Navigation assistance for call handling in mobile telephone systems

Claim 2

In a multiple access, spread spectrum communications system, a method for establishing communications between a mobile station and at least one base station, said method including the steps of: broadcasting a signal to said mobile station from at least one base station wherein the broadcast signal from said at least one base station includes data; receiving at said mobile station the broadcast signal of said at least one base station; determining a mean signal strength for said received broadcast signal; and estimating a distance between the mobile station and said at least one base station based on said data and said mean signal strength of said received broadcast signal.

Claim 3

A method according to claim 1, further including the steps of: determining an initial transmit power level to be used by said mobile station in initiating transmission to said at least one base station using said estimated distance.

Claim 4

A method according to claim 2, further including the steps of: determining signal transmission timing based on a timing reference in said data of the broadcast signal and said estimated distance; and transmitting a signal from said mobile station to said at least one base station in accordance with the determined signal transmission timing.

Claim 5

A method according to claim 2, wherein said data in said broadcast signal includes signal strengths at varying distances from said at least one base station.

Claim 6

A method according to claim 4, wherein said data in said broadcast signal further includes at least one of distance and propagation time delay from said at least one base station to neighboring base stations.

Claim 7

A method according to claim 5, wherein said data in said broadcast signal further includes bearing from said at least one base station to said neighboring base stations.

Claim 8

A method according to claim 6, wherein said data in said broadcast signal further includes an absolute position of said at least one base station and an identifier code to uniquely identify said at least one base station.

Claim 9

A method according to claim 2, further including the step of reporting from said mobile station to said at least one base station the estimated distance between said at least one base station and said mobile station and the mean signal strength received by said mobile station.

Claim 10

A method according to claim 8, further including the steps of: determining signal transmission timing based on a timing reference in said data of the broadcast signal and said estimated distance; and reporting from said mobile station to said at least one base station the determined signal transmission timing.

Claim 11

A method according to claim 9, further including the step of determining at said at least one base station signal strengths of said at least one base station at different distances by averaging a previous signal strength report from other mobile stations at similar distances from said at least one base station.

Claim 12

A method according to claim 10, further including: reporting from other mobile stations an estimated distance between said other mobile stations and said at least one base station; identifying each other mobile station at a similar distance from said at least one base station with the reported estimated distances.

Claim 13

A method according to claim 11, wherein other base stations have a timing reference in common with said at least one base station.

Claim 14

A method according to claim 12, further including the steps of: reporting from said other base stations to said at least one base station time of arrival of the mobile station signal relative to the timing reference of said at least one base station over a radio link or landline network; and identifying said other mobile stations at distances from said at least one base station using the time of arrival reports and reported estimated distances.

Claim 15

In a multiple access, spread spectrum communications system, a method for establishing communications between a mobile station and a base station including the steps of: broadcasting a signal to said mobile station from a first base station wherein said first base station broadcast signal includes first information containing a signal strength profile at different distances from said first base station in a broad direction of a second base station; broadcasting a signal to said mobile station from said second base station wherein said second base station broadcast signal includes second information containing a signal strength profile at different distances from said second base station in a broad direction of said first base station; measuring mean signal strengths of said first base station broadcast signal and said second base station broadcast signal; determining whether a beating of the mobile station from said first base station is in a broad direction of said second base station based on said first information, said second information, and the measured mean signal strengths; and estimating a distance from said mobile station to said first base station using said first base station signal strength profile if the bearing is in the broad direction of the second base station.

Claim 16

In a multiple access, spread spectrum communications system, a method for establishing communications between a mobile station and a base station including the steps of: broadcasting a signal to said mobile station from a first base station wherein said first base station broadcast signal includes first information containing a signal strength profile at different distances from said first base station in a broad direction of a second base station; broadcasting a signal to said mobile station from said second base station wherein said second base station broadcast signal includes second information containing a signal strength profile at different distances from said second base station in a broad direction of said first base station; measuring mean signal strengths of said first base station broadcast signal and said second base station broadcast signal; determining whether a beating of the mobile station from said first base station is in a broad direction of said second base station based on said first information, said second information, and the measured mean signal strengths; and estimating a distance from said mobile station to said first base station using said first base station signal strength profile if the bearing is in the broad direction of the second base station.

