802.16: IntroductionReference:

[1] S.J. Vaughan-Nichols, “Achieving Wireless Broadband with WiMax,” IEEE Computer Vol.37, No.6, PP.10-13, June 2004.

[2] IEEE Std 802.16-2004, “IEEE Standard for Local and metropolitan area networks--Part 16: Air Interface for Fixed Broadband Wireless Access Systems,” Oct. 2004.

[3] N. Liu, X. Li, C. Pei, and B. Yang, “Delay Character of a Novel Architecture for IEEE 802.16 Systems,” Proceedings of Parallel and Distributed Computing, Applications and Technologies (PDCAT 2005), PP.293-296, Dec.2005.

[4] IEEE Std 802.16e-2005, “IEEE Standard for Local and metropolitan area networks--Part 16: Air Interface for Fixed Broadband Wireless Access Systems--Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands,” Feb. 2006.

[5] C. Cicconetti,L. Lenzini,E. Mingozzi, and C. Eklund, “Qality of service support in IEEE 802.16 networks,” IEEE Network, Vol.20, No.2, PP-55, March-April 2006.

2

802.16 Architecture

3

4

802.16 Architecture(cont.)

Point-to-Multipoint

Mesh mode

5

802.16 Architecture(cont.)

6

IEEE 802.16 extensions  802.16 802.16a/d 802.16eCompleted Dec.2001 802.16a: Jan. 2003

802.16d: Oct. 2004802.16e: Feb. 2006

Spectrum 10 to 66GHz < 11 GHz < 6GHz

Channel Conditions Line-of-sight only

Non line-of sight Non line-of-sight

Bit Rate 32 to 134 Mb/s at 28MHz channelization

Up to 75 Mb/s at 20MHz channelization

Up to 15 Mb/s at 5 MHz channelization

Mobility Fixed Fixed and Portable Mobility, regional Roaming

Typical Cell Radius 1 to 3 miles 3 to 5 miles; Maximum range 30 miles

1 to 3 miles

7

IEEE Std 802.16 Protocol Layering

8

Service Specific Convergence Sublayer

• Functions– Provide transformation or mappi

ng of external network data into MAC SDU for MAC CPS

– Classify external network data and associate them to proper MAC service flow identifier (SFID) and connection id (CID)

– Payload head suppression (optional)

• Two convergence sublayer specified– ATM convergence sublayer– Packet convergence sublayer

9

MAC Common Part Sublayer• Functions

– System access – Bandwidth allocation– Connection establishment

and maintenance with service flow

• Support point-to multipoint (PMP) and mesh modes

• Support ARQ scheme

• Dynamic uplink (UL) and downlink (DL)

• Flexible MAC with various scheduling schemes for real time, non-real time and best effort services

10

Security Sublayer• Functions

– Authentication– Secure key exchange– Encryption

• Two component protocols– Encapsulation protocol for data

encryption– Privacy key management protoc

ol (PKM)

11

Physical Sublayer• WirelessMAN-SC PHY

– Single-carrier modulation– Tangeted for 10-66 GHz frequency band

• WirelessMAN-SCa PHY– Single-carrier modulation– Frequency bands below 11GHz for NLOS

• WirelessMAN-OFDM PHY– OFDM modulation with a FFT size of 256– Frequency bands below 11GHz for NLOS– AAS and MIMO (also for OFDM-PHY)

• WirelessMAN-OFDMA PHY– OFDM modulation with scalable FFT sizes– Frequency bands below 11GHz for NLOS– Hybrid-ARQ– Fast-feedback mechanisms– Handover support

12

802.16 PHY Introduction

13

802.16 PHY Introduction(cont.)

• Support framing

• Support both Time Division Duplex (TDD) and Frequency Division Duplex (FDD) , as well as half-duplex FDD (H-FDD)

• Burst transmission format which support adaptive burst profiling– Transmission parameters, including the

modulation and coding schemes (burst-profiles)

– Downlink Channel Descriptor (DCD) and Uplink Channel Descriptor (UCD)

– MAC management messages Downlink Map (DL-MAP) and Uplink Map (UL-MAP)

14

802.16 PHY Introduction(cont.)

15

802.16 QoS Type

16

802.16 QoS Support

17

802.16 QoS Support(cont.)

18

802.16 Scheduling

IEEE 802.16

PMP (Point-to-Multipoint) Internet

BS

SS

SS

Mesh

Centralized Scheduling

Distributed Scheduling

Internet

BS

SS_A

SS_BSS_CSS_D

19

BS

SSB

SSA

SSC

SSE

SSD

SSH

SSI

SSG

SSF

SSJ

SSK

InternetInternet

SSJSS

M Sender

SSL

SSJ

SSJSS

M Sender Receiver

MAC frame

MAC frame

Bandwidth request

Data flow

MAC frame

MAC frame

MAC frame

MAC frame

MAC frame

MAC frame

Centralized

• Congestion at BS• 1 SS active per time

slot• Longer route• Serious Delay

20

BS

SSB

SSA

SSC

SSE

SSD

SSH

SSI

SSG

SSF

SSJ

SSK

InternetInternet

SSJSS

M Sender

SSL

Distributed

SSJ

SSJSS

M Sender Receiver

MAC frame

Contention for bandwidth

Data flow

MAC frame

MAC frame

MAC frameMAC frame

MAC frame

4

• Larger signaling cost

802.16 Mobility Management Middle Domain and Vertical Handoff

Reference:

[1] J. Y. Hu, and C.-C. Yang, "On the Design of Mobility Management Scheme for 802.16-based Network Environment," Proceedings of IEEE 62nd Semiannual Vehicular Technology Conference (VTC-2005 Fall), PP.25-28 Sept. 2005.

