Method and apparatus for dynamically selecting transmitters for communications between a primary station and remote stations of a data communications system
First Claim
1. A method for use in a primary station of a communications system for communicating message signals via a communications medium between the primary station and a plurality of remote stations located anywhere in a geographical area that is divided into a plurality of zones, said primary station including control means, a plurality of transmitting means for transmitting message signals modulated on a first carrier signal and a plurality of receiving means for receiving message signals modulated on a second carrier signal, each zone covered by one of the transmitting means and covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the second carrier signal and receiving means for receiving message signals modulated on the first carrier signal;
- said method for selecting one of the primary station transmitting means for transmitting message signals to a selected remote station, said method comprising the steps of;
(a) measuring the signal strength of the carrier signal received by each primary station receiving means during each transmission from the selected remote station;
(b) computing an adjusted signal strength for each zone by adjusting the measured signal strength for each primary station receiving means by corresponding predetermined factors associated with the zone and combining the adjusted signal strengths; and
(c) selecting the primary station transmitting means covering the zone which had the largest adjusted signal strength for the last transmission from the selected remote station.
2 Assignments
0 Petitions
Accused Products
Abstract
A data communications system is described that covers a geographic area divided into a plurality of non-overlapping zones and includes a general communications controller (GCC), a plurality of channel communications modules (CCM) and associated transmitters and receivers, and a plurality of portable radios. Message signals carrying alphanumeric information are communicated between the GCC and the portable radios by way of a radio channel. Each CCM takes a signal strength measurement every time it receives a message signal from a portable radio. The GCC gathers the signal strength measurements from the CCM receivers receiving the same message signal and computes an adjusted signal strength for each zone. The GCC then selects the zone having the largest adjusted signal strength for determining the location of the portable radio that transmitted the message signal. Whenever the GCC transmits a message signal to a portable radio, the CCM transmitter is used that covers the zone having the largest adjusted signal strength for the last transmission from that portable radio. Since the GCC can be simultaneously transmitting message signals to portable radios in other zones using non-interfering CCM transmitters, information throughput is greatly enhanced.
120 Citations
35 Claims
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1. A method for use in a primary station of a communications system for communicating message signals via a communications medium between the primary station and a plurality of remote stations located anywhere in a geographical area that is divided into a plurality of zones, said primary station including control means, a plurality of transmitting means for transmitting message signals modulated on a first carrier signal and a plurality of receiving means for receiving message signals modulated on a second carrier signal, each zone covered by one of the transmitting means and covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the second carrier signal and receiving means for receiving message signals modulated on the first carrier signal;
- said method for selecting one of the primary station transmitting means for transmitting message signals to a selected remote station, said method comprising the steps of;
(a) measuring the signal strength of the carrier signal received by each primary station receiving means during each transmission from the selected remote station; (b) computing an adjusted signal strength for each zone by adjusting the measured signal strength for each primary station receiving means by corresponding predetermined factors associated with the zone and combining the adjusted signal strengths; and (c) selecting the primary station transmitting means covering the zone which had the largest adjusted signal strength for the last transmission from the selected remote station. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- said method for selecting one of the primary station transmitting means for transmitting message signals to a selected remote station, said method comprising the steps of;
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14. Control means for a primary station of a communications system for communicating message signals via a communications medium between the primary station and a plurality of remote stations located anywhere in a geographical area that is divided into a plurality of zones, said primary station further including a plurality of transmitting means for transmitting message signals modulated on a first carrier signal and a plurality of receiving means for receiving message signals modulated on a second carrier signal, each zone covered by one of the transmitting means and covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the second carrier signal and receiving means for receiving message signals modulated on the first carrier signal;
- said control means comprising;
means for measuring the signal strength of the carrier signal received by each primary station receiving means during each transmission from each remote station; means for computing an adjusted signal strength for each zone by adjusting the measured signal strength for each primary station receiving means by corresponding predetermined factors associated with the zone and combining the adjusted signal strengths for each remote station; and means for selecting for communicating with a selected remote station the primary station transmitting means covering the zone which had the largest adjusted signal strength for the last transmission from the selected remote station. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
- said control means comprising;
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26. A method for use in a primary station of a communications system for communicating message signals via a communications medium between the primary station and a plurality of remote station located anywhere in a geographical area that is divided into a plurality of zones, said primary station including control means and a plurality of receiving means for receiving message signals modulated on a carrier signal, each zone covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the carrier signal;
- said method for determining the zone in which each remote station is located, said method comprising the steps of;
(a) measuring the signal strength of the carrier signal received by each primary station receiving means during each transmision from each remote station; (b) computing an adjusted signal strength for each zone by adjusting the measured signal strength for each primary station receiving means by corresponding predetermined factors associated with the zone and combining the adjusted signal strengths for each remote station; and (c) selecting for each remote station the zone having the largest adjusted signal strength for the last transmission from that remote station. - View Dependent Claims (27, 28, 29)
- said method for determining the zone in which each remote station is located, said method comprising the steps of;
