Method and apparatus for performing local traffic measurements in a cellular telephone network

• US 5,946,612 A
• Filed: 03/28/1997
• Issued: 08/31/1999
• Est. Priority Date: 03/28/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Johansson, .ANG.ke
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US08/828,412
• Time in Patent Office: 886 Days
• Field of Search: 455/405, 455/67.1, 455/453, 455/442, 455/436, 455/437, 455/438, 455/439, 455/440, 455/433, 455/434, 455/450, 455/515, 455/446-449, 455/67.4, 455/423, 379/113, 379/133-138
• US Class Current: 455/405
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

A method and apparatus for measuring telephone traffic volume in a cellular telephone system which, in a first embodiment, includes a receiver located at a proposed micro-cell site for measuring the traffic volume. In a second embodiment, a test base station transmits a signal and a processor communicates with a base station controller serving macro-cells surrounding the proposed micro-cell site to extract signal strength measurement reports transmitted to the cellular telephone network from mobile stations receiving the signal transmitted by the test base station. In a third embodiment, the test base station is located at the proposed micro-cell site and is assigned a location area identity different from that of the macro-cells surrounding the proposed micro-cell. Mobile stations operating in and around the proposed micro-cell site are required to register in the new location area and transmit a signal strength report which includes the signal strength of the test base station.

Claims

1. A method for measuring cellular telephone traffic volume in a proposed cell site of a cellular telephone network comprising the steps of:

disabling mobile station power regulation within the proposed cell site;

measuring signal strength and duration of mobile station transmissions on at least one radio frequency used by a base station currently servicing the proposed cell site; and

extrapolating the cellular telephone traffic volume based on the signal strengths, the signal durations, and total number of radio frequencies used by the base station currently servicing the proposed cell site.

2. The method recited in claim 1, wherein the step of measuring signal strength and duration comprises sampling the signal strength of each time slot transmitted by mobile stations within the proposed cell site.

3. The method recited in claim 2, wherein the step of extrapolating the cellular telephone traffic volume comprises the steps of:

dividing the number of sampled time slots, wherein the signal strength exceeds a desired threshold level, by the product of total number of time slots sampled and the total number of radio frequencies measured to calculate a fractional time that the sampled signal exceeded the desired threshold level; and

multiplying the fractional time by the total number of radio frequencies used by the base station currently servicing the proposed cell site location.

4. A method for measuring cellular telephone traffic volume in a proposed cell site of a cellular telephone network comprising the steps of:

disabling mobile station power regulation within the proposed cell site;

measuring signal strength and duration of mobile station transmissions on at least one radio frequency for each of a plurality of base stations currently servicing the proposed cell site; and

extrapolating the cellular telephone traffic volume based on the signal strengths, the signal durations, and total number of radio frequencies collectively used by the plurality of base stations currently servicing the proposed cell site.

5. The method recited in claim 4, wherein the step of measuring signal strength and duration comprises sampling the signal strength of each time slot transmitted by mobile stations within the proposed cell site.

6. The method recited in claim 4, wherein the step of extrapolating the cellular telephone traffic volume comprises the steps of:

dividing the number of sampled time slots, wherein the signal strength exceeds a desired threshold level, by the product of the total number of time slots measured and the total number of radio frequencies sampled to calculate a fractional time that the sampled signal exceeds the desired threshold level; and

multiplying the fractional time by the total number of radio frequencies collectively used by the base stations currently servicing the proposed cell site.

7. A method for measuring cellular telephone traffic volume in a proposed cell site of a hierarchical cellular telephone network comprising the steps of:

establishing a test base station within the cellular telephone network;

transmitting at least one assigned radio frequency from the test base station located at the proposed cell site;

monitoring, over a period of time, the number of signal strength reports transmitted by mobile stations to the cellular telephone network containing a signal strength measurement of the test base station; and

calculating the cellular telephone traffic volume based on the total number of signal strength reports containing a signal strength measurement of the test base station wherein the strength exceeds a desired threshold level, the monitored period of time, and a period of time representing each signal strength report.

8. The method recited in claim 7, wherein the step of establishing a test base station further includes the steps of:

assigning at least one radio frequency for use by the test base station;

instructing mobile stations to include the test base station in signal strength reports; and

prohibiting mobile stations from attempting to access the test base station.

9. The method recited in claim 7, wherein the step of establishing a test base station further includes the steps of:

assigning at least one radio frequency for transmission by the test base station;

including the test base station in broadcast control channel allocation lists of cell sites surrounding the proposed cell site thereby requiring mobile stations to include measured signal strengths of the test base station in signal strength reports; and

setting a cell-bar flag to prohibit mobile stations from attempting to access the test base station.

10. The method recited in claim 7, wherein the step of transmitting the at least one assigned radio frequency comprises transmitting a broadcast control channel.

11. The method recited in claim 10, wherein the step of extracting signal strength reports from the cellular telephone network includes extracting the signal strength reports from at least one base station controller in communication with at least one base station currently servicing the proposed cell site.

12. The method recited in claim 7, wherein the step of monitoring the number of signal strength reports transmitted by mobile stations includes the steps of:

omitting the test base station from neighbor cell lists to identify signal strength reports as containing an unidentified neighbor;

extracting, from the cellular telephone network, all signal strength reports identified as an unidentified neighbor; and

recording the number of signal strength reports containing a signal strength measurement for the unidentified neighbor in which the strength exceeds a threshold level.