22

Introduction

GR: Gateway Router (Gateway of CIP or GFA of HMIP)

23

Introduction (cont.)

24

Introduction (cont.)

25

Middle-domain Mobility Management Scheme

26

Middle-domain Mobility Management Scheme (cont.)

27

Performance Evaluation-Quantitative Analysis by Simulation(1)

28

Performance Evaluation (cont.)-Quantitative Analysis by Simulation(2)

29

802.16e : Mobile Version of 802.16

MH can connect to the BS directly.

Cell Radius: 5KM Non-line-of-sight Bandwidth: 15Mbps

30

Related Work: Traditional Overlay Networks

Upper Layer Networks : larger coverage, lower bandwidth

Lower Layer Networks: smaller coverage, higher bandwidth

Upper Layer Networks

Lower Layer Networks

31

Horizontal & Vertical Handoff

2 3

1

1. Horizontal Handoff

2. Upward Vertical Handoff

3. Downward Vertical Handoff

32

Coverage-based Handoff Triggering

2

3

1

Out of cell coverage, Upward Vertical Handoff

As soon as received stronger signal strength from other cell in the same layer, Horizontal Handoff

As soon as received the signal from lower layer, Downward Vertical Handoff

Upper Layer Networks : With larger coverage size and lower bandwidth

Lower Layer Networks : With smaller coverage size but higher bandwidth

C

B

A

33

Handoff Times (Total)

Handoff Times

0

50

100

150

200

250

Speed-based Coverage-based

Scheme Type

Tota

l han

doff (t

imes

) .

High Speed

Medium Speed

Low Speed

34

Packet Loss (Total)

Packet Loss

0

100

200

300

400

500

Speed-based Coverage-based

Scheme Type

Tota

l Pac

ket L

oss (p

acke

t)

High speed

Medium Speed

Low Speed

Quality of ServiceFramework, Routing, and Scheduling

Reference:

[1] J. Chen, W. Jiao, and H. Wang, “A service flow management strategy for IEEE 802.16 broadband wireless access systems in TDD mode,” Proceedings of IEEE International Conference on Communications (ICC 2005), Vol. 5, PP. 3422-3426, May 2005.

[2] J. Chen, W. Jiao, and H. Wang, “An Integrated QoS Control Architecture for IEEE 802.16 Broadband Wireless Access Systems,” Proceedings of IEEE Global Telecommunications Conference (Globecom 2005), Vol. 5, PP. 3330-3335, Nov.-Dec. 2005.

[3] C.C. Yang, Y.T. Mai, and L.C. Tsai, “Cross-Layer QoS Support in the IEEE 802.16 Mesh Network,” Proceedings of 2006 Wireless Personal Multimedia Communications (WPMC 2006), PP.567-571, La Jolla, San Diego, California, Sept. 2006.

36

Introduction

• In IEEE 802.16 standard, scheduling algorithms for uplink and downlink bandwidth allocation in a single frame are undefined.

• There is no proposed bandwidth allocation solution considering uplink and downlink simultaneously.

37

Service Flow ManagementDSA: Dynamic Service AdditionDSC: Dynamic Service ChangeDSD: Dynamic Service Deletion

38

The hierarchical structure of the BW allocation

Hierarchical structure of bandwidth allocation

DFPQ 1st Layer

2nd Layer

1. 1. rtPS > nrtPS> BErtPS > nrtPS> BE2. 2. Downlink > UplinkDownlink > Uplink

1. 1. rtPS : EDFrtPS : EDF2. 2. nrtPS : WFQnrtPS : WFQ3. BE : RR3. BE : RR

39

Simulation Results (1)

40

Simulation Results (2)

41

Proposed Framework

• System Architecture• QoS Parameter Extraction• Centralized Route Selection with QoS

Support• Flow Setup• QoS Scheduling

42

System Architecture

43

BS

SSB

SSA

SSC

SSE

SSH

SSI SS

G

SSF

SSJ

SSK

InternetInternetQoS route request

SSJSS

L

Frame transmission

Route response &Flow table construction

Sender Receiver

network infonetwork info

192.168.3.0/24J

192.168.1.0/24M

NetworkNetworknodenode

10ms

DelayDelay

boundbound

192.168.1.3/24

192.168.3.4/23

flowIDflowID

Flow tableFlow table

rtPSI2005

QoSQoSNextNext

hophop

RRtagtag

SSM

SSD

9BEA

7nrtPSA

6rtPSA

5UGSA

T (ms)T (ms)QoS typeQoS typeNodeNode

Estimated system timeEstimated system time

44

Avg. delay and variation by service type with flow data rate 5Mbps

45

Average Throughput

Avg. throughput with flow data rate 5Mbps

46

Average Signaling Cost

　 Gain

Proposed vs. Centralized -38.11%

Proposed vs. Distributed -76.95%