Performance Comparison of Dynamic Guard Channel Assignment with Buffered Prioritized Scheme for Mobile WiMAX Network

Abstract—Priority is usually given to handover traffic in mobile communication but doing so has the tendency of increasing call blocking probability. It was said previously that non-prioritized call traffic channel assignment scheme reduces call blocking probability more than other basic channel assignment schemes at high handover traffic intensities. A comparison of channel assignment schemes by analysis and MATLAB simulation in this research has shown that dynamic guard channel assignment scheme based on channel utilization minimizes call blocking probability better than non-prioritized, prioritized guard channel and prioritized guard channel with queue/buffer. The wireless technology used was Mobile WiMAX with mobile assisted handover (MAHO) and the queueing policy employed was M/M/C/Q with FCFS service discipline

Adaptive Predictive Handoff Scheme with Channel Borrowing in Cellular Network

Previously, we presented an extension of predictive channel reservation (PCR) scheme, called HPCR_CB, for handoff motivated by the rapid evolving technology of mobile positioning. In this thesis, the author proposes a new scheme, called adaptive PCR_CB (APCR_CB), which is an extension of HPCR_CB by incorporating the concept of adaptive guard channels. In APCR_CB, the number of guard channel(s) is adjusted automatically based on the average handoff blocking rate measured in the past certain time period. The handoff blocking rate is controlled under the designated threshold and the new call blocking rate is minimized. The performance evaluation of the APCR_CB scheme is done by simulation. The result shows the APCR_CB scheme outperforms the original PCR, GC, and HPCR_CB schemes by controlling a hard constraint on the handoff blocking probability. It is able to achieve the optimal performance by maximizing the resource utilization and by adapting to changing traffic conditions automatically

Adaptive Predictive Handoff Scheme with Channel Borrowing in Cellular Network

Previously, we presented an extension of predictive channel reservation (PCR) scheme, called HPCR_CB, for handoff motivated by the rapid evolving technology of mobile positioning. In this thesis, the author proposes a new scheme, called adaptive PCR_CB (APCR_CB), which is an extension of HPCR_CB by incorporating the concept of adaptive guard channels. In APCR_CB, the number of guard channel(s) is adjusted automatically based on the average handoff blocking rate measured in the past certain time period. The handoff blocking rate is controlled under the designated threshold and the new call blocking rate is minimized. The performance evaluation of the APCR_CB scheme is done by simulation. The result shows the APCR_CB scheme outperforms the original PCR, GC, and HPCR_CB schemes by controlling a hard constraint on the handoff blocking probability. It is able to achieve the optimal performance by maximizing the resource utilization and by adapting to changing traffic conditions automatically

A Comparative Study of Prioritized Handoff Schemes with Guard Channels in Wireless Cellular Networks

Mobility management has always been the main challenge in most mobile systems. It involves the management of network radio channel resource capacity for the purpose of achieving optimum quality of service (QoS) standard. In this era of wireless Personal Communication Networks such as Global System for Mobile Communication (GSM), Wireless Asynchronous Transfer Mode (WATM), Universal Mobile Telecommunication System (UMTS), there is a continuous increase in demand for network capacity. In order to accommodate the increased demand for network capacity (radio resource) over the wireless medium, cell sizes are reduced. As a result of such reduction in cell sizes, handoffs occur more frequently, and thereby result in increased volume of handoff related signaling. Therefore, a handoff scheme that can handle the increased signaling load while sustaining the standard QoS parameters is required.This work presents a comparative analysis of four popular developed handoff schemes. New call blocking probability, forced termination probability and throughput are the QoS parameters employed in comparing the four schemes. The four schemes are:RCS-GC,MRCS-GC, NCBS-GC, and APS-GC. NCBS-GChas the leased new call blocking probability while APS-GC has the worst. In terms of forced termination probability, MRCS-GC has the best result, whileRCS-GChas the worst scheme.MRCS-GC delivers the highest number of packets per second while APS-GC delivers the least. These performance metrics are computed by using the analytical expressions developed for these metrics in the considered models in a Microsoft Excel spreadsheet environment.http://dx.doi.org/10.4314/njt.v34i3.2

Traffic modelling in WLANs and cellular networks.

Over the past several years there has been a considerable amount of research in the field of traffic modelling for WLANs and Cellular Networks as well as the integration of these networks. To date, the focus of published work has been largely on the operation of delay sensitive calls. Because the voice calls are no longer the only service in wireless and cellular systems, multi-service traffic networks now consist of integrated services with distinctive Quality of Service (QoS) requirements. Therefore, a number of different schemes have been proposed to deal with this problem. Most of these schemes only consider mobility and multi-service traffic characteristics. However, few studies have considered the impact of buffering of voice calls in integrated voice and data services. Therefore, we aim to make a critical investigation of existing traffic models and offer generic traffic schemes for WLAN and Cellular networks in order to analyse the impact of buffering of voice calls in hybrid networks. For this purpose, an analytical model for performance evaluation of a single server network with voice and data traffic is considered. In this system, voice is given priority but can be buffered in a limited way. The analysis shows that this approach can be used in fast mobile systems