Classification of cellular network drive test results

• US 7,236,779 B2
• Filed: 03/18/2003
• Issued: 06/26/2007
• Est. Priority Date: 04/01/2002
• Status: Active Grant

• Current Assignee: Schema, Inc. (TEOCO)
• Original Assignee: Schema, Inc. (TEOCO)
• Inventors: Abiri, Roni, Lahav, Shlomo, Dunsky, Tal, Hornblass, Vered, Shafran, Gil
• Primary Examiner(s): Hong; Harry S.
• Application Number:
  US10/391,437
• Publication Number:
  US 20040203725A1
• Time in Patent Office: 1,561 Days
• Field of Search: 455/422.1, 455/423, 455/424, 455/446, 455/67.11, 455/67.13, 455/67.14
• US Class Current: 455/423
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

A method for analyzing service in a wireless communication network, which includes multiple antennas, which are assigned to transmit signals over the air to mobile units on respective sets of one or more frequency channels, such that at least two of the antennas transmit the signals on a common frequency channel. The method includes recording levels of the signals received at multiple locations within a service area of the network, while the antennas are transmitting the signals on the respective sets of frequency channels, including simultaneous transmission by the at least two of the antennas on the common frequency channel. The recorded levels and the frequency channels of the received signals are analyzed so as to classify the received signals at each of the locations according to the antennas transmitting the signals.

Claims

1. A method for analyzing service in a wireless communication network, which includes multiple antennas, which are assigned to transmit signals over the air to mobile units on respective sets of one or more frequency channels, such that at least two of the antennas transmit the signals on a common frequency channel, the method comprising:

recording levels of the signals received at multiple locations within a service area of the network, while the antennas are transmitting the signals on the respective sets of frequency channels, including simultaneous transmission by the at least two of the antennas on the common frequency channel; and

analyzing the recorded levels and the frequency channels of the received signals so as to classify the received signals at each of the locations according to the antennas transmitting the signals.

2. The method according to claim 1, wherein recording the levels of the signals comprises recording the levels using a receiver mounted in a vehicle, while the vehicle travels through the service area.

3. The method according to claim 1, wherein the wireless communication network comprises a cellular network, and wherein analyzing the recorded levels and the frequency channels comprises classifying the received signals as originating from cells or sectors of the cellular network that are respectively served by the antennas.

4. The method according to claim 3, wherein classifying the received signals further comprises decoding a color code that is encoded in at least some of the signals, and assigning the signals to the cells or sectors responsively to the color code.

5. The method according to claim 1, wherein recording the levels comprises recording first and second levels of first and second signals received at one of the locations on first and second frequency channels, respectively, and

wherein analyzing the recorded levels and the frequency channels comprises classifying the first signal as having originated from one of the antennas and, responsively to having classified the first signal, classifying the second signal.

6. The method according to claim 5, wherein classifying the first signal comprises computing a first metric with respect to the first signal, indicative of which of the antennas is likeliest, among the antennas transmitting on the first frequency channel, to have transmitted the first signal, and determining a classification of the first signal responsively to the first metric, and

wherein classifying the second signal comprises computing a second metric, indicative of which of the antennas is likeliest, among the antennas transmitting on the second frequency channel, to have transmitted the second signal, wherein the second metric is computed subject to the classification of the first signal.

7. The method according to claim 5, wherein the first signal is classified as having originated from a first one of the antennas, and wherein classifying the second signal comprises classifying the second signal as having originated from a second one of the antennas, different from the first one.

8. The method according to claim 5, wherein the first signal is classified has having originated from a first one of the antennas, and wherein classifying the second signal comprises classifying the second signal as having originated from the first one of the antennas, in addition to the first signal having originated therefrom.

9. The method according to claim 5, wherein recording the levels further comprises recording a third level of a third signal received at the one of the locations on a third frequency channel, and

wherein analyzing the recorded levels and the frequency channels comprises classifying the third signal responsively to having classified the first and second signals.

