E2E-PACK: A Cross-Layer Design for Multipath Routing over Mobile Ad Hoc Networks

Multipath routing is one of the applied approaches in mobile ad hoc networks to address their limited bandwidth and high route breakage rate. Unfortunately, using multiple paths for each connection increases the number of existing flows in a system. More flows mean more potential of interference among them and also more overhead due to competition for acquiring the shared channel. Nevertheless, existing multipath routing methods rarely address these issues. In this paper a new cross-layer scheme for multipath routing, namely E2E-PACK, has been proposed which piggy-backs the end-to-end acknowledgements on MAC layer signals such as CTS or ACK. The E2E-PACK reduces the reverse flow of each connection and hence the number of existing flows in the system. In addition, the minimal size of the extra information does not significantly increase the size of MAC layer signals and therefore does not cause any side effects. To evaluate its performance, the proposed method has been used to transport multimedia content in ns-2 simulator. The results indicate that by applying the proposed E2E-PACK to a simplified video streaming application, it could recover from packet loss faster than before while consuming less bandwidth. The results also demonstrate that the negligible augmented size in the MAC layer signals do not impair the transmission performance. The new technique improves the streaming quality by up to 1.87 dB.