The Research On P2P Streaming Dissemination In Multi-hop Wireless Mesh Networks

Wireless mesh networks (WMNs) are dynamically self-organized and self-configured, with the nodes in the network automatically establishing an ad hoc network and maintaining the mesh connectivity. This feature brings many advantages to WMNs, such as low up-front cost, easy network maintenance, robustness, reliable service coverage, etc. Because of their advantages over other wireless networks, WMNs are undergoing rapid progress and have emerged as a key technology for next-generation wireless networking. There are inspiring numerous applications in WMNs such as broadband home networking, community networking, building automation, highspeed metropolitan area networks, and enterprise networking, etc.Due to the reason of limited bandwidth of wireless network, mobile users want to accelerate the downloading rate by using some innovative techniques (such as P2P) to support cooperative streaming downloading from multiple sources. Although many studies can be found on P2P streaming in wired networks, very few studies have studied the problem in wireless networks, especially in multi-hop wireless mesh networks. The current WMN infrastructure often does not provide the Quality of Service (QoS) support required by these P2P streaming applications, which maks P2P steaming in WMN is challenge. This dissertation concentrates on the P2P streaming in WMNs. Some creative works focus on the following aspects:1) To maximize the users’ satisfaction of P2P streaming in WMNs, this paper focuses on link rate allocation problem and proposes a fully distributed algorithm to efficiently utilize the upload and download bandwidth of wireless mesh nodes. Based on the experimental results from real deployment of our wireless mesh testbed, we propose an efficient P2P streaming system in WMNs. In such a system, MRs rather than MCs act as peers exchanging streaming packets with each other and MCs only be served by its corresponding MR without uploading any media content. This paper builds the network utility maximization link rate allocation problem with the consideration of load distribution in WMNs and use user density as an important weight in the problem. The proposed link rate allocation algorithm in this paper represents a cross-layer strategy, which strikes a balance between the demand of link bandwidth (link rate) at the network layer and the supply of link capacity at the physical layer. The simulation experiments demonstrate the efficiency and affectivity of the proposed rate allocation algorithm in WMNs.2) This paper proposes an interference-aware P2P streaming problem in multi-hop wireless mesh networks with the aim of providing the client peer the maximum aggregate throughput as well as bounded end-to-end communication delay. To counteract the problem, we propose a cooperative P2P streaming dissemination algorithm which joints peer selection and routing in multi-hop wireless mesh networks. Firstly, we formulate the interference-aware P2P streaming problem as a constrained optimization problem, named a Variation of Maximum Length-Bounded Disjoint Path problem (VMLBDP) and prove the VMLBDP to be NP-complete. Secondly, we propose a heuristic cross-layer algorithm which joints peer selection and routing to solve the VMLBDP. The cross-layer algorithm comprises an iterative shortest path finding procedure which determines the set of selected server peers and the shortest disjoint path. The simulation results also demonstrate that our algorithm outperforms other current algorithms and can effectively utilize wireless channels to obtain optimal streaming playback performance.3) According to the character of mesh topology and character of the different types of mesh nodes, the multi-hop wireless mesh network is modeled as cluster P2P in this paper. Moreover, in order to save the message bandwidth, this paper uses the Bloom filter as the message to represent the resource list abstract, and the message is transmitted among the constructed P2P clusters. To minimize the downloading interruption due to mobility of clients, this paper proposes a resource-density-sensitive resource query and dissemination algorithm in which the query is transmitted to the cluster that has the maximum number of replica resources. The simulation results show that the proposed resource query and distribution algorithm can provide appealing resource downloading performance.4) To efficiently and stably deliver streaming media, researchers have developed technical solutions that are either based on a tree model or based on a mesh model. The disadvantage of tree-based model is limited stability and high cost, while the disadvantage of mesh-based model is low efficiency on streaming rate when nodes churn. In this paper, we propose LRing-A Layered Ring Topology for reliable streaming system, which well balance the maximum streaming rate and reliable streaming data in the system as well as achieve high utilization of node’s cache. The simulation experiment demonstrates the effectiveness of LRing.