Frequency agile sharing technology (FAST) for a personal communications service system
First Claim
1. A personal communications system for providing a radio communication service in a dynamic communications environment in which communication transmissions from at least one other communications system occur, the personal communications system comprising:
- at least one base station;
a plurality of subscriber units, at least some of which are mobile or portable;
a means for communicating between the base station and each of the subscriber units at radio frequencies; and
a centrally located processing means for controlling the frequency of transmissions used by the communicating means, linked electronically to each base station, the processing means comprising;
a means for calculating theoretical intersystem interference to determine which frequencies are used for the other communications transmissions and which frequencies are available for use by the base station and which frequencies are available for use by the plurality of subscriber units, wherein the theoretical calculation of intersystem interference predicts available frequencies to prevent unacceptable interference, the predictions based on calculations of interference caused by the base stations and the subscriber units on transmissions of the other communications systems and interference caused by the other communications systems on transmissions of the base .stations and the subscriber units;
a verification testing means for measuring signal strength of all frequencies being used by the other communication transmissions; and
a means for comparing the results of the theoretical intersystem interference test with the signal strengths determined by the verification test to determine frequencies available for use and accumulating the frequencies into an available channel list which is used to control the frequency of transmission of the base station whereby the system adapts to a changing RF environment and shares frequencies allocated to the other communications system within the same region through the provision of centralized control.
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Accused Products
Abstract
A frequency agile sharing technology (FAST) system for controlling frequent usage in a communications system is disclosed. Specifically, a frequency agile sharing technology system of controlling frequency usage and eliminating interference for use with a Personal Communications Service (PCS) System is described. The frequency control system allows PCS systems to coexist in the same frequency band as Private Operational Fixed Microwave Service (POFS) systems without mutual interference. This system also controls frequency usage within a PCS system to eliminate interference from within the PCS system. This interference elimination system combines theoretical radio frequency interference analysis with measurements of actual frequency usage and allows for efficient and coordinated dynamic frequency allocation planning and management. To control frequency assignment and eliminate interference, the system employs several mechanisms including an intersystem interference analysis, an intrasystem interference analysis, a channel use verification (CUV) procedure, and a measured data analysis (MDA). These mechanisms are performed by a centralized controller, channel utilization controller (CUC), comprised of interference analysis/frequency planning computer programs with supporting data bases and data communication links. The system and method described allows for PCS frequency use around existing microwave users and can be readily adapted for use in any area and most efficiently make use of the available communications spectrum in that area. The system protects existing microwave users from interference while providing high quality PCS to subscribers utilizing small, low power and lightweight handsets in the same frequency band.
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Citations
51 Claims
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1. A personal communications system for providing a radio communication service in a dynamic communications environment in which communication transmissions from at least one other communications system occur, the personal communications system comprising:
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at least one base station; a plurality of subscriber units, at least some of which are mobile or portable; a means for communicating between the base station and each of the subscriber units at radio frequencies; and a centrally located processing means for controlling the frequency of transmissions used by the communicating means, linked electronically to each base station, the processing means comprising; a means for calculating theoretical intersystem interference to determine which frequencies are used for the other communications transmissions and which frequencies are available for use by the base station and which frequencies are available for use by the plurality of subscriber units, wherein the theoretical calculation of intersystem interference predicts available frequencies to prevent unacceptable interference, the predictions based on calculations of interference caused by the base stations and the subscriber units on transmissions of the other communications systems and interference caused by the other communications systems on transmissions of the base .stations and the subscriber units; a verification testing means for measuring signal strength of all frequencies being used by the other communication transmissions; and a means for comparing the results of the theoretical intersystem interference test with the signal strengths determined by the verification test to determine frequencies available for use and accumulating the frequencies into an available channel list which is used to control the frequency of transmission of the base station whereby the system adapts to a changing RF environment and shares frequencies allocated to the other communications system within the same region through the provision of centralized control. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A method of assigning variable radio frequencies, in a personal communications system, to a plurality of base stations and subscriber units including fixed, portable and mobile subscriber units without interfering with other radio frequency transmissions from at least one other communications system occurring at fixed frequencies and between fixed sites in essentially the same frequency spectrum, comprising:
