Efficient Power Allocation in E-MBMS Enabled 4G Networks

The plethora of mobile multimedia services that are expected to face high penetration, poses the need for the deployment of a resource economic scheme in Long Term Evolution (LTE) networks. To this direction, the Evolved - Multimedia Broadcast / Multicast Service (E-MBMS) is envisaged to play an instrumental role for LTE proliferation and set the basis for a successful 4th Generation (4G) standardization process. One of the most critical aspects of E-MBMS performance is the selection of the most efficient radio bearer, in terms of power consumption. This chapter presents the prevailing radio bearer selection mechanisms and examines their performance in terms of power consumption. Furthermore, it discusses problems regarding the high power requirements for the realization of E-MBMS and evaluates the proposed techniques/solutions. Finally, this chapter presents a novel mechanism for efficient power control during E-MBMS transmissions that conforms to LTE requirements for simultaneous provision of multiple multimedia sessions.

Admission Control for QoS Provision in Mobile Wireless Networks

Admission control is one of the key elements for ensuring the quality of service (QoS) in modern mobile wireless networks. Since such networks are resource constrained, supporting multimedia traffic guaranteeing its QoS levels is excessively challenging for call admission control (CAC) design. CAC is the most important radio resource management (RRM) function in wireless networks as its efficiency has a direct impact on network performance and QoS provision to end users. The goal of this chapter is to provide a thorough study of the basic concepts considering CAC design and a comprehensive analysis of the fundamental CAC schemes employed in wireless networks. The basic performance criterion considering CAC schemes is the probability of denying the access to the network for an arriving call, which is extensively studied in this chapter. Moreover, additional performance criteria are presented and discussed, which may help to provide an overall efficiency estimation of the available CAC schemes.

QoS Support Mechanisms in WiMAX

Quality of service (QoS) provisioning is an important issue in the deployment of broadband wireless access networks e.g. WiMAX (IEEE Std 802.16-2004, 2004) networks with real-time and non-real-time traffic integrated. To design a QoS support framework tailored for WiMAX networks is more challenge as wireless channel has unique characteristics such as time-varying channel and limited channel capacity. This chapter presents various QoS support mechanisms in WiMAX networks. Existing proposals with the state-of-the-art technology have been classified into three main categories: QoS support architecture, bandwidth management mechanism, and packet scheduling schemes. Representative schemes from each of the categories have been evaluated with respect to major distinguishing characteristics of the WiMAX MAC layer and PHY layer as specified in the IEEE 802.16d standard. Suggestions and research trends on QoS support in WiMAX networks are highlighted.

Mobility Management and QoS Support in Wireless Environments

Researchers are trying to find viable means to support the quality of services for fixed IP users for quite some time. This is a difficult task and even up until today there is no universally accepted mechanism to assure the quality of an operational service from the one end to the other. As years were passing, the need of IP users to keep their network connectivity while on the move, introduced a family of mobility management protocols. However, it was soon noted that these mobility management protocols were inter-working rather inefficiently with the protocols for the quality of services’ support. Thus, new protocols are under design to tackle this issue. However, even with these new protocols there are important issues left unchallenged. This chapter provides all the necessary information for this research area and its current status.

Cross-Layer Optimization for Energy-efficient QoS Support of Multimedia Streams

A major limitation for wireless video communication on portable devices is the limited energy budget. For this reason, efficient usage of the scarce energy becomes a critical design constraint, in addition to meeting the Quality of Service constraints related to the video quality. In this chapter the authors focus on minimizing the energy cost of the two main energy consumers in the handheld wireless video device: the video encoding and wireless communication tasks. For this purpose, they present a cross-layer approach that explores the tradeoff between coding and communication energies. They then exploit the Rate-Distortion-Complexity tradeoffs and flexibility of the Scalable Video Codec. The results show that by adapting the codec configuration at runtime to the specific scenarios up to 50% of the total energy can be saved with marginal video quality loss. Moreover, the approach presented is of low complexity and easily deployable in practical systems.

