Method and apparatus for increasing co-channel utilization in a multi-station data communications network with overlapping coverage
First Claim
1. A method of increasing co-channel utilization in a digital radio communications system having at least two fixed stations each transmitting into and receiving from a geographic radio coverage area on the same duplex radio channel, the geographic radio coverage area of one fixed station overlapping at least a portion of the geographic radio coverage area of a second fixed station, and a plurality of remote terminals having the capability of receiving from and transmitting to at least one of the at least two fixed stations, the method comprising the steps of:
- transmitting a station identification from a first one of the at least two fixed stations;
receiving said station identification at one of the plurality of remote terminals;
transmitting a message including said received station identification from said one of the plurality of remote terminals from the portion of the geographic radio coverage areas which overlap;
receiving said message including said received station identification at a second one of the at least two fixed stations;
transmitting an inhibit signal from said second one of the at least two fixed stations in response to said message reception, whereby at least a second of the plurality of remote terminals is prevented from transmitting;
determining a signal strength level of said received message at said second one of the at least two fixed stations; and
transmitting from said second one of the at least two fixed stations a no-inhibit signal when said signal strength is less than a first predetermined value.
1 Assignment
0 Petitions
Accused Products
Abstract
A digital radio system having improved co-channel utilization is disclosed. A remote terminal receives a station identification from one of the fixed stations having an overlapping radio coverage area with another fixed station and retransmits this station identification with its message. A second fixed station receiving the remote terminal'"'"'s transmission uses the station identification and the signal strength of the remote terminal to determine whether transmissions from other remote terminals should be inhibited. Depending upon the geographic proximity of the first fixed station to the second fixed station and the remote terminal'"'"'s signal strength at the second fixed station, a signal representative of the remote terminal'"'"'s signal strength at the second fixed station may be transmitted by the second fixed station. This representative signal may be used by a second remote terminal to determine whether the second remote terminal may transmit.
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Citations
22 Claims
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1. A method of increasing co-channel utilization in a digital radio communications system having at least two fixed stations each transmitting into and receiving from a geographic radio coverage area on the same duplex radio channel, the geographic radio coverage area of one fixed station overlapping at least a portion of the geographic radio coverage area of a second fixed station, and a plurality of remote terminals having the capability of receiving from and transmitting to at least one of the at least two fixed stations, the method comprising the steps of:
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transmitting a station identification from a first one of the at least two fixed stations; receiving said station identification at one of the plurality of remote terminals; transmitting a message including said received station identification from said one of the plurality of remote terminals from the portion of the geographic radio coverage areas which overlap; receiving said message including said received station identification at a second one of the at least two fixed stations; transmitting an inhibit signal from said second one of the at least two fixed stations in response to said message reception, whereby at least a second of the plurality of remote terminals is prevented from transmitting; determining a signal strength level of said received message at said second one of the at least two fixed stations; and transmitting from said second one of the at least two fixed stations a no-inhibit signal when said signal strength is less than a first predetermined value. - View Dependent Claims (2, 3, 4)
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5. A method for a fixed station to increase co-channel utilization in a digital radio communications system, the system having at least two fixed stations each transmitting an associated station identification and messages into and receiving messages from a geographic radio coverage area on the same duplex radio channel, the geographic radio coverage area of a first fixed station overlapping at least a portion of the geographic radio coverage area of a second fixed station, and a plurality of remote terminals having the capability of receiving the station identifications and messages from and transmitting messages to at least one of the first and second fixed stations, the method at the second fixed station comprising the steps of:
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receiving at the second fixed station a message including a received station identification from one of the plurality of remote terminals from the portion of the geographic radio coverage areas which overlap; transmitting an inhibit signal from the second fixed station in response to said message reception whereby at least a second of the plurality of remote units is prevented from transmitting; determining at the second fixed station if said received station identification in said received message is of the first fixed station; determining a signal strength level of said received message at the second fixed station; and transmitting from the second fixed station a no-inhibit signal when said signal strength is less than a first predetermined value. - View Dependent Claims (6, 7, 8)
