FIBER OPTIC TELECOMMUNICATION SYSTEM EMPLOYING CONTINUOUS DOWNLINK, BURST UPLINK TRANSMISSION FORMAT WITH PRESET UPLINK GUARD BAND

摘要

An optical communication system includes a master site connected to a plurality of subscriber interface sites by a pair of optical fibers. The downlink message is transmitted in a continuous TDM format from the master site to the subscriber interface site via the first fiber and in burst mode TDMA format from the subscriber interface site to the master site via the second fiber. Each subscriber interface site is coupled to the fiber link through multiple fan out fiber coupling pedestals at a common location of the fiber pair.;To prevent collisions between successive uplink bursts from the subscriber interface site, the guardband separates successive uplink messages from each other. The guardband duration regulates the fiber transmission distance between the common location of the uplink fiber and the subscriber interface site with the largest difference in fiber transmission distance from the common location.;The subscriber location includes a television decoder associated with the subscriber's television receiver and is input by the subscriber such that a television channel selection signal is transmitted from the subscriber interface site to the master site through the decoder. Power is provided through a replaceable battery pack housed in an underground bell structure that effectively insulates the battery pack from sudden temperature changes and ingress of moisture.