Method and apparatus for measuring the error rate of a communication device

• US 20070254643A1
• Filed: 06/09/2006
• Published: 11/01/2007
• Est. Priority Date: 04/28/2006
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Gardner, Robert, Garcia, Francisco, McGilp, Colin
• Application Number:
  US11/450,000
• Publication Number:
  US 20070254643A1
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

An apparatus and method for measuring the error rate of a wireless device, such as a WLAN card, comprising a signal generator, a signal receiver and the device under test configured to transmit and receive frames. The signal generator transmits frames to the device under test, which sends an acknowledgement if a frame has been validly received. A controller counts valid acknowledgements received and pseudo-valid acknowledgements sent by the device (up to a maximum of one per transmitted frame). The pseudo-valid acknowledgements may be corrupted acknowledgements received by the signal receiver or signals resembling an acknowledgement detected during a time when an acknowledgement is expected. Thus a frame error rate is computed based on the total number of valid and pseudo-valid acknowledgements compared to the total number of frames sent.

Claims

1. A method for measuring the error rate of a communication device, the method comprising:

configuring a signal generator and the communication device to communicate;

transmitting a signal frame from the signal generator;

sending an acknowledgement from the communication device if the signal frame is correctly received by the communication device;

determining whether a valid or pseudo-valid acknowledgment has been sent by the communication device;

counting the number of valid and pseudo-valid acknowledgements; and

computing a frame error rate based on the total number of valid and pseudo-valid acknowledgements compared to the total number of signal frames transmitted.

2. The method of claim 1 wherein the device is a wireless device.

3. The method of claim 1, wherein the signal frame comprises pre-formatted data packets.

4. The method of claim 1, wherein determining whether a valid acknowledgement has been sent by the communication device comprises detecting whether a valid acknowledgement is received.

5. The method of claim 1, wherein determining whether a pseudo-valid acknowledgement has been sent by the communication device comprises detecting whether a corrupted acknowledgement is received.

6. The method of claim 1, wherein determining whether a pseudo-valid acknowledgement has been sent by the communication device comprises detecting whether a signal resembling an acknowledgement is detected during a time when an acknowledgement is expected.

7. The method of claim 1, wherein predetermined noise is also transmitted.

8. The method of claim 1, wherein at most one valid or pseudo-valid acknowledgement is counted for each frame transmitted by the signal generator.

9. The method of claim 6, wherein detecting whether a detected signal resembles an acknowledgement comprises determining whether the signal is detected on a channel used for acknowledgements.

10. A system for measuring the error rate of a communication device, the system comprising:

a signal generator for transmitting a signal frame to the communication device;

a controller coupled to said signal generator for controlling the signal generator;

wherein said controller determines whether a valid or pseudo-valid acknowledgment has been sent by the communication device; and

wherein said controller counts the number of valid and pseudo-valid acknowledgements and computes a frame error rate based on the total number of valid and pseudo-valid acknowledgements compared to the total number of signal frames transmitted.

11. The system of claim 10, wherein the device is a wireless device.

12. The system of claim 10, further comprising a signal receiver for receiving valid and pseudo-valid acknowledgements transmitted by the communication device if the signal frame is correctly received by the device.

13. The system of claim 12, wherein the controller, signal generator and signal receiver emulate an access point.

14. The system of claim 10, wherein the frame comprises data packets.

15. The system of claim 12, wherein the signal generator is coupled to a transmit antenna and the signal receiver is coupled to a receive antenna, the transmit and receive antennae and the communication device being isolated in an anechoic chamber or other appropriate RF-shielded test fixture.

16. The system of claim 10, wherein the controller counts at most one valid or pseudo-valid acknowledgement for each signal frame transmitted.

17. The system of claim 10, wherein noise is also transmitted by the signal generator.

18. The system of claim 12, wherein the controller determines whether a valid acknowledgement has been received by the signal receiver.

19. The system of claim 12, wherein the controller determines whether a corrupted acknowledgement has been received by the signal receiver.

20. The system of claim 15, wherein the receive antenna comprises a high sensitivity antenna.

21. The system of claim 20, further comprising a signal analyzer coupled to the high sensitivity antenna, for determining whether a signal resembling an acknowledgement is detected during a time when an acknowledgement is expected.

22. The system of claim 21, wherein the signal analyzer determines whether a detected signal resembles an acknowledgement by determining whether the signal is detected on a channel used for acknowledgements.

23. The system of claim 10, further comprising an authenticating module for originating and authenticating communication with the communication device.