Digital loop carrier system with automatic reprovisioning of dedicated lines

• US 6,031,906 A
• Filed: 09/29/1997
• Issued: 02/29/2000
• Est. Priority Date: 03/29/1996
• Status: Expired due to Fees

• Current Assignee: Siemens Information And Communication Networks, Inc.
• Original Assignee: Siemens Information And Communication Networks, Inc.
• Inventors: Rao, Nagaraja
• Primary Examiner(s): Hong, Harry S.
• Application Number:
  US08/939,347
• Time in Patent Office: 883 Days
• Field of Search: 370/244, 370/264, 370/225, 370/226, 370/227, 370/228, 370/524, 379/27, 379/219, 379/220, 379/221, 379/269, 379/273, 379/279, 379/22, 379/333, 379/334, 379/335, 379/336, 379/337, 379/26, 340/825.01, 340/825.03, 340/825.05, 340/825.06, 340/825.16, 340/827
• US Class Current: 379/273
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• CPC Class Codes: H04M 3/303 and using PCM multiplexers, e.g. pair gain systems
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence
• CPC Class Codes: H04Q 2213/13039 Asymmetrical two-way transmission, e.g. ADSL, HDSL
• CPC Class Codes: H04Q 2213/13109 Initializing, personal profile
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/13167 Redundant apparatus
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13335 Simulation, emulation
• CPC Class Codes: H04Q 2213/13381 Pair-gain system, digital loop carriers
• CPC Class Codes: H04Q 2213/13395 Permanent channel, leased line

Abstract

A digital loop carrier system in a communications network that provides automatic restoration of network access for user lines in the event of a failure. The system includes a plurality of user lines and groups of transmission lines interfaced with the user lines. Each group of transmission lines includes dedicated transmission lines which are connected to the user lines, idle transmission lines and reserved transmission lines. The system also includes a reprovisioning monitor that makes a number of transmission lines among the groups of transmission lines available for user lines which have a dedicated transmission line in a group of transmission lines that fails and that couples each of such user lines to a respective available transmission line. The monitor may delay the coupling of such user lines if a sufficient number of transmission lines are not available.

Claims

1. An integrated digital loop carrier system comprising:

a plurality of user lines;

groups of transmission lines interfaced with said plurality of user lines, wherein each said group of transmission lines includes dedicated transmission lines and per-call-assigned transmission lines connected to said plurality of user lines, idle transmission lines and reserved transmission lines; and

a reprovisioning monitor for enabling automatic restoration of said plurality of user lines in the event of a failure of at least one of said groups of transmission lines, the reprovisioning monitor comprising

means for continually providing a minimal number of said reserved transmission lines;

means for identifying which of said plurality of user lines has a dedicated transmission line on said failure of at least one of said groups of transmission lines; and

means for coupling said identified user lines to said idle transmission lines if a sufficient number of said idle transmission lines are available.

2. The system of claim 1, wherein the reprovisioning monitor distributes the assignment of said dedicated transmission lines among said groups of transmission lines.

3. The system of claim 1, wherein the reprovisioning monitor determines, before coupling said identified user lines, if a sufficient number of said idle and reserved transmission lines are available.

4. The system of claim 3, wherein the reprovisioning monitor delays the coupling of said identified user lines if a sufficient number of said idle and reserved transmission lines are not available.

5. The system of claim 3, wherein the reprovisioning monitor delays the coupling of an identified user line if an idle and reserved transmission line is not available.

6. The system of claim 3, wherein the reprovisioning monitor utilizes a polling technique to determine the availability of a sufficient number of idle and reserved transmission lines when said coupling of at least two identified user lines is not accomplished.

7. The system of claim 1, wherein the reprovisioning monitor clears the assignment to a respective identified user line of each said dedicated transmission line in said group of transmission lines that fails.

8. The system of claim 1, wherein the reprovisioning monitor comprises:

means for determining which one of said groups of transmission lines has the greatest number of dedicated transmission lines and for counting the number of dedicated transmission lines in said group;

means for counting the total number of idle transmission lines within said other groups of transmission lines;

means for comparing the number of dedicated transmission lines in the group with the greatest number of said lines to said total number of idle transmission lines in order to determine a minimum number of idle transmission lines to be reserved; and

means for reserving said minimum number of idle transmission lines within said other groups of transmission lines.

9. The system of claim 8, wherein the reprovisioning monitor further comprises means for reserving an additional number of idle transmission lines within the group of transmission lines having the greatest number of dedicated transmission lines if the number of dedicated transmission lines in said group is less than said total number of idle transmission lines, said additional number of idle transmission lines corresponding to the difference between the number of dedicated transmission lines in the group with the greatest number of said lines and said total number of idle transmission lines.

10. The system of claim 9, wherein the means for reserving said additional number of idle transmission lines comprises means for comparing said minimum number of idle transmission lines to the combination of dedicated transmission lines and reserved transmission lines in the one of said other groups of transmission lines having the greatest combination of said lines.

11. The system of claim 8, wherein the reprovisioning monitor further comprises means for initially reducing said reserved transmission lines of said groups of transmission lines to zero.