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30. Control means for a primary station of a communications system for communicating message signals via a communications medium between the primary station and a plurality of remote stations located anywhere in a geographical area that is divided into a plurality of zones, said primary station further including a plurality of receiving means for receiving message signals modulated on a carrier signal, each zone covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the carrier signal, said control means comprising:
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means for measuring the signal strength of the carrier signal received by each primary station receiving means during each transmission from each remote station; means for computing an adjusted signal strength for each zone by adjusting the measured signal strength for each primary station receiving means by corresponding predetermined factors associated with the zone and combining the adjusted signal strengths for each remote station; and means for selecting for each remote station the zone having the largest adjusted signal strength for the last transmission from that remote station. - View Dependent Claims (31, 32)
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33. A method for use in a primary station of a communications systems for communicating message signals via a communications medium between the primary station and a plurality of remote stations located anywhere in a geographical area that is divided into a plurality of zones, said primary station including control means, a plurality of transmitting means for transmitting message signals modulated on a first carrier signal and a plurality of receiving means for receiving message signals modulated on a second carrier signal, each zone covered by one of the transmitting means and covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the second carrier signal and receiving means for receiving message signals modulated on the first carrier signal;
- said method for selecting one of the primary station transmitting means for transmitting message signals to a selected remote station, said method comprising the steps of;
(a) measuring the signal strength of the carrier signal received by each primary station receiving means during each transmission from each remote station; (b) computing an adjusted signal strength for each zone by adjusting the measured signal strength for each primary station receiving means by corresponding predetermined factors associated with the zone and combining the adjusted signal strengths for each remote station; and (c) selecting for communicating with a selected remote station the primary station transmitting means covering the zone which had the largest adjusted signal strength for the last transmission from the selected remote station.
- said method for selecting one of the primary station transmitting means for transmitting message signals to a selected remote station, said method comprising the steps of;
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34. A method for use in a primary station of a communications system for communicating message signals via a communications medium between the primary station and a plurality of remote stations located anywhere in a geographical area that is divided into a plurality of non-overlapping zones, said primary station including control means, a plurality of transmitting means for transmitting message signals modulated on a first carrier signal and a plurality of receiving means for receiving message signals modulated on a second carrier signal, the coverage area or one or more of the plurality of transmitting means overlapping portions of the coverage area of one or more others of the plurality of transmitting means, each zone covered by one of the transmitting means and covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the second carrier signal and receiving means for receiving message signals modulated on the first carrier signal;
- said method for substantially simultaneously transmitting message signals to two or more selected remote stations located in different zones, said method comprising the steps of;
(a) assigning only one of the primary station transmitting means for covering a zone, regardless of whether a zone is covered at least in part by two or more primary station transmitting means; (b) determining the zone in which remote stations are located by measuring the signal strength of the remote stations during each transmission therefrom; (c) modulating a message signal on the first carrier signal of the primary station transmitting means assigned to a first zone in which a first remote station is located; and (d) modulating a message signal on the first carrier signal of the primary station transmitting means assigned to a second zone in which a second remote ststion is located provided that the primary station transmitting means assigned to said second zone does not cover a portion of the first zone.
- said method for substantially simultaneously transmitting message signals to two or more selected remote stations located in different zones, said method comprising the steps of;
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35. A method for use in a primary station of a communications system for communicating message signals via a communications medium between the primary station and a plurality of remote stations located anywhere in a geographical area that is divided into a plurality of non-overlapping zones, said primary station including control means, a plurality of transmitting means for transmitting message signals modulated on a first carrier signal and a plurality of receiving means for receiving message signals modulated on a second carrier signal, the coverage area of one or more of the plurality of transmitting means overlapping portions of the coverage area of one or more others of the plurality of transmitting means, each zone covered by one or more of the transmitting means and covered by at least one receiving means, and said remote stations including transmitting means for transmitting message signals modulated on the second carrier signal and receiving means for receiving message signals modulated on the first carrier signal;
- said method for substantially simultaneously transmitting message signals to two or more selected remote stations located in different zones, said method comprising the steps of;
(a) assigning only one of the primary station transmitting means for covering a zone, regardless of whether a zone is covered at least in part by two or more primary station transmitting means; (b) determining the zone in which remote stations are located, said location determining step comprising the steps of; (i) measuring the signal strength of the carrier signal received by each primary station receiving means during each transmission from each remote station; (ii) computing an adjusted signal strength for each zone by adjusting the measured signal strength for each primary station receiving means by corresponding predetermined factors associated with the zone and combining the adjusted signal strengths for each remote station; and (iii) selecting for each remote station the zone having the largest adjusted signal strength for the last transmission from that remote station; (c) modulating a message signal on the first carrier signal of the primary station transmitting means assigned to a first zone in which a first remote station is located; and (d) modulating a message signal on the first carrier signal of the primary station transmitting means assigned to a second zone in which a second remote station is located provided that the primary station transmitting means assigned to said second zone does not cover a portion of the first zone.
- said method for substantially simultaneously transmitting message signals to two or more selected remote stations located in different zones, said method comprising the steps of;
Specification