Mobile radio communication system and fixed and mobile units used therefor
First Claim
1. A fixed unit situated in a physical area of a cellular communication system wherein the physical area is divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in said cellular communication system, such that at least those of the communication channel groups which are assigned to adjacent ones of the cells are different from each other, and radio communication is performed between the base units of the cells and a mobile unit moving in the physical area by using communication channels of the communication channel groups, said fixed unit comprising:
- a wired communication circuit configured for signal transmission/reception with a communication network via a wired line;
a control circuit for sequentially receiving signals transmitted via communication channels included in communication channel groups assigned to cells of the cellular communication system, identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which a fixed unit is situated, selecting, on the basis of the identification results, those of the communication channel groups which are not assigned to the one cell in which the fixed unit is situated, and storing the selected communication channel groups;
a radio communication circuit configured to select a communication channel to be used, on the basis of the communication channel groups stored in said control circuit, and to perform signal transmission/reception with the mobile unit via the selected communication channel; and
a communication control circuit configured to connect the wired communication circuit and the radio communication circuit in the case of performing communication between the communication network and the mobile unit.
1 Assignment
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Accused Products
Abstract
In a mobile communication system of the present invention, a cordless base unit LBU is connected to a wired subscriber line SL. The base unit LBU detects a radio channel assigned to a cell other than a cell where the base unit LBU is located, among radio channels assigned to the cells of a cellular radio communication system. This radio channel is used as a radio channel for a cordless call. On the other hand, a cellular cordless telephone CCT is provided with a mode switch. When a cordless mode is designated by the mode switch, a radio channel for a cordless call is detected, as with the case of the base unit LBU. At the time of the cordless call, a transmission power level of the cellular cordless telephone CCT is set at a weak level smaller than that for a cellular call.
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Citations
22 Claims
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1. A fixed unit situated in a physical area of a cellular communication system wherein the physical area is divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in said cellular communication system, such that at least those of the communication channel groups which are assigned to adjacent ones of the cells are different from each other, and radio communication is performed between the base units of the cells and a mobile unit moving in the physical area by using communication channels of the communication channel groups, said fixed unit comprising:
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a wired communication circuit configured for signal transmission/reception with a communication network via a wired line; a control circuit for sequentially receiving signals transmitted via communication channels included in communication channel groups assigned to cells of the cellular communication system, identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which a fixed unit is situated, selecting, on the basis of the identification results, those of the communication channel groups which are not assigned to the one cell in which the fixed unit is situated, and storing the selected communication channel groups; a radio communication circuit configured to select a communication channel to be used, on the basis of the communication channel groups stored in said control circuit, and to perform signal transmission/reception with the mobile unit via the selected communication channel; and a communication control circuit configured to connect the wired communication circuit and the radio communication circuit in the case of performing communication between the communication network and the mobile unit. - View Dependent Claims (2, 3)
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4. A mobile unit used in a cellular communication system wherein a physical area is divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in the cellular communication system, such that at least those of the communication channel groups which are assigned to adjacent ones of the cells are different from each other, and radio communication is performed between the base units of the cells and a mobile unit moving in the physical area by using communication channels of the communication channel groups, said mobile unit comprising:
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an operation circuit configured to designate the base unit or a fixed unit as a destination of communication connection; a control circuit for sequentially receiving signals transmitted via communication channels included in communication channel groups assigned to cells of the cellular communication system, identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which the mobile unit is situated, selecting, on the basis of the identification results, those of the communication channel groups which are not assigned to the one cell in which the mobile unit is situated, and storing the selected communication channel groups; a receiving circuit configured to selectively receive, in accordance with a designated result of the operation circuit, a signal sent via a communication channel of the communication channel group assigned to the cell in which the mobile unit is located or a signal sent from the fixed unit via a communication channel of one of the communication channel groups stored in the control circuit; and a transmission circuit configured to perform, in accordance with the designated result of the operation circuit, transmission in a first case of performing radio communication with the base unit and transmission in a second case of performing communication with the fixed unit. - View Dependent Claims (5, 6)
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7. A fixed unit situated in a physical area of a cellular communication system wherein the physical area is divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in the cellular communication system, such that at least those of the communication channel groups which are assigned to adjacent ones of the cells are different from each other, and radio communication is performed between the base units of the cells and a mobile unit moving in the physical area by using communication channels of the communication channel groups, said fixed unit comprising:
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a wired communication circuit configured for signal transmission/reception with a communication network via a wired line; a radio communication circuit for sequentially receiving signals transmitted via communication channels included in communication channel groups employed in the cellular communication system, identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which a fixed unit is situated, selecting, on the basis of the identification results, those of the communication channel groups which are not assigned to the one cell in which the fixed unit is situated, and storing the selected communication channel groups; and a communication control circuit configured to connect the wired communication circuit and the radio communication circuit in a case of performing communication between the communication network and the mobile unit.