10. The method according to claim 1, wherein analyzing the recorded levels and the frequency channels comprises sorting the recorded levels so as to generate a respective list, for each of at least some of the antennas, comprising measurements of the levels of the signals recorded at the one of the locations on the respective sets of frequency channels that are assigned to the antennas, and classifying the received signals based on the list.

11. The method according to claim 10, wherein classifying the received signals comprises:

computing a metric with respect to a group of the measurements in the respective list generated with respect to at least one of the antennas, wherein the metric is indicative of a likelihood that the at least one of the antennas transmitted the signals whose measurements are included in the group; and

determining a classification of at least a first signal in the respective list responsively to the metric.

12. The method according to claim 11, wherein computing the metric comprises computing multiple, respective metrics for multiple groups of the measurements, and selecting a maximal metric from among the multiple metrics.

13. The method according to claim 1, wherein the at least two of the antennas transmitting on the common frequency channel comprise first and second antennas, and wherein analyzing the recorded levels and the frequency channels comprises computing respective first and second metrics, indicative of which of the first and second antennas is likelier to have transmitted a signal that was received on the common frequency channel, and classifying the signal based on the first and second metrics.

14. The method according to claim 13, wherein computing the respective first and second metrics comprises estimating respective probabilities of error in assigning the signal to each of the first and second antennas.

15. The method according to claim 13, wherein the first and second antennas are assigned to transmit the signals on first and second frequency channels, which are mutually adjacent, and wherein the common frequency channel is the first frequency channel, and

wherein computing the second metric comprises adjusting the second metric responsively to the transmission by the second antenna on the second, adjacent frequency channel.

16. The method according to claim 13, wherein computing the first and second metrics comprises comparing the signal that was received on the common frequency channel to respective estimated path loss characteristics associated with the transmission of the signal from each of the first and second antennas, and adjusting the metrics in response to the path loss characteristics.

17. The method according to claim 1, wherein analyzing the recorded levels and the frequency channels comprises calculating a probability that a first signal transmitted by a first one of the at least two antennas is masked by a second signal transmitted by a second one of the at least two antennas, and classifying the signals based on the probability.

18. The method according to claim 1, wherein analyzing the recorded levels and the frequency channels further comprises estimating a received signal strength indicator (RSSI) with respect to at least one of the antennas.

19. Apparatus for analyzing service in a wireless communication network, which includes multiple antennas, which are assigned to transmit signals over the air to mobile units on respective sets of one or more frequency channels, such that at least two of the antennas transmit the signals on a common frequency channel, the apparatus comprising a test processor, which is adapted to receive levels of the signals measured at multiple locations within a service area of the network, while the antennas are transmitting the signals on the respective sets of frequency channels, including simultaneous transmission by the at least two of the antennas on the common frequency channel, and which is adapted to analyze the levels and the frequency channels of the measured signals so as to classify the measured signals at each of the locations according to the antennas transmitting the signals.

20. The apparatus according to claim 19, and comprising a receiver mounted in a vehicle, which is adapted to measure the levels of the signals while the vehicle travels through the service area.

21. The apparatus according to claim 19, wherein the wireless communication network comprises a cellular network, and wherein the processor is adapted to classify the received signals as originating from cells or sectors of the cellular network that are respectively served by the antennas.

22. The apparatus according to claim 21, wherein a color code is encoded in at least some of the signals, and wherein the processor is adapted to assign the signals to the cells or sectors responsively to the color code.

23. The apparatus according to claim 19, wherein the levels of the signals comprise at first and second levels of first and second signals received at one of the locations on first and second frequency channels, respectively, and

wherein the processor is adapted to classify the first signal as having originated from one of the antennas and, responsively to having classified the first signal, to classify the second signal.

