Air-to-ground communication system
First Claim
1. A method of operating one of a plurality of mobile radio units in a system for conducting communications between said plurality of mobile radio units and a plurality of base stations, said method operating to conserve frequency spectrum available for said communications, and said method comprising the steps of:
- detecting a first signal which occurs periodically within a pilot frequency channel;
identifying a first one of a predetermined number of time slots within which said first signal periodically occurs;
detecting a second signal which occurs periodically within said pilot frequency channel;
identifying a second one of said predetermined number of time slots within which said second signal periodically occurs, said first and second time slots differing from one another;
obtaining, from said first and second signals, data descriptive of voice frequency channels available for use by said one radio unit; and
establishing a voice communication link over one of said voice frequency channels.
6 Assignments
0 Petitions
Accused Products
Abstract
An air-to-ground communications system is described for controlling multiple two way radiotelephone conversations between a large number of aircraft (53) and a network of base stations (51) that are capable of being interconnected to landline telephone networks (54, 116). Plural base station controllers (90) of the system, each dedicated to control one base station (51), are in turn controlled by a single central processor (52). Means are provided for matching each aircraft with an optimal base station to afford it the strongest available communication signals, and for dynamically allocating communication channels between the base stations. The central processor (52) is designed to manage the system by recording and recognizing usage patterns (525-530) and allocating channels to most efficiently use the available radio spectrum among all the aircraft (517, 519).
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Citations
21 Claims
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1. A method of operating one of a plurality of mobile radio units in a system for conducting communications between said plurality of mobile radio units and a plurality of base stations, said method operating to conserve frequency spectrum available for said communications, and said method comprising the steps of:
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detecting a first signal which occurs periodically within a pilot frequency channel; identifying a first one of a predetermined number of time slots within which said first signal periodically occurs; detecting a second signal which occurs periodically within said pilot frequency channel; identifying a second one of said predetermined number of time slots within which said second signal periodically occurs, said first and second time slots differing from one another; obtaining, from said first and second signals, data descriptive of voice frequency channels available for use by said one radio unit; and establishing a voice communication link over one of said voice frequency channels. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of operating one of a plurality of mobile radio units in a system for conducting communications between said plurality of mobile radio units and a plurality of base stations, said method operating to conserve frequency spectrum available for said communications, and said method comprising the steps of:
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receiving first and second pilot signals transmitted from first and second ones, respectively, of said base stations; obtaining, from said first and second pilot signals, data descriptive of communication channels associated with said first and second base stations, respectively, and currently idle so that said channels may be used by said one radio unit; obtaining, from said first and second pilot signals, first and second data, respectively, describing fractions of total numbers of frequency channels available for use at said first and second base stations, respectively; selecting one of said first and second base stations with which to establish communication, said selecting being based upon said first and second pilot signals and upon a comparison of said first and second data; and adjusting a transceiver within said one mobile radio unit to operate within one of said communication channels associated with said selected one of said first and second base stations and described by said data. - View Dependent Claims (9, 10, 11, 12)
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13. A method for efficiently utilizing a predetermined number of frequency channels to simultaneously conduct communications between a plurality of mobile radio units and a plurality of spaced apart base radio units, said method comprising the steps of:
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transmitting, from a first one of said base radio units, a first pilot signal configured to communicate data descriptive of a first group of said frequency channels through which said first base radio unit can communicate with one of said mobile radio units; transmitting, from a second one of said base radio units, a second pilot signal configured to communicate data descriptive of a second group of said frequency channels through which said second base radio unit can communicate with one of said mobile radio units; dynamically allocating a first portion of said predetermined number of frequency channels to said first base radio unit and a second portion of said predetermined number of frequency channels to said second base radio unit; and monitoring, at said first one of said base radio units, a fraction of said first portion of said predetermined number of frequency channels being used to conduct communications; and requesting allocation of additional ones of said predetermined number of frequency channels to said first one of said base radio units in response to said monitored fraction. - View Dependent Claims (14)
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15. A method of operating one of a plurality of mobile radio units in a system for conducting communications between said plurality of mobile radio units and a plurality of base stations, said method operating to conserve frequency spectrum available for said communications, and said method comprising the steps of:
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receiving pilot signals broadcast from ones of said plurality of base stations which are within range of said mobile unit; analyzing said received pilot signals to identify said ones of said plurality of base stations which are within range of said mobile unit, said identified base stations together defining a radio horizon; selecting one of said base stations with which to conduct communications; analyzing said received pilot signal from said selected one of said base stations to identify a frequency channel available for use within said radio horizon; and tuning a transceiver portion of said one mobile radio unit to said frequency channel. - View Dependent Claims (16, 17)
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18. A system for efficiently utilizing a predetermined number of frequency channels to simultaneously conduct communications between a plurality of airborne mobile radio units and a plurality of spaced apart base radio units, said system comprising:
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means, coupled to one of said base radio units, for transmitting a pilot signal from said one of said base radio units, said pilot signal being configured to communicate data descriptive of a first radio horizon which includes said one base radio unit and data descriptive of a second radio horizon which includes said one base radio unit; means, coupled to said one base radio unit, for dynamically allocating a first portion of said predetermined number of frequency channels to said first radio horizon and a second portion of said predetermined number of frequency channels to said second radio horizon. - View Dependent Claims (19, 20, 21)
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Specification