Geographic Routing with Cooperation for Reliable Paths in Device-to-Device Networks

In this paper, we introduce a novel geographic routing with cooperation scheme for 5G Device-to-Device ad hoc networks. The prime focus of our scheme (coined Cooperative Routing for Reliable Paths (CRRP)) is to enhance the routing performance in cooperative communication networks in terms of the path length and reliability. In particular, it introduces novel algorithms for cooperative relay and forwarder selections, which strike the best balance between path length and achieved symbol error rate, compared to prior work in the literature. Moreover, it exhibits the flexibility of deciding cooperative vs. direct communications, on a hop-by-hop basis, depending on the scenario. Our extensive simulation study reveals valuable insights. First, CRRP reduces the path length compared with conventional Greedy Forwarding (GF) routing scheme and the recently introduced Relay Aware Cooperative Routing (RACR) scheme. GF scheme is a direct communication scheme which always selects the closest forwarder to the destination. RACR is a cooperative routing scheme that selects the closest relay to the optimum relay position and similarly selects the closest forwarder to the optimum forwarder position. The superiority of CRRP in path length results in energy saving, crucial for battery operated Device to Device communications. Second, CRRP considerably outperforms GF and RACR with respect to the path failure probability (on the average 56.5% and 50% better than GF and RACR, respectively), critical for low density networks, while maintaining the symbol error rate within acceptable limits. © 2019 IEEE.