A Gossip-based optimistic replication for efficient delay-sensitive streaming using an interactive middleware support system

While sharing resources the efficiency is substantially degraded as a result of the scarceness of availability of the requested resources in a multiclient support manner. These resources are often aggravated by many factors like the temporal constraints for availability or node flooding by the requested replicated file chunks. Thus replicated file chunks should be efficiently disseminated in order to enable resource availability on-demand by the mobile users. This work considers a cross layered middleware support system for efficient delay-sensitive streaming by using each device's connectivity and social interactions in a cross layered manner. The collaborative streaming is achieved through the epidemically replicated file chunk policy which uses a transition-based approach of a chained model of an infectious disease with susceptible, infected, recovered and death states. The Gossip-based stateful model enforces the mobile nodes whether to host a file chunk or not or, when no longer a chunk is needed, to purge it. The proposed model is thoroughly evaluated through experimental simulation taking measures for the effective throughput Eff as a function of the packet loss parameter in contrast with the effectiveness of the replication Gossip-based policy.Comment: IEEE Systems Journal 201

Priority Based Routing for Mobile Peer-To-Peer Communications

In a Mobile Peer-to-Peer (MP2P) network, mobile nodes share their resources among one another in a mobile wireless environment. Communication among nodes in MP2P network has become an important area for research due to the significance of its applications. The success of these MP2P applications depends on the number of users in the network, popularity of services offered, quick response and faster access to services. Some services offered could be more popular than others and some peers may contribute more to the network by catering to more requests compared to other peers. In priority based routing mechanism, there is an increase in the priority of a peer with the increase in the number of times it provides services to other peers. The priority of a shared service also increases as the number of requests for that service increases. Also, the mechanism of priority based mobile peer-to-peer routing provides higher priority for traffic destined to high contributing peers and the traffic of popular services, during routing. This would provide high contributing peers quicker response and faster access to services. Hence, this mechanism motivates more users to join the MP2P network and contribute more to the network

Scenarios and system dynamics of mobile peer-to-peer content distribution

Vertaisverkkoteknologian menestys kiinteissä verkoissa on johtanut vertaisverkkototeutuksiin myös mobiileissa verkoissa. Mobiilin vertaisverkkoteknologian tulevaisuuden suhteen on tosin vielä paljon epävarmuutta, koska operaattorit ja muut sidosryhmän jäsenet, jotka kärsivät laittoman tiedostonvaihdon seurauksista kiinteän verkon puolella, pelkäävät saman tapahtuvan myös mobiileissa verkoissa. Täten he saattavat yrittää estää mobiilin vertaisverkkoteknologian kehittymistä. On myös epävarmaa onko mobiilille vertaisverkkoteknologialle tarvetta loppukäyttäjän näkökulmasta, eritoten kun mobiililaitteiden suorituskyvyt ovat huomattavasti alhaisempia kuin kiinteiden. Tämä diplomityö keskittyy mobiilin vertaisverkon sisällönjakeluun. Sisällönjakelu on jaettu tiedostonvaihtoon, sisällön suoratoistoon ja kaupallisiin sisältöjärjestelmiin. Työ antaa näkemystä mobiilin vertaisverkon sisällönjakelun olennaisimpiin skenaarioihin, sidosryhmän jäseniin ja heidän kannustimiin. Mobiilin vertaisverkon sisällönjakelun epävarmuutta rajataan käyttämällä skenaarioanalyysiä ja mallinnetaan systeemidynamiikalla. Olennaisimmat skenaariot rakennetaan Schoemakerin metodilla ja niiden mallinnusta yritetään systeemidynamiikan keinoin. Tuloksena saadaan neljä eri skenaariota, jotka on kehitetty brainstorming -tilaisuuksissa ja kirjallisuuskatsauksessa löydettyjen avaintrendien ja -epävarmuustekijöiden perusteella. Skenaarioiden kvantitatiivisen mallinnuksen sijaan mallinnetaan skenaarioihin perustuvan mobiilin vertaisverkon sisällönjakelujärjestelmän dynaamista käyttäytymistä. Vaikka joitakin mobiilia vertaisverkkoteknologiaa hyödyntäviä sovelluksia on jo kehitetty ja käytössä, sekä aihetta tutkittu laajasti, vieläkin on epävarmaa mikä teknologian vaikutus tulee olemaan. Tämä diplomityö esittää mahdollisia vaikutuksia teknologialle ja antaa lähtökohdan tulevalle mobiilien vertaisverkon sisällönjakelujärjestelmien kvantitatiiviselle mallinnukselle. Systeemidynamiikka on toteuttamiskelpoinen vaihtoehto tavallisemmille mallinnustekniikoille, kuten taulukkolaskentamallinnukselle, jonka etuna on järjestelmän takaisinkytkentäsilmukkojen mallintaminen. Kun mobiili vertaisverkkoteknologia kehittyy, enemmän dataa tulee saataville ja vaihtoehtoisten systeemidynamiikkamallien rakentaminen on suositeltavaa.The success of peer-to-peer technology in the fixed networks has led to peer-to-peer implementations in the mobile networks as well. There is, however, a lot of uncertainty regarding the future of mobile peer-to-peer technology as the operators and other stakeholders that were affected negatively by illegal peer-to-peer file sharing in the fixed networks are afraid that it might happen in the mobile domain as well. Thus they might try to prevent mobile peer-to-peer technology from emerging. There is also the question whether there really is a need for peer-to-peer technology in the mobile domain from the end users' perspective, especially as the mobile device capabilities are considerably lower compared to the fixed ones. This thesis concentrates on mobile peer-to-peer content distribution. Content distribution is divided to file exchange, content streaming and commercial content systems. The thesis provides insight to the most relevant scenarios, stakeholders and their incentives related to mobile peer-to-peer content distribution. The uncertainty regarding mobile peer-to-peer content distribution will be bounded using scenario analysis and modeled using system dynamics. The most relevant scenarios regarding mobile peer-to-peer content distribution are constructed using Schoemaker's method and modeling of these scenarios is attempted with system dynamics. As a result four different scenarios are developed based on the key trends and uncertainties discovered during the literature review and brainstorming sessions. Instead of modeling the scenarios quantitatively, the dynamic behavior of a mobile peer-to-peer content distribution system based on the scenarios is modeled with system dynamics. Although there are some mobile peer-to-peer content distribution applications already developed and used, and the topic is considerably researched, it is still uncertain what the outcome of the technology will be. This thesis presents possible outcomes for the technology and provides a starting point for further quantitative modeling of mobile peer-to-peer content distribution systems. System dynamics provides a viable alternative to more common modeling techniques such as spreadsheet modeling, with a distinctive benefit of modeling the feedback loops in a system when used proficiently. As the mobile peer-to-peer technology evolves, more data becomes available and the construction of alternative system dynamics models is encouraged

