US 5,970,413 A · Using a frequency that is unavailable for carrying telephone voice information traffic for determining the position of a mobile subscriber in a CDMA cellular telephone system

Abstract

A method for determining the position of a mobile station within a cellular telephone system having a plurality of cells. Voice information signals are transmitted between a first base station transmitter and a mobile station on a transmission channel. Thereafter, transmissions from the first base station transmitter of voice information signals on the transmission channel are ceased for a predetermined period of time. During the predetermined period of time when transmissions of voice information signals from the first base station transmitter have ceased on the transmission channel, the mobile station makes positional measurements. The position of the mobile station is determined in accordance with the positional measurements.

Claims22

Dependent claims

A method for determining the position of a mobile station within a cellular telephone system having a plurality of cells, comprising the steps of:

(A) selecting a cell from said plurality of cells;
(B) designating for said selected cell a radio frequency (RF) channel that is unavailable for transmitting telephone voice information signals to mobile stations within said selected cell, said designated RF channel being a dedicated positioning channel selected from a plurality of candidate RF channels;
(C) repeating steps (A) through (B) for each of said plurality of cells such that neighboring cells within said system have different RF channels designated as unavailable for transmitting said telephone voice information signals;
(D) during an ongoing telephone call, switching said mobile station from an RF channel designated as available for transmitting telephone voice information signals to an RF channel designated as unavailable for transmitting telephone voice information signals and, while said mobile station is on said channel designated as unavailable for transmitting telephone voice information signals, making positional measurements with said mobile station on said RF channel designated as unavailable for transmitting telephone voice information signals;
(E) after making said positional measurements, switching said mobile station from said RF channel designated as unavailable for transmitting telephone voice information signals to an RF channel designated as available for transmitting telephone voice information signals;
and
(F) determining said position of said mobile station in accordance with said positional measurements.

4 more elements

Dependencies are inferred from the claim text.

Using a frequency that is unavailable for carrying telephone voice information traffic for determining the position of a mobile subscriber in a CDMA cellular telephone system

Life of this patent

Using a frequency that is unavailable for carrying telephone voice information traffic for determining the position of a mobile subscriber in a CDMA cellular telephone system

Life of this patent

Abstract

Claims22