Claim 17

A method according to claim 14, wherein said first information includes a unique identifier code to identify said second base station.

Claim 18

In a multiple access, spread spectrum communications system, a method for establishing communications between a mobile station and a base station assigned to said mobile station including the steps of: receiving at the mobile station broadcast signals from the assigned base station; measuring a received signal strength of the broadcast signals; estimating a position of the mobile station based on the received signal strength; and determining an appropriate timing advance for signal transmission from the mobile station to the assigned base station according to the estimated position.

Claim 19

In a multiple access, spread spectrum communications system, a method for establishing communications between a mobile station and a base station assigned to said mobile station including the steps of: receiving at the mobile station broadcast signals from the assigned base station; measuring a received signal strength of the broadcast signals; estimating a position of the mobile station based on the received signal strength; and determining an appropriate timing advance for signal transmission from the mobile station to the assigned base station according to the estimated position.

Claim 20

A method according to claim 16, further including the steps of: receiving broadcast signals from at least one neighboring base station; and measuring timing differences between the broadcast signals received from said at least one neighboring base station wherein said step of estimating the position of the mobile station is further based on the measured timing differences.

Claim 21

A method according to claim 17, wherein said broadcast signals from said at least one neighboring base station include a signal strength profile along a line connecting the assigned base station with said at least one neighboring base station.

Claim 22

A method according to claim 18, further including the step of receiving broadcast signals from a first neighboring base station and a second neighboring base station including radial distances and bearings between said first neighboring base station and said second neighboring base station, said first neighboring base station being adjacent to said second neighboring base station.

Claim 23

A method according to claim 18, wherein said broadcast signals received by the mobile station are synchronized transmissions from said assigned base station and said at least one neighboring base station.

Claim 24

A method according to claim 16, wherein said step of estimating position further includes the step of estimating velocity of the mobile station.

Claim 25

A method according to claim 21, wherein the estimated velocity is determined using a Kalman filtering technique.

Claim 26

A method according to claim 16, wherein said timing advance corresponds to twice a propagation delay over a distance from the mobile station to the assigned base station.

Claim 27

In a multiple access, spread spectrum communications system, a method for establishing communications between a mobile station and a base station assigned to said mobile station including the steps of: broadcasting signals from neighboring base stations and the assigned base station, said broadcast signals including bearing information; receiving the broadcast signals at said mobile station; calculating a beating of said assigned base station and said neighboring base stations with respect to the mobile station based on the broadcast signals; estimating distance from the mobile station to the assigned base station and a signal timing for transmitting a signal from said mobile station to said assigned base station according to said calculated bearings; and transmitting said signal from said mobile station to said assigned base station with said estimated signal timing.

Claim 28

In a multiple access, spread spectrum communications system, a method for establishing communications between a mobile station and a base station assigned to said mobile station including the steps of: broadcasting signals from neighboring base stations and the assigned base station, said broadcast signals including bearing information; receiving the broadcast signals at said mobile station; calculating a beating of said assigned base station and said neighboring base stations with respect to the mobile station based on the broadcast signals; estimating distance from the mobile station to the assigned base station and a signal timing for transmitting a signal from said mobile station to said assigned base station according to said calculated bearings; and transmitting said signal from said mobile station to said assigned base station with said estimated signal timing.

Claim 29

A method according to claim 24, wherein said step of estimating further includes determining a propagation delay from said mobile station to said assigned base station wherein said signal timing is approximately twice said propagation delay.

Claim 30

A method according to claim 25, wherein said broadcasting signals are broadcast using phased antennas.