Multichannel VHF, UHF and 800 MHz subway radio communications testsin Toronto

摘要

The Toronto Transit Commission (TTC) conducted a world-wide studynof subway radio communications suitable for accommodating numerous VHF,nUHF, and 800-MHz channels used by the transit system, police, fire andnother public safety entities. No operating systems were found that metnall of the requirements, but technology and products were available thatnappeared to be suitable. A 3060 ft section of the Toronto subway wasnequipped with a distributed antenna system consisting of two (Tx and Rx)nlow-loss CATV (cable television) cables equipped with taps feedingnantennas spaced approximately 200 ft apart. Two UHF on-frequency-radionrepeaters, which receive and amplify two TTC channels transmitted fromnthe CN Tower, feed the Tx cable. Whip antennas on ground planes radiatenthe Tx signals in the subway. Similar antennas receive the Rx signalsnfrom the handheld portables in the subway. The Rx cable feeds satellitenreceivers connected to the voting system. The test results have beennvery satisfactory