Efficient joint call admission control and bandwidth management schemes for QoS provisioning in heterogeneous wireless networks

Includes abstract.Includes bibliographical references (leaves 150-157).Next generation wireless network (NGWN) will be heterogeneous where different radio access technologies (RATs) coexist. This coexistence of different RATs necessitates joint radio resource management (JRRM) for enhanced QoS provisioning and efficient radio resource utilization. Joint call admission control (JCAC) algorithm is one of the joint radio resource management algorithms. The basic functions of a JCAC algorithm are to decide whether or not an incoming call can be accepted into a heterogeneous wireless network, and to determine which of the available RATs is most suitable to admit the incoming call. The objective of a JCAC algorithm is to guarantee the QoS requirements of all accepted calls and at the same time make the best use of the available radio resources. Traditional call admission control algorithms designed for homogeneous wireless networks do not provide a single solution to address the heterogeneous architecture, which characterizes NGWN. Consequently, there is need to develop JCAC algorithms for heterogeneous wireless networks. The thesis proposes three JCAC schemes for improving QoS and radio resource utilization, which are of primary concerns, in heterogeneous wireless networks. The first scheme combines adaptive bandwidth management and joint call admission control. The objectives of the first scheme are to enhance average system utilization, guarantee QoS requirements of all accepted calls, and reduce new call blocking probability and handoff call dropping probability in heterogeneous wireless networks. The scheme consists of three components namely: joint call admission controller, bandwidth reservation unit, and bandwidth adaptation unit. Using Markov decision process, an analytical model is developed to evaluate the performance of the proposed scheme considering three performance metrics, which are new call blocking probability, handoff call dropping probability, and system utilization. Numerical results show that the proposed scheme improves system utilization and reduces both new call blocking probability and handoff call dropping probability. The second proposed JCAC scheme minimizes call blocking probability by determining the optimal call allocation policy among the available RATs. The scheme measures the arrival rates of different classes of calls into the heterogeneous wireless network. Using linear programming technique, the JCAC scheme determines the call allocation policy that minimizes call-blocking probability in the heterogeneous network. Numerical results show that the proposed scheme reduces call-blocking probability in the heterogeneous wireless network

Resource Allocation for Cellular/WLAN Integrated Networks

The next-generation wireless communications have been envisioned to be supported by heterogeneous networks using various wireless access technologies. The popular cellular networks and wireless local area networks (WLANs) present perfectly complementary characteristics in terms of service capacity, mobility support, and quality-of-service (QoS) provisioning. The cellular/WLAN interworking is thus an effective way to promote the evolution of wireless networks. As an essential aspect of the interworking, resource allocation is vital for efficient utilization of the overall resources. Specially, multi-service provisioning can be enhanced with cellular/WLAN interworking by taking advantage of the complementary network strength and an overlay structure. Call assignment/reassignment strategies and admission control policies are effective resource allocation mechanisms for the cellular/WLAN integrated network. Initially, the incoming calls are distributed to the overlay cell or WLAN according to call assignment strategies, which are enhanced with admission control policies in the target network. Further, call reassignment can be enabled to dynamically transfer the traffic load between the overlay cell and WLAN via vertical handoff. By these means, the multi-service traffic load can be properly shared between the interworked systems. In this thesis, we investigate the load sharing problem for this heterogeneous wireless overlay network. Three load sharing schemes with different call assignment/reassignment strategies and admission control policies are proposed and analyzed. Effective analytical models are developed to evaluate the QoS performance and determine the call admission and assignment parameters. First, an admission control scheme with service-differentiated call assignment is studied to gain insights on the effects of load sharing on interworking effectiveness. Then, the admission scheme is extended by using randomized call assignment to enable distributed implementation. Also, we analyze the impact of user mobility and data traffic variability. Further, an enhanced call assignment strategy is developed to exploit the heavy-tailedness of data call size. Last, the study is extended to a multi-service scenario. The overall resource utilization and QoS satisfaction are improved substantially by taking into account the multi-service traffic characteristics, such as the delay-sensitivity of voice traffic, elasticity and heavy-tailedness of data traffic, and rate-adaptiveness of video streaming traffic

JOINT CALL ADMISSION CONTROL FOR MULTI-MODE TERMINALS IN HETEROGENEOUS CELLULAR NETWORKS

The heterogeneous networks are the Next Generation Wireless Networks (NWGN).The presence of heterogeneous networks leads to the necessity of multi-mode terminals i.e. single mode, dual mode, triple mode, quad-mode etc. based on number of RATs in the heterogeneous networks which results in varying mobile capability. The main problem with the heterogeneous networks is the unfairness in allocation of radio resources. In the same heterogeneous network single-mode terminals (Low-capability mobile terminals) experience high blocking probability compared to quad-mode terminals (High-capability mobile terminals) in the same network. To reduce this problem of unfair allocation of radio resources a Terminal Modality Based Joint Call Admission Control (TJCAC) Algorithm has been proposed. In this proposed algorithm the call admission decisions take into account modality (capability) of the mobile terminal, Load on each RAT and Terminal Support Index of each RAT during resource allocation. We have proposed an analytical model to evaluate the performance of the algorithm and show that there is a decrease in the call blocking and dropping probabilities

