Joseph M Sheehan

US Patent:

6388618, May 14, 2002

Filed:

Mar 31, 2000

Appl. No.:

09/539370

Inventors:

Louis A. Stilp - Berwyn PA
Joseph W. Sheehan - Newtown Square PA
Jeffrey F. Bull - Chalfont PA
Robert J. Anderson - Norristown PA

Assignee:

TruePosition, Inc. - King of Prussia PA

International Classification:

G01S 302

US Classification:

342457

Abstract:

A signal collection system (SCS) is used in a wireless location system that determines the geographical locations of mobile wireless transmitters. The SCS includes a first receiver module, a first digital signal processing (DSP) module, a control and communications module, a timing signal generator including an enhanced GPS receiver, and a bus coupling the DSP module to the communications and control module. The receiver module receives RF signals from the mobile transmitters via a plurality of antennas and digitizes said RF signals, and provides digitized RF data to the first DSP module.

US Patent:

6400320, Jun 4, 2002

Filed:

Aug 24, 2000

Appl. No.:

09/648404

Inventors:

Louis A. Stilp - Berwyn PA
Joseph W. Sheehan - Newtown Square PA
Alan E. E. Rogers - Ayer MA
Robert J. Anderson - Norristown PA
Andrew F. Harbison - Glenside PA

Assignee:

TruePosition, Inc. - King of Prussia PA
Massachusetts Insitute of Technology - Cambridge MA

International Classification:

G01S 302

US Classification:

342457

Abstract:

An antenna selection method is used in a wireless location system that determines the geographic location of a mobile wireless transmitter. The wireless location system includes signal collection systems connected to multiple antennas at a plurality of cell sites and a location processor for processing digital data provided by the signal collection systems. The antenna selection method comprises evaluating segments of data collected from a plurality of antennas at a signal collection system, selecting a subset of the segments of data, and using only the selected segments of data in location processing.

US Patent:

6463290, Oct 8, 2002

Filed:

Oct 3, 2000

Appl. No.:

09/679228

Inventors:

Louis A. Stilp - Berwyn PA
Joseph W. Sheehan - Newtown Square PA
Alan E. E. Rogers - Ayer MA
Robert J. Anderson - Norristown PA
Vineet Sachdev - Norristown PA

Assignee:

TruePosition, Inc. - King of Prussia PA
Massachusetts Institute of Technology - Cambridge MA

International Classification:

H04Q 700

US Classification:

455456, 455 69

Abstract:

The accuracy of the location estimate of a Wireless Location System is dependent, in part, upon both the transmitted power of the wireless transmitter and the length in time of the transmission from the wireless transmitter. In general, higher power transmissions and transmissions of greater transmission length can be located with better accuracy by the Wireless Location System than lower power and shorter transmissions. Wireless communications systems generally limit the transmit power and transmission length of wireless transmitters in order to minimize interference within the communications system and to maximize the potential capacity of the system. Several methods meet the conflicting needs of both systems by enabling the wireless communications system to minimize transmit power and length while enabling improved location accuracy for certain types of calls, such as wireless 9-1-1 (emergency) calls. Such methods include mobile-assisted techniques in which the mobile unit includes functionality to assist in improving location accuracy. The WLS locates the transmitter (mobile unit) while the latter is using a modified transmission sequence comprising a message sent from the wireless transmitter using transmission parameters different from the normal transmission parameters broadcast on the forward control channel by the base stations in the associated wireless communications system.

US Patent:

6519465, Feb 11, 2003

Filed:

Jul 16, 2001

Appl. No.:

09/907028

Inventors:

Louis A. Stilp - Berwyn PA
Robert J. Anderson - Norristown PA
Joseph W. Sheehan - Newtown Square PA

Assignee:

TruePosition, Inc. - King of Prussia PA

International Classification:

H04B 700

US Classification:

455456, 455404

Abstract:

The accuracy of the location estimate of a Wireless Location System is dependent, in part, upon both the transmitted power of the wireless transmitter and the length in time of the transmission from the wireless transmitter. In general, higher power transmissions and transmissions of greater transmission length can be located with better accuracy by the Wireless Location System than lower power and shorter transmissions. Wireless communications systems generally limit the transmit power and transmission length of wireless transmitters in order to minimize interference within the communications system and to maximize the potential capacity of the system. The inventive method disclosed herein meets the conflicting needs of both systems by enabling the wireless communications system to minimize transmit power and length while enabling improved location accuracy for certain types of calls, such as wireless 9-1-1 calls. The method comprises the following steps: a wireless transmitter receives normal transmission parameters from a base station; the user of the wireless transmitter initiates a call on the wireless transmitter by dialing a sequence of digits and pressing âSENDâ or âYESâ; a processor within the wireless transmitter compares the dialed sequence of digits with one or more trigger events stored within the wireless transmitter; if the dialed sequence of digits does not match the trigger event, then the wireless transmitter uses the normal transmission parameters in making the call; and if the dialed sequence of digits matches the trigger event, then the wireless transmitter uses a modified transmission sequence.

