Adaptive cellular paging system and object location system

Claim 2

The data paging system of Claim 1 wherein said transmission device comprises; a paging terminal for generating said messages as paging messages; a satellite for receiving paging messages generated by said paging terminal and for transmitting said paging messages via said transmission link to said first and second paging systems; and a satellite uplink for transmitting said generated paging messages from said paging terminal to said satellite.

Claim 3

The adaptive paging system of Claim 1 wherein said routing control circuitry is operable in first and second modes, said routing control circuitry in said first mode operating to control said transmission device to transmit said generated messages only to the one of said first and second paging systems at which said location system has determined the destination paging receiver to be located at, and in a second mode for transmitting the paging message to both said first and second paging systems, and further comprising control circuitry for switching between said first mode and said second mode in accordance with predetermined criteria to change the system throughput.

Claim 4

An object location system, comprising: a plurality of radio transmitter locations each having a radio transmitter disposed thereat for transmitting radio energy to define a pattern about said associated transmitter location within which the field strength is above a predetermined level, said radio transmitters each operable to transmit a unique location identification signal on a periodic basis; a portable location unit disposed on an object, said personal location unit having: a primary receiver for receiving from one of said radio transmitters the associated location identification signal when said personal location unit is within said pattern associated with said one of said radio transmitters, a memory for storing said received location identification signal, a unit transmitter for transmitting said stored location identification signal in association with a unit identification signal unique to said portable location unit, and a control circuit for controlling the relative time that said unit transmitter transmits said stored location identification signal and said unit identification signal, said control circuit operating in accordance with predetermined timing criteria; a location receiver for receiving the information transmitted by said unit transmitter; and a processor for determining the location of said personal location unit relative to the one of said transmitter locations associated with the received location identification signal;

Claim 5

The location system of Claim 4, wherein said radio transmitters at each of said transmitter locations are associated with a paging system and said radio transmitters are operable to transmit paging messages.

Claim 6

The location system of Claim 5, wherein said primary receiver on said personal location unit is operable to receive paging messages, said personal location unit further including paging control circuitry for processing said received paging messages.

Claim 7

The location system of Claim 4, wherein said primary receiver in said personal location unit is operable to select the strongest received signal when two signals are received as a result of said personal location unit being in patterns associated with two of said transmitter locations.

Claim 8

The location system of Claim 4, wherein said control circuit is operable to control said transmitter in accordance with said predetermined timing criteria to transmit said stored location identification signal and said associated unit identification information a predetermined time after receipt of said location identification signal from one of the radio transmitters associated with said transmitter locations.

Claim 9

The location system of Claim 4, and further comprising: a request transmitter for transmitting a request message external to said personal location unit; a request receiver associated with said personal location unit for receiving said request message transmitted by said request transmitter; and said predetermined timing criteria comprising response criteria associated with the receipt of said request message, said control circuit operable to control said transmitter to transmit said stored location identification signal and unit identification signal in response to receipt of said request message.

Claim 10

The location system of Claim 8, and further comprising an acknowledgement transmitter for transmitting to said primary receiver in said personal location unit an acknowledgement signal in response to receipt of said transmitted location identification signal by said location receiver.

Claim 11

The location system of Claim 4, and further comprising a plurality of said location receivers disposed at select ones of said transmitter locations, each for receiving said location identification signal and associated unit identification signal when the signal strength from said transmitter in said personal location unit is sufficient to reach any of said location receivers.

Claim 12

The location system of Claim 11, wherein: each of said location receivers include timing circuitry for marking the time that information is received from said personal location unit relative to a common time base, and transmitting the time marked information to said processor; and said processor further includes means for estimating the time-difference-of-arrival of all the time marked signals received by said location receivers for a given one of said personal location unit in accordance with a predetermined time-difference-of-arrival algorithm and calculating the location thereof knowing the location of each of said location receivers.