Radio telephone system

Claim 2

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system, said radio control means being located in said telephone set means; and wherein said set threshold values of said detection means include a first threshold value corresponding to a first value of said received electric field intensity and a second threshold value corresponding to a second value smaller than said first value, and said detection means selects said first threshold value when said operating member is not operated and said second threshold value when said operating member is operated.

Claim 3

A radio telephone system according to claim 1, wherein said first value corresponds to a received electric field intensity of 20 dbμV and said second value corresponds to a received electric field intensity of 10 dBμV.

Claim 4

A radio telephone system according to claim 1, wherein said first value corresponds to an electric field intensity of 20 dBμV and said second value corresponds to a received electric field intensity of 0 dBμV.

Claim 5

A radio telephone system according to claim 1, wherein said detection means enables selection and modification of said threshold values on the basis of logical product conditions that said radio line is in a completed interconnection state and that said operating member is completely operated.

Claim 6

A radio telephone system according to claim 1, wherein said detection means further includes a timer circuit which has a set predetermined timer time, and passage of said predetermined timer time after the selection and modification of said threshold value causes the threshold value to be automatically returned to said first value.

Claim 7

A radio telephone system according to claim 1, wherein said operating member is used as said dial means of said telephone set means.

Claim 8

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system, said radio control means being located in said telephone set means; and wherein said detection means continuously presets as said set threshold values, values ranging from a first value of said received electric field intensity to a second value smaller than the first value, and selects said first value when said operating member is not operated and sequentially selects one of said values close to said second value when said operating member is operated in response to an operation amount of said operating member.

Claim 9

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system, said radio control means being located in said telephone set means; and wherein said detection means continuously presets as said set threshold values, values ranging from a first value of said received electric field intensity to a second value smaller than the first value, and selects said first value when said operating member is not operated and sequentially selects one of said values close to said second value when said operating member is operated in response to an operation amount of said operating member.

Claim 10

A radio telephone system according to claim 7, wherein said first value corresponds to a received electric field intensity of 20 dBμV and said second value corresponds to a received electric field intensity of 10 dBμV.

Claim 11

A radio telephone system according to claim 7, wherein said first value corresponds to a received electric field intensity of 20 dBμV and said second value corresponds to a received electric field intensity of 0 dBμV.

Claim 12

A radio telephone system according to claim 7, wherein said detection means enables selection and modification of said threshold values on the basis of logical product conditions that said radio line is in a completed interconnection state and that said operating member is completely operated.

Claim 13

A radio telephone system according to claim 7, wherein said detection means further includes a timer circuit which has a set predetermined timer time, and passage of said predetermined timer time after the selection and modification of said threshold value causes the threshold value to be automatically returned to said first value.

Claim 14

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system, said radio control means being located in said telephone set means; and wherein said detection means stepwise presets as said set threshold values, values ranging from a first value of said received electric field intensity to a second value smaller than the first value, and selects said first value when said operating member is not operated and sequentially selects one of said values close to said second value when said operating member is operated in response to an operation amount of said operating member.

Claim 15

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system, said radio control means being located in said telephone set means; and wherein said detection means stepwise presets as said set threshold values, values ranging from a first value of said received electric field intensity to a second value smaller than the first value, and selects said first value when said operating member is not operated and sequentially selects one of said values close to said second value when said operating member is operated in response to an operation amount of said operating member.

Claim 16

A radio telephone system according to claim 12, wherein said first value corresponds to a received electric field intensity of 20 dBμV and said second value corresponds to a received electric field intensity of 10 dBμV.

Claim 17

A radio telephone system according to claim 12, wherein said first value corresponds to a received electric field intensity of 20 dBμV and said second value corresponds to a received field intensity of 0 dBμV.

Claim 18

A radio telephone system according to claim 12, wherein said detection means enables selection and modification of said threshold values on the basis of logical product conditions that said radio line is in a completed interconnection state and that said operating member is completely operated.

Claim 19

A radio telephone system according to claim 12, wherein said detection means further includes a timer circuit which has a set predetermined timer time, and passage of said predetermined timer time after the selection and modification of said threshold value causes the threshold value to be automatically returned to said first value.

Claim 20

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, and transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system, said radio control means being located in said telephone set means; and wherein said operating member is used as said dial means of said telephone set means, said detection means stepwise presets as said set threshold values, values ranging from a first value of said received electric field intensity to a second value smaller than the first value, and selects said first value when said dial means is not operated and selects a different one of said values other than the first value when the dial means is operated in response to dial information.

Claim 21

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, and transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system, said radio control means being located in said telephone set means; and wherein said operating member is used as said dial means of said telephone set means, said detection means stepwise presets as said set threshold values, values ranging from a first value of said received electric field intensity to a second value smaller than the first value, and selects said first value when said dial means is not operated and selects a different one of said values other than the first value when the dial means is operated in response to dial information.

