System and method for using mobile station signal strength measurements to collect radio frequency isolation data in a cellular network

• US 6,853,842 B1
• Filed: 07/31/2000
• Issued: 02/08/2005
• Est. Priority Date: 07/31/2000
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Baumann, Jill R., Wilson, James Eric
• Primary Examiner(s): Hudspeth, David
• Assistant Examiner(s): Nguyen, Huy D
• Application Number:
  US09/629,787
• Time in Patent Office: 1,653 Days
• Field of Search: 455/423, 455/424, 455/425, 455/67.11, 455/67.4, 455/67.6, 455/226.1, 455/435.2, 455/452.2, 455/446, 455/437, 455/447
• US Class Current: 455/423
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

A system and method collects radio frequency isolation values with the assistance of mobile stations operating within a cellular wireless communication system. A broadcast channel and a broadcast cell/sector are first chosen. Then, the broadcast channel is disabled in neighboring (or all) other cells/sectors in the system. The base station servicing the broadcast cell/sector then transmits on the broadcast cell sector. Mobile stations operating within the system are then directed to measure and report the signal strength of the broadcast channel as well as a traffic channel servicing their ongoing calls. The mobile stations then report these signal strengths to the cellular wireless communication system. The signal strength measurements are then used to calculate cell/sector radio frequency isolation values between the broadcast cell/sector and respective servicing cell/sectors. Because the broadcast channel may be transmitted at a greater level than normal transmissions, a normalization process may be required. This process is then repeated for each cell/sector in the system so that cell/sector radio frequency isolation values may be collected for these other cells/sectors. Finally, all collected cell/sector isolation values are processed and complied to create an isolation matrix.

Claims

1. A method for determining cell/sector pair radio frequency isolation values in a cellular wireless communication system the method comprising:

transmitting on a broadcast channel in a broadcast cell/sector;

disabling transmissions on the broadcast channel in neighboring cells/sectors;

directing a plurality of mobile stations operating within the cellular wireless communication system to measure be strength of the broadcast channel and to measure the strength of respective serving traffic channels;

receiving the measured strengths of the broadcast channel and respective serving traffic channels from the plurality of mobile stations;

using the measured strengths of the broadcast channel and respective serving traffic channels to determine cell/sector pair radio frequency isolation values;

normalizing a measured strength of the broadcast channel to produce a normalized broadcast channel signal strength;

calculating a cell/sector pair radio frequency isolation value using the normalized broadcast channel signal strength and a measure strength of a serving traffic channel.

2. The method of claim 1, further comprising disabling adjacent channels in the broadcast cell/sector.

3. The method of claim 1, further comprising disabling adjacent channels in at least some of the neighboring cells/sectors.

4. The method of claim 1, further comprising:

repeating the previous steps for a plurality of cell/sectors in the cellular wireless communication system to produce a plurality of measured cell/sector pair radio frequency isolation values; and

processing the plurality of measured cell/sector pair radio frequency isolation values to create an isolation matrix.

5. The method of claim 1, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels comprises issuing a mobile assisted handoff message to the plurality of mobile stations.

6. The method of claim 1, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels may alternately comprise issuing a mobile assisted channel assignment message to the plurality of mobile stations.

7. The method of claim 1, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels includes limiting such direction to mobile stations operating within a distance of the broadcast cell/sector.

8. A system-engineering server operating in conjunction with a cellular wireless communication system, the system-engineering server comprising:

a processor;

memory coupled to the processor;

an interface coupled to the processor that allows the system-engineering system server to interact with the cellular wireless communication system; and

the memory storing a plurality of instructions, the plurality of instructions comprising;

a plurality of instructions upon execution by the processor, cause the cellular wireless communication system to transmit on a broadcast channel in a broadcast cell/sector;

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to disable transmissions on the broadcast channel in neighboring cell/sectors;

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to direct a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels;

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to receive the measured strengths of the broadcast channel and respective serving traffic channels from the plurality of mobile stations;

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to use the measured strengths of the broadcast channel and respective serving traffic channels to determine cell/sector pair radio frequency isolation values;

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to normalize a measure strength of the broadcast channel to produce a normalized broadcast channel signal strength; and

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to calculate a cell/sector pair radio frequency isolation value using the normalized broadcast channel signal strength and a measured strength of a serving traffic channel.

9. The system-engineering server of claim 8, further comprising a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to disable adjacent channels in the broadcast cell/sector.

10. The system-engineering server of claim 8, further comprising a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to disable adjacent channels in at least some of the neighboring cells/sectors.

11. The system-engineering server of claim 8, further comprising:

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to repeat the previous operations for a plurality of cell/sectors in the cellular wireless communication system to produce a plurality of measured cell/sector pair radio frequency isolation values; and

a plurality of instructions that, upon execution by the processor, cause the cellular wireless communication system to process the plurality of measured cell/sector pair radio frequency isolation values to create an isolation matrix.

12. The system-engineering server of claim 8, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels comprises issuing a mobile assisted handoff message to the plurality of mobile stations.

13. The system engineering server of claim 8, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to mere the strength of the broadcast channel and to measure the strength of respective serving traffic channels comprises issuing a mobile assisted channel assignment message to the plurality of mobile stations.

14. The system-engineering sever of claim 8, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels includes limiting such direction to mobile stations operating within a distance of the broadcast cell/sector.

15. A computer readable medium that stores a plurality of software instructions that, when executed by a computer interfacing with a cellular wireless communication system, causes the cellular wireless communication system to determining cell/sector pair radio frequency isolation, the computer readable medium comprising:

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to transmit on a broadcast channel in a broadcast cell sector;

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to disable transmissions on the broadcast channel in neighboring cell/sectors;

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to direct a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels;

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to receive the measured strengths of die broadcast channel and respective serving traffic channels from the plurality of mobile stations;

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to use the measured strengths of the broadcast channel and respective serving traffic channels to determine ce/sector pair radio frequency isolation values;

a plurality of instructions that upon execution by the computer cause the cellular wireless communication system to normalize a measured strength of the broadcast channel to produce a normalized broadcast channel signal strength; and

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to calculate a cell/sector pair radio frequency isolation value using the normalized broadcast channel signal strength and a measured strength of a serving traffic channel.

16. The computer readable medium of claim 15, further comprising a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to disable adjacent channels in the broadcast cell/sector.

17. The computer readable medium of claim 15, further comprising a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to disable adjacent channels in at least some of the neighboring cells/sectors.

18. The computer readable medium of claim 15, comprising:

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to repeat the previous steps for a plurality of cell/sectors in the cellular wireless communication system to produce a plurality of measured cell/sector pair radio frequency isolation values; and

a plurality of instructions that, upon execution by the computer, cause the cellular wireless communication system to process the plurality of measured cell/sector pair radio frequency isolation values to create an isolation matrix.

19. The computer readable medium of claim 15, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels comprises issuing a mobile assisted handoff message to the plurality of mobile stations.

20. The computer readable medium of claim 15, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels comprises issuing a mobile assisted channel assignment message to the plurality of mobile stations.

21. The computer readable medium of claim 15, wherein directing a plurality of mobile stations operating within the cellular wireless communication system to measure the strength of the broadcast channel and to measure the strength of respective serving traffic channels includes limiting such direction to mobile stations operating within a distance of the broadcast cell/sector.