Wireless ATM Network Demonstrator Research Articles

Implementation of the wireless ATM access terminal

Multimedia applications with audio and video connections have created totally new bandwidth and Quality of Service (QoS) requirements for the computer data networks. In order to meet the new customer requirements also the wireless access networks have to be enhanced to support the increased demand for broadband services. Wireless ATM (WATM) technology has emerged as one of the most promising alternatives for implementing multimedia capable mobile networks. The Magic WAND (Wireless ATM Network Demonstrator) is an international research project designing a WATM network that provides indoor radio coverage and user mobility. The system is mainly targeted for customer premises networks and hot spots with a large number of people within a restricted area, such as airports. This paper describes the architecture of the wireless ATM terminal developed for the Magic WAND demonstrator. The focus is on the terminal software which supports the user mobility and the native ATM access on the Windows NT operating system environment. The first part of the paper presents the generic reference model for the broadband radio networks and describes the Magic WAND system architecture. The latter part of the document focuses on the terminal implementation presenting the structural breakdown of the terminal, the Windows NT operating system and the actual implementation. Finally, the paper depicts briefly the development process and applied design methods.

Signaling stack design for wireless ATM access networks

One of the challenges in designing a wireless ATM network is to specify control functions capable of managing data and signaling connections of moving mobile terminals. The challenge is tough, due to the facts that such control functions neither exist in the current state-of-the-art wireless networks nor are included in the existing ATM specifications and implementations. This article describes the design principles of a wireless ATM signaling stack created in the WAND project. The article identifies some common problems and presents possible solutions to the problems. To justify the feasibility of the ideas presented, some details of a reference implementation, the Wireless ATM Network Demonstrator (WAND) signaling stack, are revealed.

The Magic WAND-functional overview

The Magic WAND project (Wireless ATM Network Demonstrator) is one of the largest projects within the European Union ACTS (Advanced Communications Technologies and Services) initiative. The project aims to design, verify, implement, and demonstrate a wireless access network for ATM LAN's. The complete range of functionality, from physical data transmission to shared multimedia application, is addressed. The WAND system is designed for indoor environments with user mobility limited to walking speed. The system's functional specification has been designed and verified using SDL (specification and description language). In this paper, the WAND system functional model is given and SDL simulation results are presented, to illustrate how the protocols support some of the key operations of a wireless access network. These include initial registration, call setup, and handover.

MAC protocol and traffic scheduling for wireless ATM networks

The Medium Access Control (MAC) protocol defined in the Wireless ATM Network Demonstrator (WAND) system being developed within the project Magic WAND is presented. Magic WAND is investigating extensions of ATM technology to cover wireless customer premises networks, in the framework of the Advanced Communications Technologies and Services (ACTS) programme, funded by the European Union. The MAC protocol, known as MASCARA, uses a dynamic TDMA scheme, which combines reservation- and contention-based access methods to provide multiple access efficiency and quality of service guarantees to wireless ATM terminal connections sharing a common radio channel. The paper focuses on the description of PRADOS, a delay-oriented traffic scheduling algorithm, which aims at satisfying the requirements of the various traffic classes defined by the ATM architecture. Simulation results are presented to assess the performance of the proposed algorithm in scheduling transmission of variable bit rate connections.

Quality-of-service oriented medium access control for wireless ATM networks

The medium access control (MAC) protocol and the underlying traffic scheduling algorithm developed within project Magic WAND (Wireless ATM Network Demonstrator) are presented. Magic WAND is investigating wireless ATM technology for customer premises networks in the framework of the Advanced Communications Technologies and Services (ACTS) program funded by the European Union. The MAC protocol, known as MASCARA, is a hub-based, adaptive TDMA scheme which combines reservation- and contention-based access methods to provide multiple access efficiency and quality-of-service guarantees to wireless ATM terminal connections sharing a common radio channel. The traffic scheduling algorithm is delay-oriented to meet the requirements of the various traffic classes defined by the ATM architecture. The results of the simulation of a number of scenarios are presented to assess the performance of the proposed algorithm.