US Patent:

6661379, Dec 9, 2003

Filed:

May 29, 2002

Appl. No.:

10/158522

Inventors:

Louis A. Stilp - Berwyn PA
Joseph W. Sheehan - Newtown Square PA
Alan E. E. Rogers - Ayer MA
Robert J. Anderson - Norristown PA
Andrew F. Harbison - Glenside PA

Assignee:

TruePosition, Inc. - King of Prussia PA
Massachusetts Institute of Technology - Ayer MA

International Classification:

G01S 302

US Classification:

342457

Abstract:

An antenna selection method is used in a wireless location system that determines the geographic location of a mobile wireless transmitter. The wireless location system includes signal collection systems connected to multiple antennas at a plurality of cell sites and a location processor for processing digital data provided by the signal collection systems. The antenna selection method comprises evaluating segments of data collected from a plurality of antennas at a signal collection system, selecting a subset of the segments of data, and using only the selected segments of data in location processing.

US Patent:

20030064734, Apr 3, 2003

Filed:

Nov 4, 2002

Appl. No.:

10/287139

Inventors:

Louis Stilp - Berwyn PA, US
Robert Anderson - Norristown PA, US
Joseph Sheehan - Newtown Square PA, US

Assignee:

TruePosition, Inc.

International Classification:

H04Q007/20
H04B001/38

US Classification:

455/456000, 455/564000, 455/565000

Abstract:

The accuracy of the location estimate of a Wireless Location System is dependent, in part, upon both the transmitted power of the wireless transmitter and the length in time of the transmission from the wireless transmitter. In general, higher power transmissions and transmissions of greater transmission length can be located with better accuracy by the Wireless Location System than lower power and shorter transmissions. Wireless communications systems generally limit the transmit power and transmission length of wireless transmitters in order to minimize interference within the communications system and to maximize the potential capacity of the system. The inventive method disclosed herein meets the conflicting needs of both systems by enabling the wireless communications system to minimize transmit power and length while enabling improved location accuracy for certain types of calls, such as wireless --calls. The method comprises the following steps: a wireless transmitter receives normal transmission parameters from a base station; the user of the wireless transmitter initiates a call on the wireless transmitter by dialing a sequence of digits and pressing “SEND” or “YES”; a processor within the wireless transmitter compares the dialed sequence of digits with one or more trigger events stored within the wireless transmitter; if the dialed sequence of digits does not match the trigger event, then the wireless transmitter uses the normal transmission parameters in making the call; and if the dialed sequence of digits matches the trigger event, then the wireless transmitter uses a modified transmission sequence.

US Patent:

62660136, Jul 24, 2001

Filed:

Jan 11, 1999

Appl. No.:

9/228362

Inventors:

Louis A. Stilp - Berwyn PA
Joseph W. Sheehan - Newtown Square PA
Tim J. Harris - Bala Cynwyd PA
Jeffrey F. Bull - Chalfont PA
Robert J. Anderson - Norristown PA

Assignee:

TruePosition, Inc. - Wayne PA

International Classification:

G01S 124

US Classification:

342387

Abstract:

A signal collection system (SCS) for use in a Wireless Location System is disclosed. The SCS performs wideband energy detection and reporting at the front end of the SCS receiver. Other aspects of the SCS include a protocol for efficiently setting levels for wideband energy detection, DSP sharing within an SCS, and recursive location processing using progressively greater bandwidth from temporarily stored wideband data. The disclosed SCS includes antennas, a wideband receiver, a DSP for wideband energy detection, a memory for temporarily storing digital samples of received signals, a digital drop receiver, demodulation and normalization processors, and a communications processor. The wideband energy detection and the demodulation and normalization processors are implemented with DSP's that detect energy in a particular band, demodulate selected signals, and extract signals of interest for forwarding. The wideband energy detection unit determines the presence of a transmitted signal in the control channels monitored by the SCS. The wideband energy detection involves forming a map of the channel spectrum, and the map is used to determine when to demodulate signals within selected channels.

US Patent:

6285321, Sep 4, 2001

Filed:

Aug 24, 2000

Appl. No.:

9/645802

Inventors:

Louis A. Stilp - Berwyn PA
Joseph W. Sheehan - Newtown Square PA
Alan E. E. Rogers - Ayer MA
Robert J. Anderson - Norristown PA

Assignee:

TruePosition, Inc. - King of Prussia PA
Massachusetts Institute of Technology - Cambridge MA

International Classification:

G01S 302

US Classification:

342465

Abstract:

A station-based method for use in a wireless location system determines the geographic location of a mobile wireless transmitter. The wireless location system includes signal collection systems and location processors for processing digital data provided by the signal collection systems. The station-based method comprises receiving a transmission from a wireless transmitter at multiple antennas and at multiple signal collection systems. The transmission is converted into a digital format in a receiver connected to each antenna at the multiple signal collection systems. At each signal collection system, digital data representative of the received transmissions are stored in a memory. The transmission is then demodulated at a first signal collection system, and appropriate phase correction intervals are determined. At the first signal collection system, for each such phase correction interval, appropriate phase correction parameters are calculated, and the phase correction parameters are encoded along with the demodulated data.