The CABSINET project: a flexible cellular broadband architecture

The CABSINET (Cellular Access to Broadband Services and Interactive Television) project is part of the EC Advanced Communications Technologies and Services (ACTS) Programme. It is co-ordinated by CRL, with FUB as the Technical Manager. The project focuses on "last mile" cellular wireless access enabling delivery and use of interactive TV and broadband services. It aims to enhance the functionality of current Local Multipoint Distribution Systems (LMDS). The approach is based on a two layer network (TLN), with layer 1 composed of wide-area macrocells, supporting a layer 2 made up of local-area microcells. The layers operate at different frequencies and with different modulation techniques, in order to meet the different problems that are encountered. Further technical innovation is provided by implementation of an in-band return link using a combined CDMA/TDMA approach, to provide resilient transmission even with multipath conditions. This paper describes the TLN approach, expands on some of the technical methodology involved, and describes typical deployment scenarios of the system. The advantages with respect to a standard LMDS approach are highlighted.