24. The apparatus according to claim 23, wherein the processor is adapted to classify the first signal by computing a first metric with respect to the first signal, indicative of which of the antennas is likeliest, among the antennas transmitting on the first frequency channel, to have transmitted the first signal, and determining a classification of the first signal responsively to the first metric, and is further adapted to classify the second signal by computing a second metric, indicative of which of the antennas is likeliest, among the antennas transmitting on the second frequency channel, to have transmitted the second signal, wherein the second metric is computed subject to the classification of the first signal.

25. The apparatus according to claim 23, wherein the processor is adapted to classify the first signal as having originated from a first one of the antennas, and to classify the second signal as having originated from a second one of the antennas, different from the first one.

26. The apparatus according to claim 23, wherein the processor is adapted to classify both the first and second signals as having originated from a first one of the antennas.

27. The apparatus according to claim 23, wherein the levels of the signals further comprise a third level of a third signal received at the one of the locations on a third frequency channel, and

wherein the processor is adapted to classify the third signal responsively to having classified the first and second signals.

28. The apparatus according to claim 19, wherein the processor is adapted to sort the measured signals so as to generate a respective list, for each of at least some of the antennas, comprising measurements of the levels of the signals recorded at the one of the locations on the respective sets of frequency channels that are assigned to the antennas, and to classify the received signals based on the list.

29. The apparatus according to claim 28, wherein the processor is adapted to compute a metric with respect to a group of the measurements in the respective list generated with respect to at least one of the antennas, wherein the metric is indicative of a likelihood that the at least one of the antennas transmitted the signals whose measurements are included in the group, and to determine a classification of at least a first signal in the respective list responsively to the metric.

30. The apparatus according to claim 29, wherein the processor is adapted to compute multiple, respective metrics for multiple groups of the measurements, and to select a maximal metric from among the multiple metrics for use in determining the classification.

31. The apparatus according to claim 19, wherein the at least two of the antennas transmitting on the common frequency channel comprise first and second antennas, and wherein the processor is adapted to compute respective first and second metrics, indicative of which of the first and second antennas is likelier to have transmitted a signal that was received on the common frequency channel, and to classify the signal based on the first and second metrics.

32. The apparatus according to claim 31, wherein the respective first and second metrics are indicative of respective probabilities of error in assigning the signal to each of the first and second antennas.

33. The apparatus according to claim 31, wherein the first and second antennas are assigned to transmit the signals on first and second frequency channels, which are mutually adjacent, and wherein the common frequency channel is the first frequency channel, and

wherein the processor is adapted to adjust the second metric responsively to the transmission by the second antenna on the second, adjacent frequency channel.

34. The apparatus according to claim 31, wherein the processor is adapted to compare the signal that was received on the common frequency channel to respective estimated path loss characteristics associated with the transmission of the signal from each of the first and second antennas, and to adjust the metrics in response to the path loss characteristics.

35. The apparatus according to claim 19, wherein the processor is adapted to calculate a probability that a first signal transmitted by a first one of the at least two antennas is masked by a second signal transmitted by a second one of the at least two antennas, and to classify the signals based on the probability.

36. The apparatus according to claim 19, wherein the processor is adapted to estimate, based on the levels and frequency channels of the measured signals, a received signal strength indicator (RSSI) with respect to at least one of the antennas.

37. A computer software product for analyzing service in a wireless communication network, which includes multiple antennas, which are assigned to transmit signals over the air to mobile units on respective sets of one or more frequency channels, such that at least two of the antennas transmit the signals on a common frequency channel, the product comprising a computer readable medium, in which program instructions are stored, which instructions, when read by a computer, cause the computer to receive levels of the signals measured at multiple locations within a service area of the network, while the antennas are transmitting the signals on the respective sets of frequency channels, including simultaneous transmission by the at least two of the antennas on the common frequency channel, and further cause the computer to analyze the levels and the frequency channels of the measured signals so as to classify the measured signals at each of the locations according to the antennas transmitting the signals.

38. The product according to claim 37, wherein the levels of the signals are measured by a receiver mounted in a vehicle, while the vehicle travels through the service area.

