Broadband radio access to homes and businesses: MMDS and LMDS

This paper gives an overview of digital microwave multipoint distribution s ystems (MMDS) and local multipoint distribution systems (LMDS) originally d eveloped for digital TV broadcasting and later extended to offer interactiv e services for homes and businesses. We first describe the specification wo rk carried out by the Digital Video Broadcasting (DVB) project and the Digi tal Audio Visual Council (DAVIC) which forms the technical basis of these s ystems. Next, after presenting initial frequency allocations particularly i n Europe and North America, we discuss the potential of MMDS and LMDS to of fer broadband services to homes as well as to small- and medium-size busine sses. We also discuss the major technical issues related to the design of t hese systems, frequency planning and reuse patterns, as well as future tech nical evolutions to make them more efficient in terms of performance, capac ity, and the service offered. This discussion includes the use of higher-le vel modulations, multiple access techniques such as code-division multiple access (CDMA) and orthogonal frequency-division multiple access (OFDMA), an d of adaptive arrays for electronic beamforming. (C) 1999 Elsevier Science B.V. All rights reserved.