Claim 22

A radio telephone system according to claim 17, wherein said first value corresponds to a received electric field intensity of 20 dBμV and said second value corresponds to a received electric field intensity of 10 dBμV.

Claim 23

A radio telephone system according to claim 17, wherein said first value corresponds to an electric field intensity of 20 dBμV and said second value corresponds to a received electric field intensity of 0 dBμV.

Claim 24

A radio telephone system according to claim 17, wherein said detection means enables selection and modification of said threshold values on the basis of logical product conditions that said radio line is in a completed interconnection state and that said operating member is completely operated.

Claim 25

A radio telephone system according to claim 17, wherein said detection means further includes a timer circuit which has a set predetermined timer time, and passage of said predetermined timer time after the selection and modification of said threshold value causes the threshold value to be automatically returned to said first value.

Claim 26

A radio telephone system comprising: a base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing the actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means and said control circuit means are disposed in both of said radio control means on the side of said base unit means and said radio control means on the side of said telephone set means and said operating member is disposed in the radio control means on the side of the telephone set means so that the operation information of the operating member is transmitted to the radio control means of the base unit means through said radio line.

Claim 27

A radio telephone system comprising: a base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing the actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator; wherein said detection means and said control circuit means are disposed in both of said radio control means on the side of said base unit means and said radio control means on the side of said telephone set means and said operating member is disposed in the radio control means on the side of the telephone set means so that the operation information of the operating member is transmitted to the radio control means of the base unit means through said radio line.

Claim 28

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value and for terminating said interconnection mode when said detection means detects that said received electric field intensity is less than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator and for changing the threshold value at which said interconnection mode is terminated; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system.

Claim 29

A radio telephone system comprising: base unit means connected to a wire telephone line; telephone set means having dial means, transmitter means and receiver means; and radio control means for controlling interconnection between said base unit means and said telephone set means through a radio line, said radio control means comprising: detection means for detecting a received intensity of an electric field received through said radio line by comparing an actually received electric field intensity with a selected one of a plurality of set threshold values for the field intensity; control circuit means for maintaining an interconnection mode through said radio line when said detection means detects that said received electric field intensity is larger than said selected threshold value and for terminating said interconnection mode when said detection means detects that said received electric field intensity is less than said selected threshold value; and an operating member for selecting an arbitrary one of said plurality of set threshold values according to an arbitrary manipulation by an operator and for changing the threshold value at which said interconnection mode is terminated; wherein said detection means, said control circuit means and said operating member are disposed in said radio control means of said telephone system.

Claim 30

A radio telephone system having a base unit connected to a wire telephone line and a telephone set selectively coupled to said base unit via a radio link, comprising: establishing means for establishing the radio link between said base unit and said telephone set; measuring means coupled to said establishing means for measuring a field intensity of signals transmitted over the established radio link; setting means for setting a threshold level which is variable in response to a user's operation; comparing means coupled to said measuring means and said setting means for comparing the measured field intensity with the threshold level; maintaining means responsive to said comparing means for maintaining the established radio link if the level of the measured field intensity is above the threshold level, the threshold level being set by said setting means in response to the user's operation so as to maintain the established radio link; and terminating means responsive to said comparing means for terminating said established radio link if the level of the measured field intensity is below the threshold level set by said setting means as a termination level.

Claim 31

A radio telephone system having a base unit connected to a wire telephone line and a telephone set selectively coupled to said base unit via a radio link, comprising: establishing means for establishing the radio link between said base unit and said telephone set; measuring means coupled to said establishing means for measuring a field intensity of signals transmitted over the established radio link; setting means for setting a threshold level which is variable in response to a user's operation; comparing means coupled to said measuring means and said setting means for comparing the measured field intensity with the threshold level; maintaining means responsive to said comparing means for maintaining the established radio link if the level of the measured field intensity is above the threshold level, the threshold level being set by said setting means in response to the user's operation so as to maintain the established radio link; and terminating means responsive to said comparing means for terminating said established radio link if the level of the measured field intensity is below the threshold level set by said setting means as a termination level.

Claim 32

The radio telephone system according to claim 24, further comprising: indicator means coupled to said comparing means for providing an indication to a user of the system when the measured field intensity decreases below a predetermined level.

Claim 33

The radio telephone system according to claim 24, wherein said maintaining means fails to maintain the established radio link on the condition that the measured field intensity has been below the threshold for a predetermined time period.

Claim 36

The method according to claim 27, further comprising the step of alarming a user of the system in the event that the measured field intensity decreases below a predetermined level.

Claim 37

The method according to claim 27, further comprising the step of terminating the established radio link in the event that the measured field intensity has been below the second level for a predetermined time period.