Real-time Group Video Sharing tied with Online Social Networks

The exploding growth of OSNs (Online Social Networks) is a common trend incurrent mobile Internet era. In this paper, by linking the features of Facebook OSN andMOVi+ (Mobile Opportunistic Video-on-demand Plus) [1-3], we realize real-time P2P videosharing among mobile nodes. The realized prototype implementation clearly verifies theconvenience and economic feasibility of OSN-initiated application development

4G 네트워킹 디바이스로 구성된 이름 주소 기반 네트워크를 위한 테스트베드

학위논문 (석사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 8. 권태경.In recent years, mobile traffic (especially video traffic) explosion has become serious concern for mobile network operators. While video streaming services become crucial for mobile users, their traffic may often exceed the bandwidth capacity of cellular networks. To address the video traffic problem, we consider a future Internet architecture: Named-Data Networking (NDN). NDN is an innovative network architecture that is being considered as a successor to the Internet. In this thesis, we design and implement framework of adaptive mobile video streaming and sharing in the NDN architecture (AMVS-NDN) with multiple wireless interfaces (e.g., 4G LTE and Wi-Fi). To demonstrate the benefit of NDN, AMVS-NDN has two key functionalities: (1) in the base situation, a mobile station (MS) tries to use either 4G LTE or Wi-Fi links opportunistically, further using Multi-Interface technology, 4G LTE and Wi-Fi links can be used simultaneously, and (2) MSs can share content directly by exploiting local Wi-Fi direct connectivity. We implement AMVS-NDN over NDN and Multi-Interface, the tests are performed in a real testbed consisting of a WiMAX base station, a LTE Femtocell and Android phones. Testing with time-varying link conditions in mobile environments reveals that AMVS-NDN achieves the higher video quality and less cellular traffic than other solutions, with using Multi-Interface, AMVS-NDN can gain the highest video quality.Contents I. Introduction 6 II. Related Work 12 2.1 Named Data Networking 12 2.2 Adaptive Video Streaming 13 2.3 MS-to-MS Content Sharing 13 2.4 Multi Interface 14 III. AMVS-NDN Framework 15 3.1 AMVS-NDN illustration 15 3.2 Video Segmentation and Naming 16 3.3 Adaptive Streaming Strategy in AMVS-NDN 17 3.4 Dealing with Delays 20 IV. Video Sharing in AMVS-NDN 22 V. Details of Multi Interface 24 5.1 NDN-Femtocell for Edge Caching 24 5.2 Multi-Interface in Linux 24 5.3 Multi-interface in Android 26 VI. Implementation and Evaluation 27 6.1 Testbed Environment 29 6.2 AMVS-NDN Evaluation 30 6.3 AMVS-NDN Streaming and Sharing 33 6.4 Comparison with Pure-NDN and DASH-NDN 34 6.5 Multi Interface in Linux with LTE access to the Femtocell 36 6.6 Multi Interface in Android with LTE access 38 6.7 Live broadcasting with CCNx and Wi-Fi Direct 41 VII. Conclusion 43 VIII. References 45Maste

Track Me If You Can: On the Effectiveness of Context-based Identifier Changes in Deployed Mobile Networks

Location privacy is a major concern in an increasingly connected and highly pervasive network of mobile users. Novel location-based applications and device-to-device services (on these mobile devices) are gaining popularity, but at the same time, these services allow curious service providers and eavesdroppers to track users and their movements. Earlier research efforts on location-privacy preservation, which were mostly based on identifier-change mechanisms in spatio-temporal de-correlation regions called mix-zones, show that coordinated identifier-change techniques are reasonably effective in a simulation setting, although some smart attacks are still possible. However, a thorough analysis of these mechanisms that takes into consideration communication patterns and mobility from a real-life deployment is missing from these results. In this paper, we evaluate in a real-life setting the effectiveness of standard mix-zone-based privacy protection mechanisms against probabilistic tracking attacks. Our exper- iments involved 80 volunteers carrying smartphones for 4 months and being constantly eavesdropped on an adversarial mesh network of standard wireless Access Points (APs). To the best of our knowledge, this is the first study that provides empirical evidence about the effectiveness of mix-zone-based privacy-preserving mechanisms against practical adversaries in upcoming wireless and mobile systems

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

Flexible Application-Layer Multicast in Heterogeneous Networks

This work develops a set of peer-to-peer-based protocols and extensions in order to provide Internet-wide group communication. The focus is put to the question how different access technologies can be integrated in order to face the growing traffic load problem. Thereby, protocols are developed that allow autonomous adaptation to the current network situation on the one hand and the integration of WiFi domains where applicable on the other hand