A Novel Clustering Tree-based Video lookup Strategy for Supporting VCR-like Operations in MANETs

Mobile Peer-to-Peer (MP2P) network is a promising avenue for large-scale deployment of Video-on-Demand (VoD) applications over mobile ad-hoc networks (MANETs). In P2P VoD systems, fast search for resources is key determinants for improving the Quality of Service (QoS) due to the low delay of seeking resources caused by streaming interactivity. In this paper, we propose a novel Clustering Tree-based Video Lookup strategy for supporting VCR-like operations in MANETs (CTVL) CTVL selects the chunks with the high popularity as "overlay router" chunks to build the "virtual connection" with other chunks in terms of the popularities and external connection of video chunks. CTVL designs a new clustering strategy to group nodes in P2P networks and a maintenance mechanism of cluster structure, which achieves the high system scalability and fast resource search performance. Thorough simulation results also show how CTVL achieves higher average lookup success rate, lower maintenance cost, lower average end-to-end delay and lower packet loss ratio (PLR) in comparison with other state of the art solutions

A Resource Intensive Traffic-Aware Scheme for Cluster-based Energy Conservation in Wireless Devices

Wireless traffic that is destined for a certain device in a network, can be exploited in order to minimize the availability and delay trade-offs, and mitigate the Energy consumption. The Energy Conservation (EC) mechanism can be node-centric by considering the traversed nodal traffic in order to prolong the network lifetime. This work describes a quantitative traffic-based approach where a clustered Sleep-Proxy mechanism takes place in order to enable each node to sleep according to the time duration of the active traffic that each node expects and experiences. Sleep-proxies within the clusters are created according to pairwise active-time comparison, where each node expects during the active periods, a requested traffic. For resource availability and recovery purposes, the caching mechanism takes place in case where the node for which the traffic is destined is not available. The proposed scheme uses Role-based nodes which are assigned to manipulate the traffic in a cluster, through the time-oriented backward difference traffic evaluation scheme. Simulation study is carried out for the proposed backward estimation scheme and the effectiveness of the end-to-end EC mechanism taking into account a number of metrics and measures for the effects while incrementing the sleep time duration under the proposed framework. Comparative simulation results show that the proposed scheme could be applied to infrastructure-less systems, providing energy-efficient resource exchange with significant minimization in the power consumption of each device.Comment: 6 pages, 8 figures, To appear in the proceedings of IEEE 14th International Conference on High Performance Computing and Communications (HPCC-2012) of the Third International Workshop on Wireless Networks and Multimedia (WNM-2012), 25-27 June 2012, Liverpool, U

Controlling P2P File-Sharing Networks Traffic

Since the appearance of Peer-To-Peer (P2P) file-sharing networks some time ago, many Internet users have chosen this technology to share and search programs, videos, music, documents, etc. The total number of P2P file-sharing users has been increasing and decreasing in the last decade depending on the creation or end of some well known P2P file-sharing systems. P2P file-sharing networks traffic is currently overloading some data networks and it is a major headache for network administrators because it is difficult to control this kind of traffic (mainly because some P2P file-sharing networks encrypt their messages). This paper deals with the analysis, taxonomy and characterization of eight Public P2P file-sharing networks: Gnutella, Freeenet, Soulseek, BitTorrent, Opennap, eDonkey, MP2P and FastTrack. These eight most popular networks have been selected due to their different type of working architecture. Then, we will show the amount of users, files and the size of files inside these file-sharing networks. Finally, several network configurations are presented in order to control P2P file-sharing traffic in the network.García Pineda, M.; Hammoumi, M.; Canovas Solbes, A.; Lloret, J. (2011). Controlling P2P File-Sharing Networks Traffic. Network Protocols and Algorithms. 3(4):54-92. doi:10.5296/npa.v3i4.1365S54923

MADServer: An Architecture for Opportunistic Mobile Advanced Delivery

Rapid increases in cellular data traffic demand creative alternative delivery vectors for data. Despite the conceptual attractiveness of mobile data offloading, no concrete web server architectures integrate intelligent offloading in a production-ready and easily deployable manner without relying on vast infrastructural changes to carriers’ networks. Delay-tolerant networking technology offers the means to do just this. We introduce MADServer, a novel DTN-based architecture for mobile data offloading that splits web con- tent among multiple independent delivery vectors based on user and data context. It enables intelligent data offload- ing, caching, and querying solutions which can be incorporated in a manner that still satisfies user expectations for timely delivery. At the same time, it allows for users who have poor or expensive connections to the cellular network to leverage multi-hop opportunistic routing to send and receive data. We also present a preliminary implementation of MADServer and provide real-world performance evaluations