39. The product according to claim 37, wherein the wireless communication network comprises a cellular network, and wherein the instructions cause the computer to classify the received signals as originating from cells or sectors of the cellular network that are respectively served by the antennas.

40. The product according to claim 39, wherein a color code is encoded in at least some of the signals, and wherein the instructions cause the computer to assign the signals to the cells or sectors responsively to the color code.

41. The product according to claim 37, wherein the levels of the signals comprise at first and second levels of first and second signals received at one of the locations on first and second frequency channels, respectively, and

wherein the instructions cause the computer to classify the first signal as having originated from one of the antennas and, responsively to having classified the first signal, to classify the second signal.

42. The product according to claim 41, wherein the instructions cause the computer to classify the first signal by computing a first metric with respect to the first signal, indicative of which of the antennas is likeliest, among the antennas transmitting on the first frequency channel, to have transmitted the first signal, and determining a classification of the first signal responsively to the first metric, and further cause the computer to classify the second signal by computing a second metric, indicative of which of the antennas is likeliest, among the antennas transmitting on the second frequency channel, to have transmitted the second signal, wherein the second metric is computed subject to the classification of the first signal.

43. The product according to claim 42, wherein the instructions cause the computer to classify the first signal as having originated from a first one of the antennas, and to classify the second signal as having originated from a second one of the antennas, different from the first one.

44. The product according to claim 42, wherein the instructions cause the computer to classify both the first and second signals as having originated from a first one of the antennas.

45. The product according to claim 42, wherein the levels of the signals further comprise a third level of a third signal received at the one of the locations on a third frequency channel, and

wherein the instructions cause the computer to classify the third signal responsively to having classified the first and second signals.

46. The product according to claim 37, wherein the instructions cause the computer to sort the measured signals so as to generate a respective list, for each of at least some of the antennas, comprising measurements of the levels of the signals recorded at the one of the locations on the respective sets of frequency channels that are assigned to the antennas, and to classify the received signals based on the list.

47. The product according to claim 46, wherein the instructions cause the computer to compute a metric with respect to a group of the measurements in the respective list generated with respect to at least one of the antennas, wherein the metric is indicative of a likelihood that the at least one of the antennas transmitted the signals whose measurements are included in the group, and to determine a classification of at least a first signal in the respective list responsively to the metric.

48. The product according to claim 47, wherein the instructions cause the computer to compute multiple, respective metrics for multiple groups of the measurements, and to select a maximal metric from among the multiple metrics for use in determining the classification.

49. The product according to claim 37, wherein the at least two of the antennas transmitting on the common frequency channel comprise first and second antennas, and wherein the instructions cause the computer to compute respective first and second metrics, indicative of which of the first and second antennas is likelier to have transmitted a signal that was received on the common frequency channel, and to classify the signal based on the first and second metrics.

50. The product according to claim 49, wherein the respective first and second metrics are indicative of respective probabilities of error in assigning the signal to each of the first and second antennas.

51. The product according to claim 49, wherein the first and second antennas are assigned to transmit the signals on first and second frequency channels, which are mutually adjacent, and wherein the common frequency channel is the first frequency channel, and

wherein the instructions cause the computer to adjust the second metric responsively to the transmission by the second antenna on the second, adjacent frequency channel.

52. The product according to claim 49, wherein the instructions cause the computer to compare the signal that was received on the common frequency channel to respective estimated path loss characteristics associated with the transmission of the signal from each of the first and second antennas, and to adjust the metrics in response to the path loss characteristics.

53. The product according to claim 37, wherein the instructions cause the computer to calculate a probability that a first signal transmitted by a first one of the at least two antennas is masked by a second signal transmitted by a second one of the at least two antennas, and to classify the signals based on the probability.

54. The apparatus according to claim 37, wherein the instructions cause the computer to estimate, based on the levels and frequency channels of the measured signals, a received signal strength indicator (RSSI) with respect to at least one of the antennas.