Asynchronous transfer mode (ATM) is a digital network transport technology originally developed to accommodate multiple traffic types on high-speed wireline networks. Although ATM is only in limited use today, it is commonly assumed that the future wireline backbone networks will employ ATM transport. Because ATM provides various advantages, such as quality-of-service (QoS) guarantees, researchers have proposed to eventually adapt ATM to the wireless medium as well. Wireless ATM (WATM) would in principle offer significant advantages over existing wireless local area networking (WLAN) standards. Extending wireline ATM techniques to the wireless medium, however, is far from trivial. The difficulties in developing WATM are due primarily to the fact that ATM was originally designed for a wireline medium, in which one can assume fixed users, plentiful and reliable bandwidth, and high transmission quality. In a wireless medium, however, user connections may change as they move in and out of the service area, the bandwidth is limited and variable, and the transmission quality can be low. Because conventional wireline ATM does not provide techniques for handling these properties of wireless media, WATM requires new solutions to various fundamental networking problems.
One of the important problems to be solved in developing WATM technology is finding an efficient media access control (MAC) technique suitable for the wireless medium. In order to maintain full compatibility with existing wireline ATM networks, a wireless ATM network MAC protocol must support multiple users, multiple connections per user, and service priorities with quality of service requirements. In addition to these basic requirements, such a MAC protocol should efficiently use the limited wireless bandwidth. Known MAC protocols for wireless ATM, however, do not support the use of multiple frequency bands, and do not, therefore, make maximal use of the valuable wireless bandwidth. There is a need, therefore, for a media access control and resource allocation technique that overcomes these and other disadvantages of known MAC protocols designed for wireless ATM networks.
USPTO Backgrounds
USPTO Backgrounds