L5 System: Line-Protection Switching

Vol. 53, No. 10, December 1974 Printed, in U.S.A. L5 SYSTEM: Line-Protection Switching By J. H. GREEN and R. W. SANDERS (Manuscript received January 31, 1974) A new system has been designed to provide protection switching capability for the L5 repeatered line. This line-protection switching system, called LPSS-3, provides one standby line for protection of as many as 10 service carrying lines. Switching equipment is located in terminal, terminal main, and switching power-feed stations. Economic and reliability considerations alloiv switching spans of up to 150 miles. Either temperature pilot deviations or excessive total signal energy initiates automatic switching. Manual control of all switching functions is provided locally and via telemetry. A dedicated PCM system coordination. tary form over two checking as ivell as error immunity.