Multicast Routing in Multi-Radio

Multi-Channel Wireless Mesh Networks

Tehuang Liu and Wanjiun Liao

Department of Electrical EngineeringNational Taiwan University

IEEE Transactions on Wireless Communications, vol. 9, no. 10, October 2010

Outline

Introduction1

Proposed algorithm2

Performance Evaluation3

Conclusion4

Introduction

• Wireless mesh networks (WMNs) have received much attention in recent years due to its – low up-front cost

– easy network maintenance

– robustness

– reliable service coverage

• Each node – forwards packets in a multi-hop fashion

– is stationary and not power-constrained

Introduction

• This paper studies the minimum cost multicast tree (MCMT) problem in MR-MC WMNs.– MR: multi-radio

– MC: multi-channel

– WMN: wireless mesh network

assigned channel no.#

A

B L

D H J U

11

11

22

22

3 43

3 5

5

35

4

5

5

5

Introduction

• This paper studies the minimum cost multicast tree (MCMT) problem in MR-MC WMNs.– Cost: the total consumption of radio resource is determined by the

number of nodes that forward the multicast packets

assigned channel no.#

A

B L

D H J U

11

11

22

22

3 43

3 5

5

35

4

5

5

5

Introduction

• This paper studies the minimum cost multicast tree (MCMT) problem in MR-MC WMNs.– Cost: the total consumption of radio resource is determined by the

number of nodes that forward the multicast packets

This problem is proved to be NP-hard.

[12] R. Draves, J. Padhye, and B. Zill, “Routing in multi-radio, multi-hop WMNs,” ACM MOBICOM, 2004.

assigned channel no.#

A

B L

D H J U

11

11

22

22

3 43

3 5

5

35

4

5

5

5

Proposed Algorithm

Network Model

• Minimize

subject to:

…

• WCTB

// wireless closest terminal branching• Interference consideration

ILP Approximation Algorithm

,i kk Q i V

Y

Proposed Algorithm – Network model

• In a multi-radio Multi-Channel Wireless Mesh Network– Each node is equipped with one or multiple radios

– Each radio is tuned to a non-overlapping channel

– The channel assignment is given and static

– Q: the set of available channels

– V: the set of nodes

– s: source node, sV

– M: the set of terminals, MV

assigned channel no.#

A

B L

D H J U

11

11

22

22

3 43

3 5

5

35

4

5

5

5

Proposed Algorithm – ILP

• ILP– The optimal solution

Proposed Algorithm – ILP

• Objective function

channels

nodes

YA,2=1; YL,4=1; YJ,5=1; YH,5=1;

Proposed Algorithm – ILP

• Subject to:

multicast tree solution

channel assignment

XA-L,2=1=cA-L,2

XA-B,2=0<1=cA-B,2

Proposed Algorithm – ILP

• Subject to:

flow model based

3 – 1 = 2

Proposed Algorithm – ILP

• Subject to:

flow model based

3 – 1 = 2

Proposed Algorithm – ILP

• Subject to:flow model based

3 – 1 = 2

Proposed Algorithm – ILP

• Subject to:

k=5; 1*1=1k=5,3; 1*2>1

Proposed Algorithm – ILP

• Subject to:

YL,4=1XL-U,4=0XL-J,4=1

Proposed Algorithm – ILP

• ILP– regards the ILP as optimal solution

Proposed Algorithm – Approximation algorithm

• WCTB– Wireless Closest Terminal Branching

Proposed Algorithm – Approximation algorithm

• WCTB– Wireless Closest Terminal Branching

Dijkstra’s algorithm

Proposed Algorithm – Approximation algorithm

• WCTB– Wireless Closest Terminal Branching

Proposed Algorithm – Approximation algorithm

• WCTB– Wireless Closest Terminal Branching

Proposed Algorithm – Approximation algorithm

• Interference consideration

weight of interference

Proposed Algorithm – Approximation algorithm

• Interference consideration

Q

wP-Q,2=2wP-Q,3=1

w

Dijkstra’s algorithm

Performance Evaluation

• Area: 1000 m x 1000 m

• Source node and terminals are randomly selected

• Each node has three radios

• Transmission range: 300m

• Interference range: 600m

Performance Evaluation

|S| : number of multicast sessions = 20|V| : number of nodes = 31|M| : number of receivers = 5~30|Q| : number of channels = 7

Performance Evaluation

|S| : number of multicast sessions = 20|V| : number of nodes = 21~41|M| : number of receivers = 15|Q| : number of channels = 7

Performance Evaluation

|S| : number of multicast sessions = 20|V| : number of nodes = 31|M| : number of receivers = 15|Q| : number of channels = 5~11

Performance Evaluation

|S| : number of multicast sessions = 5~30|V| : number of nodes = 41|M| : number of receivers = 10|Q| : number of channels = 7

Conclusion

• This paper tackles the MCMT problem with the consideration of interference between multicast trees in MR-MC WMNs. – ILP

– MCTB• Interference consideration

TheENDThanks for your attention !