ADAPTIVE HYBRID. HANDOVER SCHEME OVER ATM. BASED PERSONAL COMMUNICATION. NETWORKS

Abstract

Personal communications network (PCN) is an emerging wireless network that promises new services for the telecommunication industry. Handover is the action of switching a call in progress in order to maintain the continuity and the required quality of service (QoS) of a call when a mobile terminal (MT) moves from one cell to another. In literature, queuing of handover requests, and reserving number of channels (statically or dynamically) exclusively to serve handover request are proposed. Those schemes aim to reduce the failure probability of handover requests (forced termination probability). In this dissertation a handover hybrid scheme is proposed, which combines queuing of the handover requests scheme and guard channel (or bandwidth reservation) scheme, which gives a higher access priority to handover calls by assigning them a higher capacity. In this scheme, a new call is admitted only if number of idle channels is greater than fixed number of guard channels (Nc,) and there is no handover request exists in the handover queue. While handover request is admitted if any channel is free, otherwise, it is queued in handover queue instead of blocking the request. This scheme decreases significantly the forced termination probability compared to queuing or bandwidth reservation schemes. The expense is an increase in the new call blocking probability. However, from the subscriber's point of view, forced termination of due to handover is less desirable than blocking new calls. The proliferation of demand for extending wireless services to integrated services, which support the transmission of data and multimedia information has resulted in need for broadband wireless systems that are able to provide service capabilities similar to those of wireline networks. The ATM cell-relay paradigm is one possible approach to provide switching networks for interconnection of PCN cells. The implementation is done in C++ language on Intel Celeron personal computer under DOS environment.