Design of a Delay-based Routing Protocol for Multi-rate Multi-hop Mobile Ad Hoc Networks

The temporal fluctuations in quality exhibited by the wireless links act as a major challenge in the design of efficient routing protocols in real-world Mobile Ad hoc Networks (MANETs). None of the existing link metrics fully account for the characteristics of data loss and delay on the links of a MANET. This paper provides the design of a novel delay-based link quality metric that uses real-time statistics from the wireless driver to take into account wireless contention, congestion, channel loss and mobility. The proposed delay metric is additive, does not introduce much additional overhead and is reflective of the varying wireless link quality. We design an efficient Link Delay-aware Routing (LDAR) protocol based on the proposed link metric. The proposed protocol has been implemented on a MANET test bed consisting of 5 laptop nodes. The evaluation of our protocol performed through extensive experimentation on the 5-node multi-hop MANET testbed and network simulator NS-2 demonstrate the superior benefits of the new protocol.