Scanning the literature

Abstract

This paper describes the Shadow Cluster concept, a novel idea that can be used to improve the resource allocation and the call admission procedures in wire less networks. Shadow clusters can be used to allocate resources that need to be reserved for call hand-offs, and to determine if a new call should be admitted to a wireless network based on the call’s requirements and local traffic conditions. The shadow cluster concept is targeted for ATM-based wireless networks with a micro/n.ano-cellular architecture, where service will be provided to users with very diverse requirements. In these n.etworks, and as a consequence of the small cell sizes, mobile users will typically experience a high number of cell hand-offs during their connections’ lifetime. ‘With shadow clust.ers, the quality of service of mobile calls can be improved by reducing the number of dropped calls during hand-offs, and by disallowing the establishment of new calls that are highly likely to later result in a dropped call. The framework of a shadow cluster system is completely distributed, and can be viewed as a message system where a mobile terminal informs the base stations in the neighborhood about i.ts requirements, position, and movement parameters, so that the base stations project future demands, reserve resources accordingly, and admit onlv Permission to ma:ke digital/hard copies of all or part of this material for Personal or classroom use is granted without fee provided that the copies are not made or distributed for profit or commercial advantage, the copyright notice, the title of the publication and its date appear, and notice is given that copyright is by permission of the ACM, Inc. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires specific permission and/or fee. MOBICOM 95 Berkeley CA USA Q 1995 ACM 0-89791-814-2/95/10..$3.50 :Mahmoud Naghshineh IBM T.J. Watson Research Center Yorktown Heights, NY 10598 Tel: (914)-784-6231 E-Mail: mahmoud@wat.son.ibm.com those calls that can be supported adequately. In this paper, we describe how base stations define and main tain shadow clusters by multicasting probabilistic information on the future position of their mobiles with active calls. In addition, we propose resource allocation and call admission algorithms based on the information provided by the shadow clusters.