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Ho, Chi-Jui. "Call admission control in cellular networks." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/15730.
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Dimitriou, Nikos. "Call admission control for multimedia CDMA." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/930/.
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Cheung, Michael. "Call admission control in wireless communications networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/NQ53488.pdf.
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Naghavi, Nika. "Call admission control in wireless mesh networks." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/call-admission-control-in-wireless-mesh-networks(01d122ee-b6fe-4baa-b78c-9f5093136956).html.
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Efficiency in managing scarce wireless resources has been a major design obstacle in wireless mobile networks since its advent. A large body of work has been published on the subject in relation to the first two generation and third generation (3G) of wireless networks. However, these solutions are not readily applicable to the future IP based multi-hop wireless networks. Increased trend in the number of users accessing multimedia rich traffic, and the impacts of mobility management support mechanisms alongside the shared nature of backhaul nodes demand exploration of new avenues of resource management policies. In this thesis a set of schemes are proposed to address the issue of Call Admission Control (CAC) in future multi-hop IP based mobile networks. The first scheme is based on a joint CAC and route assignment design mechanism in Wireless Mesh Networks (WMNs) environment, addressing issues such as pricing policies, wireless resource constraints of the access and backhaul links as well as maximising network provider's revenue. Study's focus is then shifted towards CAC design in Mobility Agent (MA) based Proxy Mobile IPv6 (PMIPv6) networks. A novel class-based CAC mechanism was proposed with the aim of eliminating bottleneck effect at the MAs. To further improve the overall capacity of the network, in conjunction with the proposed CAC mechanism, a modified version of a previously proposed Route Optimisation (RO) scheme is implemented. The performance of the proposed schemes is investigated and analysed through extensive simulations. Comparative studies are then carried out to examine the network provider's total revenue gain in WMNs environment, total blocking probability and per class blocking probability in PMIPv6 networks.
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Hossain, Firoz, and Abu-Shadat-Mohammad Sohab. "Mathematical Modelling of Call Admission Control in WCDMA Network." Thesis, Blekinge Tekniska Högskola, Avdelningen för signalbehandling, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2933.
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WCDMA is an interference limited multiple access technique .It is widely used in the 3rd generation mobile networks like UMTS. When a new call arrives in the system to get admission, it checks whether the call is admitted or not based on some parameters like signal to interference ratio (SIR), transmission power of the Node B and the air interface load .If the call is accepted this will increase some interference to the ongoing calls. This new interference would degrade the ongoing calls and this will also add some extra load which may also lead to the exceeding capacity. So that the system has to decide this admission policy in a systematic way that all the users should maintain their communication with guaranteed quality of service. This decision making algorithm belongs to the radio resource management functionalities of the Radio Network Controller (RNC) in a WCDMA based UMTS network. This thesis paper focuses on the mathematical representation of the call admission control in an interference based environment. There is also a comparative study with different methods.
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De, Alwis Priyan Mihira. "Call admission control and resource utilization in WCDMA networks." Thesis, University of Canterbury. Electrical Engineering, 2005. http://hdl.handle.net/10092/9608.
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Unlike FDMA or TDMA systems, CDMA is interference limited and has a soft capcity that changes depending on the interference felt at the base station at a given time. Admitting a new call and user movement increases the interference level in the system. Therefore a robust Call Admission and Power Control Mechanism is needed. This thesis discusses the main approaches mentioned in the literature on Call Admission Control and Power Control and analyses two modern solutions, namely the QoS aware Power Control and Handoff Prioritization scheme introduced by [T. Rachidi, A. Y. Elbatji, M. Sebbane, and H. Bouzekri 2004] and the Received Power based simulation model discussed in [A. Capone and S. Redana 2001], in greater detail. Then we proceed to recommend improvements that are then tested in a MATLAB simulation environment. The recommended changes improve the overall dropping and handoff loss probabilities. The impact of the NRT overload mechanism discussed in [T. Rachidi, A. Y. Elbatji, M. Sebbane, and H. Bouzekri 2004] is also investigated. The investigations determined the optimum solution achievable with the NRT overload parameter settings.
As the final task, a discrete time dynamic feedback control system that aims to keep the dropping and handoff loss rates for RT services below a target value regardless of the traffic dynamics or the bandwidth requirements is designed. A simple Integral Feedback controller is chosen for this task because a controller that is capable of reducing steady state error is required. The controller is used for the NRT overload mechanism while the NRT error rate is left as best effort. The controller parameters are tuned using simulations and the final result is benchmarked against two algorithms that have fixed NRT overload parameters by simulating in environments under various Poisson call arrival rates and traffic loads. The NRT overload mechanism with our controller performed best by holding the RT error rate at the required target value while producing comparatively lower NRT error rates.
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Foo, Yu Chiann. "Call admission control for high altitude platform station UMTS." Thesis, University of Surrey, 2002. http://epubs.surrey.ac.uk/689/.
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Liu, Hui. "Dynamic call admission control under partial separation in ATM networks." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/8975.
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A dynamic call admission control scheme is proposed for ATM networks to support multiple Quality of Service (QoS) requirements. The scheme is based on the notion of partial separation. It divides the overall traffic flows into classes, within which each traffic source has similar QoS requirements, but may have different traffic characteristics, and the bandwidth of a link is dynamically allocated among the classes. A dynamic bandwidth allocation strategy is introduced. It achieves the goal of bandwidth allocation by optimizing a cost function defined as an estimate of the overall cell loss rate that would be generated by the total offered load. It is dynamic in the sense that the bandwidth allocation is adjusted each time when a connection requires for an acceptance or a leave. While optimizing the overall cell loss rate across classes, cell level constraint is satisfied for each class by deploying the cell loss rate estimate algorithm, proposed by H. Esaki in Connection Admission Control in ATM Networks. A simulation program is developed to validate the accuracy of the algorithm. Extensive numerical and simulation results are presented. Numerical search method is deployed to locate the optimal bandwidth assignment set. Numerical results are presented to evaluate the efficiency and adequacy of the CAC scheme.
