Wireless Multimedia Multicasting In Next Generation Small Cell Networks

The explosive increase of mobile broadband connections and network traffic introduces many challenges and requirements for next generation wireless access networks in the aspects of network density,capacity,and quality of experience.Small cells offload traffics from macro-cells to solve the traffic explosion problem,since they are deployed close to users.Video traffic will occupy 90% of network traffic in the future,moreover,it is popular for playing novel multimedia video with ultra high definition(UHD),which will be the dominant network traffic.The typical applications include virtual reality,augmented reality,etc.Besides high resolution,the novel multimedia traffic has the characteristics of multiple view points,free viewpoint switching,high bandwidth requirement,high quality-of-service(QoS),bringing new challenges for the traditional small cell networks.To solve challenges,this dissertation studies resource allocation in the next generation small cell networks for transmitting the novel multimedia,which work will be analyzed from three aspects including multicast source,multicast group,and multicast transmission.This dissertation will solve the following questions.First,in the aspect of multicast source,1)we study multicast source management for real-time multi-view video traffic.A cache based solution is proposed to solve the unsynchronized transmission for multi-view streams in the network,which will degrade users' quality-of-experience(QoE)when they freely switch views.An optimization problem is formulated to maximize the throughput under the cache constraint.Then,we formulate a cache cost formula,calculate coverage probability and ergodic rate for multicast groups,introduce a relay choice scheme.Through theoretical analysis and simulation,the proposed relay choice scheme achieves higher performance than that of existing schemes regarding relay-choice-gain and system throughput.Also,the proposed scheme can achieve close-to-optimal performance.2)We study multicast source management for multimedia traffic with ultra high definition and extremely high bandwidth requirement.A mobile edge computing(MEC)based solution is proposed for users' devices with limited decoding capacity,which will delay the promotion of novel multimedia traffic.We formulate an optimization problem for maximizing the ratio of user satisfaction over bandwidth requirement,propose a solution to the problem based on Lagrangian and series method.From theoretical analysis and simulation,this work can improve the ratio of user satisfaction over bandwidth requirement for the case where users' devices have limited decoding capacity.Second,in the aspect of multicast group,1)we study multicast group management for real-time multi-view video traffic.A multicast group division scheme based on video redundancy is introduced to solve the bandwidth waste problem when transmitting redundant multi-view video in wireless networks.We introduce a video model for redundancy division,a multicast group division model,and a bandwidth saving formula for base stations.From theoretical analysis and simulation,the proposed models can significantly save video transmission bandwidth and reduce system bandwidth and power consumption.2)We study multicast group management for multimedia traffic with multi-view and free-view video.A multicast group division scheme on the basis of both user mobility and view switching is designed to solve the problem of users' frequently switching among multicast groups for view-switching.We design a location and view-switching based Markov model,an optimization to maximize the system throughput followed by an area choice scheme.In theoretical analysis and simulation,it shows that the proposed area choice scheme achieves better performance than that of existing schemes under a different number of multicast groups and user distributions.Further,the proposed scheme can reach close-to-optimal performance.Third,in the aspect of multicast transmission,1)we study multicast transmission management for multimedia traffic with ultra high resolution and extremely high qualityof-service(QoS).A resource management problem is studied under a multicast scenario with soft frequency reuse(SFR)scheme.An optimization problem of minimizing power consumption under QoS constraint is introduced to solve inter-cell interference(ICI)caused users' QoS degrading in wireless networks with SFR scheme.A solution and the corresponding resource allocation scheme are proposed.Theoretical analysis and simulation illustrates that the proposed resource allocation scheme can obtain a better performance in terms of power consumption than that of existing schemes under a different number of multicast groups.In addition,the proposed scheme can reach close-to-optimal performance.2)We study multicast transmission management for multimedia traffic with ultra high bandwidth requirement.Resource management for both traditional multicast groups and device-to-device communication based multicast groups is studied to solve bandwidth bottleneck when transmitting novel multimedia traffic in wireless networks with limited capacity.An optimization problem to maximize throughput under multiple kinds of multicast groups and a resource allocation scheme are proposed.From theoretical analysis and simulation,the proposed scheme has higher performance than that of existing schemes in terms of throughput and multicast-group-gain under a different number of multicast groups.Moreover,the proposed scheme can achieve close-to-optimal performance.This dissertation focuses on the transmission of the novel multimedia traffic in small cell networks,which work includes mathematical model formulation,optimization problem introduction,theoretical analysis,algorithm design and performance evaluation.This dissertation is an interdiscipline research and we hope the work can stimulate the future research.