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Distributing video content over wireless networks using Device-to-Device (D2D) communication

Student thesis: Doctoral ThesisDoctor of Philosophy

The Device-to-Device (D2D) communication is considered to be a promising form of technology to distribute video contents to nearby users and devices at a high data rate and with small delays. In this thesis, we propose utilizing the D2D services and cache of mobile devices to improve the quality of service in terms of achieving the minimum startup-time and playback-delay of popular video files in a cellular network. To achieve the minimum startup-time, we propose the concept of D2D communication as a Bootstrapping-D2D (BD2D) in which each mobile device can cache and share the beginning portion or beginning-segments of the most popular video files to proximate users via a D2D communication link. To achieve the low playback-delay, we propose to cache the later segments of the video files fully or partially depending on the users’ video abandonment behavior and popularity of videos. We formulate optimisation problems that maximise the cache-hit and cache-throughput ratio of beginning-segments of the most popular video files. To maximise the cache-hit and cache-throughput ratio of later segments, we further propose and evaluate caching algorithms for large and small size video content. We evaluate the performance of the proposed caching algorithms through extensive simulations under real wireless network conditions such as interference, fading and shadowing. Our simulation results showed that the caching algorithm for beginning-segments achieved the average throughput-ratio from 83.9%-93.6%, among which 79% of users can start the video with zero startup-time through the local cache, while 13% of requests can be satisfied through the direct D2D link. Our simulation results also prove that the caching algorithm for short length videos outperforms all caching policies. For instance, 50% to 95% users not only can start the video with zero startup-time through the local cache, 47.5% of users can download the remaining segments with zero playback-delay through the local-cache, and 31% of users can download the remaining segments of the desired short length videos from their neighboring devices. We also propose a network-assisted D2D architecture called Mobile Content Delivery Network assisted-BD2D (M-BD2D) that assists the BD2D system in the discovery of devices that have cached the beginning-segments of the requested video files, in cache placement decisions, and also in the registration of potential D2D devices at the core network. We propose this architecture based on a comprehensive survey of the last decade in the peer-assisted content delivery network (PA-CDN).
Original languageEnglish
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Supervisors/Advisors
Award date1 Jun 2019

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