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Saintillan, Yves. "Performance evaluation of online call routing and admission control algorithms." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0005/MQ43558.pdf.
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Yang, Xu. "Call admission control in wireless networks using a neuroevolution algorithm." Thesis, Queen Mary, University of London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515513.
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Chevrollier, Nicolas. "Coexistence and call admission control in a heterogeneous wireless environment." Evry, Institut national des télécommunications, 2006. http://www.theses.fr/2006TELE0011.
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In today’s digital world, various types of users, applications and wireless technologies interact to create a complex and heterogeneous environment. In this thesis, we address two issues introduced by the heterogeneity of the digital world. First, we evaluate the interference generated when multiple wireless technologies operate in close proximity. We develop two coexistence mechanisms to mitigate interference in the 2. 4 GHz frequency band: a scheduling scheme for Bluetooth devices known as bluetooth interference aware scheduling and a scheme based on Layer 2 triggered handovers. Second, we investigate how to integrate vertical handovers into call admission control algorithms in order to limit the communication disruption and quality of service discontinuity. We evaluate the impacts of those handovers in terms of packet loss and disruption latency, and develop two call admission control algorithms, namely the probabilistic call admission control and handover-based call admission control algorithms. The former is based on a probabilistic admission decision and the latter includes a bandwidth reservation policy along with preemptive handovers. Both aim at reducing the occurrence of hard handovers in a heterogeneous wireless environmentDans le monde digital qui nous entoure, différents types d'utilisateurs, d'applications et de technologies sans fil interagissent pour créer un environnement complexe et hétérogène. Le travail effectué dans cette thèse traite de problématiques introduites par le caractère hétérogène du monde digital. Le premier sujet d'étude s'attache à évaluer les interférences générées dans le bande de fréquence 2. 4 GHz lorsque plusieurs technologies sans fil opèrent en même temps dans un espace limité. Deux solutions sont proposées pour réduire ou éviter ces interférences. La première est un mécanisme d'ordonnancement des paquets au niveau de la couche MAC Bluetooth. La deuxième utilise des passages inter ou intra technologie déclenchés par des indicateurs de niveau 2. Le deuxième sujet d'étude s'attarde sur la mobilité verticale dans un environnement sans fil hétérogène. Les effets de cette mobilité sont évaluées sur le flux applicatif et la discontinuité de qualité de service que ces passages introduisent est analysée. Par la suite, deux algorithmes de contrôle d'admission qui prennent en compte le caractère néfaste de certains passages entre technologies sont proposés. Flexible et robuste, le premier repose sur une décision probabilistique d'admission dans une cellule WLAN. Le second utilise un système de réservation pondéré de bande passante et des passages préemptifs pour diminuer les nombres de passages de type "hard" et améliorer la qualité de service perçue par les utilisateurs
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Ma, Zhongjing 1975. "Call admission control and routing control in integrated communication networks via dynamic programming." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82615.
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The problems of Connection-oriented Networking Call Admission Control (CAC) and Routing Control (RC) in Integrated Networks are formulated as finite and infinite horizon finite-state Stochastic Dynamic Programs. In particular, Poisson Markovian communication networks are analysed in detail. Because of the complexity of communication networks and of the operation of some kind of communication networks, such as the Internet, by multi-agents, it is effectively impossible to obtain the optimal solutions. Currently it is reasonable to use decentralized aggregation methods to obtain sub-optimal solutions for CAC and RC communication problems. In this thesis, stochastic dynamic programming methods for the optimal control of such network are studied. The notion of a doubly stochastic network, which possesses Markovian aggregated dynamics, is introduced, this is exploited in the hierarchical stochastic control of such hierarchical networks.
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Mansingh, Suhas. "Call admission control for leaky bucket regulated traffic in ATM networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0026/MQ51616.pdf.
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Ramaswamy, Srinivasan. "Dynamic call admission control and quality-of-service regulation in ATM networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq23061.pdf.
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Zhang, Meng. "The impact of mobility on call admission control and scheduling in wireless networks /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20ZHANGM.
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Levine, David A. "Resource allocation, call admission, and media access control protocols for wireless multimedia networks." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/14766.
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Li, Bin. "Bandwidth allocation and call admission control in multi-services mobile wireless cellular networks /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20LI.
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Bates, Stephen. "Traffic characterisation and modelling for call admission control schemes on asynchronous transfer mode networks." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/1373.
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Allocating resources to variable bitrate (VBR) teletraffic sources is not a trivial task because the impact of such sources on a buffered switch is difficult to predict. This problem has repercussions for call admission control (CAC) on asynchronous transfer mode (ATM) networks. In this thesis we report on investigations into the nature of several types of VBR teletraffic. The purpose of these investigations is to identify parameters of the traffic that may assist in the development of CAC algorithms. As such we concentrate on the correlation structure and marginal distribution; the two aspects of a teletraffic source that affect its behaviour through a buffered switch. The investigations into the correlation structure consider whether VBR video is selfsimilar or non-stationary. This question is significant as the exponent of self-similarity has been identified as being useful for characterising VBR teletraffic. Although results are inconclusive with regards to the original question, they do show that self-similar models are best able to capture the video data's behaviour. The investigations into the marginal distributions are in two parts. The first considers applying a structured Markovian model to ATM data and demonstrates how model parameters can be estimated from measurable properties of teletraffic data. This has implications for parametric CAC. The second part considers the use of stable distributions in teletraffic characterisation and modelling. We show that several teletraffic datasets are heavy tailed and then develop a framework for the estimation of stable distribution parameters. We finish by considering the effective bandwidths of stable distributions and models and by considering the effect of stable parameters on model behaviour. This is done in an attempt to develop a CAC algorithm based on the paradigms of self-similarity and stable distributions.
