Method for determining hand-off candidates in a neighbor set in a CDMA communication system

• US 6,195,342 B1
• Filed: 11/25/1997
• Issued: 02/27/2001
• Est. Priority Date: 11/25/1997
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Rohani, Kamyar
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): BOAKYE, ALEXANDER O
• Application Number:
  US08/977,913
• Time in Patent Office: 1,190 Days
• Field of Search: 370/335, 370/331, 370/332, 370/337, 375/200, 375/206, 455/33.4, 455/422, 455/442
• US Class Current: 370/331
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data

Abstract

A CDMA communication system (400) includes a plurality of base stations (410, 420 and 430) transmitting at least a corresponding plurality of pilot signals. A mobile station (401) in a coverage area of the system (400) receives at least one of the plurality of pilot signals and transmits a Pilot Strength Measurement Message that includes a Neighbor Set of a list of a plurality of candidate pilots for a and-off routine. A method and apparatus for determining the Neighbor Set includes finding a location of the mobile station (401) in the coverage area of system (400) and determining the list of plurality of candidate pilots in the Neighbor Set according to the location of the mobile station (401).

Claims

1. A method of determining a Neighbor Set in a communication system, the communication system providing wireless communication, the communication system including a plurality of base stations which provide wireless coverage over a corresponding plurality of cell areas, and a mobile station located in one of said plurality of cell areas, the mobile station transmitting a Pilot Strength Measurement Message including a Neighbor Set of a list of a plurality of hand-off candidate base stations, the method comprising the steps of:

associating a plurality of regions corresponding to said plurality of cell areas where each region extends beyond its corresponding cell area;

determining overlapped areas where two or more of said plurality of regions are overlapping;

determining whether said mobile station location is in one of the overlapped areas, said list of said plurality of hand-off candidate base stations in said Neighbor Set including at least the base stations having associated regions that overlap the area where said mobile station is located;

wherein the extent of one of said plurality of regions is at least as far as covering a partial area of another cell area in said plurality of cell areas.

2. The method as recited in claim 1 wherein the extent of one of said plurality of regions is as far as at least covering a partial area of a nearest cell area in said plurality of cell areas.

3. A method of determining a Neighbor Set in a communication system, the communication system providing wireless communication in a coverage area, the communication system including a plurality of base stations transmitting at least a corresponding plurality of pilot signals, and a mobile station receiving at least one of the plurality of pilot signals and transmitting a Pilot Strength Measurement Message including a Neighbor Set of a list of a plurality of candidate pilots, the method comprising the steps of:

finding a location of said mobile station in said coverage area;

determining said list of plurality of candidate pilots in said Neighbor Set according to the location of said mobile station; and

determining an attribute of said mobile station in said coverage area to be used in determining said list of plurality of candidate pilots, said attribute comprising one of a speed of said mobile station movement in said coverage area, and a direction of said mobile station movement in said coverage area.

4. A method of determining ads recited in claim 3, wherein said attribute is used in deciding a frequency of performing said determining step.