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creating technical databases comprising information pertaining to the characteristics of the personal communications system base station and subscriber unit transmissions, and to the other radio frequency transmissions; predicting intersystem interference indicating which frequency transmissions could cause intersystem interference between the base station and subscriber units and the other communications systems utilizing a predetermined set of representative subscriber unit locations which represent possible positions of subscriber locations; predicting intrasystem interference indicating which frequency transmissions could cause intrasystem interference between the base stations and subscriber units utilizing the set of representative subscriber unit locations; measuring signal strength in selected frequency channels; comparing the intersystem and intrasystem interference results with the measured signal strengths; and creating an available channel list at a central controller for each base station listing available frequency channels for use by the base station and the associated subscriber units which will not interfere with the other base stations, other subscriber units transmitting to and from other base stations and transmissions to and from the other radio frequency communications systems, whereby the system can adapt to a changing RF environment and share frequencies allocated to the other communications system within the same region through the provision of centralized control. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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41. A personal communications system for providing a high capacity portable radio communication service in a frequency spectrum with frequency channels where other radio frequency transmissions from at least one other communications system occur, comprising:
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a plurality of subscriber units each having means for transmitting and receiving communications signals; a plurality of base stations, each base station comprising at least one base transmitter and base receiver; and a means for centrally controlling the frequency channels used by the subscriber units and the base stations, comprising; means for calculating theoretical performance characteristics of the other radio frequency transmissions and the transmissions from the base stations and the subscriber units, comprising means for predicting interference by the other radio frequency transmissions on transmissions to and from the base stations and representative subscriber units and interference by the base stations and representative subscriber units on the other radio frequency transmissions; means for storing the theoretical performance characteristics of the other radio frequency transmissions and the transmissions from the base stations and the subscriber units; means for collecting actual performance characteristics of the other radio frequency transmissions and the transmissions from the base stations and the subscriber units; means for storing the collected actual performance characteristics of the other radio frequency transmissions and the transmissions from the base stations and the subscriber units; and processing means for determining possible intersystem and intrasystem interference based on the stored theoretical and the stored actual performance characteristics to determine which of the frequency channels are available frequency channels for use by the subscriber units and the base stations whereby the system adapts to a changing RF environment and shares frequencies allocated to the other communications system within the same region through the provision of centralized control. - View Dependent Claims (42, 43, 44)
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45. A method for determining available frequency channels for use in an adaptable centrally controlled personal communications system having a plurality of base stations and subscriber units, each of the frequency channels being in a changing RF environment where the frequency spectrum is also used by other fixed site stations, the steps comprising:
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entering information about the other fixed site stations; entering information about the personal communications system base stations; selecting intersystem interference test thresholds; predicting interference at base stations and other fixed site stations by determining theoretical signal strengths based on entered information; generating an available frequency channel list based on predicted interference results wherein cochannel and adjacent channel frequencies are excluded from the list if predicted signal strengths exceed predetermined intersystem interference thresholds; choosing a set of grid points representative of subscriber units located around each base station location; predicting interference at subscriber unit grid points based on other fixed site theoretical signal strengths; excluding cochannel and adjacent channel frequencies from the available frequency channel list if other fixed site theoretical signal strengths exceed predetermined intersystem interference thresholds; predicting interference at other fixed site stations based on theoretical subscriber unit signal strengths; excluding cochannel and adjacent channel frequencies from the available frequency channel list if theoretical subscriber unit signal strengths exceed predetermined intersystem interference thresholds; selecting intrasystem interference thresholds; predicting interference at subscriber unit grid points based on theoretical undesired base station signal strengths; excluding cochannel and adjacent channel frequencies from the available frequency channel list if theoretical undesired base stations signal strengths exceed predetermined intrasystem interference thresholds; predicting interference at desired base station based on theoretical subscriber unit signal strengths; excluding cochannel and adjacent channel frequencies from the available frequency channel list if theoretical subscriber unit signal strengths exceed predetermined intrasystem interference thresholds; and storing the completed available frequency channel list in data storage at a central controller. - View Dependent Claims (46, 47)
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48. A centralized control system in a personal communications system, the personal communications system containing a plurality of subscriber units, communications links, a central controller, and a base station for controlling the frequency usage and allocating frequency channel assignments based on theoretical and actual interference analysis in a shared frequency spectrum environment where personal communications system transmissions share frequencies used in common with private operational fixed site station transmissions from at least one other communications system within the same region, the centralized control system comprising:
