Multipath Routing Protocol In Ad Hoc Networks

Ad Hoc Network means a multi-hop temporary self-organized system, which consist of a set of mobile terminals with the radio devices. Each mobile terminal is both a host and router, performing route setup and packet forwarding according to a routing algorithm.This paper firstly reviews the characteristics and design constraints of Ad Hoc Network, analyses the nature of proactive and reactive routing protocols, and that of single-path and multi-path reactive routing protocol. We also review SASR, a single-path routing protocol in detail. Secondly, we propose a new algorithm SAMSR — Sequence number Aided Multipath Source Routing. In SAMSR, duplicate RREQs are recorded to obtain more topology information, resulting in discovering more node-desjoint reachable paths. Intermediate nodes send Re-selection packets after receiving duplicate RREPs to ensure node-disjoint paths. Lastly, we evaluate the perfomance of SAMSR with NS-2 in C++. The result concludes that, compared to SASR, SAMSR improves the Packet Delivery Fraction, reduces the average End-to-End Delay, though it increases the Total Bandwith Cost.