| 摘要 |
The described method and system provide an efficient routing of data packets protocol in an event-driven and delay-constrained WSN (wireless sensor network) that optimizes the sleep/wake schedule of nodes to maximize the lifetime of the WSM, subject to a constraint on the source-to-sink delay. Online forwarding techniques may be used to transfer data reports from monitoring nodes to the sink. A delay-constrained and energy-efficient routing protocol (DCEER) for asynchronous WSNs may be used to maximize the lifetime of the WSN while remaining within the maximum allowable delay requirements. With DCEER, each node may maintain the historical cost of forwarding a packet from itself to the sink as its virtual coordinate, and packets are forwarded in the direction of descending coordinates. The cost-based coordinates may change dynamically with a time-varying channel or topology. Nodes may apply a relay-selection scheme to choose a next-hop relay from a set of multiple potential relay candidates, based on a tradeoff between forwarding energy consumption (FEC) and waiting costs. The optimal stopping time for the relay-selection process may be determined based on expected forwarding and waiting costs, and the nodes may operate according to an optimal sleep/wake schedule based on waiting costs and expected traffic flow. |
