In a multimedia streaming system,we need jitter-less bandwidth that satisfies playback rate to transmitmedia data fromsupplying peers. There is a challenge to provide high quality real-time streaming over wireless network. We have to know the available resources of each client to provide QoS support. However, when the application transmits data over wireless network, it is very difficult to know the available bandwidth due to unstable physical carrier. In this thesis, we investigate two problems: (1) how to efficiently estimate available bandwidth and (2) how to efficiently manage bandwidth according to the given QoS parameters for each connection. We develop a bandwidth management system to solve these problems. The system is an underlying part of a peer-to-peer media streaming system. It provides approximate bandwidth information and bandwidth management service to upper layer QoS management. By managing bandwidth according to available bandwidth dynamically, a peer-to-peer system can select appropriate supplying peers dynamically to provide QoS support. It also prevents media streaming being affected by other network traffic. Thus, high quality playback can be achieved over wireless network.