S-WTP: shifted waiting time priority scheduling for delay differentiated services

The delay differentiated service was proposed as a DiffServ model to provide quality of service (QoS) guarantee on the Internet. In this model, packets are scheduled for transmission according to some specific delay metrics. waiting time priority (WTP) is one of this kind of scheduling algorithms that assign the priority to the packet according to its waiting time. WTP incurs implementation difficulty due to its computational complexity. In this paper, we propose a modified algorithm based on WTP called shifted waiting time priority (S-WTP). S-WTP reduces the computational complexity of WTP from O(n) to O(log(n)) without losing the basic functionality of WTP. Simulation results illustrate the effectiveness of S-WTP for delay differentiated service.