Non-priority Scheme Research Articles

Handover Analysis in WIMAX using NPS and RCS

WiMAX can provide at home or mobile internet access across whole cities or countries. It provides enhance data rates as compared to digital subscriber line (DSL).It also provide support for mobile wireless access beside support for wireless broadband access (BWA).Due to the high traffic load in the cell problems like blocking, handover failure, forced termination and of not completed call arises. Therefore, two channel allocation scheme Non priority scheme (NPS) and Reserve channel scheme (RCS) has been proposed in Wimax.

Performance Analysis of Adaptive QoS Handoff Mechanism Using Service Degradation and Compensation

User mobility management is one of the important components of mobile multimedia environments. That is, mobile users should obtain network resources after handoff for seamless service supports. So, an adaptive handoff scheme has been proposed to minimize the connection dropping probability for handoff connections. This paper shows the comparative performance analysis for the adaptive QoS handoff mechanism with existing solutions such as non-priority scheme (NPS) and guard-channel scheme (GCS). It has been shown from the performance evaluations that the adaptive QoS mechanism provides lower dropping and blocking probability than existing schemes.

Determination of optimal call admission control policy in wireless networks

This paper investigates the optimal call admission control (CAC) policy for non-priority scheme (NPS) and reserved channel scheme (RCS) in wireless networks, respectively. Both new call and handoff call arrival processes are assumed to be Poisson processes, and the call holding times are exponentially distributed with different rate for new call and handoff calls. Admitting each call would bring a reward to the network provider but holding each call in the system would also incur some expenses (or cost) to the provider. We concentrate on the optimization problems of when to admit or reject a call in order to achieve the maximum total expected discounted reward. By establishing a discounted semi Markov decision process (SMDP) model, we verify that the optimal policies are state-related control limit policies for both NPS and RCS. Our numerical results explained in both tables and diagrams are consistent with our theoretic results.

Adaptive multi-component service model for Wideband Code Division Multiple Access systems

In this paper, we propose and evaluate an adaptive resource allocation scheme for Wideband Code Division Multiple Access multimedia systems. We give a discussion on the inherently multi-component nature of multimedia applications for wireless communication systems, and describe our multi-component model. Subsequently, we introduce our adaptive resource allocation scheme based on the described teleservice model. The multimedia traffic and the adaptive scheme are modelled and analysed next, using queuing theory. The scheme is evaluated and compared against the conventional schemes, namely, the Non-Priority scheme and the Guard Channel scheme, using performance results for blocking and dropping probability. We demonstrate that the proposed scheme is more flexible and efficient in guaranteeing Quality of Service than the conventional schemes.

Link quality-aware call admission strategy for mobile cellular networks with link adaptation

In this paper, the performance of mobile cellular systems with link adaptation (LA) is analytically evaluated. Half- and full-rate vocoders are considered in the analysis. Mathematical expressions for the new call blocking, handoff failure, and forced termination probabilities are obtained. To our knowledge, no similar analysis considering LA exists in the literature. Also, the link quality-aware dual fractional channel reservation (LQA DFCR) scheme is proposed. In LQA DFCR, user differentiation is implemented in terms of link quality. Preference is given to users with good link quality because they require fewer resources than users with bad link quality. Numerical results show that the proposed LQA DFCR scheme effectively increases system capacity: LQA DFCR achieves more than a 11% capacity gain relative to systems with the non priority scheme (NPS) and with LA, and approximately 3% relative to the fair access prioritisation scheme (FAPS) strategy. Numerical results also show that LA yields an approximately 18% capacity increase relative to a cellular system without LA when no admission control is employed (admission control strategies further increase system capacity.) The synergy between LA and admission control strategies yields more than a 31% capacity gain

Performance analysis of dynamic channel assignment algorithms in cellular mobile systems with hand‐off

AbstractIn this paper, the traffic performance of dynamic channel assignment (DCA) in cellular mobile system with hand‐off is investigated. A traffic model for cellular system incorporating hand‐off is established first. Under the framework of the model, a hand‐off priority scheme is developed to reduce the forced termination of calls in progress. This paper analyses and derives the traffic performance bound for DCA strategies with hand‐off by extending the maximum packing (MP) scheme to include the hand‐off procedure. For practical implementation, a distributed DCA algorithm (DDCA) is also proposed. A non‐priority scheme and the proposed priority scheme can be combined with either MP or DDCA. It is shown that the simulation results of DDCA scheme are comparable with the analytical bounds given by MP for both the non‐prioritized case and prioritized case. A reasonable trade‐off between the new call blocking probability and forced termination probability can be achieved by using the proposed prioritized scheme in DCA. Copyright © 2002 John Wiley & Sons, Ltd.

Teletraffic performance evaluation of microcellular personal communication networks (PCN's) with prioritized handoff procedures

Evaluates four handoff priority-oriented channel allocation schemes. These give priority to handoff calls by reserving channels exclusively for handoff calls. The measurement-based handover channel adaptive reassignment scheme (MHAR-A) exclusively uses reserved handover channels for newly originated calls if a certain criterion is satisfied. All four schemes studied differ from the conventional guard channel-based handover priority-oriented channel allocation scheme. To study the schemes, a personal communication network (PCN) based on city street microcells is considered. A teletraffic simulation model accommodating a fast moving vehicle is developed, and the performance parameters are obtained. The performances of all four schemes are compared with the nonpriority scheme and the conventional guard channel-based handover priority-oriented channel allocation scheme. It was found that some of the channel allocation algorithms studied improved the teletraffic capacity over the nonpriority and the conventional guard case. Also, the probability of new call blocking and carried traffic was improved for three of the schemes when compared to the conventional guard scheme. The MHAR-A scheme did not perform up to expectation. Nevertheless, it can be used to finely control the communication service quality equivalent to the control obtained by varying the number of handoff channels in a fraction of one. Increasing the number of reserved handover channels in fraction of one can never be achieved in the conventional guard channel-based handover priority-oriented channel allocation scheme.

Letter to the Editor—Note on a Criterion for Head-of-the-Line Priority Expressway Merging for Buses

Suppose that an expressway on-ramp is two lanes wide up to some point (“merge” point) and then narrows to one lane at the ramp nose. The priority scheme is to give exclusive use of the left lane of the ramp to buses, and to give buses priority right-of-way at the merge point. Assume that buses and cars arrive independently and Poissonwise. Well-known results about priority queues show that this priority scheme is preferable to the standard nonpriority scheme if the ratio of expected ramp delay times for buses and cars is less than the ratio of average “cost” per vehicle per unit delay time.