Person location system
First Claim
1. A person location system comprising:
- a plurality of radio base stations, connected to a public switched telephone network, for respectively covering microcells, each of said base stations being uniquely identified by an identifier and having a memory;
a user station located in one of said microcells and uniquely identified by a user'"'"'s address, said user station detecting field intensities of signals transmitted from surrounding radio base stations and transmitting a field intensity signal containing detected field intensities, identifiers of the surrounding base stations and said user'"'"'s address to one of the surrounding base stations;
a radio central station for covering an area containing all of said microcells, the radio central station being connected to said public switched telephone network for receiving a polling signal containing said user'"'"'s address via the public switched telephone network and broadcasting a copy of the polling signal within said area, said radio central station serving as a transmitting station of a radio paging system for transmitting said polling signal and a radio paging signal having a message for radio pagers owned by subscribers of the radio paging system; and
a management center connected to said public switched telephone network for transmitting said polling signal through a switched connection established by said public switched telephone network to said central station,each of said base stations receiving the field intensity signal from said user station and storing the received field intensity signal into said memory, each of the base stations being responsive to said polling signal for notifying the field intensities and the identifiers contained in the stored field intensity signal through a switched connection established by said public switched telephone network to said management center if the user'"'"'s address in said polling signal matches the user'"'"'s address in said field intensity signal,said management center determining the location of said user station based on the field intensities and the identifiers notified by the base station.
0 Assignments
0 Petitions
Accused Products
Abstract
A person location system comprises radio base stations and a radio central station, all stations being connected to a public switched telephone network. The base stations respectively cover small areas, or "microcells", in one of which is located a user station, and the central station covers an area containing all of the microcells. The central station receives a polling signal containing the user'"'"'s address via the telephone network and broadcasts a copy of the polling signal. A management center is connected to the telephone network for transmitting the polling signal to the central station when a location demand arises. Each base station is responsive to the polling signal from the central station for returning field intensity data of the user station through the telephone network to the management center if the polling signal identifies the user station.
-
Citations
7 Claims
-
1. A person location system comprising:
-
a plurality of radio base stations, connected to a public switched telephone network, for respectively covering microcells, each of said base stations being uniquely identified by an identifier and having a memory; a user station located in one of said microcells and uniquely identified by a user'"'"'s address, said user station detecting field intensities of signals transmitted from surrounding radio base stations and transmitting a field intensity signal containing detected field intensities, identifiers of the surrounding base stations and said user'"'"'s address to one of the surrounding base stations; a radio central station for covering an area containing all of said microcells, the radio central station being connected to said public switched telephone network for receiving a polling signal containing said user'"'"'s address via the public switched telephone network and broadcasting a copy of the polling signal within said area, said radio central station serving as a transmitting station of a radio paging system for transmitting said polling signal and a radio paging signal having a message for radio pagers owned by subscribers of the radio paging system; and a management center connected to said public switched telephone network for transmitting said polling signal through a switched connection established by said public switched telephone network to said central station, each of said base stations receiving the field intensity signal from said user station and storing the received field intensity signal into said memory, each of the base stations being responsive to said polling signal for notifying the field intensities and the identifiers contained in the stored field intensity signal through a switched connection established by said public switched telephone network to said management center if the user'"'"'s address in said polling signal matches the user'"'"'s address in said field intensity signal, said management center determining the location of said user station based on the field intensities and the identifiers notified by the base station. - View Dependent Claims (3)
-
-
2. A person location system as claimed in claim 2, wherein each of said base stations comprises means for erasing the stored field intensity signal if a prescribed timeout period expires after the reception of the field intensity signal from the user station.
-
4. A location system comprising:
-
a plurality of radio base stations, connected to a public switched telephone network, for respectively covering microcells, each of said base stations being uniquely identified by an identifier; a user station located in one of said microcells and uniquely identified by a user'"'"'s address, said user station having a memory and detecting at intervals, field intensities of signals transmitted from surrounding base stations and storing the detected field intensities into said memory and being responsive to a polling signal containing said user'"'"'s address, said user station for transmitting a field intensity signal containing the stored field intensities and identifiers of the surrounding base stations to one of the surrounding base stations; a management center connected to said public switched telephone network for transmitting said polling signal through a switched connection established by said public switched telephone network; and a radio central station for covering an area containing said microcells, the radio central station being connected to said public switched telephone network for receiving said polling signal via said switched connection from said management center and broadcasting a copy of the polling signal within said area, said radio central station serving as a transmitting station of a radio paging system for transmitting said polling signal and a radio paging signal having a message for radio pagers owned by subscribers of the radio paging system, each of said base stations receiving the field intensity signal transmitted from said user station and being responsive to said polling signal for notifying the field intensities and the identifiers contained in the field intensity signal to said management center through a switched connection established by said public switched telephone network, said management center determining the location of said user station from the field intensities and the identifiers notified by the base station. - View Dependent Claims (5, 6, 7)
-
Specification