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Ni, Wenlong. "Optimal Call Admission Control Policies in Wireless Cellular Networks Using Semi Markov Decision Proces." University of Toledo / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1227028023.
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Parvez, Asad. "Impact of actual interference on capacity and call admission control in a CDMA network." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4496/.
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An overwhelming number of models in the literature use average inter-cell interference for the calculation of capacity of a Code Division Multiple Access (CDMA) network. The advantage gained in terms of simplicity by using such models comes at the cost of rendering the exact location of a user within a cell irrelevant. We calculate the actual per-user interference and analyze the effect of user-distribution within a cell on the capacity of a CDMA network. We show that even though the capacity obtained using average interference is a good approximation to the capacity calculated using actual interference for a uniform user distribution, the deviation can be tremendously large for non-uniform user distributions. Call admission control (CAC) algorithms are responsible for efficient management of a network's resources while guaranteeing the quality of service and grade of service, i.e., accepting the maximum number of calls without affecting the quality of service of calls already present in the network. We design and implement global and local CAC algorithms, and through simulations compare their network throughput and blocking probabilities for varying mobility scenarios. We show that even though our global CAC is better at resource management, the lack of substantial gain in network throughput and exponential increase in complexity makes our optimized local CAC algorithm a much better choice for a given traffic distribution profile.
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Ni, Wenlong. "Optimal call admission control policies in wireless cellular networks using Semi Markov Decision Process /." Connect to full text in OhioLINK ETD Center, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1227028023.
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Phan, V. V. (Vinh V. ). "Smart packet access and call admission control for efficient resource management in advanced wireless networks." Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514276779.
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Efficient management of rather limited resources, including radio spectrum and mobile-terminal battery power, has been the fundamental design challenge of wireless networks and one of the most widespread research problems over the years. MAC (Medium Access Control) for packet access and CAC (Call Admission Control) for connection-oriented service domains are commonly used as effective tools to manage radio resources, capacity and performance of wireless networks while providing adequate QoS (Quality of Service) to mobile users. Hence, analysis and synthesis of efficient MAC and CAC schemes for advanced wireless networks have significant academic and practical values. This dissertation addresses that topic and presents seven separate contributions of the author: four on adaptive MAC schemes for centralized PRN (Packet Radio Networks), referred to as SPA (Smart Packet Access) and three on CAC schemes for cellular networks, referred to as SCA (Smart Call Admission). These contributions are published in eighteen original papers by the author, which are listed and referred to as Papers I–XVIII in this thesis.
In SPA, the first contribution, reported in Papers II and IV, studies implementation losses of adaptive feedback-control MAC schemes for the uplink of DS-CDMA (Direct-Sequence Code Division Multiple Access) PRN in the presence of various system imperfections. The second contribution, reported in Papers XI, XII, XV and XVI, proposes a bit-rate adaptive MAC scheme for DS-CDMA PRN, referred to as SPR (Smart Packet Rate). The third contribution, reported in Papers III, XIII and XIV, develops two alternative MAC schemes with adaptive packet-length over correlated fading channels in DS-CDMA PRN, referred to as SPL (Smart Packet Length). The fourth contribution, reported in Papers XVII and XVIII, develops alternative adaptive MAC schemes for optimal trade-offs between throughput and energy consumption of TCP (Transmission Control Protocol) applications in advanced cellular networks. These include a so-called SPD (Smart Packet Dispatching) for HSPA (High Speed Packet Access) and, again, SPL for LSPA (Low Speed Packet Access).
Moving on to SCA, the first contribution, reported in Papers V and VII, provides a simple and accurate analytical method for performance evaluation of a class of fixed-assignment CAC schemes with generic guard-channel policy and queuing priority handoffs in cellular networks. The second contribution, reported in Papers VI, IX and X, proposes a simple and effective SCAC (Soft-decision CAC) scheme for CDMA cellular networks. This is evaluated against fixed-assignment and measurement-based CAC schemes with a simple and reliable method provided as a part of the contribution. The third contribution, reported in Papers I and VIII, incorporates alternative QoS differentiation paradigms and resource partitioning into CAC, defines GoS (Grade of Service) for multimedia cellular networks, and provides an in-hand tool for efficient capacity and GoS management.
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Ahmed, Mohamed Hossam. "Capacity enhancement and performance analysis of call admission and load control in wireless communication networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ60948.pdf.
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Keung, Yik. "Dynamic threshold call admission control policy of multi-service wireless cellular networks : a statistical approach /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202004%20KEUNG.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 80-81). Also available in electronic version. Access restricted to campus users.
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Tsai, Ming-Ying, and 蔡明穎. "Call Admission Control in ATM Networks." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/18121525023789473329.
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碩士國立交通大學
電信研究所
83
In this thesis, we mainly investigate the traffic control performed at the call setup phase in an ATM network loaded with heterogeneous sources. And this is what so called "Call Control". Under this topic, it is still divided into two categories:first, based on the numerical comparison results between the allowable number of connections from the exact analysis and that from the effective bandwidth method, here, we propose a new bandwidth allocation method for the call admission control to heterogeneous on-off sources in an infinite-buffer queueing system, which the network system accommodating the delay-tolerable but almost loss-free required sources. In the second part, we propose an optimum quantization scheme for the Markov-modulated sources in a bufferless fluid- flow model of an ATM network. Following the real-time computation algorithm for on-off sources proposed in \cite{duann}, with little modification, we extend the application to a more general source model, Markov-modulated sources. Furthermore, considering the quantization loss that might be caused under the computation algorithm in \cite{duann}, we suggest a policy for the sources to minimize the loss and achieve better utilization of link capacity.
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Shi, YuFei. "ATM traffic generation and Call Admission Control." 1998. http://hdl.handle.net/1993/19409.
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Cheng, Sheng-Wang, and 鄭昇旺. "Call Admission Control for Information Retrieval Service." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/70877032143772809821.
