Wireless interworking architectures to support mobile IP over ATM

The growing demand for mobile and wireless access to Internet services has generated interest in how to use broadband infrastructures to provide such services. In this paper we provide, as a first step, an introductory presentation of alternative architectures for providing wireless Internet access, and in particular, the mobile IP service, when the fixed backbone network, either in the Internet or the public switched telephone network (PSTN) contains ATM entities. All the architectures use an interworking function (IWF) which encapsulates the functions of protocol adaptation, inter-BSC handoff encryption, authentication and packet routing and addressing. The first architecture we consider provides a wireless Internet access service only, without integration with voice services or provision for non-Internet data services (e.g. messaging or fax), and uses a centralized IWF. The second architecture is similar but uses a distributed IWF. We then consider two architectures where voice and data services are integrated. In architecture 3, voice and data services share the radio system only, with switching and other functions being provided separately for each service. architecture 4 not only allows voice and data to share the PSTN switching resources, but also considers the interworking of ATM switches in the PSTN backbones with narrowband PSTN switches as well as Internet ATM transport.