Optimal Delay Region for Cross-Layer Resource Allocation

This paper characterizes the delay region that is quite useful for multi-user packet scheduling. In a quasi-static channel, the optimal delay region is defined as every set of total delay vectors achieved by some scheduling policies when there are no further packet arrivals. Each user´s total delay is equivalent to the amount of time until that user´s queue backlog is cleared. The optimal delay region shows the fundamental limit on each user´s achievable queueing delay and describes the trade-off among the users in terms of queueing delay when different scheduling policies are applied. In addition, the concept of the delay region is shown to be extendable to each packet´s average delay as well as total delay.