Method and system for identifying and analyzing downlink interference sources in a telecommunications network

• US 6,332,076 B1
• Filed: 06/28/1999
• Issued: 12/18/2001
• Est. Priority Date: 06/28/1999
• Status: Expired due to Fees

• Current Assignee: LOPEZ, KERMIT D., ERICSSON, INC.
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Shah, Ali R., Hʼmimy, Hossam
• Primary Examiner(s): Nguyen, Lee
• Assistant Examiner(s): NGUYEN, SIMON
• Application Number:
  US09/370,777
• Time in Patent Office: 904 Days
• Field of Search: 455/423, 455/63, 455/62, 455/64, 455/67.3, 455/424, 455/501, 455/504, 455/135, 455/161.3, 455/283, 455/296
• US Class Current: 455/423
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

A method and system for determining sources of downlink interference in a telecommunications network having offending cells and disturbed disposed therein. Initially, mobile traffic events in offending cells within the telecommunications network are identified. Disturbance events in disturbed cells within the telecommunications network are also determined. The identified mobile traffic events are then correlated with the identified disturbance events in order to detect possible sources of disturbance within the telecommunications network. A disturbance distribution for each disturbed cell within the telecommunications network is thereafter computed, when all identified mobile traffic events are correlated with the all identified disturbance events, thereby enabling network engineers to optimize the telecommunications network by minimizing downlink interference. The method and system are thus based on measurements and not predictions, so that the measurements take into account the behavior of all mobiles within the telecommunications network rather than a particular mobile event.

Claims

1. A method for analyzing downlink interference in a telecommunications network, said method comprising the steps of:

recording real-time channel seizure events associated with first traffic channels within a first cell associated with said telecommunications network;

identifying real-time disturbance events associated with second traffic channels within a second cell;

correlating said real-time channel seizure events with said real-time disturbance events; and

computing a disturbance distribution for said second cell by determining which ones of said real-time channel seizure events are causing ones of said real-time disturbance events within said second cell.

2. The method of claim 1 further comprising the step of determining that an external interfering source exists in response to a determination that not all of said real-time disturbance events have been correlated with one of channel seizure events.

3. The method of claim 1 wherein said step of correlating further comprises the step of correlating said real-time channel seizure events with start times and stop times associated with said real-time disturbance events.

4. The method of claim 1 wherein said real-time disturbance events are identified when sufficient signal strength is correlated in time with degraded speech quality associated with a particular traffic channel for a predefined duration.

5. The method of claim 4 wherein said step of identifying further comprises the step of identifying a particular one of said real-time disturbance events within said second cell with a high error rate having a signal strength greater than a particular threshold level.

6. The method of claim 1 further comprising the step of verifying said real-time disturbance events by utilizing propagation considerations within said telecommunications network.

7. An apparatus for analyzing downlink interference in a telecommunications network, comprising:

means for recording real-time channel seizure events associated with first traffic channels within a first cell associated with said telecommunications network;

means for identifying real-time disturbance events associated with second traffic channels within a second cell;

means for correlating said real-time channel seizure events with said real-time disturbance events; and

means for computing a disturbance distribution for said second cell by determining which ones of said real-time channel seizure events are causing particular ones of said real-time disturbance events within said second cell.

8. The apparatus of claim 7 further comprising means for determining that an external interfering source exists in response to determining that not all real-time disturbance events have been correlated with one of said real-time channel seizure events.

9. The apparatus of claim 7 wherein said means for correlating further comprises means for correlating said real-time channel seizure events with start times and stop times associated with said real-time disturbance.

10. The apparatus of claim 7 further comprising means for identifying said real-time disturbance events by identifying sufficient signal strength correlated in time with degraded speech quality associated with a particular traffic channel for a predefined duration.

11. The apparatus of claim 10 further comprising means for identifying a particular one of said real-time disturbance events within said second cell with a high error rate having a signal strength greater than a particular threshold level.

12. The apparatus of claim 7 further comprising means for verifying said real-time disturbance events by utilizing propagation considerations within said telecommunications network.

13. The apparatus of claim 7 wherein all of said means are included within a mobile switching center (MSC) serving said fast cell and said second cell.

14. An apparatus for analyzing radio interference in a telecommunications network wherein said telecommunications network includes two or more cells, each cell being served by a radio transceiver device, further comprising:

a first monitor monitoring real-time channel seizure events associated with first traffic channels within a first cell associated with said telecommunications network;

a determiner for identifying real-time disturbance events associated with second traffic channels within a second cell;

a computer for correlating said real-time channel seizure events with said real-time disturbance events, wherein said computer further computes a disturbance distribution for said second cell by determining which ones of said real-time channel seizure events are causing particular ones of said real-time disturbance events.

15. The apparatus of claim 14 wherein said computer correlates said real-time channel seizure events with start times and stop times associated with said real-time disturbance events.

16. The apparatus of claim 14 wherein said determiner identifies a particular real-time disturbance event when sufficient signal strength is correlated in time with degraded speech quality associated with a particular traffic channel for a predefined duration.

17. The apparatus of claim 16 wherein said determiner further identifies a particular one of said real-time disturbance events having a high error rate with a signal strength greater than a particular threshold level.

18. The apparatus of claim 14 wherein said computer utilizes propagation consideration when computing said disturbance distribution.

19. The apparatus of claim 14 wherein said computer comprises a mobile switching center (MSC) associated with said first cell and said second cell.