SYSTEMS AND METHODS FOR USING PROTOCOL INFORMATION TO TRIGGER WAVEFORM ANALYSIS

• US 20140254647A1
• Filed: 03/05/2013
• Published: 09/11/2014
• Est. Priority Date: 03/05/2013
• Status: Active Grant

• Current Assignee: Keysight Technologies Singapore (Holdings) Pte. Limited. (Keysight Technologies, Inc.)
• Original Assignee: Ixia (Keysight Technologies, Inc.)
• Inventors: Alexander, Thomas, Stott, Lester Noel, Wicker, David Jennings Jr., Marker, Jeffrey Dean, Rekow, Alexander David, Bennington-Davis, Timothy Earl
• Granted Patent: US 9,369,369 B2
• Time in Patent Office: Days
• US Class Current: 375/224
• CPC Class Codes: H04L 1/206 for modulated signals
• CPC Class Codes: H04L 41/24 using dedicated network management hardware
• CPC Class Codes: H04L 43/08 Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
• CPC Class Codes: H04L 43/12 Network monitoring probes
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

Systems and methods are disclosed herein to provide communication test systems for the testing of packet data communication devices, systems and networks. According to one aspect of the subject matter described herein, a test system containing an integrated traffic, protocol and waveform analyzer is disclosed that includes a traffic generator/analyzer and a protocol engine that triggers a waveform analyzer to analyze the signal waveform of a device under test at a predetermined point. Such a test system may offer improved capabilities such as a more selective and accurate measurement of complex signal waveforms, more automated measurements of waveforms pertaining to wireless communication data streams, and more rapid identification and measurement of waveforms corresponding to errored packets.

Claims

1. A system for testing a data communication device under test (DUT), comprising:

a packet transmission datapath for encoding and transmitting packetized data streams to said DUT;

a packet reception datapath for receiving and decoding packetized data streams from said DUT;

a protocol engine coupled to said packet transmission datapath and said packet reception datapath, and operative to implement a communication protocol;

a trigger signal generator configured to generate a trigger signal operative to indicate a predetermined step within said communication protocol; and

a signal analyzer configured to couple to said DUT, and operative to perform an analysis function on said DUT;

wherein said trigger signal causes said signal analyzer to perform said analysis function.

2. The system of claim 1, wherein said signal analyzer is adapted to analyze communication signal waveforms.

3. The system of claim 2, wherein said analysis function is performed on said packetized data streams transmitted by said DUT.

4. The system of claim 2, wherein said signal analyzer is further adapted to analyze the spectral characteristics of said communication signal waveforms.

5. The system of claim 2, wherein said signal analyzer is further adapted to analyze the modulation accuracy of said communication signal waveforms.

6. The system of claim 1, wherein said signal analyzer is integrated within said packet reception datapath.

7. The system of claim 6, wherein said packet reception datapath contains an analog to digital converter to digitize the signal received from said DUT, and said signal analyzer is adapted to utilize said digitized signal.

8. The system of claim 1, wherein said trigger signal is generated at a time delay relative to said predetermined step within said communication protocol.

9. The system of claim 1, wherein said trigger signal is generated to indicate a predetermined packet relative to said predetermined step within said communication protocol.

10. The system of claim 9, wherein said predetermined step within said communication protocol corresponds to a first type of packet, and wherein said predetermined packet corresponds to a second type of packet.

11. The system of claim 9, wherein said first type of packet has a different modulation format from said second type of packet.

12. The system of claim 1, wherein said signal analyzer is adapted to perform said analysis function a plurality of times, responsive to a plurality of occurrences of said trigger signal.

13. The system of claim 12, wherein the data from said plurality of analysis function results is combined.

14. The system of claim 1, wherein said protocol engine and said packet transmission datapath are further adapted to cause said DUT, responsive to said communication protocol, to transmit a plurality of packet types.

15. The system of claim 14, wherein said trigger signal is operative to indicate the occurrence of a first packet type of said plurality of packet types.

16. The system of claim 14, wherein said first packet type is selected in accordance with a specific test requirement.

17. A system for testing a wireless data communication device under test (DUT), comprising:

a packet transmission datapath for encoding and transmitting wireless data packets to said DUT, said transmitted data packets being associated with a plurality of identifiable traffic flows;

a packet reception datapath for receiving and decoding wireless data packets from said DUT, said received data packets being associated with said plurality of identifiable traffic flows;

a protocol engine coupled to said packet transmission datapath and said packet reception datapath, and operative to implement a wireless communication protocol;

a trigger signal generator configured to generate a trigger signal operative to indicate a first traffic flow selected from said plurality of identifiable traffic flows; and

a radio frequency analyzer configured to couple to said DUT, and operative to perform an analysis function on said wireless data packets received from said DUT;

wherein said trigger signal causes said radio frequency analyzer to perform said analysis function.

18. The system of claim 17, wherein said radio frequency analyzer is adapted to analyze the modulation accuracy of the wireless data packets transmitted by said DUT.

