Asynchronous Transfer Mode (ATM) is a technology designed for the high-speed transfer of voice, video, and data through public and private networks using cell relay technology. ATM is an International Telecommunication Union Telecommunication Standardization Sector (ITU-T)standard. Ongoing work on ATM standards is being done primarily by the ATM Forum, which was jointly founded by Cisco Systems, NET/ADAPTIVE, Northern Telecom, and Sprint in 1991.

A cell switching and multiplexing technology, ATM combines the benefits of circuit switching(constant transmission delay, guaranteed capacity) with those of packet switching (flexibility, efficiency for intermittent traffic). To achieve these benefits, ATM uses the following features:

Over the last few years, enterprises have increasingly deployed wireless local area networks (WLANs) to drive productivity, reduce cost, and improve work quality. While the return on investment has been substantial, enterprises recognize they have reaped only a fraction of the potential benefits. Today, they are looking to leverage wireless technology for even greater value, by extending it to more users and by expanding the scope of wireless services and applications.

At the same time, a number of business and technology trends are creating a new set of requirements for wireless networks that can deliver the increased value that enterprises are demanding. Emerging developments such as the high-throughput 802.11n standard hold the promise of providing significantly more powerful WLANs. But current WLAN architectures stand in the way of realizing those benefits. Consequently, a new approach is needed to deliver the next generation of high performance wireless networks.

This article identifies the requirements for next-generation WLANs, examines the limitations of existing approaches,and describes an innovative WLAN architecture, which overcomes those limitations.