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碩士中華大學
資訊工程學系碩士班
93
The thesis is a research of call admission control (CAC) for information retrieval service. A CAC Model called "Constant Bit Rate and Port Based Bandwidth Reservation" (CBR-PBBR) was proposed in this thesis to guarantee the Quality of Service and try to enhance the performance of transmission. For the data flow to be transmitted on the architecture of Integrated Service or Differentiated Service, if the bandwidth request and the total size of the data flow are known, we can use the CAC Model of CBR-PBBR to transmit it. We hope this CAC model is to be efficient, economic and predictable on QOS. The model of CBR-PBBR will be suitable to the real time and interactive transmission. An example is VoIP. But the flows which with greatly variable request to bandwidth or unable to be restricted the transmission time will not be applicable. These flows need to be transformed into a constant bit rate transmission first if they can be. As for the non-real time or non-interactive Transmission, the model of CBR-PBBR still can be used because of the feature that transmission is easy to be transformed into a fixed size data flow. This is for the guarantee of QOS of SLA (service level agreement) or avoiding the network congestion. According to the discussion and simulation in the thesis, we can find the model of CBR-PBBR has better perfomance than UBR (non-CAC) transmission when the network is congested. In the points of average queue length, average transmission time to every packet and packet drop rate, the model of CBR-PBBR has good simulation result. Keywords : Call Admission Control, Bandwidth Reservation, CBR-PBBR, Quality of Service, Integrated Service, Differentiated Service
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Lo, Yu-Shun, and 羅友舜. "Multicast Congestion Control Strategy based on Call Admission Control." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/50978700387936967876.
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碩士國立中正大學
通訊工程研究所
90
In Multicast Congestion Control research, “drop-to-zero” is a well-known problem. It means a slower receiver slows down faster receiver in the same multicast group. This is because the sender has to adapt its rate or window size to the slowest path, so that a multicast group performance could be dropped. In this paper, we propose that a call admission control (CAC) scheme manage receivers in multicast group to handle “drop-to-zero” problem and improve multicast performance. For this purpose, we integrate multicast congestion control protocol with CAC scheme and utilize the group member’s network information obtained from multicast congestion control protocol to calculate group reward. The basic idea is two-fold. First, the sender can observe the group performance in accordance with calculated group reward. Second, the sender can decide the permission that receiver ask for to join the multicast group in accordance with group reward. We expect to improve group performance and get better group reward and use simulation to analyze CAC scheme of group performance, member counts and group reward. We will show our CAC scheme can effectively drop slower receivers in multicast group and serve the majority of group receivers. The multicast group can build up the group performance and group reward to resolve “drop-to-zero” problem.
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Lu, We-Ran, and 盧尉然. "Call Admission Control Scheme in Wireless Mobile Network." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/fd98ep.
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碩士銘傳大學
資訊傳播工程學系碩士班
92
The purpose of future telecommunications networks is to provide multiple services with together. To support various combined multiple services with quality of service (QoS) requirement in these wireless networks, the call admission control (CAC) plays an important role in resource management. We propose a novel call admission control scheme with buffer to guarantee QoS for both new calls and handoff calls. The queuing model is developed to estimate the threshold, which determines the channels dedicated to the handoff calls. In addition, the proposed scheme adopts the pseudo channel to improve the dropping rate of handoff calls, and employs a new mechanism to partially allocate channels for new calls when the channel occupancy is higher than threshold in order to refine the blocking rate. From the simulation, the proposed scheme significantly improves the dropping rate and the blocking rate in comparison with the existing methods
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Tsai, Chi-lin, and 蔡其琳. "Utility-based Call Admission Control in Cellular Networks." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/97518327320338479568.
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碩士國立臺灣科技大學
電機工程系
102
The demand for cellular mobile services is rapidly growing. When the demand for bandwidth exceeds the supply, congestion will occur so that the QoS of users degrades and the revenue is reduced. Hence, it is important to use the limited bandwidth in the most efficient way. Call Admission Control (CAC) is a strategy to control the number of users into the networks to achieve congestion reduction. Nevertheless, only CAC cannot provide incentives to the users to use the network resources rationally and efficiently. One of the common approaches to deal with the problem is congestion pricing, where the behavior of users are affected by changing the charged price. In this work, we study how to maximize the utility by combining call admission control and congestion price in cellular networks. It is assumed that the utility is a function of the weighted blocking probability, which is a weighted sum of the new call blocking probability and the handoff failure probability. We consider two scenarios: single-cell and multi-cell. In single-cell scenarios, the handoff call arrival rate is assumed to be independent of the new call arrival rate. In multi-cell scenarios, the handoff call arrival rate depends on the new call arrival rate and other system parameters. On the other hand, the handoff call droppings are assumed to be less acceptable than new call blockings. Therefore, some guard channels may be reserved for handoff calls exclusively. We propose a utility-based CAC which adopts a higher congestion price when the channel occupancy exceeds a threshold. We derive the analytical models for the systems considered. An iterative algorithm is developed to find the steady state probability distribution and the performance measures of interest. The performance measures of interest are the new call blocking probability, the handoff failure probability, the give-up probability, the weighted blocking probability, the aggregate utility, and revenue. We study the effect of various system parameters on different performance measures. For comparison, we also present the performance of the traditional schemes with or without congestion price. Last but not least, the computer simulation is used to verify the accuracy of the analytical results.
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Kevin and 劉文周. "A Call Admission Control Design for Transport Network." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/94515929656162805855.
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碩士國立清華大學
工業工程與工程管理學系
88
This thesis proposes a call admission control scheme based on a method of estimating cell loss quality for individual bursty traffic source. The estimate is expressed in terms of virtual cell lose probability for decreasing the influence of the optimization problems of the buffer size. The role of call admission control in high-speed networks is to maintain the network utilization at high level, while ensuring that the quality of service requirement of the individual calls are met. We use the term convolution call admission control to achieve the high level of network utilization by increasing the user connection numbers. Meanwhile we consider the Markov Decision Process﹙MDP﹚for developing the routing table. As we know the MDP will decide the available virtual path route that will maximize the expectation of networks revenue.
