Mobile ATM: A generic and flexible network infrastructure for 3G mobile services

This paper presents the concept of “mobile ATM,” a proposal for third-generation (3G) mobile communication network infrastructure capable of supporting flexible evolution of radio technologies from today´s cellular and data services towards future wireless multimedia services. Mobile ATM provides generic mobility management and QoS-based transport capabilities suitable for integration of multiple radio access technologies including cellular voice, wireless data, and future broadband wireless services. The architecture of a mobile ATM network is outlined in terms of the newly-defined “W-UNI” interface at the radio link and “M-UNI” and “M-NNI” interfaces within the fixed network. The concept of a “proxy-UNI” interface which supports unified access for WATM and non-ATM mobile terminals through corresponding interworking functions (IWF) is explained, leading to an understanding of how different radio access technologies are supported by the same ATM-based core network infrastructure. Generic mechanisms for handoff and location management within the core mobile network are discussed, and related protocol extensions over the “W-UNI” and “M-UNI/NNI” interfaces are proposed. The issue of “crossover switch (COS)” selection in mobile ATM is considered, and a unified handoff signaling syntax which supports flexibility in COS selection is described. Typical signaling sequences for call connection and handoff using the proposed protocols are outlined. Experimental results from a proof-of-concept mobile ATM network prototype are presented in conclusion.