Adaptive control of telecommunications systems with measurements of varying time-delays

• US 6,385,173 B1
• Filed: 02/16/1999
• Issued: 05/07/2002
• Est. Priority Date: 02/16/1999
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Crona, Anneli, Lindskog, Peter, Helmersson, Ke Wang
• Primary Examiner(s): NGO, RICKY QUOC
• Application Number:
  US09/250,639
• Time in Patent Office: 1,176 Days
• Field of Search: 370/241, 370/249, 370/252, 370/310, 370/311, 370/328, 370/332, 370/333, 370/340, 455/422, 455/423, 455/67.1, 455/68, 455/69, 455/560, 455/115
• US Class Current: 370/252
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports

Abstract

A method and system that enables the changing of the gain in a closed loop (e.g., self-configuring) telecommunications system based on the age of the available measurements. A high gain is used when measured data are “fresh”, so as to obtain a good performance (e.g., a fast response) for the telecommunications system. The gain is then reduced when the age of the measurements increases. The decreased gain results in a slower system response, but this is a desirable result in order to preserve stability. The system and method may be applied, for example, in many mobile telecommunications systems (e.g., GSM, WCDMA, etc.). In one embodiment, the system and method of the present invention modify the closed loop gain in an adaptive fashion and use one or more fuzzy membership functions for specifying what is meant by “fresh” measurements.

Claims

1. A telecommunications system having a set of elements that may be adaptively controlled using values of varying time delays, comprising:

a plurality of elements, each of said plurality of elements configured for determining at least one first value and at least one first associated time indication;

a monitoring mechanism, said monitoring mechanism for receiving said at least one first value and said at least one first associated time indication from said each of said plurality of elements, said monitoring mechanism producing a second value and a second associated time indication;

at least one controller in communication with said monitoring mechanism, said at least one controller receiving said second associated time indication and a reference time, whereby said at least one controller adjusts a gain of the telecommunications system responsive to a difference between said reference time and said second associated time indication.

2. The telecommunications system according to claim 1, wherein said plurality of elements comprise network elements.

3. The telecommunications system according to claim 1, wherein the telecommunications system comprises a wireless network system.

4. The telecommunications system according to claim 1, wherein said at least one first value comprises a traffic level associated with a cell of a wireless network system.

5. The telecommunications system according to claim 1, wherein said each of said plurality of elements are further configured for recording said at least one first associated time indication when said at least one first value is determined and for transmitting said at least one first value and said at least one first associated time indication to said monitoring mechanism.

6. The telecommunications system according to claim 1, wherein said plurality of elements are substantially interconnected.

7. The telecommunications system according to claim 1, wherein said at least one first associated time indication comprises a plurality of first associated time indications and said second associated time indication is determined responsive to a minimum of said plurality of first associated time indications.

8. The telecommunications system according to claim 1, wherein said monitoring mechanism is distributed over at least part of the telecommunications system.

9. The telecommunications system according to claim 1, wherein said monitoring mechanism and said at least one controller are comprised, at least partly, of software.

10. The telecommunications system according to claim 1, wherein said difference is applied to a function, said function being designed such that a first difference results in a greater reduction of said gain than a second difference when said first difference is greater than said second difference.

11. The telecommunications system according to claim 10, wherein said function comprises at least one fuzzy membership function.

12. The telecommunications system according to claim 1, wherein said controller comprises a filter, and said controller adjusts said gain of the telecommunications system further responsive to an output of said filter.

13. The telecommunications system according to claim 1, wherein:

said at least one controller comprises a summer, a function result determiner, and a filter;

said summer produces said difference, said difference is applied to said function result determiner, and a result of said function result determiner is applied to said filter; and

an output of said filter comprises a weighting factor for said gain.

14. The telecommunications system according to claim 1, wherein said at least one controller receives said second value and a reference value, whereby said at least one controller produces at least one control command responsive to said gain, said second value, and said reference value.

15. The telecommunications system according to claim 14, wherein said at least one controller is configured to transmit said at least one control command to at least one of said plurality of elements, said at least one of said plurality of elements responding to said at least one control command.

16. A method in a telecommunications system for adapting a control process that operates with time-delayed values, the control process including a gain, comprising the steps of:

receiving at least one determined value and a time associated with said at least one determined value;

determining whether said time associated with said at least one determined value renders said at least one determined value stale based, at least in part, on a reference time and using, at least partly, a functional relationship; and

if so, reducing the gain of the control process.

17. The method according to claim 16, further comprising the steps of:

receiving a reference value; and

determining a control command based, at least in part, on said at least one determined value, said reference value, and the gain.

18. The method according to claim 17, further comprising the step of:

transmitting said control command to at least one network element; and

altering, by said at least one network element, a traffic load of said at least one network element in response to said control command.

19. The method according to claim 16, further comprising the steps of:

determining, by at least one network element, said at least one determined value by measuring said at least one determined value;

recording, at said at least one network element, a time of measuring of said at least one determined value as said time associated with said at least one determined value; and

sending, by said at least one network element, said at least one determined value and said time associated with said at least one determined value to a wireless network operation system of the telecommunications system.

20. The method according to claim 16, wherein said step of determining whether said time associated with said at least one determined value renders said at least one determined value stale based, at least in part, on a reference time and using, at least partly, a functional relationship further comprises the step of determining whether said time associated with said at least one determined value renders said at least one determined value stale using a low pass filter to retard the rate of change of the gain.

21. The method according to claim 16, wherein said functional relationship comprises a fuzzy membership function.

22. A method for adaptively controlling a telecommunications network system having a plurality of network elements, comprising the steps of:

determining, by at least one of said plurality of network elements, a first value and a first associated time indicator;

determining a second associated time indicator based, at least in part, on said first associated time indicator;

ascertaining a reference time; and

determining a gain based, at least in part, on said second associated time indicator and said reference time.

23. The method according to claim 22, further comprising the steps of:

determining a second value based, at least in part, on said first value;

ascertaining a reference signal; and

determining a control command based, at least in part, on said second value, said reference signal, and said gain.

24. The method according to claim 23, further comprising the step of responding, by at least one of said plurality of network elements, to said control command.

25. The method according to claim 22, wherein said telecommunications network system comprises a wireless network system.

26. The method according to claim 22, wherein said telecommunications network system operates based, at least in part, on an Internet protocol.

27. The method according to claim 22, wherein said first value comprises a traffic load of said at least one of said plurality of network elements.

28. The method according to claim 22, wherein said step of determining a gain based, at least in part, on said second associated time indicator and said reference time further comprises the step of determining a difference between said second associated time indicator and said reference time.

29. The method according to claim 28, wherein said step of determining a gain based, at least in part, on said second associated time indicator and said reference time further comprises the step of applying said difference to a functional relationship.

30. The method according to claim 29, wherein said step of determining a gain based, at least in part, on said second associated time indicator and said reference time further comprises the step of passing to a low pass filter a result of said step of applying said difference to a functional relationship.

31. The method according to claim 29, wherein a result of said step of applying said difference to a functional relationship approaches zero as said difference increases.

32. The method according to claim 29, wherein said functional relationship comprises a fuzzy membership function.

33. The method according to claim 29, wherein said step of determining a gain based, at least in part, on said second associated time indicator and said reference time further comprises the step of applying said difference to a functional relationship such that said gain decreases when said difference increases.