video Subcommitee,” American Natinal Standard(Home Digital Network Interface Specification), ANSI/SCTE, 26, 2001

KJH 62 IEEE 802.11 Wireless LAN IEEE 802.15 Wireless PAN Fast Ethernet IEEE 1394 QoS guaranteed technology in Home networks

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Quality of Service Basics

Definition ‰ A collective measure of the level of service delivered to the customer QoS basic performance criteria ‰ Error performance, response time and throughput ‰ Lost calls or transmissions due to network congestion ‰ Connection set-up time, speed of fault detection and correction For the transmission of time sensitive information over a network ‰ Bandwidth ‰ Latency ‰ Jitter ‰ Packet Error Rate

KJH 64 QoS Requirements by Service Type

Service Payload Rate Latency Jitter PER (Mbps) (ms) (ms) High Quality Voice 0.064 X 2 streams 10 5 10-3 Medium Quality Voice 0.008 X 2 streams 30 ±20 10-3 Video Conference 1.5 X 2 streams 10 ±5 10-5 HDTV 19.68 90 ±10 10-5 SDTV 3 90 ±10 10-5 CD Quality Audio 0.256 100 ±10 10-5 High Speed Data 10 >100 >100 0

Medium Speed Data 2 >100 >100 0 Low Speed Data 0.5 >100 >100 0

ƒReference [10] L. Chinitz, “Quality of Service in the Home Networking Model,” Home RF working group, Aug., 2001.

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Data Rates Supported by Multiple Technologies Interconnectivity Speed Technology IEEE 1394b 800 Mbps IEEE 1394a 400 Mbps USB 2.0 480 Mbps USB 1.1 12 Mbps Fast Ethernet 100 Mbps IEEE 802.11a 54 Mbps IEEE 802.11b 11 Mbps HiperLAN2 54 Mbps HomePNA 2.0 10 Mbps HomePlug 1 Mbps HomeRF 1 Mbps

KJH 66 Two QoS Support Categories

Priority(Differentiated) based QoS Parameter(Scheduled) based QoS Priority Parameter Differentiated Access Planed opportunities Media IEEE 802.11e QoS [EDCA] IEEE 802.11e [HCCA] Access HomePNA IEEE 1394 HomePlug IEEE 802.15.3 Differentiated Queues Per-flow state and signaling at every hops Forwarding IEEE 802.1P/Q /Queuing IEEE 802.3 PSTN Last Mile xDSL Cable Home 1.1 Access Cable Modem (DOCSIS v.1.1) FTTH ¾Media Access : Access the shared media ¾Packet Forwarding : Packets forward in home gateways, routers or bridges

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Application of a Priorities-Based QoS System CableHome QoS Portal (CQP): QoS Sub-Element of the PS ‰ Priorities-QoS queuing/forwarding ‰ Responsible for communication of QoS characteristics to various devices QoS Boundary Point (QBP): QoS Sub-Element of the BP ‰ Responsible for the reception of QoS characteristics information from PS

Apps/EP Apps/EP Cable BP QBP CH BP QBP Head End Apps CH D BP QBP CRG Network O PS Segment Q-Domain C S CQP I Apps/EP Network S Segment BP QBP CH Cable Home Network Network

Example of cable QoS elements (Adapted from ITU-T J.190) CRG : Cablehome Residential Gateway, CH : CableHome host, BP : Boundary Point, PS : Portal Service

KJH 68 The elements for providing QoS in CableHome network PS forwarding ‰ Prioritized queuing and packet forwarding functionality in the CQP. PS media access ‰ Prioritized shared media access functionality in the CQP. QoS management server ‰ Maintain QoS priority BP media access ‰ Prioritized shared media access functionality in the QBP. QoS management client ‰ Determines QoS characteristics that a particular application/device needs to use

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WiFi QoS Access Timing Example

Assumptions ‰ WME default parameters backoff values shown are for initial CW equal to CWmin = 15 AIFS Voice 2Slots 0~3 Slots AIFS Video 2Slots 0~7 Slots AIFS Best Effort 3Slots 0~15 Slots AIFS Background 7 Slots 0~15 Slots

