Use of in-hop cooperative relays in trajectory-based forwarding in dense wireless sensor networks

Source routing techniques like Trajectory Based Forwarding (TBF) are suitable for dense wireless sensor networks (WSNs) due to their low power requirement. Though usual opportunistic coordination adds reliability to TBF, it also increases delay and coordination complexity. Alternatively, this work proposes the use of multiple cooperative relays within every single hop of a trajectory so that two adjacent forwarders do not communicate directly. While minimizing energy consumption further, this novel arrangement ensures an upper bound on delay, which is essential for delay-sensitive mission-critical WSNs. Analytical results show that the use of in-hop relays improves both energy efficiency and robustness.