Two-way paging system and apparatus
First Claim
1. A wireless paging unit for receiving alert messages addressed thereto transmitted by a paging network and for transmitting an acknowledgment in response to receipt thereof, comprising:
- antenna means for receiving and transmitting signals;
antenna coupling means coupled to said antenna means and controlled by a control means to adapt said antenna means for one of reception and transmission;
a receiver connected via said antenna coupling means to said antenna means for receiving a signal and generating a time-of-arrival indication upon detecting a predetermined signal pattern;
said control means also for receiving said time of arrival indication and in response thereto for adapting said antenna means for transmission and for activating a transmitter at a time based on said indicated time-of-arrival; and
wherein said transmitter is coupled via said antenna coupling means to said antenna means and activated by said control means to transmit a digitally coded acknowledgment signal at said time.
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Accused Products
Abstract
Paging systems typically include a network of ground stations or orbiting satellites equipped with transmitters and antennas for transmitting paging messages to small, battery-operated paging receivers that are worn about the person, known as pagers. Conventional pagers are receive-only devices and the network receives no confirmation that paging has been successful. The present invention includes the provision of two-way pagers that contain a transmitter for transmitting an acknowledgment confirming reception of a paging message, and a network of receiving stations able to receive said acknowledgments. The network makes use of advanced phased-array antenna signal processing techniques to render the return link operable with much less transmitter power in the portable unit than employed by the base station.
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Citations
19 Claims
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1. A wireless paging unit for receiving alert messages addressed thereto transmitted by a paging network and for transmitting an acknowledgment in response to receipt thereof, comprising:
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antenna means for receiving and transmitting signals; antenna coupling means coupled to said antenna means and controlled by a control means to adapt said antenna means for one of reception and transmission; a receiver connected via said antenna coupling means to said antenna means for receiving a signal and generating a time-of-arrival indication upon detecting a predetermined signal pattern; said control means also for receiving said time of arrival indication and in response thereto for adapting said antenna means for transmission and for activating a transmitter at a time based on said indicated time-of-arrival; and wherein said transmitter is coupled via said antenna coupling means to said antenna means and activated by said control means to transmit a digitally coded acknowledgment signal at said time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A wireless paging unit capable of receiving alert messages transmitted thereto from a paging network and capable of transmitting an acknowledgment of receipt thereof, comprising:
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antenna means for receiving and transmitting signals; a receiver connected to said antenna means for receiving a signal and converting said signal to numerical samples when indicated by a timing control means; memory means for storing said numerical samples in time order of reception; processing means for processing said stored numerical samples to determine a location in said memory means of a predetermined signal pattern and to generate a time-of-arrival indication based on said location; and timing control means for receiving said time-of-arrival indication and for activating a transmitter to transmit a digitally coded reply with a predetermined timing related to said indicated time-of-arrival. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A wireless paging unit capable of receiving alert messages transmitted from a paging network and of transmitting a reply in response to receipt thereof, comprising:
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a first oscillator means for determining a receiver power down period based on a calibration count value; a second oscillator means for determining operating channel frequencies of said receiver and of a transmitter; said receiver being activated by a signal controlled by said first oscillator means to receive and process a signal received on a receive operating channel frequency and to produce a time-of-arrival and frequency error indication from said received signal; frequency correction means for using said frequency error indication to correct said second oscillator means and to use said corrected second oscillator means to perform a calibration measurement to determine said calibration count value; and timing control means for receiving said time of arrival indication and in response thereto for activating a transmitter to transmit a digitally coded reply having a predetermined timing related to said indicated time-of-arrival and at an operating channel frequency derived from said second oscillator means and compensated for said frequency error.
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Specification