Delay-Sensitive Packet Scheduling for a Wireless Access Link

As the delay is a critical QoS factor, packet scheduling over a wireless access link that often becomes congested needs to have the objective of meeting each user´s delay requirement. To incorporate the delay into the scheduler design, we consider the objective of maximizing the total utility (UT). However, since a utility-based scheduler that concerns delay requires high complexity, we introduce the concept of marginal utility. Representing the objective as minimizing the total marginal utility (mt), we develop some related properties for maximizing U_T and minimizing M_T. For the case with fixed service time, we show that the outcome of M_T minimization becomes equivalent to that of U_T maximization. For the more complicated case of varying service time, the M_T minimization sheds light on the design of a simple scheduler. Overall, the marginal utility requires significantly low complexity for packet scheduling compared to the ordinary utility. Through simulations, we confirm that the marginal utility gives a way of flexible scheduling in meeting various delay requirements