Optimal call admission and call dropping control in links with variable capacity (original) (raw)
Related papers
Call Admission Control for Next Generation Wireless Networks Using Higher Order Markov Model
Computer and Information Science, 2010
The Next generation wireless networks (NGWN) will be heterogeneous which will have different radio access technologies (RATs) operating together. The Radio Resource Management (RRM) is one of the key challenges in NGWN. The Call admission control (CAC) mechanism is one of the Radio Resource Management technique plays instrumental role in ensuring the desired QoS to the users working on different applications which are having the diversified nature of QoS requirements to be fulfilled by the wireless networks. One of the key challenges to be addressed in this prevailing scenario is the distribution of the available channel capacity amongst the multiple traffic with different bandwidth requirements so as to guarantee the QoS requirements of the traffic .The call blocking probability is one such QoS parameter for the wireless network and for better QoS it is desirable to reduce the call blocking probability. In this customary scenario it is highly advantageous to bring about an analytic Performance model. In this paper we propose a call admission control framework based on higher order Markov chains to effectively handle the call blocking probability in NGWN and to provide optimal QoS for the mobile users. In the proposed algorithm we have considered three classes of traffic having different QoS requirements. The results obtained from the Performance model are encouraging and optimistic and indicates the need of an intelligent decision making system for CAC.
Springer eBooks, 2013
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 twodimensional 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.
Call admission control: solution of a general decision model with state related hand-off rate
2000
This paper studies call admission policies for access control in cellular networks by means of a Markov Decision Process (MDP). This approach allows us to study a wide class of policies, including well known pure stationary as well as randomized policies, in a way that explicitly incorporates the dependency between the hand-off rate and the system state, assuming that the hand-off rate arriving to a cell is proportional to the occupancy level of the adjacent cells. In particular, we propose and analyze a nonpreemptive prioritization scheme, we term the cutoff priority policy. This policy consists of reserving a number of channels for the high priority requests stream. Using our analytical approach, we prove the proposed scheme to be optimal within the analyzed class.
Call admission control in wireless multimedia networks
2003
This paper addresses the call admission control problem for the multimedia services that characterize the third generation of wireless networks. In the proposed model each cell has to serve a variety of classes of requests that differ in their traffic parameters, bandwidth requirements and in the priorities while ensuring proper quality of service levels to all of them. A Semi Markov Process is used to model multi-class multimedia systems with heterogeneous traffic behavior, allowing for call transitions among classes. It is shown that the derived optimal policy establishes state-related threshold values for the admission policy of handoff and new calls in the different classes, while minimizing the blocking probabilities of all the classes and prioritizing the handoff requests. It is proven that in restrictive cases the optimal policy has the shape of a Multi-Threshold Priority policy, while in general situations the optimal policy has a more complex shape.
Optimal and Structured Call Admission Control Policies for Resource-Sharing Systems
IEEE Transactions on Communications, 2000
Many communication and networking systems can be modeled as resource-sharing systems with multiple classes of calls. Call admission control (CAC) is an essential component of such systems. Markov decision process (MDP) tools can be applied to analyze and compute the optimal CAC policy that optimizes certain performance metrics of the system. But for most practical systems, it is prohibitively difficult to compute the optimal CAC policy using any MDP algorithm because of the "curse of dimensionality." We are, therefore, motivated to consider two families of structured CAC policies: reservation and threshold policies. These policies are easy to implement and have good performance in practice. However, since the number of structured policies grows exponentially with the number of call classes and the capacity of the system, finding the optimal structured policy is a complex unsolved problem. In this paper, we develop fast and efficient search algorithms to determine the parameters of the structured policies. We prove the convergence of the algorithms. Through extensive numerical experiments, we show that the search algorithms converge quickly and work for systems with large capacity and many call classes. In addition, the returned structured policies have optimal or near-optimal performance, and outperform those structured policies with parameters chosen based on simple heuristics.
Global Telecommunications Conference, . GLOBECOM . IEEE, 2004
Providing multimedia services with quality of service (QoS) guarantees in next generation wireless cellular networks poses great challenges due to the scarce radio bandwidth. Effective call admission control (CAC) is important for the efficient utilization of the limited bandwidth. In this paper we present an optimal Markov decision-based call admission control (MD-CAC) policy for the multimedia services that characterize the
An adaptive threshold-based call admission strategy for wireless networks
1999
More and more accurate trafic management mechanisms are necessary in wireless networks of the immediate future, when a minimum Quality of Service (QoS) level has to be guaranteed to the mobile users. To this aim, in this paper we propose a call admission mechanism based on the Guard Channel policy and, in order to lower the handover drop probability, we consider this mechanism distributed: the admission threshold of a cell is a function of the number of active users in the adjacent cells. Call admission is based on a MINBLOCK approach, whose target is to minimize the new-call block probability, maintaining the handover drop probability below a given threshold. A Markov-based analytical model is introduced to calculate the parameters of , the Guard Channel mechanism and to compare the pelformance of the proposed mechanism with that of a pure Guard Channel one, which uses local information only.
Optimal call admission control and bandwidth adaptation in multimedia cellular mobile networks
Proc. ASMTA
Third and future generations of cellular mobile networks are designed to provide adaptive multimedia services with QoS guarantees. In this scenario call admission control and bandwidth adaptation work together in order to improve the system's performance by reducing blocking probability of multimedia calls. However, this improvement is done at cost of the QoS degradation of ongoing multimedia calls, which may be unacceptable to the users of real time services as videoconference, videophone, so on. Another problem concerns with the bandwidth adaptation is that it may consume a lot of wireless and wireline resources due to extra signalling overhead as well as battery power in the mobile station. In addition, frequent bandwidth switching among different bandwidth levels may be worse than a large degradation ratio. Thus, an important aspect to be considered in the design of Radio Resource Management is how to optimize the system's performance by minimizing blocking probability, controlling bandwidth adaptation, and maximizing user's satisfaction. In this paper we address this subject by proposing a Semi-Markov Decision Model that seeks an optimal stationary policy that match this goal. Results show that the optimal policy outperforms the performance of a non-optimal adaptive resource allocation scheme that seeks only to improve blocking probability.