Abstract: An integrated network element includes the functions of multiple Ring add-drop-multiplexers and a digital cross connect. A user may provision cross connections between input and output path-level units of bandwidth referred to herein as “logical tributaries.” Each port within the integrated network element may be combined with one or more other ports to form a user-provisioned association of optical interface ports that is used for line protection (or SDH multiplex section protection) in a particular type of network configuration, referred to as a “port protection group”. Each port within a port protection group may have a plurality of logical tributaries associated with it.

Abstract: A unique trace word is assigned to each incoming signal routed by a sliced switch fabric having two or more parallel switches. The unique trace word is encoded into each incoming signal following an overall format that ensures that each sliced trace word (i.e., the subset of bits in the overall format routed by each parallel switch) also uniquely identifies each incoming signal. In this way, the present invention ensures that the switch configuration of each and every parallel switch can always be verified. As such, any improper switch configuration can be detected, including those misconfigurations in which all but one of the parallel switches are correctly configured as well as those misconfigurations in which all of the parallel switches are identically, but incorrectly configured.

Abstract: An errorless line protection switching system utilizes a variable delay (29) in the spare channel (21-24, 26-29, 31-33) adjusted to provide data signal alignment with an impaired regular channel before substituting the spare channel for the regular channel. This switching system is able to provide bit error free channel substitution between the spare and any regular channel in a digital radio system by virtue of the data signal alignment capability. Data signal alignment is provided by first aligning clocking signals in fine incremental steps with each clocking signal derived from one of the two channels undergoing the substitution. Data signal alignment is then provided by shifting the spare channel in full bit positions until data alignment is indicated by a detector (119). Data signal alignment is also utilized to restore service to a regular channel so the spare channel may be removed from service.