Quality of Experience-Aware Progressive Video Caching and Adaptive Device-to-Device Video Streaming for Cellular Networks with High User Density

Abstract

The increasing popularity of video streaming is escalating the growth of data traffic over cellular networks. Consequently, new techniques are much needed to help serving this increasing video traffic. Furthermore, the new techniques should consider the complex, dynamic, and delay-sensitive nature of video streaming traffic to support good Quality of Experience (QoE) video streaming services over cellular networks. The work in this thesis is focused on proposing algorithms and techniques to enhance the delivery of video contents and to improve the QoE of video streaming over cellular networks with high user density. First, we propose two algorithms for progressive caching of video segments in User Equipments (UEs) and Device-to-Device (D2D) transmission of video contents among UEs in the cell. The algorithms are employed, by the Base-Station (BS), to send segments of video files to selected UEs in the cellular network (called Storage Members (SMs)), to cache and forward the segments to requesting UEs using D2D communication. We study the performance of both algorithms 2016 [4], and it is expected to account for over three-fourths of the world's mobile data traffic by 2021 [4]. Hence, new techniques are needed to help serving video traffic over cellular networks, which is becoming the main source of data traffic. Device-to-Device (D2D) communication, introduced by the Long Term Evolution-Advanced (LTE-A) standard [5], is a new communication paradigm that allows direct 2 communication between nearby User Equipments (UEs) without routing the traffic through the Base-Station (BS) and the network infrastructure. This direct communication between UEs provides many benefits. The capacity of the network can be improved due to the reuse of frequency resources, as D2D transmission usually takes place over short distance. Moreover, this short distance transmission potentially has favorable propagation conditions, which leads to data rate gains. D2D communication can also be utilized to extend the cell coverage and improve the service for users at the cell-edge. As such, D2D communication is an important technology that is adopted by the Fifth Generation (5G) cellular networks [6], and much research has been conducted in recent years on D2D communication and developing applications for it in cellular networks [7]-[11]. We propose two algorithms for BS-assisted progressive caching of video segments in UEs and Peer-to-Peer (P2P) transmission of video contents among UEs using D2D communication, to improve video transmission in cellular networks [12]-[16]. Our algorithms are inspired by the architecture proposed in [17], which exploits D2D communications for video transmission improvement. The main idea is to utilize popular video contents that is cached in the UE devices. If cached video files are requested, they will be sent to the requesting devices from the caching UEs over D2D links. The proposed algorithms do not only consider the transmission of video segments to requesting UEs over D2D links, but also caching of video se...