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8. A mobile unit of a cellular communication system used in a mobile communication system comprising the cellular communication system wherein a physical area is divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in the cellular communication system, such that at least those of the communication channel groups which are assigned to adjacent one of the cells are different from each other, and radio communication is performed between the base units of the cells and the mobile unit moving in the physical area, and a fixed unit situated in said physical area of the cellular communication system and connected to a communication network via a wired line, said mobile unit comprising;
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a connection destination determining circuit configured to determine the base unit or the fixed unit as a destination of radio connection; a first radio communication circuit configured to perform radio communication with the base unit of one of the cells, when the base unit is determined as the destination of radio connection by the connection destination determining circuit, by selectively using a communication channel of the communication channel group assigned to the cell in which the mobile unit is located; a control circuit for sequentially receiving signals transmitted via communication channels included in communication channel groups assigned to cells of the cellular communication system, identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which the mobile unit is situated, selecting, on the basis of the identification results, those of the communication channel groups which are not assigned to the one cell in which the mobile unit is situated, and storing the selected communication channel groups; and a second radio communication circuit configured to perform radio communication with the fixed unit, when the fixed unit is determined as the destination of radio connection by the connection destination determining circuit, by selectively using a communication channel of one of the communication channel groups stored in the control circuit. - View Dependent Claims (9, 10, 11, 12)
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13. A mobile communication system comprising:
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a cellular communication system covering a physical area which is divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in the mobile communication system, such that at least those of the communication channel groups which are assigned to the adjacent ones of the cells are different from each other; a communication network; a mobile unit movable in the physical area and configured to communicate with a base unit of a cell in which the mobile unit is located using a communication channel in the communication channel group associated with the cell in which the mobile unit is located; and a fixed unit connection to the communication network, wherein said fixed unit comprises; a control circuit for sequentially receiving signals transmitted via communication channels included in communication channel groups assigned to cells of the cellular communication system, identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which a fixed unit is situated, selecting, on the basis of the identification results, those of the communication channel groups which are not assigned to the one cell in which the fixed unit is situated, and storing the selected communication channel groups; and a radio communication circuit configured to select a communication channel to be used, on the basis of the communication channel groups stored in said control circuit, and to perform signal transmission/reception with the mobile unit via the selected communication channel. - View Dependent Claims (14)
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15. A system comprising a fixed unit connected to a communication network and a mobile unit configured to communicate with a base unit of a cell in which the mobile unit is located, the cell being in a cellular communication system having a plurality of cells wherein said fixed unit comprises:
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a control circuit for sequentially receiving signals transmitted via communication channels included in communication channel groups assigned to cells of the cellular communication system, identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which a fixed unit is situated, selecting, on the basis of the identification results, those of the communication channel groups which are not assigned to the one cell in which the fixed unit is situated, and storing the selected communication channel groups; and a radio communication circuit configured to select a communication channel to be used, on the basis of the communication channel groups stored in said control circuit, and to perform signal transmission/reception with the mobile unit via the selected communication channel. - View Dependent Claims (16)
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17. A mobile communication system comprising:
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a cellular communication system for covering a geographical area which is geographically divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in said cellular communication system, such that at least those of the communication channel groups which are assigned to adjacent ones of the cells are different from each other, wherein radio communication is performed between the base unit, and a mobile unit moving in the geographical area, using a communication channel included in the one of the communication channel groups and a first transmission output level; and a fixed unit connected to a communication network via a wired line, wherein said mobile unit and said fixed unit comprise; identification means for sequentially receiving communication channels included in the communication channel groups employed in said cellular communication system, and identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which the mobile unit is situated; storage means for selecting, on the basis of the identification results, those of the communication channel groups employed in said cellular communication system which are not assigned to the one of the cells at which the mobile unit is situated, and storing the selected communication channel groups; and means for performing radio communication between the mobile unit and the fixed unit, using a communication channel included in the communication channel groups stored in the storage means, and a second transmission output level lower than the first transmission output level.
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18. A mobile communication system comprising:
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a cellular communication system for covering a geographical area which is geographically divided into a plurality of cells, each cell comprising a base unit and being assigned one of a plurality of communication channel groups employed in said cellular communication system, such that at least those of the communication channel groups which are assigned to adjacent ones of the cells are different from each other, wherein radio communication is performed between the base unit and a mobile unit moving in the geographical area, using a communication channel included in the one of the communication channel groups and a first transmission output level; and a fixed unit connected to a communication network via a wired line, wherein said mobile unit and said fixed unit comprise; identification means for sequentially receiving communication channels included in the communication channel groups employed in said cellular communication system, and identifying, on the basis of the reception results, the one of the communication channel groups which is assigned to the one of the cells in which the mobile unit is situated; storage means for selecting, on the basis of the identification results, those of the communication channel groups employed in said cellular communication system which are not assigned to the one of the cells at which the mobile unit is situated, and storing the selected communication channel groups; and means for performing radio communication between the mobile unit and the fixed unit, using a communication channel included in the communication channel groups stored in the storage means. - View Dependent Claims (19, 20, 21, 22)
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Specification