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Chen, Yuon-Haan, and 陳詠翰. "Fuzzy Call Admission Control in a CDMA Cellular." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/22631464888768636198.
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碩士國立交通大學
電信工程系
88
Multiuser detection (MUD) is a very popular topic in recent years. Its impressive increase in capacity has caused that more and more latest wireless code division multiple access (CDMA) systems adopt this new technology. A lot of methods to implement the MUD were proposed and most of them tried to upgrade their performances and make them more feasible. The capacity limit, however, still exists due to other cells' multiple access interference (MAI) in a cellular system. As a result, a call admission control (CAC) scheme is required to control the number of voice users when using MUD. In this thesis, we first make a survey of the major types of MUDs and make comparisons among them, such as the important concepts, the performances, and the complexities, etc. Then we propose a fuzzy CAC using uplink MUD of successive interference cancellation (SIC), which has lower complexity and more advantages under the fading channel and imperfect power control. The fuzzy CAC considers both intra-cell and inter-cell MAI and it provides more accurate management of capacity than conventional (SIR-based) CAC in the CDMA cellular system.
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Lai, Chich-Feng, and 賴志峰. "Fuzzy Call Admission Control for CDMA Cellular Systems." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/41798463949346212630.
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碩士國立中央大學
資訊工程研究所
88
Recently, the wireless personal communication system grows very fast and the CDMA has become the key technology for multiple accesses in the third generation wireless communication systems. Unlike conventional FDMA and TDMA systems, the capacity of CDMA is limited by the interference. Moreover, it is difficult to make call admission decisions under the wireless network conditions that are varying with the terrain and location. Therefore, a new call admission control policy is proposed to adapt to the changing network conditions for CDMA networks. Due to the fuzzy logic control has the capability to make decisions under ill-defined network environment, a call admission control policy using fuzzy logic control for CDMA networks is proposed in the thesis. The fuzzy rule set and the membership functions are obtained by using genetic algorithms to achieve the near-optimal solution. Simulation results show that, as the system load increases, the proposed CAC policy still can guarantee the dropping probability of handoff calls not beyond a pre-determined value and thus the quality of communications for handoff calls is offered.
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Duann, Shii-Tyng, and 段喜亭. "A Call Admission Control Scheme for ATM Networks." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/23279709478319432340.
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碩士國立交通大學
電信研究所
81
This thesis proposes a new CAC scheme for ATM networks based on both long-term time averaged and instantaneous cell probabilities for global and individual bursty traffic The long-term time averaged cell loss probability is defined on a logically bufferless fluid flow traffic model. This investigates mainly the relation between bursty layer traffic cell loss probability. The overload period and underload period aggregated traffic are also discussed. Based on the model, relation between the average length of an underload period global cell loss probability is derived. The average length of underload period can also be used as a criterion for admission control because it is equivalent to global cell probability. In addition to long-term time averaged cell probability, we also analyze the instantaneous cell probability, considering the dynamic nature of the traffic, when a network is subject to an admission control. The proposed CAC procedure is divided into two sub-procedures. One called Preliminary CAC (PCAC) procedure designed based on long-term time averaged quality, another Advanced CAC (ACAC) procedure is designed based on quality. An on-line evaluation method is used to implement PCAC procedure, and a table look-up method is used to the ACAC procedure for real-time operation. The operation of proposed CAC scheme requires only two traffic parameters: peak and mean rates. The most important advantage the proposed procedure is that it can be performed in real time.
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Wang, Wei-Tin, and 王偉廷. "IEEE 802.11e Performance Analysis and Call Admission Control." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/65878468373122836062.
Full textAbstract:
碩士國立成功大學
電腦與通信工程研究所
93
We investigate the performance of the emerging IEEE 802.11e standard by introducing a novel analytical model for the enhanced distributed coordination function (EDCF). The EDCF is modeled as a Markov chain which encapsulates AIFS (arbitrary inter-frame spacing), the minimum backoff window size, retry limit, freezing mechanism in backoff, different packet size. Saturation throughputs and saturation delays of different priority classes are derived based on the proposed model. The influences of different parameters like AIFS and packet size on the EDCF service differential schemes are demonstrated analytically. IEEE 802.11e EDCF aims at supporting relative service differentiation in the MAC layer. However, the backoff mechanism may cause huge packet delay and jitter. In order to guarantee quality of service for voice and video flows, we propose an ABR-QoS control scheme integrated with a measurement-based admission control scheme for the IEEE 802.11e enhanced distributed channel access. In the proposed admission control strategy, the access point makes bandwidth reservations according to individual real-time source’s requirement, while the ABR-QoS control mechanism based on a dynamic adjustment of the IEEE 802.11e EDCA parameters. The performances of the proposed scheme are extensively investigated by simulations. Simulation results show that, with the proposed ABR-QoS control and the admission control scheme, real-time multimedia traffic obtains great quality of service while the channel capacity is fully ultilized.
36
Sigwele, Tshiamo, Prashant Pillai, and Yim Fun Hu. "Call admission control in cloud radio access networks." 2014. http://hdl.handle.net/10454/10791.
Full textAbstract:
NoOver the past decade, wireless communications has experienced tremendous growth, and this growth is likely to multiply in the near future. The proliferation of mobile users and an ever increasing demand for multimedia services has resulted in greater capacity requirements. Radio frequency spectrum is scarce and cannot meet this ever increasing demand and the required Quality of Service (QoS) will no longer be achieved if efficient Radio Resource Management (RRM) solutions are not found. Conventional Radio Access Networks (RAN) have standalone Base Stations (BS) with capacity preconfigured for peak loads. These RANs have high call blocking and dropping rates since BSs resources cannot be shared. Cloud based RANs (C-RAN) have been proposed as a cost and energy efficient way of meeting high capacity demand of future wireless access networks by consolidating BSs to the cloud. Instead of relying on rejection of new call requests due to limited BS resources, C-RAN takes benefit of the cloud elasticity, which allows dynamic provisioning of cloud BS resources. This paper presents a novel C-RAN Call Admission Control (C-RAN CAC) to ensure Grade of Service (GoS) by improving blocking probability and improvement of call waiting times. Call blocking probability, call average waiting time and system utilization are used to evaluate the performance of the proposed CAC algorithm.
