Partition-Aware TCP for Mobile Ad-Hoc Networks

In Mobile Ad-Hoc Networks (MANETs), due to mobility and lossy wireless links, multiple link breakages can occur within a localized area. As a result, networks are likely to be partitioned and this leads to disrupted communications. Legacy TCP reacts inappropriately in such network conditions, thus leading to poor throughput performances. In this paper, a partition-aware TCP (PAT) scheme is proposed to handle partition problems in MANETs. This is done by enhancing legacy TCP Backoff Mechanism and Retransmission Time-out values based on disconnection durations in MANET. Using disconnection duration information of nodes under various mobility models, namely, Random Waypoint (RW), Reference Point Group Mobility (RPGM), Manhattan Grid (MG) and Gauss Markov (GM), various enhancements are designed to complement the specific mobility model that they are applied to. The performance of PAT is evaluated against the legacy TCP and existing TCP-enhanced scheme known as Fixed-RTO. Using simulations, the results show that the PAT scheme offers much throughput improvements compared to the original TCP. In addition, it has significant throughput improvements comparable to that of the Fixed RTO scheme but yields only half the number of retransmissions. When evaluated in networks with multiple flows, it outperforms Fixed-RTO scheme in terms of throughput.