Research On Key Technologies For The IPTV System Based On IMS And P4P

With the rapid progress and popularization of internet technology, P2P-based multimedia application has been the most important web service. At the same time, the development of IPTV service based on P2P is booming. The percentage of IPTV service as a proportion of the P2P application is increased year by year. Because of the increase of user quantity and the demand of high-definition of video, traditional P2P network cannot afford the IPTV service continuously and effectively. The disadvantage of P2P technology has already hindered the growth of the IPTVservice based on P2P.Because of the inherent defects of the P2P network, there are many shortcomings in the P2P-based IPTV service. It is difficult to effectively manage P2P-based IPTV and charging. It is unable to manage and monitor network resources. And it is hard to maintain user account information and digital right. In this paper, IMS and P4P technology is used to compensate the lack of P2P-based IPTV system, and a number of key technical issues which are involved will be studied and discussed. An IMS and P2P-based IPTV converged architecture is proposed to effectively manage P2P-based IPTV service. While this architecture cannot monitor and manage network resource, then an IPTV architecture based on IMS and P4P and a network route select policy are proposed. Based on the IPTV architecture, QoS and EPG system is deeply studied. Based on the above work, the main contributions of this dissertation are as follows.(1) To manage P2P-based IPTV service effectively, an IPTV architecture based on IMS and P2P is proposed. In this architecture, IMS CSCF modules act as the core module. Application server is composed of a group of individual entities. A presence server manages and maintains the presence information of users. To distribute multimedia content and transfer multimedia stream, a hybrid P2P network with supernode is applied. User end and content end are redesigned to make users subscribe and accept various IMS services, and the user end can provide IMS service as the content provider end. The proposed IPTV architecture can provide IPTV service together with other IMS service, and supports IMS service jumping among various ends. A VOD session is illustrated by an example to show how the IPTV modules work and how the session maintains continuity when it jumps among various ends. It is showed that the proposed IPTV architecture can manage P2P-based IPTV service more effectively.(2) An IPTV architecture based on IMS and P4P is proposed to reduce the enormous load of internet backbone brought by P2P application and optimize P2P network structure. On the basis of the IPTV architecture based on IMS and P2P, P4P network is introduced to improve the IPTV architecture. An iTracker module is constructed that user node can communicate with internet service providers to obtain network topology information. User node can actively choose content provider node which connects with the user node in low network resource cost. Network resource is managed effectively.(3) A network route select policy is proposed to reduce P4P network cost in transmitting multimedia flow. The network cost of a path of the P4P network is defined as the sum of all cost of links belongs to the path. The link cost is the product of the delay and flow of the link. The criterion P4P-distance of the distance of two P4P network nodes set by iTracker is the minimum network cost of the cost of all pathes between the two nodes, and the path network cost only counts the links belong to the backbone network. If the network cost of the links in two nodes’ current path which belong to the backbone is higher than the P4P-distance, the path of the two nodes must be redirected to a new path with lower network cost. Then, it is demonstrated if the policy can balance the P4P network load and reduce network cost. At last, an optimized algorithm to choose a path to the target node is proposed, and the procedure how network flow is controlled by the algorithm is illustrated as well.(4) To optimize the QoS of the IPTV architecture based on IMS and P4P by shortening the channel start/switch time. User node of P4P network can receive data provided in a short time by its neighbor nodes to fasten the channel start/switch process. An algorithm to choose efficient neighbor nodes to shorten channel start/switch time is proposed. It is verified that the speed of channel start/switch is improved efficiently by a simulation. The users’waiting time is shortened and QoS is improved. Beside this, the backbone is not be afford with too much extra load.(5) A hybrid EPG recommender module which supports recommendation between users is proposed on the basis of the IPTV architecture based on IMS and P4P. The module is composed of two modules. One is the recommend engine for the local IPTV system, the other one can manage information exchange between users and recommendation between users. The two modules’structure and recommendation mechanism is illustrated. Local EPG recommend module is composed of mobile end and fixed end, and the mobile end is a lighter recommend engine for its low calculating capability. EPG schedule can jump between various ends when the user end is in various scenarios. The recommendation between users module can realize EPG recommend information exchanging between usews and recommending between users by the information exchanging network based on P4P network.To improve the current IPTVsystem based on P2P, an IPTV architecture based on IMS and P2P is proposed to manage the IPTV service based on P2P; an IPTV architecture based on IMS and P4P is proposed to monitor and control IPTV network based on P2P; a novel network route select policy is proposed to balance network load and reduce network flow; a mechanism which will shorten channel start/switch time is proposed to improve QoS; a hybrid EPG recommendation module is proposed to change EPG information and recommend between users. All the research achievements will promote the development of IPTV services, allow users quickly and easily enjoying high-quality multimedia services anywhere, anytime.