| In the next generation high-speed wireless networks, providing quality-of-service (Q0S) guarantees for multimedia applications is very important. Bandwidth allocation when a handoff occurs for broadband wireless networks, including wireless ATM, is mainly studied. A brief survey of the mobility management of wireless ATM is presented, and its network structure, handoff concept and handoff schemes are introduced. The specification of handoff is discussed, and basic schemes of bandwidth allocation for handoff, such as complete sharing, complete partitioning, reservation policy, borrowing policy are introduced. Several handoff schemes, such as no- bandwidth-reservation scheme, adaptive-bandwidth-reservation scheme, bandwidth- borrowing-scheme are analyzed, their performance are simulated, their advantages and disadvantages are compared. Based on above analysis and study, a new bandwidth allocation scheme for handoff is presented. The performance of the proposed scheme is evaluated through simulation, the results show that the proposed scheme provides small handoff dropping probability for broadband traffic and achieves high bandwidth utilization. Finally, in a multimedia wireless ATM network based on TDMAITDD, the performance of reservation policy is investigated by computer simulation. The results show that the scheme can satisfy both of constraints on the forced termination probability of CBR subclasses and the packet delay of UBR. |
