Network Assisted Media Streaming in Multi-Hop Wireless Networks
Delivery of high-quality streaming services over multi-hop wireless mesh networks (WMNs) is a challenging research problem because of quality fluctuation and interference of wireless links in WMNs, as well as strict throughput, delay, and reliability requirements of streaming applications. In this paper, we propose a Network Assisted Peer-to-Peer (NAP2P) system for file-based media streaming services such as video-on-demand in WMNs. In NAP2P, mesh routers dynamically cache content and form a P2P network with end user devices. This architecture enables several efficient and scalable communication mechanisms, for example, automatic caching and multi-source multi-path streaming for optimizing system performance. We address the design issues in NAP2P. Especially we design a multi-source multi-path routing mechanism to meet the QoS requirements of streaming sessions. A mathematical formulation for such source selection and routing optimization problem is presented, which determines the optimal content sources and streaming paths for multiple concurrent flows in the presence of wireless interference and subject to flow QoS constraints. By leveraging the unique architecture of NAP2P, we investigate the performance gain by applying mesh cache routers as network peers in P2P networks, as well as the benefits of allowing end user devices to provide content to their peers.