An improved handover algorithm for scheduling services in IEEE802.16e

In IEEE802.16e, handover means that an MS (Mobile Subscirber) migrates from the network served by one BS (Base Station) to the network served by another BS. Scheduling services represent the data handling mechanisms determined by a set of QoS parameters that quantify the transmission. Taking five types of scheduling services into consideration, UGS (Unsolicited Granted Scheduling), rtPS (Real-Time Polling Scheduling), ertPS (Extended Real-Time Polling Scheduling), nrtPS (Non-Real-Time Polling Scheduling) and BE (Best Effort), this paper analyzes five types of handover mechanisms. And it proposes an improved handover algorithm by dynamically selecting an optimal handover mechanism for different scheduling services, which minimizes the traffic requirement of handover process with guaranteed delay performance. Analysis results show that, with qualified QoS performance, the usage of transmission resource is improved using the proposed handover algorithm.