Performance Evaluation of Handover Scheme Considering Uplink and Downlink Signals in IEEE 802.16e Systems

1 good. The conventional handover scheme is performed considering only downlink information. However uplink and downlink signal qualities can be asymmetric in Time Division Duplexing (TDD)/Orthogonal Frequency Division Multiple Access (OFDMA) systems like IEEE 802.16e systems. Therefore conventional handover schemes based on the downlink signal could degrade the uplink quality of service (QoS). Moreover, in these days, the demand of the uplink quality has been increased due to the peer to peer multimedia service. For this reason we propose hard handover scheme using uplink and downlink signal information. Using OPNET, we modeled the wireless channel and handover message flows in IEEE 802.16e systems. Simulation results show that the proposed scheme can reduce the handover outage probability and the service interruption time.