Joint call admission control algorithms: Requirements, approaches, and design considerations

It is envisioned that next generation wireless network (NGWN) will be heterogeneous where different radio access technologies coexist. This vision of NGWN has led to the development of new call admission control (CAC) algorithms specifically designed for heterogeneous wireless networks. This paper reviews recent call admission control algorithms for heterogeneous wireless networks. Benefits and requirements of joint CAC (JCAC) algorithms are discussed. We examine eight different approaches for selecting the most appropriate radio access technology (RAT) for incoming calls in NGWN and classify the JCAC algorithms based on these approaches. The advantages and disadvantages of each approach are discussed. We analyze six different design considerations for JCAC algorithms. These design considerations are centralization, optimization, number of network selection criteria, call type, centricity, and prediction. A more thorough understanding of JCAC in heterogeneous wireless networks and its research trends may help one to design better JCAC algorithms. (C) 2007 Elsevier B.V. All rights reserved.