A nondisruptive multi-path handoff scheme for peer-to-peer live video streaming

The key challenge to provide a seamless peer-to-peer live video delivery over mobile heterogeneous networks is to handle dynamic changes of networks due to vertical handoff. To adapt to the network changes, it is required to support path adaptation which changes an overlay path by selecting a new sending peer and adjusts a reception rate to the new overlay path. In order to handle the path adaptation seamlessly, multi-path handoff schemes have been proposed, which preserve an old overlay path in an overlapped area while adapting to a new network. In the existing schemes, however, flows from old and new paths may compete for the bandwidth of a shared link with each other and this causes user´s video quality degradation during handoff, which we call a shared bottleneck problem. We propose a nondisruptive handoff scheme to solve the shared bottleneck problem. By detecting a shared bottleneck link when probing potential paths, the proposed scheme adjusts underestimated bandwidth of potential paths during peer selection and makes the flow from an old path yield its bandwidth smoothly during rate adaptation.