A Multicast Routing Algorithm Using Movement Prediction for Mobile Ad Hoc Networks Huei-Wen Ferng, Ph.D. Assistant Professor Department of Computer Science and Information Engineering (CSIE) Nation Taiwan University of Science and Technology (NTUST) Wireless Communications and Networking Engineering (WCANE) Lab URL:

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab2 Outline Introduction Description of the proposed protocol Numerical examples and discussions Conclusions

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab3 Introduction (1/2) The multicast communication is a challenging issue in MANETs because of frequent topology changes. Approaches to update states of neighbors  Soft state approach vs. Hard state approach Two categories of multicast algorithms  Mesh-based vs. Tree-based A few routing algorithms in MANETs  Ad-hoc On-demand Distance Vector (AODV)  On Demand Multicast Routing Protocol (ODMRP)

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab4 Introduction (2/2) Goal  To propose a tree-based routing algorithm with hard state update called Tree-based Multicast Routing Algorithm with Movement Prediction (TMRAMP) Features  Less overhead  Prediction-based  Local path search and recovery

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab5 Outline Introduction Description of the proposed protocol Numerical examples and discussions Conclusions

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab6 TMRAMP The algorithm is composed of three parts  Movement prediction  Routing protocol  Local path search and recovery

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab7 Movement Prediction Assume that the moving speeds, coordinates, and directions of two mobile nodes, say node 1 and node 2, are given, then we can calculate the connection time D t using the following equation (by Su, Lee, and Gerla) where

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab8 Routing Protocol The source first broadcasts a Join Request packet which includes the necessary information. A node upon receiving a Join Request packet determines if it is a duplicate. If it is not duplicate and the Hop Count (HP) is still smaller a pre-specified threshold, movement prediction is applied to estimate the link connection time (LCT) between this node and its upstream node. Set RCT=min( LCT, RCT), where RCT stands for Route Connection Time. The modified packet is broadcasted to neighbors.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab9 Routing Protocol For a group member, it further chooses the path with the largest RCT since multiple Join Request packets may be received from different paths. Of course, a member routing table is maintained at each node such that Join Reply packets sent by group members are able to return back to the sender along the chosen paths.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab10 Local Path Search and Recovery We assume that all necessary information is available and is put into packets so as to make GPS work. By setting a threshold BeginHandoff, a node can estimate the time when the link will terminate. When the estimated connection time falls below the threshold, the node will issue the Rejoin packet to its neighbors.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab11 Local Path Search and Recovery A neighboring node upon receiving the packet first checks  Duplicate? On-tree node? If it is not duplicate and an on-tree node, a Reply Rejoin (with estimated connection life time) is sent; otherwise, Rejoin packet is broadcasted to neighbors. For the disconnected node, a path with the longest life time is chosen as a new path. If no path can be found, the disconnected node tries repeatedly to contact any on-tree node with scope one hop larger until at least one is found.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab12 Local Path Search and Recovery

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab13 Outline Introduction Description of the proposed protocol Numerical examples and discussions Conclusions

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab14 Simulation Arrangements

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab15 Performance Metrics (Data) packet delivery ratio Number of control packets transmitted per data packet received -> reflect overhead Number of data packets received per data packet transmitted -> represent routing efficiency

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab16 Simulation Results TMRAMP outperforms ODMRP by reducing 20% to 60% of overhead.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab17 Simulation Results TMRAMP performs better by gaining 10% to 15% more routing efficiency than ODMRP.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab18 Simulation Results TMRAMP outperforms ODMRP by reducing 10% to 30% of overhead. In general, about 40% improvement can be achieved by TMRAMP as compared to ODMRP.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab19 Outline Introduction Description of the proposed protocol Numerical examples and discussions Conclusions

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab20 Conclusions TMRAMP is about 20% to 60% higher under various moving speeds and 10% to 30% higher under various group sizes than ODMRP in overhead. TMRAMP outperforms ODMRP in routing efficiency by 10% to 15% under various moving speeds and up to 40% under various group sizes. A scheme using tree-based routing is more suitable than that using mesh-base routing when applied to an environment with a large group. Hence, we suggest TMRAMP to be used in MANETs.

5/30/2005 VTC 2005-SpringNTUST/WCANE Lab21 Thank You!