Trajectory Based Forwarding Group 2 Andrew Doherty, Aaron Wroblewski, Raghav Chawla Raghav

Introduction Dynamic Source Routing (DSR) High Overhead in Dynamic, Dense, Low Power Sensor Networks TBF Combines DSR with Cartesian Forwarding Source Specifies a continuous path, and then nodes forward based on distance from the path Trades Communication for Computation Raghav

Background and Motivation Advances in MEMS technology allow for large scale, highly dense ad-hoc sensor networks Smartdust, disposable networks, etc Wireless Sensor Networks face different problems than Wired Networks Potentially millions of nodes Battery life, mobility of nodes, sleeping nodes Raghav

The Problem Statement Problem: How can we efficiently forward packets in a dense ad-hoc network, while dealing with issues of scalability and a dynamic network topology? Previous Approaches Source based routing has problem of packet overhead increasing with path length Cartesian routing defines a single forwarding policy: greedy, along a straight line Raghav

General Overview TBF is a hybrid between Source Based Routing and Cartesian Forwarding S Andrew D D

Forwarding Methods “Minimum Deviation” (N2) MFR (N4) Centroid of the Set (N3) Most Battery Left Random Andrew

Applications of TBF Unicast Routing Multipath Routing Mobility Discovery Broadcasting Multicast Aaron

Adverse Conditions Sparse Networks Imprecise Locations Loop Method Alternatives to Positioning (GPS) LPS – Local Positioning System DV-Hop Aaron

Performance Evaluation Model Simulations were run to test: Unicast Routing and Discovery Broadcasting Location Data Dependence Aaron

Unicast Routing and Discovery Andrew

Naïve Broadcasting Andrew

Optimized Broadcast Andrew

Exploring Location Data Aaron

Location Data Dependence Deviation decreases with density Small difference in deviation between routing with warped or true positions Warped network not always longer TBF robust in face of realistic corruptions of node positioning Aaron

Related Work “Position Centric” Routing “Node Centric” Routing Routers responsible for polygonal regions Cartesian Routing LAR (Location Aided Routing) “Node Centric” Routing DSR (Dynamic Source Routing) Terminode Routing “Data Centric” Routing Routing driven by Interests Aaron

Critique Research is still being performed on determining, specifying and modifying trajectories Source needs copious information about network topology to design a path Lack of performance comparison to other protocols Raghav

Summary and Conclusions TBF is an optimized hybrid of Cartesian Forwarding and Source Based Routing Trades off Communication for Computation Robust in Adverse Conditions such as Sparse Networks and Imprecise Positioning Raghav