Energy-Efficient Routing Energy-Efficient Routing Protocol Adapted to Mobile Protocol Adapted to Mobile Sensors for Multiple Sinks in Sensors for Multiple Sinks in Wireless Sensor NetworksWireless Sensor Networks

Tomoki Kimura and Iwao Sasase

Dept. of Information and Computer Science, Keio UniversityYokohama, Kanagawa, Japan

The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC’07)

Outline

Introduction Related Works Proposed Algorithm Simulations Conclusions

Introduction

Wireless Sensor Networks Sensor Node Sink Node

Data Transmission is an important issue in WSN Query Comment Sensing Data

Sensor nodes have very limited battery capacity Energy efficient routing protocol is needed

Maximize Network and Node Lifetime

Introduction

Multiple Sink nodes Multicast Issue

S

12

3

4Sink

Sink

SinkSink

Sensor

Query

Query

Query

Query

Related Works

Energy-efficient Multicast Routing Protocol For WSN

Branch Aggregation Multicast (BAM)

For MANET MultiCAST for Multiple Geographical region (MgCast)

Branch Aggregation Multicast (BAM) Published in MASS 2005

13

4

2

Source

ASink

BSink

CSink

MultiCAST for Multiple Geographical region (MgCast) Published in SECON 04

Destination set = {d1, d2, d3, d4, d5, d6}

Motivations

Power saving multicast protocol adapted to mobile sensor networks is needed.

For BAM, if hop count is cost, it’s not adapted to mobile sensor environment Hop count is not fixed.

For MgCast, routes reconstruct by using periodic HELLO messages Energy consumption is high.

Proposed Algorithm

All nodes have accurate location information

Source Process Grouping Sinks

Forwarding Node Process Selecting Unicasting or Multicasting

MAC Base on S-MAC

Source Node Grouping sinks

Example is 4 groups

90°

Nearest sink to Src

The centroid of the tetragon (S1, S2, S3, S4)

Source Node Selecting forwarding node

Forwarding node

Forwarding Node

Unicast or Multicast ? Branch Point ? L ? HS and HN ?

Forwarding Node

Multicast The case that there is a sink in the radio range o

f the forwarding node. The case that HN and HS are on the other side fo

r A. The case that HN and HS are on the same side for

A, and HS is nearer to A than HN. Unicast

Medium Access Control (MAC)

S-MAC No Hello Message

Broadcast

Simulations

All sinks are static.

Conclusions

A new power saving protocol for multiple sinks which is adapted to mobile sensors.

Do not construct routes before sending data

Do not use periodic HELLO message

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