In next generation network (NGN), end-to-end QoS is one of the critical issues for real-time multimedia communications and applications. Such applications are sensitive to the availability of bandwidth for a given path. Measuring bandwidth has attracted considerable research efforts in the networking community. This paper intends to the contribution to the available bandwidth measurement for NGN where interoperability and end-to-end QoS are primary objectives. Our discussions of the algorithms focus on the following properties: (1) Efficiency: the applications should not wait too long for data convergence due to traffic that may interfere with the networks; (2) High accuracy: our algorithms should perform error control/cancellation to achieve high measurement accuracy; (3) Interoperability: our algorithms should adaptively apply to different types of networks.