Distributed Ordering Transmissions for Latency-Sensitive Estimation in WSNs

In wireless sensor networks, sensor nodes have limited energy budget, in general. Energy efficiency is a critical issue which is directly related to the network lifetime. On the other hand, stringent latency requirements are enforced in some applications. To save energy, ordering transmissions is an effective approach in which sensor nodes transmit more informative data to the fusion center earlier. Ordering, however, does not perform well in latency-sensitive scenarios. In this paper, we propose a distributed method based on the framework of ordered transmissions. The proposed algorithm is illustrated in the discretized estimation problem with latency constraint. In our proposed method, each sensor node has specific time slots to transmit data, and can determine its transmission order independently. The proposed algorithm can greatly reduce latency without loss of estimation accuracy, while the increased number of transmissions is negligible. Simulation results validate its effectiveness.