ABSTRACT:

Routing protocols for wireless sensor networks should address the challenges of reliable packet delivery at increasingly massive scales and with highly constrained node resources. Attempts to scale back routing state can lead to undesirable worst-case routing performance, as measured by stretch, which is that the ratio of the hop count of the chosen path to that of the optimal path. We present a replacement routing protocol, Small State and Small Stretch (S4),which jointly minimizes the state and stretch. S4 uses a mix of beacon distance-vector based mostly global routing state and scoped distance-vector primarily based native routing state to achieve a worst-case stretch of three using O(pN) routing state per node in an N-node network. Its average routing stretch is shut to 1. S4 any incorporates native failure recovery to achieve resilience to dynamic topology changes. We use multiple simulation environments to assess performance claims at scale, and use experiments in a forty two-node wireless sensor network testbed to guage performance beneath realistic RF and failure dynamics. The results show that S4 achieves scalability, efficiency, and resilience in a very big selection of situations.