Performance monitoring and test system for a telephone network

• US 5,691,976 A
• Filed: 09/07/1993
• Issued: 11/25/1997
• Est. Priority Date: 04/02/1992
• Status: Expired due to Term

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: Applied Digital Access, Inc. (Lumentum Holdings Inc.)
• Inventors: Hartmann, Paul R., Cadieux, Kevin, Pope, Kevin, Engdahl, Thomas L.
• Primary Examiner(s): Blum, Russell W.
• Application Number:
  US08/118,443
• Time in Patent Office: 1,540 Days
• Field of Search: 370/13, 370/14.55, 370/68, 370/241, 370/242, 370/244, 370/248, 370/250, 370/252, 379/1, 379/9, 379/10, 379/14, 379/15, 371/15.1, 371/28.1
• US Class Current: 370/242
• CPC Class Codes: H04J 3/0608 Detectors therefor, e.g. correlators, state machines
• CPC Class Codes: H04J 3/0623 Synchronous multiplexing systems, e.g. synchronous digital hierarchy/synchronous optical network (SDH/SONET), synchronisation with a pointer process
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04M 3/22 Arrangements for supervision, monitoring or testing
• CPC Class Codes: H04M 3/244 for multiplex systems

Abstract

A DS3 level access, monitor and test system for a telephone network. The system provides selective, and hitless, bit overwrite in any of the embedded DS1, DS0 and subrate channels in a DS3 signal. Multiple DS0 and subrate channels can be tested via the asynchronous time slot interchange in conjunction with the recombiner of the present invention. The present invention further includes a lookahead reframer for framing to the DS3 signal. The present invention also includes a facilities data link (FDL) handler for capturing the FDL channel data in every DS1 channel in a DS3 signal. A high speed bit-for-bit compare is interfaced to a protect path to provide 1:1 fault protection in the system of the present invention. Full time performance monitoring on DS1 and DS3 signals is performed by a shared resource. The system of the present invention provides an integrated approach to synchronization measurement and relative synchronization.

Claims

1. In a telephone network, a DS3 signal access system comprising:

means for identifying a bit in the DS3 signal;

means for generating a selected bit; and

a combiner for substituting the identified bit with the selected bit in the DS3 signal.

2. The system defined in claim 1, additionally comprising:

a DS3 receiver providing a regenerated DS3 signal to the combiner; and

a DS3 transmitter providing a regenerated DS3 signal from the combiner.

3. The system defined in claim 1, wherein the generating means includes a DS1 signal router for routing the selected bit to the combiner.

4. The system defined in claim 3, wherein the generating means includes a DS1 test system for receiving the identified bit and providing the selected bit to the DS1 router.

5. The system defined in claim 1, wherein the generating means includes a DS0 signal router for routing the selected bit to the combiner.

6. The system defined in claim 5, wherein the generating means includes a DS0 test system for receiving the identified bit and providing the selected bit to the DS0 router.

7. The system defined in claim 1, wherein the system is an integrated assembly.

8. The system defined in claim 1, wherein the combiner is synchronous to the DS3 signal.

9. A system for accessing a plurality of embedded channels in a DS3 signal, the system comprising:

a demultiplexer for extracting at least one of the DS2 channels in the DS3 signal;

an asynchronous time slot interchange for communicating at least one of the DS0 channels in the DS2 channel into an asynchronous time slot on a bus; and

means for selectively inserting data from the bus into the DS3 signal.

10. The system defined in claim 9, wherein the means for selectively inserting includes means for overwriting at least one bit in the DS3 signal.

11. The system defined in claim 9, wherein the bus is clocked at rate higher than any one DS0 channel.

12. The system defined in claim 9, wherein each of the asynchronous time slots are selectively assigned to any DS0 channel in any DS1 channel.

13. The system defined in claim 9, wherein a DS1 channel is inserted into the DS3 signal.

14. The system defined in claim 9, wherein a DS0 channel is inserted into the DS3 signal.

15. The system defined in claim 9, wherein a subrate channel is inserted into the DS3 signal.

16. The system defined in claim 9, wherein the bus includes means for bit stuffing.

17. The system defined in claim 16, wherein the means for bit stuffing includes a line for carrying valid bit data.