Minimum Wait Random Backoff Wait

Previous Next Residential packet N Slots 0~m Slots packet Gateway Host Host Host Minimum Wait Random Backoff Wait SIFS Media Access Host Host

KJH 70 WiFi QoS Packet Forwarding Queues

Four Access Categories are actually 4 independent queues in the client

Voice Video Best Effort Background Mapping to Access Category(AC) Data Data Data Data

Four Transmit Queues

Air Residential Gateway Host Host Host

Host Host Packet Forwarding

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Paremeter-Based QoS Guaranteed Technology

Real-time OS Linux Solaris Windows CE

Application Conversation Streaming Interactive Background

Generic Middware

Middleware Queue Bridge Bandwidth QoSQoS Classifier manager manager manager supportsupport

UPnP Jini HAVi Echonet IPHN

MAC HomePNA IEEE 1394 Ethernet WLAN PHY xDSL DOCSIS WDM UWB Zigbee

KJH 72 TheThe elementselements ofof QoSQoS ManagerManager

The elements of QoS Manager ‰ Classifier ¾ Identify different categories of packets coming from different network interfaces ¾ Classify packet into various classes ‰ Queue manager ¾ Efficient and fair allocation of buffer resources ‰ Bridge manager ¾ Support priority-based routing and load balancing ‰ Bandwidth manager ¾ Allocate system bandwidth efficiently and fairly among all stations sharing each physical medium ‰ Channel monitor ¾ Track of the Quality of a channel ‰ Port scheduler ¾ Policy-based channel-dependent scheduler

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QoS issues in Home Networks

Different kinds of QoS protocol in Home networks ‰ Transmission rate, QoS parameters ‰ Packet format, Traffic characterized various priority PHY Layer ‰ Wireless channel environment ‰ QoS supported devices or no supported devices MAC Layer ‰ Various QoS supported protocol Middleware ‰ Exist many different kinds of middleware such as UPnP, HAVi, Jini etc Network Layer ‰ IP based or non IP based protocols OS ‰ Support Real-time OS or not ¾ GQoS API (802.1p priorities or RSVP parameters) is requested through Winsock2 ¾ Linux Kernel 2.4.14 and above with skb-priority using the vconfig utility KJH 74 Research Scope

First of all, Need the QoS definition Survey the more detailed information of existing QoS guaranteed technologies in Home networks Seek for the problem of the process that multimedia input streams come to good output streams in Home networks Need unified QoS parameter mapping structure

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Reference

[1] “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications :Higher- Speed Physical Layer Extension in the 2.4 GHz Band”, IEEE Std 802.11b-1999, 1999 [2] “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications Amendment 4: Further Higher Data Rate Extension in the 2.4 GHz Band”, IEEE Std 802.11g.-2003, 2003 [3] “Part 15.1: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Wireless Personal Area Networks (WPANs)”, IEEE Std 802.15.1™-2002, 2002 [4] “Specification of the Bluetooth System”, BLUETOOTH SPECIFICATION Version 1.1, Feb. 2001 [5] http://www.ieee802.org/15/pub/TG2.html [6] “Part 15.3: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for High Rate Wireless Personal Area Networks (WPAN)”, Draft P802.15.3/D17, Feb. 2003 [7] “Part 15.4: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low- Rate Wireless Personal Area Networks (LR-WPANs)”, IEEE Std 802.15.4™-2003, 2003 [8] “Engineering Committee, Digital Video Subcommitee,” American Natinal Standard(Home Digital Network Interface Specification), ANSI/SCTE, 26, 2001 [9] M. Nakagawa, “Ubiquitous Homelinks Based on IEEE 1394 and Ultra Wideband Solutions,” IEEE Communications Magazine, pp. 74-82, Apr., 2003. [10] L. Chinitz, “Quality of Service in the Home Networking Model,” Home RF working group, Aug., 2001. [11] S. Weinstein, “Integrated networking,” ELE6905, Spr., 2004. [12] http://www.commsdesign.com/showArticle.jhtml?articleID=18100157

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