SPREAD - A Routing Protocol to Meet End-to-end Adjusted Deadline in Real Time Wireless Sensor Networks

摘要

Background: Real Time Wireless Sensor Networks (RT-WSN) have hard real time packetdelivery requirements. Due to resource constraints of sensors, these networks need to trade-off energyand latency.Objective: In this paper, a routing protocol for RT-WSN named “SPREAD” has been proposed. Theunderlying idea is to reserve laxity by assuming tighter packet deadline than actual. This reservedlaxity is used when no deadline-meeting next hop is available.Methods: As a result, if due to repeated transmissions, energy of nodes on shortest path is drained out,then time is still left to route the packet dynamically through other path without missing the deadline.Result: Congestion scenarios have been addressed by dynamically assessing 1-hop delays and avoidingtraffic on congested paths.Conclusion: Through extensive simulations in Network Simulator NS2, it has been observed thatSPREAD algorithm not only significantly reduces miss ratio as compared to other similar protocolsbut also keeps energy consumption under control. It also shows more resilience towards high datarate and tight deadlines than existing popular protocols.