Cross-layer adaptive multipath routing for multimedia Wireless Sensor Networks under duty cycle mode

Abstract Multimedia transport over Wireless Sensor Networks (WSN) has been a challenging task due to the limited available resources of such networks. The capability of Multipath routing to balance and distribute the load of a given flow on different disjoint non correlated paths is a viable solution to ensure the required high throughput. Moreover, operating the WSN under a duty-cycle mode reinforces the challenge as nodes become subject to frequent alternation between the active and inactive states in the quest to prolong the network life and minimize the energy consumption. In this context, we propose a cross-layer multi-path routing approach taking into account diverse contextual information in order to establish non-correlated and node-disjoint paths able to concurrently transport multimedia content from sources to the sink. The approach relies on a tight cooperation between the routing and MAC layers in order to appropriately adjust and regulate the wake-up scheduling of involved nodes in the forwarding phase. It incorporates a continuous observation of local contextual data to improve the routing process. Independently of the initial duty-cycle scheduling, the conducted mathematical analysis proves that our adjustment rules provide a maximal overlapping interval between the activity periods of the involved nodes. We compare our approach against the single path option and FMRP, a multipath routing protocol designed for always-on WSNs using non-correlated paths. Simulation results showed significant improvements in terms of latency and throughput. The proposed approach attains 27% energy conservation, and it enhances the delay and goodput by 50% over the single path option and up to 90% over the FMRP.