Call control in the mobile terminal of a wireless ATM network

In the frame of the Research and Development Programme ACTS (advanced communications technologies and services) of the European Union, a high-speed indoor Wireless ATM (asynchronous transfer mode) access network is being investigated in the project “Wireless ATM Network Demonstrator (WAND)”. The main objective of the project WAND is to support integrated multimedia services with QoS (quality of service) in a wireless ATM environment. Another important goal of the project is to build a wireless ATM demonstrator, hereafter denoted as WAND Demonstrator, on which user trials will be carried out in order to verify the proposed architecture of the target system. In the WAND project, specifications of a target wireless ATM system have been defined. Based on this system, the WAND Demonstrator has been built. Three controlled user trials using the applications “medical consultation” and “mobile computing” are currently planned to be carried out in Finland, Germany and Switzerland. This demonstrator platform will be used for evaluating the performance, technical feasibility and usability of the designed concept. This paper describes the general architecture of the WAND Demonstrator-which is composed of five subsystems: network server (NS), ATM switch, control station (CS) of the ATM switch, access point (AP) and mobile terminal (MT)-and focuses on the control software of the MT, in particular, the ATM signalling and its related call control (CC) software. The detailed description of the call control functional block helps to focus on the problems encountered when adapting an ATM signalling stack. Issues such as the management of allocated resources or data modelling for the CC information storage can be considered as crucial for any wireless ATM product