Packet prioritization in multihop latency aware scheduling for delay constrained communication

This paper addresses the problem of optimizing the packet transmission schedule in a multihop wireless network with end-to-end delay constraints. The emphasis is to determine the proper relative weights assigned to the remaining distance and the remaining lifetime in order to rank the urgency of a packet. We consider a general class of cross-layer transmission schemes that represent such relative weights using a single lifetime-distance factor, which includes, as special cases, schedules such as earliest-deadline-first and largest-distance-first. We propose an analytical framework, based on recursive non-homogeneous Markovian analysis, to study the effect of the lifetime-distance factor on packet loss probability in a general multihop environment, with different configurations of peer-node channel contention. Numerical results are presented to illustrate how various network parameters affect the optimal lifetime-distance factor. We demonstrate quantitatively how the proper balance between distance and lifetime in a transmission schedule can significantly improve the network performance, even under imperfect schedule implementation.