Service-Oriented Bandwidth Borrowing Scheme for Mobile Multimedia Wireless Networks

Multimedia applications (audio phone, video on demand, video conference, file transfer, etc.) will be integrated into future mobile communication systems. Bandwidth is the most critical resource in mobile multimedia wireless networks. Due to mobile user mobility and limited bandwidth in the mobile wireless communications networks, the quality-of-service (QoS) guarantee becomes very complicated for multimedia applications. Therefore, the available bandwidth of wireless networks should be managed in the most efficient manner. In order to provide mobile hosts (MHs) with highly satisfying degree of QoS in mobile communication systems, new and efficient bandwidth allocation schemes must be developed. In this paper, we propose and evaluate a novel scheme for bandwidth borrowing in mobile multimedia wireless networks. We employ a service-oriented bandwidth borrowing strategy to reduce the overhead of bandwidth reconfiguration and to satisfy QoS requirements of ongoing MHs in cellular systems. Furthermore, we design efficient call admission control algorithms for different multimedia services. The QoS guarantees can be maintained at a comfortable level in cellular systems. Simulation results show that our proposed scheme outperform the previously proposed scheme

Admission Control for Multiuser Communication Systems

During the last few years, broadband wireless communication has experienced very rapid growth in telecommunications industry. Hence, the performance analysis of such systems is one of the most important topics. However, accurate systems’ analysis requires first good modeling of the network traffic. Moreover, broadband wireless communication should achieve certain performance in order to satisfy the customers as well as the operators. Therefore, some call admission control techniques should be integrated with wireless networks in order to deny new users/services if accepting them will lead to degrade the network performance to less than the allowed threshold. This thesis mainly discusses the above two issues which can be summarized as follows. First issue is the traffic modeling of wireless communication. The performance analysis is discussed in terms of the quality of services (QoS) and also the grade of services (GoS). Different scenarios have been studies such as enhancing the GoS of handover users. The second issue is the admission control algorithms. Admission Control is part of radio resource management. The performance of admission control is affected by channel characteristics such as fading and interference. Hence, some wireless channel characteristics are introduced briefly. Seven different channel allocation schemes have been discussed and analyzed. Moreover, different admission control algorithms are analyzed such as power-based and multi-classes fuzzy-logic based. Some simulations analyses are given as well to show the system performance of different algorithms and scenarios.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Efficient resource allocation and call admission control in high capacity wireless networks

Resource Allocation (RA) and Call Admission Control (CAC) in wireless networks are processes that control the allocation of the limited radio resources to mobile stations (MS) in order to maximize the utilization efficiency of radio resources and guarantee the Quality of Service (QoS) requirements of mobile users. In this dissertation, several distributed, adaptive and efficient RA/CAC schemes are proposed and analyzed, in order to improve the system utilization while maintaining the required QoS. Since the most salient feature of the mobile wireless network is that users are moving, a Mobility Based Channel Reservation (MBCR) scheme is proposed which takes the user mobility into consideration. The MBCR scheme is further developed into PMBBR scheme by using the user location information in the reservation making process. Through traffic composition analysis, the commonly used assumption is challenged in this dissertation, and a New Call Bounding (NCB) scheme, which uses the number of channels that are currently occupied by new calls as a decision variable for the CAC, is proposed. This dissertation also investigates the pricing as another dimension for RA/CAC. It is proven that for a given wireless network there exists a new call arrival rate which can maximize the total utility of users, while maintaining the required QoS. Based on this conclusion, an integrated pricing and CAC scheme is proposed to alleviate the system congestion

EVEREST IST - 2002 - 00185 : D23 : final report

Deliverable públic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version

A directionally based bandwidth reservation scheme for call admission control

This paper proposes a new advanced Call Admission Control(CAC) strategy involving for the first time, a bandwidth reservation scheme that is influenced by the direction attribute of a mobile terminal (MT). Aside from the Quality-of-Service (QoS) parameters, the direction attribute plays a key role in efficiently reserving resources for MTs supporting multimedia communications for different QoS classes. The framework for a direction-based CAC system is entirely distributed and may be viewed as a message passing system, where MTs inform their neighbouring base stations (BS) not only of their QoS requirements, but also of their mobility parameters. The base stations then predict future demand and reserve resources accordingly, only admitting those terminals that can be adequately supported. The bandwidth reservation scheme proposed in this paper, integrates the direction attribute into the conventional Guard Channel (GC) scheme. Simulation results prove that this new scheme offers significant improvements in both Call Blocking Probability (CBP) and bandwidth utilization, under a variety of differing traffic conditions