Scanning receiver allocation method and apparatus for cellular radiotelephone systems

• US 4,726,050 A
• Filed: 07/13/1987
• Issued: 02/16/1988
• Est. Priority Date: 02/18/1986
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Graziano, Victor, Tayloe, Daniel R., Menich, Barry J., Schaeffer, Dennis R., Lev, Valy
• Primary Examiner(s): Lev, Robert
• Application Number:
  US07/073,916
• Time in Patent Office: 218 Days
• Field of Search: 379/58, 379/59, 379/60, 379/63, 455/33, 455/54, 455/62
• US Class Current: 455/425
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method and apparatus for utilizing voice channel transceivers as temporary scanning receivers in a handoff event for a cellular radiotelephone system is disclosed. Voice channel transceiver identifications are stored in link lists according to priority, sectorization, and last use. When a signal strength measurement is required, those cell sectors having available voice channel transceivers are identified and a table providing optimum transceiver selection is utilized to select those voice channel transceivers which will make the signal strength measurement.

Claims

1. A method of scanning receiver allocation in a cellular radiotelephone system consisting of a plurality of remote telephone units at least one of which is engaged in two way commuications with another telephone unit via fixed equipment covering geographically distinct areas by radio, the engaged remote telephone unit requiring a handoff from serving fixed equipment in one area to fixed equipment in another area, comprising the steps of:

obtaining a voice channel transceiver identification from at least one link list;

determining which voice channel transceiver of the fixed equipment may be available for use as a temporary scanning receiver in an area not serving the engaged remote telephone unit;

selecting at least one said available voice channel transceiver; and

instructing said selecting voice channel transceiver to tune to a radio frequency currently in use by the engaged remote telephone unit and to measure the received signal strength of the engaged remote unit on said radio frequency.

2. A method in accordance with the method of claim 1 further comprising the step of recalling said voice channel transceiver identification from one of at least two reuse lists within said at least one link list.

3. A method in accordance with the method of claim 2 further comprising the step of returning said voice channel transceiver identification to said one of at least two reuse lists of said at least one link list in accordance with a predetermined radio frequency reuse pattern and an association of said voice channel transceiver with a primary antenna.

4. A method in accordance with the method of claim 2 further comprising the step of selecting said voice channel transceiver identification from a preferred one of said at least two reuse lists.

5. A method in accordance with the method of claim 4 wherein said step of selecting said voice channel transceiver identification further comprises the step of selecting on a first-in, first-out basis.

6. A method in accordance with the method of claim 1 further comprising the step of returning said voice channel transceiver identification to said at least one link list.

7. A method in accordance with the method of claim 6 wherein said step of returning a voice channel transceiver identification to said in at least one link list further comprises the step of selecting a guard timing link list for said transceiver identification storage if said voice channel transceiver is in a guard timing mode and selecting an idle channel link list for said transceiver identification storage if said voice channel transceiver is in an idle channel mode.

8. A method in accordance with the method of claim 1 wherein said step of selecting at least one available voice channel transceiver further comprises the step of obtaining a representation of available voice channel transceivers in areas not serving the engaged remote unit.

9. A method in accordance with the method of claim 8 further comprising the step of mapping said obtained representation into one of a plurality of predeterminedly selected geographic area patterns of available voice channel transceivers.

10. A method in accordance with the method of claim 1 further comprising the step of aborting said step of instructing said at least one selected voice channel transceiver to tune to a radio frequency if said selected voice channel transceiver were simultaneously selected to serve a second remote telephone unit as a voice channel transceiver.

11. A base site controller for a cellular radiotelephone system which consists of a plurality of remote telephone units at least one of which may be engaged in two way communications with another telephone unit via fixed equipment, including at least one base site controller and a plurality of voice channel transceivers, covering geographically distinct areas by radio, the engaged remote telephone unit requiring a handoff from serving fixed equipment in one area to fixed equipment in another area, the base site controller comprising:

means for obtaining a voice channel transceiver identification from at least one link list;

means for determining which voice channel transceivers may be available for use as a temporary scanning receiver in at least one area not serving the engaged remote telephone unit;

means for selecting at least one said available voice channel transceiver; and

means for instructing said at least one selected voice channel transceiver to tune to a radio frequency currently in use by the engaged remote telephone unit and to measure the received signal strength of the engaged remote unit on said radio frequency.

12. A base site controller in accordance with claim 11 wherein said means for recalling further comprises second means for recalling said voice channel transceiver identification from one of at least two reuse lists in within said at least one link list.

13. A base site controller in accordance with claim 12 wherein said means for determining further comprises means for returning said voice channel transceiver identification to said one of at least two reuse lists of said at least one link list in accordance with a predetermined radio frequency reuse pattern and an association of said voice channel transceiver with a primary antenna.

14. A base site controller in accordance with claim 12 wherein said first means for recalling further comprises third means for recalling said voice channel transceiver identification from a preferred one of said at least two reuse lists.

15. A base site controller in accordance with claim 14 wherein said third means for recalling said voice channel transceiver identification further comprises fourth means for recalling on a first-in, first-out basis.

16. A base site controller in accordance with claim 11 wherein said first means for recalling a voice channel transceiver identification in at least one link list further comprises means for selecting a guard timing link list for said transceiver identification storage if said voice channel transceiver is in a guard timing mode and for selecting an idle channel link list for said transceiver identification storage if said voice channel transceiver is in an idle channel mode.

17. A base site controller in accordance with claim 11 wherein said means for selecting at least one available voice channel transceiver further comprises means for obtaining a representation of available voice channel transceivers in areas not serving the engaged remote unit.

18. A base site controller in accordance with claim 17 further comprising means for mapping said obtained representation into one of a plurality of predeterminedly selected geographic area patterns of available voice channel transceivers.