Minimum-energy packet forwarding over lossy networks under deadline and reliability constraints

This paper studies minimum-energy packet forwardingover multi-hop lossy networks under deadline andreliability constraints. We assume a routing topology in theform of a directed graph with packet loss processes on linksdescribed by finite-state Markov chains, and formulate the forwardingproblem as a finite-horizon constrained Markov decisionprocess. We show that the minimum energy forwarding policyunder hard deadline and reliability constraint can be computedusing dynamic programming, and that the optimal forwardingpolicy is a randomized policy over two history-independent anddeterministic policies. Closed-form optimal policies are derivedfor some particular scenarios. Numerical examples show thatthe transmission energy cost of achieving reliabilities close to themaximum can be significant when links are bursty. In addition,transmission power adjustments can further reduce energy cost.Finally, we develop simple heuristic policies with a good balancebetween transmission energy cost and reliability.QC 20121120