It has long been recognized that in multi-cell WCDMA networks the admission of a new session into the system can have undesirable impact on the neighboring cells. Although admission control algorithms that take into account such multi-cell impact have been studied in the past, little attention has been paid to multi-cell admission and rate control algorithms when traffic is elastic. In this thesis, we propose a model for multi-cell multi-service WCDMA networks to study the impact of multi-cell admission and rate control algorithms on key performance measures such as the class-wise blocking and outage probabilities, block error rates, and the noise rise violation probabilities. By means of simulation we compare the performance of load based multi-cell algorithms with that of a single cell algorithm. We find that with multi-cell based algorithms the system capacity and performance (in terms of the above mentioned measures) are (in some cases significantly) better in homogeneous load scenarios as well as in the heterogeneous ’hotspot’ and ’hotaround’ scenarios. / Det har länge varit känt att i multi-cellulära WCDMA nät så kan insläppandet av en ny användarei systemet ha en icke önskvärd effekt på intilliggande celler. Fastän insläppskontrollalgoritmer (AC)som tar hänsyn till sådana multi-cellulära effekter har studerats tidigare, så har endast begränsaduppmärksamhet ägnatsåt multi-cellulär insläpps- och bittaktskontrollalgoritmer när trafiken är elastisk.I detta arbete föreslår vi en modell för WCDMA-nät med multipla celler och multipla tjänster ochsom är applicerbar för studier av av hur multi-cellulär insläpps- och bittaktskontroll inverkar påviktiga prestandamått som klassvisa spärr- och utslagningssannolikheter, blockfelssannolikheter, ochsannolikheten för överträdande av tillåten interferensnivå. Med simuleringar jämför vi prestanda förlastbaserade multi-cellalgoritmer med prestanda för singel-cellalgoritmer. Vi har funnit att med multicellalgoritmerså är systemskapacitetet och prestanda (i termer av tidigare nämnda mått) i några fallbetydligt bättre i homogena lastscenarier, samt i heterogena lastscenarier av typerna ’hotspot’ och’hotround’.

no / This paper is focused on the design of an adaptive Connection Admission Control (CAC) algorithm for a Universal Mobile Telecommunication System (UMTS) based satellite system with variable link capacity. The main feature of the proposed algorithm is to maximize the resource utilization by adapting to the link conditions and the antenna gain of the users. The link quality of the user may vary depending on the weather condition, user mobility and any other propagation factors. The algorithm is compared against a non-adaptive admission control algorithm under different test cases. The proposed CAC algorithm is simulated using MATLAB and the performance results are obtained for a mix of multimedia traffic classes such as video streaming, web browsing, netted voice and email. The simulation results indicate a higher system performance in terms of the blocking ratio and the number of admitted connections.

This paper presents a Call Admission Control (CAC) algorithm based fuzzy logic to maintain the quality of service using cell breathing concept. When a new call is accepted by a cell, its current user is generally affected due to cell breathing. The proposed CAC algorithm accepts a new call only if the current users in the cell are not jeopardized. Performance evaluation is done for single-cell and multicell scenarios. In multicell scenario dynamic assignment of users to the neighboring cell, so called handoff, has been considered to achieve a lower blocking probability. Handoff and new call requests are assumed with handoff being given preference using a reserved channel scheme. CAC for different types of services are shown which depend upon the bandwidth requirement for voice, data and video. Distance, arrival rate, bandwidth and nonorthogonality factor of the signal are considered for making the call acceptance decision. The paper demonstrates that fuzzy logic with the cell breathing concept can be used to develop a CAC algorithm to achieve a better performance evaluation.

In recent years, there has been an exponential growth in the use of multimedia applications. A satellite system offers great potential for multimedia applications with its ability to broadcast and multicast a large amount of data over a very large area as compared to a terrestrial system. However, the limited transmission capacity along with the dynamically varying channel conditions impedes the delivery of good quality multimedia service in a satellite system which has resulted in research efforts for deriving efficient radio resource management techniques. This issue is addressed in this thesis, where the main emphasis is to design a CAC framework which maximizes the utilization of the scarce radio resources available in the satellite and at the same time increases the performance of the system for a UMTS based satellite system supporting unicast and multicast traffic. The design of the system architecture for a UMTS based satellite system is presented. Based on this architecture, a CAC framework is designed consisting of three different functionalities: the admission control procedure, the retune procedure and the pre-emption procedure. The joint use of these functionalities is proposed to allow the performance of the system to be maintained under congestion. Different algorithms are proposed for different functionalities; an adaptive admission control algorithm, a greedy retune algorithm and three pre-emption algorithms (Greedy, SubSetSum, and Fuzzy). A MATLAB simulation model is developed to study the performance of the proposed CAC framework. A GUI is created to provide the user with the flexibility to configure the system settings before starting a simulation. The configuration settings allow the system to be analysed under different conditions. The performance of the system is measured under different simulation settings such as enabling and disabling of the two functionalities of the CAC framework; retune procedure and the pre-emption procedure. The simulation results indicate the CAC framework as a whole with all the functionalities performs better than the other simulation settings.

