The Terrace Network for Low-Cost Broadband AJ/LPI Communication in the LMDS Band

Period of Performance: 12/18/1998 - 06/18/1999


Phase 1 SBIR

Recipient Firm

Radix Technologies, Inc.
329 N. Bernardo Avenue
Mountain View, CA 94043
Principal Investigator

Research Topics


The Backtalk airlink, developed for AJ/LPI communications in intraflight communication systems, is applied here to broadband multipoint data distribution in the U-NII and LMDS bands. The resultant airlink, referred to here as the Terrace system, employs a novel stacked-carrier multiple access (SCMA) communications format, blind adaptive reception, retrodirective transmission (smart airlines), (optional) smart antennas, and multihop network topologies to optimally exploit the spatial and spectral diversity present in Army communication networks. The resultant airlink can adaptively separate fixed and mobile in-cell nodes operating in the same frequency band, and can remove jamming encountered by the network during the reception process. Each Terrace node can also adaptively direct energy away from other Terrace nodes and jammers during transmission operations, allowing the network to continuously optimize its capacity and present minimal energy to other radios operating in the Terrace band. The airlink also incorporates simple means for removing features that could allow the link to be intercepted during the transmission process. The Phase I project will develop a Terrace concept, architecture, and rough cost estimate optimized for the LMDS band, and will validate performance using propagation data and testbeds provided by the Virginia Polytechnic Institute, a license holder in the LMDS band. BENEFITS: Potential near-term (LMDS) applications include broadband wireless backhaul systems; wireless enterprise networks and wireless local loops; broadband wireless ATM Internet access systems; and wireless LANs, PBXs, and corporate Intranets. Potential medium-to-long term applications (LMDS and non-LMDS band) include next-generation satellite communications systems; next-generation cellular mobility systems (IMT2000); true wireless Internet systems (amorphous wireless networks); and cordless and supercordless (tetherless) telephones.