Design considerations for mobile wideband wireless network architectures

Abstract

The paper discusses aspects of high speed terrestrial ATM transmissions in a mobile environment. It includes both near term and far term goals of high speed terrestrial ATM transmissions to provide an extension of the fiber based network. The wireless video, voice, and data communication services will make possible new capabilities for information distribution. The rapid advancement of commercial technology has allowed the consideration of placing advanced technology in the mobile battlefield environment. Two possible environments are described: (1) short-range, low-mobility, and (2) long-range, high-mobility. The high speed communication links will allow video teleconferencing, video image retrieval, real-time video and other high information content services. The use of ATM cells for this study has been made, because ATM currently is believed to be the high speed technology of the future. At the proposed RF carrier frequency of 5 to 30 GHz the use of repeaters is required to provide coverage for wide geographical areas. Both ground and airplane based repeaters are explored for their capabilities, ease-of-use and liabilities. Repeater-routing within a wireless ATM mobile network is discussed. Although the high RF frequencies require the use of repeaters, they do offer the advantage of small antenna size. For high data rate communications to be successful, methods for reducing the deleterious effects of dispersion and fading must be developed. In particular, the benefits and costs of implementing an orthogonal frequency division multiplexing (OFDM) high data rate network are discussed. A suggested modulation constellation for the OFDM subcarriers is discussed. In the area of FEC, the use of turbo codes is examined.