The development of Mobile WiMAX was considered to fulfill requirements for all major traffic types present today. This means that it will have to support voice, data and video, even simultaneously in real time applications. The hard handoff (HHO) is performed, when the connection to the serving BS is broken before creating the new connection with the target BS, but has a much poorer performance for long service interruption time. Since IEEE802.16e standard is proposed to support mobility, handover has become one of the most important Quality of Service (QoS) factors. QoS and Service Level Agreements (SLAs) are maintained during HOs, and applications like mobile Voice over Internet Protocol (VoIP), multimedia gaming greatly benefits from low-latency. Therefore, flawless mobility with slight interruption of service under HHO is a major issue with IEEE802.16e Mobile WiMAX. Considering QoS, high HO latency may be unacceptable to real-time, delay sensitive applications. To solve this problem, a improved handover scheme is proposed in which CID assignment strategy is used to avoid confliction of CIDs of handing over services with that of ongoing services in the target BS.