Patent ID: 6181676
Filing Date: 2001-01-30
Classification: H04B,H04J,H04L

Abstract:
In a SONET/SDH radio communication network comprising a plurality of main radio communication terminals and a plurality of repeaters intermediate the communication terminals, with wayside communication paths being established between pairs of said repeaters via two radio channels carrying the same data, a method for determining whether to effect protection switching of a wayside path to the better of said two channels, comprising using different radio overhead bits to record, for each of a plurality n of wayside tributary paths, FEC (Forward Error Correction) and PEC (Parity Error Count) using t=f+p bits for each tributary path (f for FEC and p for PEC), subject to the following conditions:(1) at an ADD site, set to zero the entire t bits corresponding to the added tributary,(2) at a DROP or THRU site, accumulate the section FEC and PEC by adding the main traffic's section FEC and PEC to the FEC bits and the PEC bits corresponding to the wayside stream to be passed through or dropped, and(3) at any DROP site, compare the FEC and PEC corresponding to the tributary to be dropped with predetermined thresholds to determine whether protection switching is required.