TDMA-based scheduling for multi-hop wireless sensor networks with 3-egress gateway linear topology

We have studied packet transmission scheduling on multi-hop wireless sensor networks with 3-egress gateway linear topology, called Y-shaped topology. In every one cycle period, each node generates and forwards data packets that are bounded for either of the gateways at edges. In this paper, we focus on centrally-managed Time Division Multiple Access (TDMA)-based slot allocations and design a packet transmission scheduling framework combining with the basic redundant transmission to reduce and recover packet losses. On each of three types of path models to cover all possible routing on Y-shaped topology, we efficiently derive a global static time-slot allocation. The derived time-slot allocation exactly maximizes the probability that all packets are successfully delivered to one of the gateways within one cycle period, which cannot be achieved by existing scheduling schemes.