37
Su-Chih, Kao, and 高蘇志. "Call Admission Control/Congestion Control in WCDMA with Bursty Multimedia Traffic." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/30893653808263610388.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
90
The third generation wireless communication system is expected to provide an efficient method that allows anybody to conduct multimedia communication in any place at any time. Different services usually have different transmission characteristics and quality of service requirements. Therefore, how to design an efficient media access control protocol is an important issue in terms of performance of wireless communication system. We consider wireless communication systems supporting video, voice and data services, where call admission control (CAC) is used to guarantee that existing and new connections can have enough resource to maintain QoS at the connection level; and congestion control is used to guarantee QoS at the packet level. The call admission control adopted in the thesis is a simple threshold scheme, i.e., the number of voice terminals in use can not exceed the threshold. The congestion control used is dynamic reservation assignment, and thus the capacity of real-time traffic and channel utilization can be improved. Via computer simulation, we make use of proper Markovian models for studying the performance measures of video traffic and voice traffic respectively, and studying the data average message delay of data traffic with different data message arrival process, e.g., Poisson message arrival process and self-similar message arrival process. We also study the effects of different system parameter on video packet loss probability, voice packet loss probability, voice call blocking probability, and data average message delay.
38
Chen, Tsung-Chin, and 陳宗群. "A Ratio-Based Call Admission Control for ATM networks." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/18458921551342480773.
Full textAbstract:
碩士國立中山大學
電機工程學系研究所
89
We propose a novel call admission control which makes use of ratio-based traffic measurement to estimate the required bandwidth when a new call is issued. Existing approaches fail to estimate properly the required bandwidth. To alleviate the problem, we calculate the ratio between the measured mean rate and the mean rate declared by UPC parameters. The ratio and the target cell loss rate are used to estimate the required bandwidth to make decision if a new call is accepted or rejected. Because of more accurate estimation of required bandwidth, our method can provide a better control on quality of service.
39
Hung-Erh, Huang, and 黃宏二. "A Study of Wireless Dynamic Call Admission Control Mechanism." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/10933613392825547657.
Full textAbstract:
碩士國防管理學院
國防資訊研究所
91
Abstract In the field of wireless mobile communication, the performance of base stations is crucial to the quality of communication, the quality of service for base stations will be measured by the new calls block rate and hand off calls drop rate. When the integral demand of the base stations is greater than the total channel span, hand off calls and new calls will not be available due to the congestion of base stations. Therefore, the kernel of the question lies in the efficiency of utilizing the precious channel resources. This research has set its goal on raising the frequency in using the channels of base stations through “Call Admission Control” (CAC). From the view point of the distribution of channel resources, we categorize the wireless communication environment into two approaches, namely “Fixed Channel Allocation” and “Dynamic Channel Allocation”. Then we introduce the “Setting In Advance” and “Random Early Detection Mechanism” respectively into these two approaches to simulate the operations of the base stations. From the result of simulation, both the cut off rate of new calls and that of the hand off calls, we can compare these two mechanisms and thus raise the performance of the base stations.
40
Chung, Yu-Fen, and 鍾玉芬. "Call Admission Control with Neural network in ATM networks." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/84887464996173855331.
Full textAbstract:
碩士義守大學
資訊工程學系
89
Asynchronous Transfer Mode (ATM) netowrks is an essential technology for integrating multimedia services in high-speed networks and recommended by International Telecommunications Union (ITU) for broadband integrated services digital networks (B-ISDN). It provides different quality of services (QoS) for different types of traffic sources with widely varying traffic characteristics. In order to guarantee the QoS requirements and to achieve high network utilization, it is necessary to implement a call admission controller. In this thesis, we investigate a CAC algorithm with neural network first. Owing to the self-learning capacity, the neural networks can be trained to fit the uncertainty of the traffic source. However, increasing the inputs result in increasing the complexity of the neural network. We think that different types of inputs can be processed separately, such as network status and traffic characteristics. Therefore, we increase the inputs of neural networks to promote its ability. Secondly, we propose a CAC scheme with two algorithms, named B&WCAC. In many literatures, they always apply only one algorithm to implement CAC. In ATM networks, we think it can adopt more than one algorithm to implement CAC scheme according to different types of traffic sources. We expect that it can be more precise and efficient for CAC by dividing traffic sources and algorithms into two types, black and white.
41
Yeh, Chih-Hsiang. "Call Admission Control for VoIP in IEEE 802.11 WLANs." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-3008200714485700.
Full text
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Yeh, Chih-Hsiang, and 葉志祥. "Call Admission Control for VoIP in IEEE 802.11 WLANs." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/78164127982022930515.
Full textAbstract:
碩士臺灣大學
電機工程學研究所
95
Voice over Internet Protocol (VoIP) is no longer only feasible in wired networks, but also applicable through wireless networks as prevalence of wireless networks grows with the technology maturity and rising demand. While making a VoIP call over WiFi wireless networks is applicable, this is not a service with guaranteed quality. With limited bandwidth, an overloaded AP may cause wireless users to experience delayed packets, high packet loss rate, and even low throughput. IEEE 802.11 wireless Local Area Network (WLAN) was originally designed only for data traffic transmission, and therefore deficiency in real-time traffic transmission, such as VoIP applications, is inevitable. Not being able to timely transmit real-time packets not only fails to meet the demand of users, but also increases unnecessary loading in the wireless network. Industries and academies have made lots of efforts on providing QoS for real-time voice traffic which usually coexists with other classes of traffic. In this thesis, a call admission control mechanism is proposed which not only timely monitors the wireless networks, but also dynamically adjusts the number of admissible clients to wireless networks. New VoIP users not only know the network condition before entering it, but also accurately predict transmission quality through sending probing packets. With the mechanism, existing VoIP users in the wireless networks have their service protected, and potential VoIP users can expect good quality of service once admitted.
