Dynamic call admission control and resource reservation with interference guard margin (IGM) for CDMA systems (original) (raw)
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Interference-based guard margin call admission control for CDMA multimedia wireless systems
ABSTRACT A call admission control (CAC) scheme and a resource reservation estimation (RRE) method suitable for the wideband code division multiple access (W-CDMA) systems are proposed in this work. The proposed CAC scheme gives preferential treatment to high priority calls, such as handoff calls, by pre-reserving a certain amount of channel margin against the interference effect. It is called the interference guard margin (IGM) scheme.
2013
In Code Division Multiple Access (CDMA) mobile cellular network, quality of service (QoS) provisioning of diverse user applications is a great challenge due to scarcity of wireless radio resources and the different QoS requirements demanded by the users. An effective call admission control (CAC) algorithm is needed for optimization of existing resources and better admission control to improve the overall performance of the cellular network system. Realizing that interference is caused by users in own-cell and other-cell which brings about the near-far effect causing some calls to be blocked/dropped, we set a signal-to- interference-noise ratio threshold (SINR) target for calls. For a multi-traffic wireless network, call blocking probability as a QoS metric should be reduced to the barest minimum. In this paper, an intelligent admission control model based on fuzzy logic is proposed to handle the imprecision and uncertainty surrounding the different classes of traffic for both real t...
Capacity Design and Performance of Call Admission Control in Cellular CDMA Systems
IEEE Journal on Selected Areas in Communications, 1997
Since code-division multiple-access (CDMA) capacity is interference limited, call admission control (CAC) must guarantee both a grade of service (GoS), i.e., the blocking rate, and a quality of service (QoS), i.e., the loss probability of communication quality. This paper describes the development of a new capacity design method based on these two concepts. Theoretical expressions for GoS and QoS as functions of traffic intensity and CAC thresholds are first derived from the traffic theory viewpoint, and then a design method using these expressions is presented. At that time, two strategies for CAC are assumed. One is based on the number of users, and the other is based on the interference level. Computer simulation results are presented that strongly support the proposed design method. Furthermore, numerical examples and a performance comparison of the two strategies considering various propagation parameters, nonuniform traffic distributions, and various transmission rates are shown
Mobility Based Call Admission Control for CDMA System Supporting Integrated Voice / Data
International Conference on Computational Intelligence and Multimedia Applications (ICCIMA 2007), 2007
A CAC (Call Admission Control) schemes is effectively regulate the traffic load of a network such that uninterrupted service is provisioned to every admitted user without over penalising the new admission requests. This task can be accomplished by properly managing the available network resource power in an optimum way. In CDMA (Code division multiple access) system, capacity is limited but the total interference power at each base station, which dynamically changes with time. Thus, the total power received from the system is a useful indicator of traffic load. In this work, an algorithm is proposed to accurately estimate the updated received power due to new calls based on the periodical measure of the received power. Using the proposed logic, it is possible to maximize the resource utilization and as well guarantee minimum blocking rates.
Call admission control for reducing dropped calls in CDMA cellular systems
Computer Communications, 2002
Call admission control algorithms that reduce dropped calls in CDMA cellular systems are discussed in this paper. The capacity of a CDMA system is confined by interference of users from both inside and outside of the target cell. Earlier algorithms for call admission control is based on the effective traffic load for the target cell if one call is accepted. These algorithms ignore the interference effect of the to-be-accepted call on the neighboring cells. In our algorithms, the call admission decision is based on the effective traffic loads for both the target cell and the neighboring cells. In addition, to prioritize handoff calls, we also introduce the idea of soft guard channel, which reserves some traffic load exclusively for handoff calls. Stochastic reward net (SRN) models are constructed to compare the performance of the algorithms. The numerical results show that our algorithms can significantly reduce the dropped calls with a price of increasing the blocked calls. To show the potential gain due to our algorithms, we introduce two new metrics: the increased blocking ratio for our algorithms and the increased dropping ratio for the conventional algorithms. From the numerical results, it is shown that our algorithms can reduce the dropped calls significantly while the blocked calls are increased at a relatively small rate under both homogeneous and hot spot traffic loads.
INFOCOM 2000. Nineteenth Annual …, 2000
Call admission control algorithms that reduce dropped calls in CDMA cellular systems are discussed in this paper. The capacity of a CDMA system is confined by interference of users from both inside and outside of the target cell. Earlier algorithms for call admission control is based on the effective traffic load for the target cell if one call is accepted. These algorithms ignore the interference effect of the to-be-accepted call on the neighboring cells. In our algorithms, the call admission decision is based on the effective traffic loads for both the target cell and the neighboring cells. In addition, to prioritize handoff calls, we also introduce the idea of soft guard channel, which reserves some traffic load exclusively for handoff calls. Stochastic reward net (SRN) models are constructed to compare the performance of the algorithms. The numerical results show that our algorithms can significantly reduce the dropped calls with a price of increasing the blocked calls. To show the potential gain due to our algorithms, we introduce two new metrics: the increased blocking ratio for our algorithms and the increased dropping ratio for the conventional algorithms. From the numerical results, it is shown that our algorithms can reduce the dropped calls significantly while the blocked calls are increased at a relatively small rate under both homogeneous and hot spot traffic loads.
A New Call Admission Control Scheme Based on Mobile Position Estimation in DS-CDMA Systems
Call dropping is considered more annoying than call blocking in wireless cellular networks. The cost of the classical method of employing guard channels to decrease the call dropping rate is the increase in call blocking rate. Since subscriber mobility changes in time, the number of handoff attempts in each cell is subject to fluctuations, making static assignments (or periodical update) of a given number of guard channels inefficient. In this paper, we propose an adaptive scheme that employs reservations, instead of static assignments, to adaptively adjust the number of guard channels in each cell according to the current requirements. Thus, unnecessary allocation of guard channels is avoided resulting in a lower cost in terms of call dropping. The reservation requests are made according to the recent mobility pattern of the subscriber. A likelihood value is associated with each reservation request so that fewer channels are reserved by benefiting from the statistical accumulation of the requests. The channels are reserved by considering the interference that would be created once they are in use. The proposed scheme is evaluated against the classical guard channel scheme with a realistic mobility model.
A call admission control scheme for packet data in CDMA cellular communications
IEEE Transactions on Wireless Communications, 2000
In a wireless multimedia code division multiple access (CDMA) system, the resources in terms of transmission rate and power should be efficiently distributed to each user to guarantee its quality-of-service (QoS) requirements. In this paper, a resource allocation algorithm which combines packet scheduling and power assignment is proposed to achieve efficient resource utilization under QoS constraints. The packet scheduling is based on the fair packet loss sharing (FPLS) principle, and the power assignment is determined by the received power limited (RPL) scheme. The basic idea of FPLS is to schedule the transmission of multimedia packets in such a way that all the users have a fair share of packet loss according to their QoS requirements, which maximizes the number of the served users with QoS satisfaction. The RPL scheme minimizes the received power for each packet. Given the propagation path loss, it in turn minimizes the transmitted power as well. The intercell interference from the scheduled packets is also limited in order to increase the system capacity.
I 3 E: A Novel Call Admission Control Scheme for W-CDMA Systems
2006
Abstract Efficient Call Admission Control (CAC) techniques are of paramount importance to achieve a flexible radio resource utilization with W-CDMA systems like UMTS. In order to accept or reject a call, the CAC scheme should be able to estimate if the system can provide a Signal-to-Interference Ratio (SIR) high enough to the new call and to all the others. With symmetric traffic the more critical direction for the system capacity is the uplink and the CAC can consider this direction only.