Enhanced multiframe alignment for tandem connection trials

Details Enhanced multiframe alignment for tandem connection trials Enhanced multiframe alignment for tandem connection trials

2000-09-05

2004-09-28

Pham, Chi (Department: 2662)

Multiplex communications

Diagnostic testing

Fault detection

C370S907000

Reexamination Certificate

active

06798748

ABSTRACT:

CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of European Patent Application No. 99307104.2, which was filed on Sep. 7, 1999.
FIELD OF THE INVENTION
The invention relates to multiframe alignment in general and especially to a multiframe alignment for tandem connection trails at Non Intrusive Monitoring (NIM) Trail Termination (TT) sink functions and for TT sink functions in a Synchronous Digital Hierarchy (SDH) and Synchronous Optical Network (SONET) system.
BACKGROUND
The problem addressed with this invention typically arises in Synchronous Digital Hierarchy (SDH) and Synchronous Optical Network (SONET) systems in cases of protection switches within a Tandem Connection Trail. For a better understanding of SDH and SONET systems, reference is made to “Understanding of SONET/SDH”, ISBN 0-9650448-2-3, Andan Publisher, New Jersey.
In the before-mentioned network system a tandem connection is intended to provide an administrative monitoring domain which is operating independent of the end to end path. Rules for the establishment of a tandem connection trail are defined in ETSI EN 300 417-4-1 and ITU-T G.783.
The operation and also the establishment of a tandem connection trail shall influence the rest of the network system as less as possible. Under certain circumstances (i.e. if switching actions are performed within a tandem connection trail), current Tandem Connection Monitoring (TCM) implementations according to the current versions of the standards unnecessarily enlarge signal disturbances.
Accordingly, there is a need to reduce the influence of protection switches within a tandem connection trail in a Synchronous Digital Hierarchy (SDH) or in a Synchronous Optical Network (SONET) System by avoiding enlargements of signal disturbances caused by protection switches.
SUMMARY OF THE INVENTION
Detecting an aligned signal reception or an in multiframe signal transmission state subsequent to an interruption, distortion or switching operation of the signal transmission path on the basis of any received frame alignment signal (FAS) value avoids any undue interruption of the signal transmission caused by the insertion of all one's while searching for the received frame alignment signal (FAS) only at a predetermined position.
If consequently a “FAS found at presumed position” signal is replaced by a “FAS found” signal and generated regardless of the position of a detected multiframe alignment signal and every detected multiframe alignment signal (FAS) is accepted as a valid frame alignment signal (FAS) then the shortest realignment time periods are realized.


REFERENCES:
patent: 4987568 (1991-01-01), Shinada et al.
patent: 5555248 (1996-09-01), Sugawara
patent: 6452906 (2002-09-01), Afferton et al.
patent: 196 16286 (1997-10-01), None
“EN 300 417-1-1 v1.1.2” European Standard (Telecommunications Series) ETSI. Nov. 1998. pp. 1-112.*
Choi, DooWhan. “Frame Alignment in a Digital Carrier System—A Tutorial”. IEEE. Feb. 1990. pp. 47-54.*
European Search Report, dated Mar. 6, 2000.

Affiliated with

Also associated with

Rating

Enhanced multiframe alignment for tandem connection trials does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Enhanced multiframe alignment for tandem connection trials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enhanced multiframe alignment for tandem connection trials will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3197492