An air interface for high bandwidth cellular digital communications on microwave frequencies

An air interface for use in high throughput digital cellular networks is presented. The design of the interface is one of the contributions to the multidisciplinary Mobile Multimedia Communications (MMC) project at Delft University of Technology. The targets include 155 Megabit per second sustained throughput for high-level users, support for inexpensive mobile stations and support for the Internet protocol (IP), as well as an option for asynchronous transfer mode (ATM). The design consists of an hierarchical frame structure that employs a combination of frequency division multiplexing (FDM) and time division multiplexing (TDM). A comparison is made with the published results of two other research projects, namely MBS (Mobile Broadband Systems) and Median. A protocol is presented that allows transport of control information and data over this link. This protocol features automatic repeat request (ARQ), support for multiple qualities of service (QoS) and graceful degradation of service quality when the load becomes higher than the capacity. A detailed description of the implementation is given.