Method and apparatus for balancing the forward link handoff boundary to the reverse link handoff boundary in a cellular communication system

Claim 2

In a system having a plurality of base stations capable of bi-directional communication with a mobile unit wherein information is communicated to said mobile unit from said plurality of base stations on a forward link and information is communicated to said plurality of base stations from said mobile unit on a reverse link and wherein each base station defines a forward link coverage area and a reverse link coverage area, a method of controlling said base station coverage areas comprising the steps of: measuring a reverse link power level received at a first base station; and adjusting a forward link power level at said first base station based on said reverse link power level measurement at said first base station to preserve a balance of said forward link coverage area to said reverse link coverage area.

Claim 3

The method of claim 1 wherein the forward link power level is adjusted at said first base station such that the product of said reverse link power level at said first base station and said forward link power level at said first base station remains equal to a constant.

Claim 4

The method of claim 1 further including the steps of: measuring a reverse link power level received at said second base station; and adjusting a forward link power level at said second base station based on said reverse link power level measurement at said second base station such that the product of said reverse link power level at said second base station and said forward link power level at said second base station remains equal to a constant.

Claim 5

In a system having a plurality of base stations, each of said plurality of base stations having a corresponding forward link coverage area and a corresponding reverse link coverage area wherein each of said plurality of base stations is capable of communicating to a mobile unit located within said corresponding forward link coverage area and each of said plurality of base stations is capable of receiving communication from a mobile unit located within said corresponding reverse link coverage area, a method of aligning a location of a first forward link coverage area to a location of a first reverse link coverage area corresponding to a first base station comprising the steps of: changing, at said first base station, a level of artificial loading associated with said first reverse link coverage area to alter a location of said first reverse link coverage area; and changing a level of transmit power from said first base station based upon change in said level of artificial loading in order to correspondingly alter said location of said first forward link coverage area.

Claim 6

In a system having a plurality of base stations, each of said plurality of base stations having a corresponding forward link coverage area and a corresponding reverse link coverage area wherein each of said plurality of base stations is capable of communicating to a mobile unit located within said corresponding forward link coverage area and each of said plurality of base stations is capable of receiving communication from a mobile unit located within said corresponding reverse link coverage area, a method of aligning a location of a first forward link coverage area to a location of a first reverse link coverage area corresponding to a first base station comprising the steps of: changing, at said first base station, a level of artificial loading associated with said first reverse link coverage area to alter a location of said first reverse link coverage area; and changing a level of transmit power from said first base station based upon change in said level of artificial loading in order to correspondingly alter said location of said first forward link coverage area.

Claim 7

The method of aligning of claim 4 wherein said level of artificial loading of said reverse link coverage area is changed in response to a measured level of loading, said measured level of loading being determined from energy received at said first base station from a set of mobile units located within said first reverse link coverage area.

Claim 8

The method of aligning of claim 5 wherein said measured level of loading is further determined on the basis of energy received from a non system user and a set of mobile units located within a reverse link coverage area corresponding to a second base station.

Claim 9

In a system including a plurality of base stations, a method for defining a coverage boundary associated with a first base station comprising the steps of: transmitting a forward link signal at a selected power level from a first base station, said selected power level defining a first forward link coverage area and being chosen such that said first forward link coverage area intersects a second forward link coverage area of a second base station and thereby defines a forward link equality location at which a mobile unit receives communication with the same performance level with said first base station and said second base station; receiving a reverse link signal at a first power level at said first base station, said first power level corresponding to a first reverse link coverage area which intersects a second reverse link coverage area of a second base station and thereby defines a reverse link equality location at which said first base station and said second base station receive communication from a mobile unit with the same performance level, said selected power level being further chosen such that said forward link equality location and said reverse link equality location are the same.

Claim 10

In a system including a plurality of base stations, a method for defining a coverage boundary associated with a first base station comprising the steps of: transmitting a forward link signal at a selected power level from a first base station, said selected power level defining a first forward link coverage area and being chosen such that said first forward link coverage area intersects a second forward link coverage area of a second base station and thereby defines a forward link equality location at which a mobile unit receives communication with the same performance level with said first base station and said second base station; receiving a reverse link signal at a first power level at said first base station, said first power level corresponding to a first reverse link coverage area which intersects a second reverse link coverage area of a second base station and thereby defines a reverse link equality location at which said first base station and said second base station receive communication from a mobile unit with the same performance level, said selected power level being further chosen such that said forward link equality location and said reverse link equality location are the same.

Claim 11

The method of claim 7 further comprising the steps of: receiving at said first base station said reverse link signal at a second power level higher than said first power level received at said first base station, thereby defining a second smaller reverse link coverage area of said first base station and defining a new reverse link equality location; and transmitting from said first base station said forward link signal at a lower power level defining a second forward link coverage area and a new forward link equality location such that said new forward link equality location is the same as said new reverse link equality location.

Claim 12

The method of claim 7 wherein each of said plurality base stations in said system transmits a pilot signal, said forward link signal from said first base station consisting of said pilot signal corresponding to said first base station.

Claim 13

The method of claim 7 wherein each of said plurality of base stations in said system transmits a pilot signal and message signals, said forward link signal from said first base station consisting of said pilot signal and said message signals corresponding to said first base station.

Claim 14

The method of claim 7 wherein the product of said selected power level of said forward link signal from said first base station and said first power level of said reverse link signal from said first base station is equal to a constant.

Claim 15

The method of claim 11 wherein said constant is dynamic and varies over time.

Claim 16

The method of claim 7 wherein said first power level of said reverse link signal at said first base station includes a level of artificial power chosen such that the product of said selected power level of said forward link signal from said first base station and said power level of said reverse link signal from said first base station is equal to a constant.

Claim 19

The apparatus of claim 14 further including means for setting said product to a constant when said power level of said incoming signal is minimum.