Novel ETX-Based Metrics for Overhead Reduction in Dynamic Ad Hoc Networks

In recent years most of wireless ad hoc networks usually include a larger number of mobile nodes. To take this into account, routing protocols, initially proposed for static networks, need to be upgraded. Higher network performance can be achieved if a suitable routing metric is included, such as frequently used Expected Transmission Count (ETX). However, with ETX metric routing overhead is increased making it unusable for networks with a large number of mobile nodes. Therefore, we proposed ETX-based routing metrics called Light ETX (L-ETX), Light Reverse ETX (LR-ETX), and Power Light Reverse ETX (PLR-ETX) that reduce overhead and improve other network performances. In order to test the impact of proposed metrics on the network performance, all three metrics are implemented in the Network Simulator 3 (NS-3) within Ad hoc On Distance Vector (AODV) routing protocol. Since the NS-3 lacks standardized tools for network performance analysis, we developed Network Performance Analysis Framework (NPAF) and use it to compare the proposed metrics. NPAF provides support for network analysis based on key performance indicators such as throughput, packet delivery ratio (PDR), useful traffic ratio (UTR), end-to-end (E2E) delay, jitter, etc. NS-3 source code extensions are publicly available.