Load Balancing Routing Scheme in Mars Sensor Network CS 215 Winter 2001 Term Project Prof : Mario Gerla Tutor: Xiaoyan Hong Student : Hanbiao Wang & Qingying Li

Objective " Balancing sensors’ energy consumption by diffusing data traffic into their closest neighbourhoods. " Prolong network lifetime by alleviating the load unbalance problem.

Problem of Original Design for JPL Sensor network In the original implementation, it forms a spinning tree for routing path Node 35  Handle data traffic for cluster 1 Node 74  Handle data traffic for cluster 2 Conclude : Node 35 and 74 died out fast Cluster 2 Cluster 1

Proposed Algorithm : We propose an multi path routing scheme to diffuse data traffic of the sensor to its neighbourhood that is still in the shortest path back to the base station. " Routing table construction stage, the sensor network self- organized into a configuration of N levels. – a) The base station is the sink with level = 0 ( black in the figure) b) All the nodes that can directly hear from the base station are labelled as level = 1 ( blue in the figure ). All the nodes that could directly talk with level 1 nodes are labelled as level = 2 (green in the figure), but they couldn't directly talk with level 0 node, and so forth. " data transmission step, node i at level (N+1) will randomly chooses next hop j from its neighbours at level N with equal probability.

Design Issue 1 : Construct Routing Table When a node receives request packages from other nodes,it will check it against its own routing table: 1. HopNumber ( Incoming packet) > HopNumber( record )  discarded ; 2 HopNumber(Incoming packet) < HopNumber ( record )  delete old path and record new path; 3. HopNumber(Incoming packet) = HopNumber(record)  insert this new path into its routing table

Example for Node i " Assuming Node i received a package from Node J at first. The node J indicates that its distance to the base is 3, hence, Node i will record its distance to the base is 4 ; " Then another package from K arrives and indicates its distance to the base is 2. Hence, Node i compare this with its record, it will delete the path via Node J and update its distance to the base as 3, also record the path via node K. " When the package from Node L arrives and indicates its distance to the base is 2. Node i will add this entry to its routing table that gave same shortest distance of 3 to the base, via Node L. " Node M has same situation as Node L.

Level Level Level 4 Flooding request package 2 Level 3 Base i J K L M 3

Data Transmission from Node D To Base Station " Node D starts to send data package to the base station via Node i since it is the only path in its routing table. " Node i will randomly pick one of the entry ( choose the next hop from routing table entry, via K, or via L, or via M) with equal probability to determine which path to forward the data. " Assuming K is chosen by Node i and now node K will check its routing table, determine its next hop, either via Node X or Node Y. " Suppose X is chosen and its next hop is the base station and the package is now transmitted from Node D to the base station. " During this Data Forwarding, we used routing path 1

Transmitting Data from Node D to Base with 4different path: Path 1 -- Grey Path 2 -- Red Path 3 -- Green Path 4 -- Yellow 2 3 Base D i K L M X Y

Multi Path Nodes for Senor Network Level 0  Black Level 1  Blue Level 2  Green Level 3  pink Level 4  white Level 5  yellow Level 6  Grey

Multi Path for Sensor network Node has alternative path to send data to base station.

100 nodes with 2 Hour Simulation Result Level 3 Nodes Power consumption Red Curve = nodes’ power consumption in original implementation in JPL sensor network Blue Curve = nodes’ power consumption in multi path design. Original power consumption Range :{110.29w,260.27w} Our power consumption Range:{116.73w, w} No packages lost in new implementation

100 Nodes with 2 Hour Simulation Result Level 4 Nodes Power consumption Red Curve = nodes’ power consumption in original implementation in JPL sensor network Blue Curve = nodes’ power consumption in multi path design. Original power consumption Range :{92.31w,186.16w} Our power consumption Range:{95.84w, w} No packages lost in new implementation

200 nodes with 5 Hour Simulation Result Level 1 Nodes Power consumption ( test when the nodes are more dense) Red Curve= nodes’ power consumption in original implementation in JPL sensor network Blue Curve = nodes’ power consumption in multi path design. Original power consumption Range :{373w, w} Our power consumption Range:{408.61w, w} No packages lost in new implementation

Conclusion and Future work Advantage : 1) Balancing Node Work Load 2) Prolong network life time 3)No performance disgrade Future Proposal : Data transmission : when Node I of level N+1 tries to pick next Hop J of level N, it should chooses according to : Probability (I picks J)  E j / Pij E j = Energy Left in Node J Pij = Power needed for transmitting data from I to J

Reference " Xiaoyan Hong et al., The Mars Sensor Network: efficient, power aware communications, (Milcom 2001) " Chalermek Intanagonwiwat, Ramesh Govindan, and Deborah Estrin, Directed Diffusion: A Scalable and Robust Communication Paradigm for Sensor Networks, Proceedings of the Sixth Annual International Conference on Mobile Computing and Networks (MobiCOM 2000), August 2000, Boston, Massachusetts " Marc R. Pearlman et al., On the impact of Alternative Path Routing for Load Balancing in Mobile Ad Hoc Networks, MobiHoc " Ya Xu, John Heidernmann and Deborah Estrin, Geography- informed Energy Conservation for Ad Hoc Routing., MobiCOM 2001.