ATM Infrastructure

ATM networks embody a key technology for supporting broadband multimedia services not only in WANs but also in LANs, and eventually in home areas. Motivated by the growing acceptance of ATM as a standard for broadband multimedia communication. ATM meets the needs of customers, who want a unified end-to-end networking platform with high performance and robust service characteristics. It closes the gaps between existing voice-oriented wireless systems such as Global System for Mobile Communications (GSM)

Musty digital and Security Systems Limited consider wireless ATM concepts for small LANs, especially for future consumer applications. We describe a wireless ATM LAN framework architecture that supports wireless ATM communications in environments with and without fixed ATM infrastructure. For the configuration with ATM infrastructure, a distributed ATM switched backbone is proposed, which enables a smart ATM switching element to be embedded in every wireless and fixed access point. For bandwidth efficiency and ease of operation (place-and-play), Musty Digital and Security

System limited's wireless ATM LAN concept based on the same 5 GHz wireless ATM air interface as is currently under standardization. Since cost scalability is essential throughout our system design, we consider forwarding between ad hoc subnets and interworking with the fixed network as important but optional features.

In the wireless ATM-to-the-home scenario, WATM can be used for extending the set-top box into portable appliances to provide residential access for alternative carriers after deregulation of the local communication markets, occurring very rapidly in various parts of the world. Important considerations for a consumer market include low cost, especially in terms of initial investment, plug-and-play operation, and high flexibility in terms of setting up partial networks and changing network configurations over time. There are two general methods to realize WATM. The first method is to design the air interface of the wireless LAN independent of the ATM cell format and provide protocol conversion at the wireless access point connected to an ATM-based backbone.

The second method is to provide a seamless extension of the ATM services and the associated QoS control over the wireless medium. The two methods result in different locations of ATM adaptation layer (AAL). For the first method, AAL is located in the base station (BS). Since ATM connections are terminated in the fixed access point, requirements on the air interface can be simplified. The main disadvantage of this approach is the loss of a native ATM application programming interface (API) in the mobile terminal. Furthermore, the complexity of the BS increases with the average number of active users. Therefore, the current trend of the WATM concept discussion is aimed at protocol architecture for seamless wireless ATM extension.