Method and apparatus for backhaul link diagnostic in a wireless repeater system

• US 20020028675A1
• Filed: 12/13/2000
• Published: 03/07/2002
• Est. Priority Date: 12/29/1999
• Status: Active Grant

• Current Assignee: Rateze Remote Mgmt. L.L.C. (Intellectual Ventures LLC)
• Original Assignee: AirNet Communications Corporation (Tecore Incorporated)
• Inventors: Schmutz, Thomas R., Komara, Michael A.
• Granted Patent: US 6,748,212 B2
• Time in Patent Office: Days
• US Class Current: 455/424
• CPC Class Codes: H04B 17/0085 using test signal generators
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters

Abstract

The invention discloses a method and apparatus for diagnosing a backhaul communications link between a repeater station and a base transceiver station of a wireless communication system. Adjacent and co-channel interference can severely degrade the performance of the backhaul communication link. As a result, the conditions on the backhaul link channels can be continually monitored to ensure optimal performance of the link.

Each RF channel on the backhaul communication link is individually diagnosed. A signal is then sent over the RF channel and the signal strength is measured along with any adjacent and co-channel interference. The measured statistics are then sent back to the base transceiver station.

In a further embodiment of the invention, the power level of a RF carrier signal on the backhaul communication link is measured and the carrier signal is then turned off. The power levels on the adjacent channels—above and below are then measured. Based on these measurements and other channel statistics, the power level of the RF carrier signal is accordingly adjusted.

Claims

1. In a wireless communication system having a base station located within a home cell, and a plurality of substantially adjacent cells, at least one of said plurality of cells having a repeater station located therein, a method for diagnosing a backhaul communication link between said base station and said repeater, comprising:

automatically measuring an interference level for said backhaul communication link; and

responsive to said measured interference level, selectively modifying the operation of said backhaul link to overcome any adverse effect of said interference level.

2. The method according to claim 1, wherein said modifying step comprises at least one of increasing a power level of signals transmitted over said backhaul link, decreasing said power level of signals transmitted over said backhaul link, assigning an alternative frequency for use as said backhaul link, and sending a message to an operations maintenance center.

3. The method according to claim 2, wherein said measuring step comprises automatically measuring said interference level on an RF carrier frequency of a backhaul channel assigned for said backhaul communications link.

4. The method according to claim 3, wherein said measuring step further comprises, automatically measuring said interference level on at least one RF channel adjacent to said RF carrier frequency of said backhaul channel.

5. The method according to claim 3, wherein said measuring step further comprises disabling signal transmissions on said backhaul link and measuring at least one of a noise level and an interfering signal level on said RF carrier frequency of said backhaul channel.

6. The method according to claim 5, wherein said measuring step further comprises transmitting a test signal on said RF carrier frequency of said backhaul channel and measuring an adverse effect of at least one of a noise level and an interfering signal level on said test signal.

7. The method according to claim 6, wherein said adverse effect is measured by determining at least one of a carrier-to-noise level, a carrier-to-interference level, a bit error rate, and a block error rate.

8. The method according to claim 1, wherein said measuring step is performed in accordance with at least one of a predetermined interval, upon detection of a predetermined number of detected bit errors, upon detection of a predetermined number of detected block errors, and upon detection of a predetermined number of frame erasures.

9. In a wireless communication system having a base station located within a home cell, and a plurality of substantially adjacent cells, at least one of said plurality cells having a repeater station located therein, a system for diagnosing a backhaul communication link between said base station and each of said repeater, comprising:

interference measuring means for automatically measuring an interference level for said backhaul communication link; and

link modification means for selectively modifying the operation of said backhaul link to overcome any adverse effect of said interference level, said adjustment being responsive to said measured interference level.

10. The system according to claim 9, wherein said link modification means comprises at least one of increase a power level of signals transmitted over said backhaul link, decrease said power level of signals transmitted over said backhaul link, assignment of an alternative frequency for use as said backhaul link, and send a message to an operations maintenance center.

11. The system according to claim 10, wherein said interference measuring means automatically measures said interference level on an RF carrier frequency of a backhaul channel assigned for said backhaul communications link.

12. The system according to claim 11, wherein said link measuring automatically measures said interference level on at least one downlink RF channel adjacent to said RF carrier frequency of said backhaul channel.

13. The system according to claim 11, wherein said link measuring means disables signal transmissions on said backhaul link and measures at least one of a noise level and an interfering signal level on said RF carrier of said backhaul channel.

14. The system according to claim 13, wherein said link measuring means further comprises means for transmitting a test signal on said RF carrier frequency of said backhaul channel and means for measuring an adverse effect of at least one of a noise level and an interfering signal level on said test signal.

15. The system according to claim 14, wherein said adverse effect is measured by determining at least one of a carrier-to-noise level, a carrier-to-interference level, a bit error rate, and a block error rate.

16. The system according to claim 9, further comprising means for performing said measuring at one of a predetermined interval, upon detection of a predetermined number of detected bit errors, upon detection of a predetermined number of detected block errors, and upon detection of a predetermined number of frame erasures.