Understanding and Improving the Spatial Reuse in Multi-hop

Wireless Networks

Tae-Suk Kim, Hyuk Lim, and Jennifer C. Hou.The Department of Computer Science,

University of Illinois, Urbana-Champaign

IEEE Transactions on Mobile Computing, Vol. 7, No. 10, October 2008

Outline

• Introduction• Network Model and Analysis• Power and Rate Control Algorithm• Simulation Study• Conclusions

Introduction

• In Multi-hop Wireless Networks– Collision problem

• 4 way-handshake• Physical carrier sensing range

– Spatial reuse • Power control• Lower data rate

Goal

• Propose a distributed algorithm– Power control Spatial reuse – Rate adaption Higher data rate

Interference Model and Analysis

Network Capacity Model and Analysis

carrier sensing in an area

Power and Rate Control AlgorithmStep 1• Determine the power range

– TX0 : Pmin TX(1,2,3,4,5,6) : Pmax

>

Algorithm – Step 2

• Determine the carrier sense threshold–

Algorithm – Step 2

• The interference level perceived at TX

Simulation Study : (NS2 v2.28)

• Algorithm: PRC, Static, DSB, and Greedy Power Control

• Scenario : Random and Grid

Simulation Results : Random Topology

Simulation Results : Rrid Topology

Conclusions

• The relation of two control knods in the PHY/MAC layer– Transmission power– Carrier sense threshold

• Proposed a localized PRC algorithm– Higher data rate Ptx/Tcs

– Spatial Reuse Efficient power control scheme

Thank You.