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9. A method for enabling a remote terminal to transmit in a digital radio communications system while increasing co-channel utilization, the system having at least two fixed stations each transmitting a station identification and messages into and receiving messages from remote terminals in a geographic radio coverage area on the same duplex radio channel, the geopraphic radio coverage area of one fixed station overlapping at least a portion of the geographic radio coverage area of a second fixed station, and the remote terminals having the capability of receiving the station identifications and messages from and transmitting messages to at least one of the at least two fixed stations, the method at the remote terminal comprising the steps of:
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receiving the message and the station identification from one of the fixed stations; determining a signal strength of said received message and station identification; comparing said signal strength to a first predetermined value; determining, in response to said signal strength exceeding said first predetermined value, if a no-inhibit signal has been transmitted from said one of the fixed stations; and transmitting a message if said no-inhibit signal is determined to have been transmitted. - View Dependent Claims (10, 11)
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12. A digital radio communications system having improved co-channel utilization and employing at least two fixed stations each transmitting into and receiving from a geographic radio coverage area on the same duplex radio channel, the geographic radio coverage area of one fixed station overlapping at least a portion of the geographic radio coverage area of a second fixed station, and a plurality of remote terminals having the capability of receiving from and transmitting to at least one of the at least two fixed stations, the digital radio communications system comprising:
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means for transmitting a station identification from a first one of the at least two fixed stations; means for receiving said station identification at one of the plurality of remote terminals; means for transmitting a message including said received station identification from said one of the plurality of remote terminals from the portion of the geographic radio coverage areas which overlap; means for receiving said message including said received station identification at a second one of the at least two fixed station; means for transmitting an inhibit signal from said second one of the at least two fixed stations in response to said message reception, whereby at least a second of the plurality of remote terminals is prevented from transmitting; means for determining a signal strength level of said received message at said second one of the at least two fixed stations; and means for transmitting from said second one of the at least two fixed stations a no-inhibit signal when said signal strength is less than a first predetermined value. - View Dependent Claims (13, 14, 15)
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16. A fixed station for a digital radio communications system having improved co-channel utilization, the system having at least two fixed stations each transmitting an associated station identification and messages into and receiving messages from a geographic radio coverage area on the same duplex radio channel, the geographic radio coverage area of a first fixed station overlapping at least a portion of the geographic radio coverage area of a second fixed station, and a plurality of remote terminals having the capability of receiving the station identifications and messages from and transmitting messages to at least one of the first and second fixed stations, the second fixed station comprising:
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means for receiving a message including a received station identification from one of the plurality of remote terminals from the portion of the geographic radio coverage areas which overlap; means for transmitting an inhibit signal from the second fixed station in response to said message reception whereby at least a second of the plurality of remote units is prevented from transmitting; means for determining if said received station identification in said received message is of the first fixed station; means for determining a signal strength level of said received message at the second fixed station; and means for transmitting a no-inhibit signal when said signal strength is less than a first predetermined value. - View Dependent Claims (17, 18, 19)
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20. A remote terminal for a digital radio communications system having improved co-channel utilization, the system having at least two fixed stations each transmitting a station identification and messages into and receiving messages from remote terminals in a geographic radio coverage area on the same duplex radio channel, the geographic radio coverage area of one fixed station overlapping at least a portion of the geographic radio coverage area of a second fixed station, and the remote terminals having the capability of receiving the station identifications and messages from and transmitting messages to at least one of the at least two fixed stations, the remote terminal comprising:
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means for receiving the message and the station identification from one of the fixed stations; means for determining a signal strength of said received message and station identification; means for comparing said signal strength to a first predetermined value; means for determining, in response to said signal strength exceeding said first predetermined value, if a no-inhibit signal has been transmitted from said one of the fixed stations; and means for transmitting a message if said no-inhibit signal is determined to have been transmitted. - View Dependent Claims (21, 22)
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Specification