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Call Admission Control

About: Call Admission Control is a research topic. Over the lifetime, 3010 publications have been published within this topic receiving 35965 citations.


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Journal ArticleDOI
TL;DR: This work proposes a bandwidth routing protocol for quality-of-service (QoS) support in a multihop mobile network and examines the system performance in various QoS traffic flows and mobility environments via simulation.
Abstract: The emergence of nomadic applications have generated much interest in wireless network infrastructures that support real-time communications. We propose a bandwidth routing protocol for quality-of-service (QoS) support in a multihop mobile network. The QoS routing feature is important for a mobile network to interconnect wired networks with QoS support (e.g., ATM, Internet, etc.). The QoS routing protocol can also work in a stand-alone multihop mobile network for real-time applications. This QoS routing protocol contains end-to-end bandwidth calculation and bandwidth allocation. Under such a routing protocol, the source (or the ATM gateway) is informed of the bandwidth and QoS available to any destination in the mobile network. This knowledge enables the establishment of QoS connections within the mobile network and the efficient support of real-time applications. In addition, it enables more efficient call admission control. In the case of ATM interconnection, the bandwidth information can be used to carry out intelligent handoff between ATM gateways and/or to extend the ATM virtual circuit (VC) service to the mobile network with possible renegotiation of QoS parameters at the gateway. We examine the system performance in various QoS traffic flows and mobility environments via simulation. Simulation results suggest distinct performance advantages of our protocol that calculates the bandwidth information. It is particularly useful in call admission control. Furthermore, "standby" routing enhances the performance in the mobile environment. Simulation experiments show this improvement.

552 citations

Journal ArticleDOI
TL;DR: It is shown that the distributed call admission control scheme limits the handoff dropping or the cell overload probability to a predefined level almost independent of load conditions, an important requirement of future wireless/mobile networks with quality-of-service (QoS) provisioning.
Abstract: The major focus of this paper is distributed call admission control in mobile/wireless networks, the purpose of which is to limit the call handoff dropping probability in loss systems or the cell overload probability in lossless systems. Handoff dropping or cell overload are consequences of congestion in wireless networks. Our call admission control algorithm takes into consideration the number of calls in adjacent cells, in addition to the number of calls in the cell where a new call request is made, in order to make a call admission decision. This is done by every base station in a distributed manner without the involvement of the network call processor. The admission condition is simple enough that the admission decision can be made in real time. Furthermore, we show that our distributed call admission control scheme limits the handoff dropping or the cell overload probability to a predefined level almost independent of load conditions. This is an important requirement of future wireless/mobile networks with quality-of-service (QoS) provisioning.

488 citations

Journal ArticleDOI
TL;DR: It is shown that the well-known Guard Channel policy is optimal for the MINOBJ problem, while a new Fractional Guard Channelpolicy is optimalFor the MINBLOCK and MINC problems.
Abstract: Two important Quality-of-Service (QoS) measures for current cellular networks are the fractions of new and handoff “calls” that are blocked due to unavailability of “channels” (radio and/or computing resources). Based on these QoS measures, we derive optimal admission control policies for three problems: minimizing a linear objective function of the new and handoff call blocking probabilities (MINOBJ), minimizing the new call blocking probability with a hard constraint on the handoff call blocking probability (MINBLOCK) and minimizing the number of channels with hard constraints on both of the blocking probabilities (MINC). We show that the well-known Guard Channel policy is optimal for the MINOBJ problem, while a new Fractional Guard Channel policy is optimal for the MINBLOCK and MINC problems. The Guard Channel policy reserves a set of channels for handoff calls while the Fractional Guard Channel policy effectively reserves a non-integral number of guard channels for handoff calls by rejecting new calls with some probability that depends on the current channel occupancy. It is also shown that the Fractional policy results in significant savings (20-50\%) in the new call blocking probability for the MINBLOCK problem and provides some, though small, gains over the Guard Channel policy for the MINC problem. Further, we also develop computationally inexpensive algorithms for the determination of the parameters for the optimal policies.

427 citations

Journal ArticleDOI
TL;DR: It is observed that due to the mobility, some assumptions may not be valid, which is the case when the average values of channel holding times for new calls and handoff calls are not equal.
Abstract: Call admission control (CAC) plays a significant role in providing the desired quality of service in wireless networks. Many CAC schemes have been proposed. Analytical results for some performance metrics such as call blocking probabilities are obtained under some specific assumptions. It is observed, however, that due to the mobility, some assumptions may not be valid, which is the case when the average values of channel holding times for new calls and handoff calls are not equal. We reexamine some of the analytical results for call blocking probabilities for some call admission control schemes under more general assumptions and provide some easier-to-compute approximate formulas.

408 citations

Proceedings ArticleDOI
24 Mar 1996
TL;DR: It is shown that the well-known guard channel policy is optimal for the MLNOBJ problem, while a new fractional guard channels policy is ideal for the MINBLOCK and MINC problems.
Abstract: Two important quality-of-service (QoS) measures for current cellular networks are the fractions of new and handoff "calls" that are blocked due to unavailability of "channels" (radio and/or computing resources). Based on these QoS measures, we derive optimal admission control policies for three problems: minimizing a linear objective function of the new and handoff call blocking probabilities (MINOBJ), minimizing the new call blocking probability with a hard constraint on the handoff call blocking probability (MINBLOCK) and minimizing the number of channels with hard constraints on both of the blocking probabilities (MINC). We show that the well-known guard channel policy is optimal for the MLNOBJ problem, while a new fractional guard channel policy is optimal for the MINBLOCK and MINC problems. The guard channel policy reserves a set of channels for handoff calls while the fractional guard channel policy effectively reserves a non-integral number of guard channels for handoff calls by rejecting new calls with a probability that depends on the current channel occupancy. It is also shown that the fractional policy results in significant savings (20-50%) in the new call blocking probability for the MINBLOCK problem and provides some, though small, gains over the integral guard channel policy for the MINC problem. Further, we also develop computationally inexpensive algorithms for the determination of the parameters for the optimal policies.

388 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20233
20226
202112
202016
201918
201822