Reliable Stream Scheduling with Minimum Latency for Wireless Sensor Networks

As sensor networks are increasingly deployed for critical applications, reliability and latency guarantee become more important than ever to meet industrial requirements. In this paper, we investigated the impact of link burstiness on stream scheduling using a data trace of 3,600,000 packets collected from an indoor testbed. We demonstrate that a good tradeoff between reliability and latency can be achieved by allocating certain time slots on each link for stream transmissions based on its burst length and frequency distributions. With this observation, we design transmission scheduling and routing algorithms for data streams to meet a specified reliability requirement while minimizing end-to- end latency. For the multi-stream scheduling problem, we prove its NP-hardness and design an algorithm that achieves the reliability guarantee and an O(log n) approximation of minimizing the maximum end-to-end latency for any stream. Trace- driven simulations show that our solution meets specified end-to-end reliability requirements with latency up to 9.18 times less than existing solutions.