Multichannel VHF, UHF and 800 MHz subway radio communications tests in Toronto

摘要

The Toronto Transit Commission (TTC) conducted a world-wide study of subway radio communications suitable for accommodating numerous VHF, UHF, and 800-MHz channels used by the transit system, police, fire and other public safety entities. No operating systems were found that met all of the requirements, but technology and products were available that appeared to be suitable. A 3060 ft section of the Toronto subway was equipped with a distributed antenna system consisting of two (Tx and Rx) low-loss CATV (cable television) cables equipped with taps feeding antennas spaced approximately 200 ft apart. Two UHF on-frequency-radio repeaters, which receive and amplify two TTC channels transmitted from the CN Tower, feed the Tx cable. Whip antennas on ground planes radiate the Tx signals in the subway. Similar antennas receive the Rx signals from the handheld portables in the subway. The Rx cable feeds satellite receivers connected to the voting system. The test results have been very satisfactory.