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Chien-An, Chen. "Multi-Criteria Call Admission Control in IEEE 802.11 WLAN for Multi-Criteria Call Admission Control in IEEE 802.11 WLAN for Distributed Access Point Selection." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0009-0112200611284515.
Full text
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Chiu, Chin-Lien, and 邱進連. "Joint call admission control/congestion control for wireless integrated voice/data networks." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/53527107919468149937.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
89
The next generation wireless personal communication is expected to provide an efficient method that allows anybody to conduct multimedia communication in any place at any time. Different traffics usually have different transmission characteristics and quality of service requirements. Therefore, how to design an efficient media access control protocol is an important issue in terms of performance of wireless communication system. We consider wireless communication systems supporting both voice and data services, where call admission control (CAC) is used to guarantee that existing and new connections can have enough resource to maintain QoS at the connection level; and congestion control is used to guarantee QoS at the cell level. The call admission control adopted in the thesis is a simple threshold scheme, i.e., the number of voice terminals in use can not exceed the threshold. The congestion control used is D-TDMA/PRPTS, where data request packets can be transmitted in a minislot only if no voice request packets have already started at the same minislot. Therefore, collisions between voice request packets and data request packets can be avoided, the voice packet loss probability is reduced, and thus the capacity of voice terminals and channel utilization can be improved. Furthermore, to avoid excessive delay due to minislot contention, voice request packet is dropped if it can not succeed in the frame at which it originates. We study the effect of voice interarrival time and voice threshold on voice packet loss probability, voice call blocking probability, data packet average delay, and channel utilization. With a Markovian model, the voice packet loss probability, voice blocking probability and channel utilization of voice traffics are derived, and the analytical results are verified with the simulation results. Due to the mathematical complexity, for integrated voice/data scenarios, computer simulation is used to evaluate the effect of proposed CAC and congestion control on the performance measures of both voice and data traffics.
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Ramlakhan, Niven Bhimraj. "Downlink call admission control in mixed service CDMA cellular networks." Thesis, 2007. http://hdl.handle.net/10413/8990.
Full textAbstract:
Since the ascendance of CDMA (Code Division Multiple Access) as the generally accepted
multiple access technology of choice for next generation networks, the rate of development of
the wireless cellular communication industry has been phenomenal. Next generation wireless
cellular networks offer a myriad of voice, video, data and text based information services for the
future multimedia and information society. This mixed service scenario implies that the same
[mite resource i.e. the air interface must be shared amongst different classes of user, each with a
specific quality of service. With multiple services competing for the same resource and with the
inherent soft capacity nature of CDMA, call admission control becomes a formidable task. The
problem is further compounded by the introduction of priorities between classes. Call admission
control is an essential component of these next generation networks and the open nature of the
current standards, such as UMTS (Universal Mobile Telecommunication System) allow for
vendor implementation of different call admission control policies.
The main area of focus in this dissertation is on a proposed downlink, load-based, mixed service
call admission policy. In a CDMA environment with symmetrical service and equal bandwidths
in each direction, the uplink is commonly considered to be the bottleneck. Based on the
asymmetric nature of the expected traffic in next generation networks the downlink is envisaged
as the future bottleneck. Some of the more common choices for downlink call admission control
include number based as well as power based call admission policies. A load-based call
admission policy has been chosen as the maximum load threshold that can be supported varies
with the state of the system and thus effectively models the behaviour of a soft capacity CDMA
network. This dissertation presents a teletraffic performance analysis model of a load-based call
admission control policy for downlink mixed service CDMA cellular networks.
The performance analysis yields customer oriented grade-of-service parameters such as call
blocking probability which is essential for network planning. In our analysis we incorporate a
Birth-Death Markov queuing model. This mathematical model is verified though computer
simulation.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2007.
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Jia-Ci, He, and 何嘉奇. "Call Admission Control with Restriction and Degradation in Wireless Networks." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/37668246141601999930.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
93
It is expected that various kinds of services, e.g., voice, video, multimedia data, etc., will be provided in the next generation of mobile/wireless communication systems. For multimedia traffic to be supported successfully over wireless links, it is necessary to provide quality of service (QoS) guarantees between the end-systems in wireless networks. We propose a call admission control with restriction and degradation (CAC-RD) for wireless networks which uses adaptive bandwidth allocation to provide users multi-level QoS. We derive the associated analytical model and the expressions for new call blocking probability, handoff failure probability, and average bandwidth. Due to mathematical complexity, degradation ratio and upgrade/degrade frequency are found via computer simulation. The simulation program is written in C language not only to verify the accuracy the analytical results but also to understand and control the details of various CAC schemes. It is shown that the analytical results are in reasonable agreement with simulation results, especially when the offered load is light. For comparison purposes, the model for CAC with restriction but no degradation (CAC-R) is also shown. It is shown that, with service degradation (CAC-RD), the new call blocking probability and handoff failure probability are smaller than those without service degradation (CAC-R). The effects of restriction threshold, traffic mix and call holding time on performance measures are also studied. It is concluded that CAC for wireless networks should take into account the offered load, traffic mix, and the call holding time in order to satisfy all required QoS requirements.
47
Liu, Cheng-Tse, and 劉政澤. "Optimization on Call Admission Control in Multiple-Service Wireless Networks." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/ar23a8.
