Performance analysis of an enhanced DOA for mobile ad-hoc networks

The two ad-hoc routing protocols, Ad-hoc On demand Distance Vector (AODV) and Dynamic Source Routing (DSR) suffer a number of shortcomings. The main issues are longer path set up time in case of link failures, scalability problem because of routing overhead and etc. A combination of the two routing protocols called DOA (DSR over AODV) is used to overcome these issues. DOA is usually implemented using a model called Way Point Routing model in which the problem of position estimation errors occurs. This work enhances DOA with a new algorithm called Exponential Weighted Moving Average (EWMA) for on-line updating of nodal contact probability to minimize the possibilities of position estimation errors. In this work, new packet called Delay to Send (DTS) packets instead of NACK packets has been used in addition to RTS and CTS packets. Here DTS packets are to recover the delayed data within a certain time period instead of dropping the packet after final retransmission in case of delay due to unexpected traffic in packet delivery. A Simulation analysis is carried out to analyze the performance of DOA with EWMA compared to AODV and DSR. It proves that DOA with EWMA reduces the routing overhead by 80% and scalability problem that occurred in AODV and DSR.