Hybrid Approach to Integrated QoS Capable Protocols for Wireless LANs

The recent evolution of wireless networking has led the market to increased service demands. Thus, the emerged necessity is to develop specialized mechanisms that provide efficient QoS (Quality of Service) for both traditional and modern network applications in the challenging wireless environment. The respective IEEE proposal comes from the 802.11e workgroup which has developed the Hybrid Coordination Function (HCF). HCF is definitely capable of providing QoS, however, it exhibits significant limitations. This work presents an alternative protocol with improved behavior and performance. The Priority Oriented Hybrid Access (POHA) is a complete channel access mechanism able to provide integrated QoS for all types of traffic and network applications. POHA combines a polling based and a TDMA access scheme, adapts to the dynamic conditions of modern WLANs, improves channel utilization and station feedback, provides medium contention fairness, eliminates collisions, differentiates traffic based on priorities, supports dynamic resource assignment, and instantly negotiates the quality levels of the offered traffic streams trying to support multiple streams with best possible quality. POHA, compared with HCF, exhibits generally superior performance.

Enhanced QoS through Cooperating Schemes in Next Generation Wireless Networks

This chapter addresses the critical issue of Quality of Service (QoS) provisioning in next generation wireless networks. While the QoS offered to users may be enhanced through innovative protocols and new technologies, future trends should take into account the efficiency of the resource allocation strategies and the network/terminal cooperation as well. 4G networks will be characterized by an heterogeneous environment where several access networks will be available. The purpose of this chapter is to summarize techniques that enable efficient distribution of resources exploiting the existing infrastructure. Such techniques may involve either smart selection mechanisms or cooperating schemes among network entities. Since decision-making processes are examined, the use of game theory is considered as a valuable asset in the authors’ work. To this end, the chapter also collects applications of both non-cooperative and cooperative game theory applications in wireless networks. The main aspects of both game types are presented and several games are modeled.

QoS-Predictions Service

The success of emerging mobile services depends on the serviceability of the underlying wireless networks, expressed in terms of Quality of Service (QoS) provided by a network available to service user at a given geographical location and time. In general, this serviceability is a priori unknown. As a solution the authors propose a QoS-predictions service, providing predictions of QoS of networks available at a given user’s geographical location and time. In a case study they prove the feasibility of deriving predictions from historical data collected by a mobile service user. They have chosen this mobile user to be a patient, who uses a personalized health telemonitoring service in his daily environments for a period of one month. They consider the QoS-predictions service as a novel support for mobile services operational in 4G heterogeneous network environments.

4G Wireless Networks

Fourth generation (4G) wireless networks aim at supporting various multiservice applications over IP architectures which satisfy enhanced users demands through innovative services of increased Quality of Service (QoS). QoS can be assured through independent optimal design of network components or by optimizing interoperability. The supported services impose also their classification into IP network service models and their specifications description. The integration of different wireless access technologies into the 4G network architecture leads to a heterogeneous network environment that raises several issues. An overview of various approaches employed to provide QoS in 4G networks concerning their architectures, different access technologies interoperability and resource management techniques are investigated in this chapter. Dynamic resource allocation, admission control, QoS provision using mobile management and pricing policies are presented. Concluding, in the demanding 4G environment under variable network conditions, appropriate schemes and architectures may provide a robust network management tool for QoS provision and efficient resource utilization.

TPC and Non-TPC Based Topology Control Approaches for QoS Improvement in MR-WMN

A grand challenge in Multi-Radio Wireless Mesh Networks (MR-WMN) is to limit the interference such that its net capacity increases without compromising scalability and stability. In this chapter, the authors first provide an insight into the implications of transmit power control (TPC) on the MR-WMN topology and QoS. In this regard, a review of some of the key work is carried out they then explore the approach of non-TPC based topology control schemes for limiting the interference in a static nodes based MR-WMN system that uses a distributed, light-weight, cooperative multiagents. A path reduction (PR) algorithm is the principle behind our topology control scheme and its viability is explained through NetLogo tool based simulation results. The effectiveness of the PR algorithm is shown in terms of improved interference cost reduction and decrease in path length. The focus of this chapter is mainly on non-TPC approach rather than the TPC approach.