Full textAbstract:
碩士國立交通大學
電信工程系所
92
With the third-generation mobile phone system coming, it provides multiple-service by higher transmission rate. Since wireless resources are limited, how to allocate the bandwidth is interesting. That is, call admission control is considerable. If we want to minimize the system cost, what can we do? In this thesis, we model channels by Markov chains and find the optimal policy based on Markov decision process. In single service network, the Guard Channel policy is the optimal policy. We will modify it for multiple-service networks, then use this policy to do one-step policy improvement. The next policy is near to the optimal policy.
48
Wu, Chen-Feng, and 吳振鋒. "Prediction-Based Call Admission Control Schemes for Wireless Cellular Networks." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/39590136584552354323.
Full textAbstract:
博士大同大學
資訊工程學系(所)
95
Due to the rapid progression for wireless technology, the cellular networks are also evolved from the first generation to the third generation and even beyond the third generation further. The subscriber services are gradually changed from voice to multimedia since higher speed of transmission will be provided by newer cellular technologies. Consequently, the multimedia services are getting to become the major trend in next-generation cellular networks, and the Call admission control (CAC) will play the key role for guaranteeing the quality of service (QoS) in wireless cellular networks, owing to the scarce wireless spectrum. Because the user mobility is so indeterminate, the goal which keeps both call dropping probability (CDP) and call blocking probability (CBP) below a lower level simultaneously is more difficult and seldom literatures were focused on such issue. Thus, the appropriate prediction information will be useful for a CAC scheme to meet QoS issues of both CDP and CBP at the same time. There have been so many studies focusing on the prediction of user mobility, and they are fallen into two considerations: the cell approach consists in recording handoff statistics on each cell each time; the user approach consists in computing a roaming profile for each user and recording each visited cell during a call. The design issues of a CAC should be also considered in different scenarios by the same token. Moreover, it will be an important issue for the operation of cellular networks to integrate CAC scheme with the prediction of user mobility produced according to the demand of real situation. In terms of prediction of user mobility, two CAC schemes that are coupled with different prediction methods are proposed in this dissertation. Upon actually using scenarios that may be geography constraint, possession constraint of individual information, and so on, two prediction methods for user mobility are proposed simultaneously. For user approach, the Hidden Markov Models (HMM) concept which is suitable for solving a dynamic situation is applied to predict user mobility then provides information for the correspondingly proposed CAC scheme, and the time series prediction which can predict most information, such as system utilization and CDP, is combined with the correspondingly proposed CAC scheme for cell approach. The SMPL (SiMulation Programming Language) has been adopted for the simulation to evaluate the performance of the proposed schemes. The simulation results of both user and cell approaches show that the proposed CAC schemes are superior to the traditional guard channel schemes in terms of CDP and CBP, and better utilization can be also achieved by the proposed schemes. Indeed, according to the simulation results, the proposed CAC schemes that are combined with the appropriate prediction method of user mobility can do some contributions on wireless cellular networks.
49
He, Jia-ci, and 何嘉奇. "Call Admission Control with Restriction and Degradation in Wireless Networks." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/31260814022936206084.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
93
It is expected that various kinds of services, e.g., voice, video, multimedia data,etc., will be provided in the next generation of mobile/wireless communication systems. For multimedia traffic to be supported successfully over wireless links, it is necessary to provide quality of service (QoS) guarantees between the end-systems in wireless networks. We propose a call admission control with restriction and degradation (CAC-RD) for wireless networks which uses adaptive bandwidth allocation to provide users multi-level QoS. We derive the associated analytical model and the expressions for new call blocking probability, handoff failure probability, and average bandwidth. Due to mathematical complexity, degradation ratio and upgrade/degrade frequency are found via computer simulation. The simulation program is written in C language not only to verify the accuracy the analytical results but also to understand and control the details of various CAC schemes. It is shown that the analytical results are in reasonable agreement with simulation results, especially when the offered load is light. For comparison purposes, the model for CAC with restriction but no degradation (CAC-R) is also shown. It is shown that, with service degradation (CAC-RD), the new call blocking probability and handoff failure probability are smaller than those without service degradation (CAC-R). The effects of restriction threshold, traffic mix and call holding time on performance measures are also studied. It is concluded that CAC for wireless networks should take into account the offered load, traffic mix, and the call holding time in order to satisfy all required QoS requirements.
50
Hunag, Chin-yin, and 黃金崟. "Analysis of Call Admission Control of Multirate Cognitive Radio Networks." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/98729080305363107687.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
101
In the past few years, the technology of cognitive radios has captured the attention of many researchers in that it promises an effective way of enhancing spectrum usage and solving the problem of heterogeneity of radio devices. We study the multirate cognitive radio networks where the users of each class have a different bandwidth requirement. There are one class of primary users, PU, and two classes of secondary users, SU1, and SU2. We consider two call admission control policies: CAC1 and CAC2, where PU new calls have the preemptive priority over ongoing SU1 and SU2 calls, and some sub-channels are reserved for SU1 against SU2 new calls. Furthermore, under CAC1, SU1 handoff calls can preempt SU2 ongoing calls, whereas under CAC2, SU1 handoff calls cannot preempt SU2 ongoing calls. The system can be modeled as a three-dimensional Markov process. We propose an iterative algorithm to find the steady state probability distribution and compute the performance measures. The performance measures of interest are new call blocking probability, forced termination probability, and throughput. With the same system parameters, first, it is shown that the new call blocking probabilities of PU, SU1, and SU2 calls remain the same no matter CAC1 or CAC2 is enforced. Second, the forced termination probability of SU1 calls is lower than that of SU2 calls under CAC1, except for small PU service rates or large SU2 service rates. The forced termination probability of SU1 calls is higher than that of SU2 calls under CAC2, except for large SU1 service rates or small SU2 service rates. Third, the throughput of SU1 (SU2) calls remains almost the same no matter CAC1 or CAC2 is enforced. The throughput of SU1 calls is higher than that of SU2 calls except for small SU1 arrival rates. Last but not least, we verify the accuracy of the analytical results by the simulation program written by visual C++. In most cases studied, the analytical results are reasonably close to the simulation results.