Minimal Hop Count Path Routing Algorithm for Mobile Sensor Networks Jae-Young Choi, Jun-Hui Lee, and Yeong-Jee Chung Dept. of Computer Engineering, College of Engineering Wonkwang Univ., Ik-san, Jeonbuk, , Korea International Multi-Symposiums on Computer and Computational Sciences (IMSCCS'06)

Outline Introduction Related Work Minimal Hop Count Path Routing (MHCR) Algorithm for Mobile Sensor Networks Evaluating MHCR algorithm Conclusions

Introduction Sensor network is composed of a large number of sensor nodes Wireless sensor networks are being develop for a wide range of civil and military applications

Introduction LEACH and LEACH-C have been shown to achieve good communication efficiency It is not appropriate for mobile sensor network since a sensor node entering or leaving cluster after the “Set-up Phase”

Related Works LEACH LEACH-C

LEACH LEACH (Low-Energy Adaptive Clustering Hierarchy) Key feature of LEACH Distributed Randomized rotation of cluster head Local data fusion

LEACH BS

LEACH Set-up phase Randomly elect local cluster-heads Cluster-head Advertisement Cluster Set-Up Transmission schedule creation

LEACH Steady-state phase Data transmission to cluster-heads Data transmission to base station After a certain period of time the network is refreshed by entering the set-up phase again

LEACH-C Main idea Set-up phase A centralized algorithm to form cluster Steady-state phase The same with LEACH

LEACH-C Time START Set-up Frame Round Steady-state 1.Each node send location and energy level to BS 2.BS using the simulated annealing algorithm to find K optimal clusters

Minimal Hop Count Path Routing Algorithm For Mobile Sensor Network

MHCR algorithm processing stages MHCR algorithm consists of two stages Cluster and routing path creation stage Data transmitting stage Additional stage for reconfiguration the networks for fault tolerant

Cluster and routing path creation stage Broadcast form sink node at the start of each round

Cluster and routing path creation stage Process of Cluster_Creation Message (CCmsg)

Selection of cluster heads Choosing n as a random number between 0 and 1. If n < threshold T(n), node becomes a cluster head for the current round If p=0.05, N=100 r=0, T(n)=5%=0.05 r=1, T(n)=5%/95%= r=2, T(n)=5%/90%= …

Selection of cluster heads Each node that has selected as a cluster head for the current round broadcasts a CCmsg to the other nodes under its cluster area. Cluster heads send an IMUCHILD message back to CCmsg sender for organizing routing path

Data transmitting from sensor nodes to sink A sensor node needs to transmit data to sink node, broadcasts ReqRMmsg If a cluster head receive ReqRMmsg, replies ReplyRMmsg to the message sender When a sensor node receives ReplyRMmsg, it analyzes received message and select one of cluster heads which has minimal hop count routing path to sink node

Data query from sink node In MHCR, sink node request data to a specific node without location information Sink node makes flooding of the query message on routing path tree, and then cluster heads relay the query message

Data query from sink node Sensor nodes will analyze received query message and selects the one which has minimal hop count routing path The network will be reconfigured itself at each periodic round Cluster heads transmit periodic hello message to the parental and the child cluster head on routing path tree

Evaluating MHCR algorithm

The percentage of cluster head for the network

The data transfer success rate with nodes failure

Conclusions This paper proposed minimal hop count path routing algorithm for mobile sensor network A mobile sensor can transmit data to sink for energy efficiency Even in case of node failure, it shows robust transmission efficiency

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