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a first means for storing private operational fixed site station information; a means for selecting a set of grid points, the grid points representing possible positions of subscriber units located around a base station location; a second means for storing personal communications system base station and subscriber unit information; means for determining, connected to the first and second storage means, frequency channels which meet acceptable interference criteria and are thereby available for the base station to establish communications links to subscriber units, comprising; means for simulating propagation performance of transmissions from the base station, the plurality of subscriber units and the private operational fixed site station; a means for calculating intersystem interference to determine, from the selected grid points, the information stored in the first and second storage means and the simulated propagation performance, available frequency channels for the base station and subscriber unit transmissions which do not unreasonably interfere with and do not receive unreasonable interference from the private operational fixed site station transmissions, wherein the intersystem interference calculating means utilizes the selecting means to calculate predicted interference to and from the subscriber units; a means for calculating intrasystem interference to determine, from the selected grid points, the information stored in the first and second storage means and the simulated propagation performance, available frequency channels for the base station and subscriber unit transmissions which do not unreasonably interfere with and do not receive unreasonable interference from other base station and subscriber unit transmissions, whereby the intrasystem interference calculating means utilizes the selecting means to calculate predicted interference to and from the subscriber units; and a means for accumulating the available frequencies into an available frequency channel list whereby the personnel communications system adapts to a changing RF environment and shares frequencies allocated to the other communications system within the same region through the provision of centralized control.
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49. A mobile communications unit in a personal communications system having a plurality of base stations, subscriber units and a central controller, for measuring signal strengths in a communications environment in which other communications transmissions from at least one other communications system share a common frequency spectrum, the mobile communications unit comprising:
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input means for capturing satellite based position information at various grid point locations located around the base station location; means, connected to the input means, for storing the position information; a means for receiving communications transmissions from base stations, subscriber units and other communications transmissions; a means for measuring, connected to the receiving means, the signal strengths of communications transmissions from base stations, subscriber units and other communications systems at the various grid point locations; means for storing the signal strengths of communications transmissions; and means for transmitting the stored position information and stored signal strengths of the communications transmissions to a central controller for verifying theoretical interference performance predictions with the measured signal strengths whereby the personnel communications system adapts to a changing RF environment and shares frequencies allocated to the other communications system within the same region through the provision of centralized control.
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50. A method for determining available frequency channels for use in a personal communications system having a plurality of base stations and subscriber units, each of the frequency channels being in a frequency spectrum used by other fixed site stations, the steps comprising:
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entering information about the other fixed site stations; entering information about the personal communications system base stations; selecting intersystem interference test thresholds; predicting interference at base stations and other fixed site stations by determining theoretical signal strengths based on entered information; generating an available frequency channel list based on predicted interference results wherein cochannel and adjacent channel frequencies are excluded from the list if predicted signal strengths exceed predetermined intersystem interference thresholds; choosing a set of grid points representative of subscriber units located around each base station location; predicting interference at subscriber unit grid points based on other fixed site theoretical signal strengths; excluding cochannel and adjacent channel frequencies from the available frequency channel list if other fixed site theoretical signal strengths exceed predetermined intersystem interference thresholds; predicting interference at other fixed site stations based on theoretical subscriber unit signal strengths; and excluding cochannel and adjacent channel frequencies from the available frequency channel list if theoretical subscriber unit signal strengths exceed predetermined intersystem interference thresholds.
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51. A method for determining available frequency channels for use in a personal communications system having a plurality of base stations, a central controller and subscriber units, each of the frequency channels being in a frequency spectrum used by other fixed site stations, the steps comprising:
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entering information about the personal communications system base stations; selecting intrasystem interference thresholds; predicting interference at subscriber unit grid points based on theoretical undesired base station signal strengths; excluding cochannel and adjacent channel frequencies from the available frequency channel list if theoretical undesired base stations signal strengths exceed predetermined intrasystem interference thresholds; predicting interference at desired base station based on theoretical subscriber unit signal strengths; excluding cochannel and adjacent channel frequencies from the available frequency channel list if theoretical subscriber unit signal strengths exceed predetermined intrasystem interference thresholds; and storing the completed available frequency channel list in data storage at a central controller.
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Specification