13. The method recited in claim 7, wherein the step of calculating the cellular telephone traffic volume includes the steps of:

multiplying the total number of signal strength reports containing a signal strength measurement of the test base station, wherein the signal strength of the test base station exceeds a desired threshold level, by the period of time representing each signal strength report to obtain a duration of time when the test base station signal strength exceeds the threshold level; and

dividing the duration of time by the monitored period of time.

14. An apparatus for measuring cellular telephone traffic volume in a proposed cell site of a hierarchical cellular telephone network comprising:

a radio transmitter located at the proposed cell site for transmitting a broadcast control channel;

at least one base station for receiving signal strength reports containing signal strength measurements of the radio transmitter from mobile stations; and

a processor for monitoring the signal strength reports received by the base station, and further, for calculating the cellular telephone traffic volume based on the signal strength reports, signal durations and total number of radio frequencies used by the radio transmitter.

15. A method for measuring cellular telephone traffic volume in a proposed cell site of a cellular telephone network comprising the steps of:

establishing a test base station within the cellular telephone network;

transmitting at least one assigned radio frequency from the test base station located at the proposed cell site;

monitoring, over a period of time, the number of signal strength reports transmitted by mobile stations to the cellular telephone network containing a signal strength measurement of the test base station;

extracting the signal strength reports from at least one base station-controller in communication with at least on base station currently servicing the proposed cell site; and

calculating the cellular telephone traffic volume based on the total number of signal strength reports wherein the signal strength measurement of the test base station exceeds the signal strength measurement of a base station currently serving the mobile station, the monitored period of time, and a period of time representing each signal strength report.

16. The method recited in claim 15, wherein the step of establishing a test base station further includes the steps of:

assigning a radio frequency for use by the test base station;

instructing mobile stations to include the test base station in signal strength reports; and

prohibiting mobile stations from attempting to access the test base station.

17. The method recited in claim 15, wherein the step of establishing a test base station further includes the steps of:

assigning a radio frequency for transmission by the test base station;

including the test base station in broadcast control channel allocation lists of cell sites surrounding the proposed cell site thereby requiring mobile stations to include measured signal strengths of the test base station in signal strength reports; and

setting a cell-bar flag to prohibit mobile stations from attempting to access the test base station.

18. The method recited in claim 15, wherein the step of transmitting the at least one assigned radio frequency comprises transmitting a broadcast control channel.

19. The method recited in claim 15, wherein the step of monitoring the number of signal strength reports transmitted by mobile stations includes the steps of:

omitting the test base station from neighbor cell lists to identify signal strength reports as containing an unidentified neighbor;

extracting, from the cellular telephone network, all signal strength reports identified as containing an unidentified neighbor; and

recording the number of signal strength reports containing a signal strength measurement for the unidentified neighbor in which the strength of the test base station exceeds the signal strength of a base station currently serving the mobile station.

20. The method recited in claim 15, wherein the step of calculating the cellular telephone traffic volume includes the steps of:

multiplying the total number of signal strength reports, wherein the signal strength of the test base station exceeds the signal strength of the base station currently serving the mobile station, by the period of time representing each signal strength report to obtain a duration of time when the test base station signal strength exceeds the signal strength of the base station currently serving the mobile station; and

dividing the duration of time by the monitored period of time.

21. A method for measuring cellular telephone traffic volume in a proposed cell site of a cellular telephone network comprising the steps of:

locating a test base station within the cellular telephone network;

assigning the proposed cell site a new location area identity different from cell sites surrounding the proposed cell site thereby forcing idle mobile stations to register with the test base station;

transmitting a broadcast control channel from the test base station;

receiving location updating requests and a signal strength measurement reports transmitted by idle mobile stations;

responding with a rejection to the location updating request, the response being delayed until a signal strength measurement report has been received by the test base station; and

multiplying the number of signal strength reports transmitted to the test base station, wherein the strength of the test base station exceeds a desired threshold level, by a statistical ratio of the number of active to idle mobile stations to determine the cellular telephone traffic volume.

22. The method recited in claim 21, wherein the base station is disconnected from the cellular telephone network.

23. A method for measuring cellular telephone traffic volume in a proposed cell site of a cellular telephone network comprising the steps of:

locating a test base station within the cellular telephone network;

assigning the proposed cell site a new location area identity different from cell sites surrounding the proposed cell site thereby forcing idle mobile stations to register with the test base station;

transmitting a broadcast control channel from the test base station;

receiving location updating requests and a signal strength measurement reports transmitted by idle mobile stations;

responding with a rejection to the location updating request, the response being delayed until a signal strength measurement report has been received by the test base station; and

multiplying the number of signal strength reports transmitted to the test base station, wherein the signal strength of the test base station exceeds signal strengths of base stations surrounding the proposed cell site, by a statistical ratio of the number of active to idle mobile stations to determine the cellular telephone traffic volume.

24. The method recited in claim 23, wherein the base station is disconnected from the cellular telephone network.

25. Apparatus for measuring cellular telephone traffic volume in a proposed cell site of a cellular telephone network comprising:

a test base station assigned a distinct location area identity and located at the proposed cell site, the test base station for broadcasting a control channel and receiving both location updating requests and signal strength reports containing signal strength measurements of the test base station from mobile stations, the base station further for transmitting a rejection denying service by the test base station to the mobile station in response to receipt of the location updating request and the signal strength report, and

a processor communicating with the test base station, the processor for recording signal strength reports received by the test base station and further for calculating cellular telephone traffic volume based on the signal strength reports, signal durations and total number of radio frequencies used by the test base station.