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US 4,891,637 AGranted
Acknowledge back pager with apparatus for controlling transmit frequency
AssigneeMotorola, Inc.
InventorsKazimierz Siwiak, James M. Keba, Francis R. Steel
Life of this patent
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AssigneeMotorola, Inc.
InventorsKazimierz Siwiak, James M. Keba, Francis R. Steel
Estimating the term…
An acknowledge back (ack-back) pager is provided for use in a paging system including a central station which transmits a group of message signals to a group of ack-back pagers which are addressed as a group. The users of the group of addressed ack-back pagers indicate a response to their respective pagers thus providing ack-back data. The pagers in the group of addressed ack-back pagers then simultaneously transmit back to the central station their ack-back data on different frequency sub-bands, a different frequency sub-band being allocated to each of the pagers in the group. To accurately control the ack-back transmit frequency, the pager receives and down-converts the F.sub.RX signal thus producing a down-converted F.sub.C signal, the frequency of which is measured and stored. The pager selects which sub-band of a plurality of frequency sub-bands within a predetermined range of frequencies is to be used for transmission of the ack-back signal. The pager determines a frequency offset F.sub.D corresponding to the selected sub-band, such offset being with respect to a predetermined frequency within such range of frequencies. The pager generates an acknowledge back signal at a frequency (F.sub.C +F.sub.D)-F.sub.CTX and up-converts such signal to a transmit frequency F.sub.TX corresponding to said selected sub-band, F.sub.CTX being the frequency of a down-converted sample of the F.sub.TX signal.
In a radio paging system including a central paging station for transmitting paging signals including a group of pager addresses on a paging channel frequency F.sub.RX to a group of corresponding remotely located acknowledge back radio pagers, said central station transmitting said pager addresses in a predetermined order over a first time interval, each acknowledge back pager capable of controlling a sub channel frequency F.sub.TX on which it transmits acknowledge back signals, an acknowledge back pager of said system comprising:
In a radio paging system including a central paging station for transmitting paging signals on a paging channel frequency F.sub.RX to a plurality of remotely located acknowledge back radio pagers, a method of controlling a sub-channel frequency F.sub.TX on which an acknowledge back pager of said system transmits an acknowledge back signal, said method comprising the steps of;
In a radio paging system including a central paging station for transmitting paging signals on a paging channel frequency F.sub.RX to a plurality of remotely located acknowledge back radio pagers, a method of controlling a sub-channel frequency F.sub.TX on which an acknowledge back pager of said system transmits an acknowledge back signal, said method comprising the steps of;
In a radio paging system including a central paging station for transmitting paging signals on a paging channel frequency F.sub.RX to a plurality of remotely located acknowledge back pagers, an acknowledge back pager capable of controlling a sub-channel frequency F.sub.TX on which it transmits acknowledge back signals, said pager comprising:
Dependencies are inferred from the claim text.