Sharif Digital Repository

The emerging peer-to-peer (P2P) networks become more popular among researchers in different applications such as file sharing, and video streaming. Since various P2P networks provide high performance and scalable interaction among peers, they are very efficient in designing distributed multimedia applications such as live streaming, IPTV, VoIP, and multimedia broadcasting. In order to improve the network throughput and downloading performance of P2P networks for multimedia streaming, network coding is a technique which can be used for these purposes. In this thesis, we propose a peer-to-peer (P2P) video streaming protocol which presents an implementation of network coding technique. The... 

Information Technology In the recent years, Peer-to-Peer Networking and Applications has received significant attention from both the Internet users and research area. One of the most successful Applications of P2P networks is streaming the video which is applicable in Internet TV. On the other hand, Complex networks describe a wide range of networked systems in technology, nature and society, such as Internet, WWW networks, P2P networks, biological networks and social interactions.In this thesis we focus on mesh-pull based streaming networks and our goal is to propose a complex network model for such a P2PIPTV topology. To reach to this aim we consider the microscopic processes on each node... 

Peer-to-Peer networks are invented to enable participants (peers) to share their resources and find and use the shared resources of the others. So the main issue is the mechanism of finding granted resources of the other peers. In Peer-to-Peer networks, there is no central server to index shared resources of the peers. So peers should collaborate to provide a fully distributed mechanism for searching resources. Considering the huge size of peer-to-peer systems, it is apparent that efficiency of the search mechanism is very critical. In this thesis, to have efficient seach in Peer-to-Peer networks, we propose two approaches. Then based on these approaches, we propose the third approach to... 

Streaming video over the Internet has become popular in recent years. There are also popular solutions for data delivery, but these approaches are very inflexible and unpleasant because no appropriate error recovery technique isprovided in the application level of these systems for multimedia contents. In the past few years numerous error resilience Peer-to-Peer (P2P) systems have been introduced but still there is no fully dynamic error recovery technique. In this thesisthe researcher proposed a frame-based hybrid FEC-ARQ (Forward Error Correction – Automatic Repeat request) error recovery in Variable Bit Rate (VBR) video streams based on the network situation in a way that before... 

Nowadays, deployment of peer-to-peer video streaming systems over wireless mesh networks has attained increasing popularity among a large number of users around the world. In this thesis, we present an efficient peer-to-peer live video streaming architecture over multi-hop wireless mesh networks. In our proposed architecture, we take the physical topology of the network into account and based on a distributed locality-aware neighbor selection algorithm in the overlay construction phase, we generate an efficient mesh-based overlay on top of wireless mesh networks. In locality-aware neighbor selection algorithm, instead of choosing randomly, peers find their best neighbors based on their... 

Complex networks science have become the major method in the modeling of topological features of networks and graphs. Although file sharing Peer-to-Peer systems can be modeled by networks with un-weighted nodes and links, using these networks for Peer-to-Peer streaming systems have not led to a suitable model.In this research, we aim to model Peer-to-Peer streaming networks with weighted nodes and weighted links so that present the performance of nodes and the amount of streaming that is transmitted between nodes respectively. Due to lack of information about upload bandwidth distribution in networks we assume this distribution as uniform. Because of dynamics of network, this distribution... 

Hybrid CDN-P2P architecture has been introduced to combine scalability advantage of P2P and reliability of CDN networks. Although it has been proved that CDN-P2P is more efficient than other architectures for live video streaming, there is still the question, “How is it possible to be more efficient in providing higher service quality?” Quality degradation in P2P and Hybrid CDN-P2P is mainly connected to the lack of exploiting role of peers’ heterogeneity in the system. Most of currently deployed live video streaming systems don’t adapt to bandwidth of the peers and just send one version of video to all users. To tackle this issue, many researches combine P2P solution with scalable video... 

This thesis presents a dynamic multidimensional data structure, which is called Improved Skip Quadtree for peer-to peer networks. This data structure is the Improved version of Skip Quadtree which originally presented jointly by D.Eppstein, M.T.Goodrich, and J.Z.Sun. It tries to combine the best features of two well-known data structures; hieracical structure search quadtree, and skip list. In this thesis, it is tried to focus on algorithms for inserting and deleting points in both skip quadtree and Improved skip quadtree, which is fast method for performing point location and approximate range queries. The result of experimentation and implementation of this structure shows that it can be... 

The Use of peer-to-peer architectures instead of traditional client-server architecture can be beneficial in many aspects such as increasing scalability of the systems, enhancing fault tolerance in critical situations, extending the system resources and various other advantages. Nowadays, many applications are based on peer-to-peer architectures and as a result, a large portion of the internet traffic is produced by these applications. This has been a motivation to many researchers to focus on reducing the amount of this traffic while satisfying the content distribution demands. One of the main problems that can result in generating large amount of traffic and also long response times for... 

Resource sharing is the most important feature of a Grid. Resource discovery enables users to find the most suitable resources to run Grid jobs on. Resource discovery systems are often centralized or hierarchical. These structures are usually prone to a single point of failure, and unbalanced distribution of processing and storage load, making them inefficient as the Grid grows. These challenges have led researchers to adapt distributed approaches, such as Peer-to-Peer file sharing solutions. The important differences between Grid resource discovery and P2P file discovery (e.g. different resource attributes, queries, change patterns etc.) make it difficult to port the existing solutions to... 

Today, peer to peer networks have become quite popular due to their ability to easy access to shared resources regardless of their location in World. In these systems files are stored at the end user machines which named peer, rather than at a central server, in contrast to the traditional client-server systems, files are transferred directly between peers. sending and receiving those data, occupy a large amount of the internet bandwidth. So, by improving the efficiency of these networks, the total efficiency of the internet will improved. These systems are usually constructed on the other networks such as TCP/IP as an underlay or physical networks. Despite of structure of peer to peer... 

The accessibility of broadband Internet to home users has pushed video broadcasting applications up in the list of the most favorite IP-based applications. A Peer-to-Peer overlay network is an attractive foundation for video streaming as it can shift the burden of content distribution from the network routers and servers to the clients. However, live Peer-to-Peer media streaming systems face many challenges such as bandwidth heterogeneity, node churn, and selfish nodes. Although many tree based and mesh based streaming protocols have been proposed, each has its own drawbacks such as unreliability and unfairness in the tree based and long startup delay and complex scheduling in mesh based... 

The accessibility of broadband Internet to home users has pushed video broadcasting applications up, in the list of most favorite applications in todays Internet. Such applications involve delivering the data which generated in a single sender to a set of users which are scattered around the world. While it was formerly believed that the IP-Multicasting is the mean to provide this kind of services, the trend has altered to the use of Application Layer Multicasting techniques due to their deployment simplicty. Since their advent, Peer to Peer applications has mitigated many problems previously unsolved in the field of communication. File sharing, distributed file systems, distributed data... 

Internet video networks have already attracted millions of Internet users, and Internet video is one of the fast growing Internet services. The peer-to-peer (P2P) network is an efficient solution to supporting large scale video streaming on the Internet. P2P networks can deliver live multimedia content to millions of users with low cost at any time, and at anywhere they want. In this thesis, we investigate solutions to enhancing the performance of the unstructured mesh-based. Locality awareness or network proximity is one of the essential characteristics of P2P networks. In live P2P video streaming we face to some challenges like bandwidth heterogeneity of peers, and peer churn. In the P2P...