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<p>In this thesis we study radio resource management (RRM) in two types of CDMA-based wireless networks, cognitive radio networks (CRNs) and cooperative communication networks. In the networks, all simultaneous transmissions share the same spectrum and interfere with one another. Therefore, managing the transmission power is very important as it determines other aspects of the network resource allocations, such as transmission time and rate allocations. The main objective of the RRM is to efficiently utilize the available network resources for providing the mobile users with satisfactory quality of service (QoS).</p> / Doctor of Philosophy (PhD)

No / In this paper, the requirements for personal environments mobility are addressed from terminal and network perspectives. Practical mobility and Quality of Service (QoS) aware solutions are proposed for a heterogeneous network, comprising of satellite and terrestrial access networks connected to an IP core network. The aim, in adopting a heterogeneous environment, is to provide global, seamless service coverage to a specific area, allowing access to services independently of location. An important assumption is that nomadic user terminals attached to a particular segment should be able to exchange information with any other terminal connected to the network. This is to ensure transparency of device technology. Different communication scenarios are investigated in support of IPv4 and IPv6 operating on user platforms and over access segments. The heterogeneous network necessitates the need to perform handover between access segments to enable coverage extension and seamless connectivity. Handover procedures are analyzed, and an approach is presented that enables various operation and segment specific parameters to be taken into account when deciding upon the need to perform handover and in selecting the optimum access segment. In order to ensure transparency of network technology, the need for end-to-end QoS support is discussed, bearing in mind the deployment of both IntServ and DiffServ enabled routers in the core network. Following this, a new admission control scheme, named Gauge&Gate Reservation with Independent Probing (GRIP), is proposed. The paper concludes with a description of a laboratory testbed, which has been developed in order to verify the presented procedures, together with performance measurements of the handover and the GRIP algorithms.

No / This paper proposes a novel call admission control (CAC) algorithm and develops a two-dimensional markov chain processes (MCP) analytical model to evaluate its performance for heterogeneous wireless network. Within the context of this paper, a hybrid UMTS-WLAN network is investigated. The designed threshold-based CAC algorithm is launched basing on the user’s classification and channel allocation policy. In this approach, channels are assigned dynamically in accordance with user class differentiation. The two-dimensional MCP mathematical analytic method reflects the system performance by appraising the dropping likelihood of handover traffics. The results show that the new CAC algorithm increases the admission probability of handover traffics, while guarantees the system quality of service (QoS) requirement.

We develop and analyze a class of CAC algorithms for resource management in wireless networks with the goal not only to satisfy QoS constraints, but also to maximize a value or reward objective function specified by the system. We demonstrate through analytical modeling and simulation validation that the CAC algorithms developed in this research for resource management can greatly improve the system reward obtainable with QoS guarantees, when compared with existing CAC algorithms designed for QoS satisfaction only. We design hybrid partitioning-threshold, spillover and elastic CAC algorithms based on the design techniques of partitioning, setting thresholds and probabilistic call acceptance to use channel resources for servicing distinct QoS classes. For each CAC algorithm developed, we identify optimal resource management policies in terms of partitioning or threshold settings to use channel resources. By comparing these CAC algorithms head-to-head under identical conditions, we determine the best algorithm to be used at runtime to maximize system reward with QoS guarantees for servicing multiple service classes in wireless networks. We study solution correctness, solution optimality and solution efficiency of the class of CAC algorithms developed. We ensure solution optimality by comparing optimal solutions achieved with those obtained by ideal CAC algorithms via exhaustive search. We study solution efficiency properties by performing complexity analyses and ensure solution correctness by simulation validation based on real human mobility data. Further, we analyze the tradeoff between solution optimality vs. solution efficiency and suggest the best CAC algorithm used to best tradeoff solution optimality for solution efficiency, or vice versa, to satisfy the system's solution requirements. Moreover, we develop design principles that remain applicable despite rapidly evolving wireless network technologies since they can be generalized to deal with management of 'resources' (e.g., wireless channel bandwidth), 'cells' (e.g., cellular networks), "connections" (e.g., service calls with QoS constraints), and "reward optimization" (e.g., revenue optimization in optimal pricing determination) for future wireless service networks. To apply the CAC algorithms developed, we propose an application framework consisting of three stages: workload characterization, call admission control, and application deployment. We demonstrate the applicability with the optimal pricing determination application and the intelligent switch routing application. / Ph. D.