US 2012/0058775 A1 · SERVICES AND APPLICATIONS FOR A COMMUNICATIONS NETWORK

Abstract

A location system is disclosed for commercial wireless telecommunication infrastructures. The system is an end-to-end solution having one or more location centers for outputting requested locations of commercially available handsets or mobile stations (MS) based on, e.g., CDMA, AMPS, NAMPS or TDMA communication standards, for processing both local MS location requests and more global MS location requests via, e.g., Internet communication between a distributed network of location centers. The system uses a plurality of MS locating technologies including those based on: (1) two-way TOA and TDOA; (2) pattern recognition; (3) distributed antenna provisioning; (5) GPS signals, (6) angle of arrival, (7) super resolution enhancements, and (8) supplemental information from various types of very low cost non-infrastructure base stations for communicating via a typical commercial wireless base station infrastructure or a public telephone switching network. Accordingly, the traditional MS location difficulties, such as multipath, poor location accuracy and poor coverage are alleviated via such technologies in combination with strategies for: (a) automatically adapting and calibrating system performance according to environmental and geographical changes; (b) automatically capturing location signal data for continual enhancement of a self-maintaining historical data base retaining predictive location signal data; (c) evaluating MS locations according to both heuristics and constraints related to, e.g., terrain, MS velocity and MS path extrapolation from tracking and (d) adjusting likely MS locations adaptively and statistically so that the system becomes progressively more comprehensive and accurate. Further, the system can be modularly configured for use in location signaling environments ranging from urban, dense urban, suburban, rural, mountain to low traffic or isolated roadways. Accordingly, the system is useful for 911 emergency calls, tracking, routing, people and animal location including applications for confinement to and exclusion from certain areas.

A method for locating a mobile station using wireless signal measurements obtained from transmissions between said mobile station and a plurality of fixed location communication stations, wherein each of said communications stations includes one or more of a transmitter and a receiver for wirelessly communicating with said mobile station, comprising:

providing first and second mobile station location evaluators, wherein said location evaluators determine information related to one or more location estimates of said mobile station when said location estimators are supplied with data having values obtained from wireless signal measurements obtained via transmissions between said mobile station and the communication stations, wherein:
(A) said first location evaluator performs one or more of the following techniques (i), (ii) and (iii) when supplied with a corresponding instance of said data:
(i) a first technique for determining, for at least one of the communication stations, one of:
a distance, and a time difference of arrival between the mobile station and the communication station, wherein said first technique estimates a time of arrival (TOA) of a received signal relative to a time reference at each one of a plurality of wireless signal monitoring stations using an inverse transform whose resolution is greater than Rayleigh resolution;
(ii) a second technique for estimating a location of said mobile station, using values from a corresponding instance of said data obtained from signals received by the mobile station from one or more satellites;
(iii) a third technique for recognizing a pattern of characteristics of a corresponding instance of said data, wherein said pattern of characteristics is indicative of a plurality of wireless signal transmission paths between the mobile station and each of one or more of the communication stations;
and
(iv) a fourth technique for estimating a location of said mobile station using a USW model, wherein the following steps (a)-(d) are performed:
(a) receiving at an antenna array provided at one of the communication stations, signals originating from the mobile station, wherein the signals comprise p-dimensional array vectors sampled from p antennas of the array;
(b) determining from the received signals, a signal signature, wherein the signal signature comprises a measured subspace, wherein the array vectors are approximately confined to the measured subspace;
(c) comparing the signal signature to a database comprising calibrated signal signatures and corresponding location data, wherein the comparing comprises calculating differences between the measured subspace and calibrated subspaces;
and
(d) selecting from the database a most likely calibrated signal signature and a corresponding most likely location of the mobile station by using the calculated differences;
(v) a fifth technique for estimating a location of said mobile station using an E model, wherein the following steps (a)-(e) are performed:
(a) receiving, at a multiplicity of the communication stations, a signal transmitted by the mobile station;
(b) forwarding, by each of a multiplicity of the communication stations, said received signal and timing information to a central processing center;
(c) calculating, within said central processing center, a time difference of arrival (TDOA) location estimate of said mobile station based upon said timing information;
(d) calculating, within said central processing center, a timing advance (TA) location estimate of said mobile station based upon said timing information;
and
(e) determining said position of said mobile station using said TDOA and TA location estimates;
(vi) a sixth technique for estimating a location of said mobile station using an ST model, wherein the following steps (a)-(e) are performed:
(a) receiving, in a SPS receiver co-located with the mobile station, SPS signals from at least one SPS satellite;
(b) transmitting cell based communication signals between:
a communications system having a first of the communication stations coupled to said SPS receiver, and a second of the communication stations which is remotely positioned relative to said mobile station, wherein said cell based communication signals are wireless;
(c) determining a first time measurement which represents a time of travel of a message in said cell based communication signals in a cell based communication system having at least some of the communication stations which comprises said second communication station and said communication system;
(d) determining a second time measurement which represents a time of travel of said SPS signals;
(e) determining a position of said mobile station from at least said first time measurement and said second time measurement, wherein said cell based communication signals are capable of communicating data messages in a two-way direction between said first cell based transceiver and said communication system;
(vii) a seventh technique for estimating a location of said mobile station using an TE model, wherein the following steps (a)-(l) are performed:
(a) transmitting from said mobile station M samples of a signal;
(b) receiving at one of the communication stations, said M samples together with multipath components and noise;
(c) determining an estimated channel power profile for each of said M samples;
(d) selecting a first set of N samples from said M samples;
(e) performing incoherent integration for said estimated channel power profiles for said first set of N samples to form a first integrated signal;
(f) if a quality level of said first integrated signal with respect to signal to noise is less than a predetermined threshold, selecting another sample from said M samples;
(g) performing incoherent integration for said estimated channel power profiles for said first set of N samples and said another sample to form a second integrated signal;
(h) if a quality level of said second integrated signal with respect to signal to noise is greater than or equal to said predetermined threshold, determining a time-of-arrival of a maximum level of said second integrated signal;
(i) entering said time-of-arrival into a time-of-arrival versus frequency of occurrence array;
(j) selecting a second set of N samples from said M samples;
(k) repeating all of said performing through said entering steps for said second set of N samples;
and
(l) determining a minimum value estimated time-of-arrival from said array;
(viii) an eighth technique for estimating a location of said mobile station using an SigT model, wherein the following steps (a)-(e) are performed:
(a) within the mobile station, transmitting a locating signal composed of at least two tone components;
(b) within each of a plurality of the communication stations, receiving the locating signal at one or more antennas, and within at least one of the communication stations, receiving the locating signal with at least two antennas;
(c) coupling each antenna to a receiver;
(d) within each receiver, generating amplitude and phase values from the locating signal as received by the antenna, the values indicative of amplitude and phase of at least two tone components of the locating signal, as received at the corresponding antenna and measured at defined times;
and
(e) combining the values indicative of amplitude and phase for the tone components from a plurality of the receivers to determine the position of the mobile station;
(ix) an ninth technique for estimating a location of said mobile station using a TLME model, wherein the following steps (a)-(h) are performed therefor in a mobile radio system providing at least some of the communication stations, said mobile radio system including a network controller and at least three of the communication stations, each of said at least three communication stations including an uplink TOA measuring unit operable to communicate with said network controller, a control unit, and a time reference unit operable to provide timing reference signals to said uplink TOA measuring unit, at least one of said at least three communication stations co-located with and connected to a second mobile station, said second mobile station coupled to said network controller via a radio interface, and a service node operable to store known positions of at least two of said at least three communication stations:
(a) receiving a request in said mobile radio system to determine the geographical position of said mobile station;
(b) determining and reporting the position of said second mobile station to said service node;
(c) directing said mobile station to transmit digital signals uplink on a traffic channel when said mobile station is not transmitting or transmitting only analog signals;
(d) measuring in each uplink TOA measuring unit an uplink TOA of the digital signals transmitted by the mobile station;
(e) receiving in said network controller said uplink TOA measurements from said at least three communication stations and a traffic channel number to said traffic channel;
(f) translating said traffic channel number to an identity of said mobile station;
(g) conveying said uplink TOA measurements and said mobile station identity to said service node;
and
(h) calculating in said service node the position of said mobile station using said known positions of said at least three communication stations and said uplink TOA measurements;
(x) a tenth technique for estimating a location of said mobile station using an N model, wherein the following steps (a)-(d) are performed:
(a) receiving global positioning system satellite (GPS) signals from a plurality of global positioning system satellites;
(b) receiving a plurality of cellular position signals that do not contain data in a GPS-like format;
(c) calculating the geographic position of the mobile station using said received global positioning system satellite signals when a requisite number of the plurality of global positioning system satellites are in view of a global positioning system receiver;
and
(d) calculating the geographic position of the mobile station using both said received plurality of cellular position signals and substantially all of said received global positioning system satellite signals when the requisite number of the plurality of global positioning system satellites are not in view of the global positioning system receiver;
(B) for at least a particular one of said techniques performed by said first location estimator, said second location evaluator performs a different one of said techniques when supplied with a corresponding instance of said data for the different technique;
first generating, by said first location estimator, first location related information that is dependent upon an availability of a first corresponding instance of said data;
second generating, by said second location evaluator, second location related information that is dependent upon an availability of a second corresponding instance of said data;
determining a resulting location estimate of the mobile station dependent upon at least one of:
(a) a first value obtained from said first location related information, and (b) a second value obtained from said second location related information.

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Services and applications for a communications network

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Services and applications for a communications network

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Abstract

Claims8