19. The system of claim 17, wherein said trigger signal is further operative to indicate a first data packet within a plurality of wireless data packets comprising said predetermined traffic flow.

20. The system of claim 17, wherein said radio frequency analyzer performs said analysis function on said first data packet.

21. The system of claim 17, wherein said trigger signal is further conditioned according to a data value present within said first data packet.

22. The system of claim 21, wherein said first data packet selectably indicates the presence of a second data packet within said plurality of wireless data packets, and further wherein said radio frequency analyzer performs said analysis function on said second data packet.

23. The system of claim 21, wherein said data value is a Frame Check Sequence (FCS) value, and further wherein said FCS value selectably indicates the error status of said first data packet.

24. The system of claim 17, wherein said trigger signal is further operative to indicate a predetermined packet exchange within said wireless communication protocol for said first traffic flow.

25. The system of claim 24, wherein said predetermined packet exchange is an RTS/CTS exchange.

26. The system of claim 24, wherein said predetermined packet exchange is a CTS-to-self exchange.

27. The system of claim 17, wherein said protocol engine is further operative to cause said DUT to transmit data packets of a predetermined type in accordance with a specific test requirement.

28. A system for testing a wireless data communication device under test (DUT), comprising:

a reception datapath for receiving and decoding wireless data from said DUT, the wireless data being formatted according to a format for communicating wireless data, said format including a framing structure, said framing structure further including a plurality of symbols, said symbols containing information corresponding to a plurality of data packet streams, and extracting packet data from said wireless data;

a trigger signal generator coupled to said reception datapath, and operative to receive a plurality of receive data packet streams and to generate a first trigger signal generated for indicating a first region within said framing structure; and

a radio frequency analyzer configured to couple to said DUT, and operative to perform an analysis function on said symbols within said wireless data formatted according to said format;

wherein said first trigger signal causes said radio frequency analyzer to perform said analysis function.

29. The system of claim 28, wherein said first region indicates a first stream of said plurality of receive data packet streams.

30. The system of claim 29, wherein said first region further indicates a first one of a plurality of packets comprising said first stream.

31. The system of claim 28, further comprising:

test traffic generation logic operative to generate a plurality of transmit data packet streams;

a transmission datapath coupled to said test traffic generation logic and operative to accept said transmit data packet streams and encode and transmit them as wireless data, formatted according to said format, to said DUT; and

a second trigger signal generated by said test traffic generation logic, and operative to indicate a second region within said framing structure;

wherein said second trigger signal causes said radio frequency analyzer to perform said analysis function.

32. The system of claim 31, further comprising:

a protocol engine coupled to said test traffic generation logic and test traffic analysis logic, operative to implement a communications protocol; and

a third trigger signal generated by said protocol engine, and operative to indicate a predetermined step within said communications protocol;

wherein said third trigger signal causes said radio frequency analyzer to perform said analysis function.

33. The system of claim 32, further comprising trigger combination logic that selectably combines said first trigger signal, said second trigger signal, and said third trigger signal, wherein said analysis function is performed according to the results of said trigger combination logic.

34. The system of claim 28, further comprising header decoding logic for decoding a plurality of header symbols within said framing structure.

35. The system of claim 34, wherein said first trigger signal is further conditioned by said header decoding logic.

36. The system of claim 35, wherein said first trigger signal is further conditioned by an indication of a receive error.

37. A method of analyzing a waveform generated by a data communication device under test (DUT), comprising the steps of:

communicating with said DUT, in accordance with a communication protocol; and

performing an analysis function on the waveform of signals received from said DUT,

wherein said analysis function is triggered at a predetermined point within said communication protocol.

38. The method of claim 37, wherein said analysis function is a spectral analysis function.

39. The method of claim 37, wherein said analysis function is a modulation accuracy analysis function.

40. The method of claim 39, wherein said modulation accuracy analysis function is an error vector magnitude analysis function.

41. The method of claim 37, wherein said predetermined point within said communication protocol is indicated by decoding at least a first packet of a predetermined type.

42. The method of claim 37, wherein said analysis function is performed a plurality of times, responsive to said communications protocol, to yield a plurality of analysis function results.

43. The method of claim 42, wherein the data from said plurality of analysis function results is combined.

44. The method of claim 37, further including the steps of:

transmitting at least a first packet to said DUT, in accordance with said communication protocol;

delaying by a predetermined interval; and

performing said analysis function on at least a second packet received from said DUT.

45. The method of claim 37, further including the steps of:

transmitting at least a first packet to said DUT, in accordance with said communication protocol;

receiving and decoding a plurality of packets transmitted by said DUT;

waiting until at least a second packet of a predetermined type has been received from said DUT; and

performing said analysis function on said at least second packet.

46. The method of claim 45, wherein said second packet is identified by at least a sequence number field present within said second packet.

47. The method of claim 45, wherein said second packet is identified by at least one address field present within said second packet.

48. A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:

communicating with said DUT, in accordance with a communication protocol; and

performing an analysis function on the waveform of signals received from said DUT,

wherein said analysis function is triggered at a predetermined point within said communication protocol.