12. The system of claim 8, wherein the means for reserving said minimum number of idle transmission lines comprises means for continually reserving a single transmission line within said other groups of transmission lines that have an idle transmission line and a certain minimum number of dedicated transmission lines and reserved transmission lines.

13. The system of claim 1, wherein the reprovisioning monitor further comprises means for determining the maximum number of said reserved transmission lines to be provided, which includes:

means for determining which one of said groups of transmission lines has the greatest number of dedicated transmission lines and for counting the number of dedicated transmission lines in said group;

means for calculating an integer value which is at least equal to the total number of said user lines divided by one less than the total number of said groups of transmission lines; and

means for comparing said integer value to said number of dedicated transmission lines in order to determine a maximum number of idle transmission lines to be reserved.

14. The system of claim 1, further comprising a switching system, that provides network access for the user lines, coupled to said groups of transmission lines.

15. The system of claim 1, wherein said plurality of user lines are a plurality of non-concentrated subscriber lines.

16. The system of claim 15, wherein said groups of transmission lines are Digital Signal Level 1 lines including a plurality of Digital Signal Level 0 lines.

17. The system of claim 16, wherein said non-concentrated subscriber lines are interfaced with said Digital Signal Level 1 lines by a remote terminal.

18. The system of claim 1, wherein said plurality of user lines are a plurality of Integrated Service Digital Network lines.

19. The system of claim 17, wherein said plurality of user lines are a plurality of Integrated Service Digital Network lines.

20. A digital loop carrier system in a communications system, comprising:

a plurality of user lines;

groups of transmission lines interfaced with said plurality of user lines, wherein each said group of transmission lines includes dedicated transmission lines connected to said plurality of user lines, idle transmission lines and reserved transmission lines;

a reprovisioning monitor that enables automatic restoration of network access for said plurality of user lines in the event of a failure of at least one of said groups of transmission lines, including;

means for distributing said dedicated transmission lines among said groups of transmission lines and for continually providing a number of said reserved transmission lines; and

means for identifying said user lines which have a dedicated transmission line in a group of transmission lines that fails and then coupling each of said identified user lines to a respective available transmission line in another group from the idle and the reserved transmission lines therein.

21. The system of claim 20, further comprising means for determining if a sufficient number of said idle and reserved transmission lines are available and for delaying coupling of said identified user lines if a sufficient number of said idle and reserved transmission lines are not available.

22. The system of claim 20, further comprising means for determining if a sufficient number of said idle and reserved transmission lines are available and for delaying coupling of an identified user line if an idle and reserved transmission line is not available.

23. A communications network, comprising:

a plurality of user lines;

a switching system for providing network access for the user lines;

a plurality of transmission lines that connect the user lines to the switching system;

an interface that assigns and connects a first set of user lines to the transmission lines on a provisioned basis and assigns and connects a second set of user lines to the transmission lines on a per call basis; and

a reprovisioning device that reserves a number of un-provisioned transmission lines and that couples each user line which has a provisioned transmission line that fails to a respective available transmission line from the reserved un-provisioned transmission lines and the idle un-provisioned transmission lines.

24. The system of claim 23, wherein the reprovisioning device couples a user line to a respective available transmission line in a group of transmission lines other than the group with the failed transmission line.

25. The system of claim 23, wherein the reprovisioning device couples a user line by clearing the assignment of the user line to the failed transmission line and re-assigning the user line to the coupled available transmission line.

26. The system of claim 23, wherein the reprovisioning device re-couples the user line to a second respective available transmission line from the reserved un-provisioned transmission lines and the idle un-provisioned transmission lines in the event the coupled transmission line fails.

27. The system of claim 23, wherein the reprovisioning device distributes the assignment of the provisioned transmission lines among respective groups of transmission lines.

28. The system of claim 23, wherein the reprovisioning device delays the coupling of a user line if a transmission line is not available.

29. A communications network, comprising:

a plurality of user lines, a first set of user lines having a plurality of channels;

a switching system for providing network access for the user lines;

a plurality of transmission lines that connect the user lines to the switching system;

an interface that assigns and connects the first set of user lines to the transmission lines on a provisioned basis and assigns and connects a second set of user lines to the transmission lines on a per call basis, said interface assigning and connecting each channel of a user line of the first set to a respective provisioned transmission line; and

a reprovisioning device that reserves a number of un-provisioned transmission lines and that couples each user line which has a provisioned transmission line that fails to a respective available transmission line from the reserved un-provisioned transmission lines and the idle un-provisioned transmission lines.

30. The system of claim 29, wherein the interface assigns and connects each channel of a user line of the first set to a provisioned transmission line of a respective group of transmission lines.

31. The system of claim 29, wherein the interface assigns and connects each channel of a user line of the first set to a provisioned transmission line of a respective pre-selected group of transmission lines.

32. The system of claim 29, wherein the user lines of the first set are Integrated Service Digital Network lines and the channels of each line include two B channels and a D channel.

33. The system of claim 29, wherein the reprovisioning device couples a user line to a respective available transmission line in a group of transmission lines other than the group with the failed transmission line.

34. The system of claim 29, wherein the reprovisioning device delays the coupling of a user line if a transmission line is not available.