Author_Institution :
Dept. of Electr. & Comput. Eng., Concordia Univ., Montreal, Que.
Abstract :
The reallocation of point to point microwave systems operating in many bands in the GHz region to fiber optic, satellite or other frequencies has paved the way to new frontiers, whereby both fixed and mobile personal communications and miscellaneous commercial applications would be accommodated. However, mutual interference and frequent outages may be so destructive and not known nor predictable in advance especially during the migration process for mobile applications in these LOS based UL bands. We envision new distributed access communications systems without: base stations, cellular structure, backbone PSTN, or otherwise, operating in these unlicensed bands. This entails the design of new modulation, access, and routing techniques. A multitude of codulation, TDMA, slow frequency hopping, direct sequence, carrier sense, adaptive and GPS driven dynamic routing techniques, the most effective spanning tree algorithms, and configurations will be devised to provide frequency and space agility, adequate error performance and to alleviate network congestion. Roaming and forwarding data base optimization are important items for research as well. The major application herein is MYMAR, a new mobile yellow page messaging and retrieval system. In this system, hotels, restaurants, all kinds of road services, hospitals, police, stores... all faces of activities would transmit their GPS location followed by a short commercial message, and the region digital map to travelers, dwellers...etc., to enable them to quickly determine the locations of intended services and easily guide them easily to destination. The receiver detects all such messages, stores, and sorts them by activity for subsequent retrieval, via a user friendly, voice recognition based command system. Services include short messaging, paging, SOS, transportation fleet management commands, among other non-real time 2 way services. The distributed and inherently broadcast wireless environment and the service type (non-real time) shapes the codulation, access, routing...etc. techniques
Keywords :
Global Positioning System; Internet; information retrieval; microcellular radio; paging communication; personal communication networks; radio networks; spread spectrum communication; GPS driven dynamic routing; LOS based UL bands; MYMAR; TDMA; access techniques; adaptive routing; broadcast wireless environment; carrier sense; codulation; digital map; direct sequence; distributed access communications systems; forwarding data base optimization; frequency agility; local wireless Internet; microcells; mobile personal communications; mobile yellow page messaging; mobile yellow page retrieval; modulation; mutual interference; paging; roaming; short commercial message; short messaging; slow frequency hopping; space agility; spanning tree algorithms; transportation fleet management commands; unlicensed bands; voice recognition based command system; Artificial satellites; Base stations; Frequency; Global Positioning System; Interference; Optical fibers; Routing; Spine; Spread spectrum communication; Time division multiple access;