Cordless telephone and method for selecting communication channel thereof
First Claim
1. A cordless telephone on Frequency Hopping Spread Spectrum (FHSS) system comprising:
- a handset unit;
a base unit including a main controller of said base unit, a storing unit of said base unit, and a communication unit of said base unit communicating with said handset unit;
wherein said handset unit i) measures field strength on a channel for use in communication, and ii) when communicating condition of the channel is determined to be bad based on a result of the measurement, grades the channel as an inferior channel and notifies the base unit of the value of the field strength together with the channel number, and said base unit i) stores the channel number and the field strength in said storing unit of said base unit, and, ii) when the number of the inferior channels has become not less than a predetermined number and when notified by said handset unit of information about a further inferior channel, compares field strength of the inferior channel with the field strength value of the stored inferior channel, determines the channel of better communicating condition as the channel to be used, and sends said handset unit a notice to switch the channel for use in communication to the channel to be used.
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Accused Products
Abstract
In a cordless telephone on frequency hopping system, base unit and handset unit conduct communication after selecting channels of good communicating condition. The handset unit determines whether the communicating condition of each channel is bad based on electric field strength or CRC error rate (CRCE). Of a channel of bad communicating condition, the handset unit notifies the base unit of the channel number and electric field strength or CRCE. The base unit stores such information. When the number of the inferior channels becomes not less than a predetermined number and, further, information of a new inferior channel is notified by the handset unit, the base unit compares the information and information of stored inferior channels and judges the better of the channels as the channel to be used. The base unit notifies the handset unit of the channel information.
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Citations
13 Claims
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1. A cordless telephone on Frequency Hopping Spread Spectrum (FHSS) system comprising:
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a handset unit;
a base unit including a main controller of said base unit, a storing unit of said base unit, and a communication unit of said base unit communicating with said handset unit;
whereinsaid handset unit i) measures field strength on a channel for use in communication, and ii) when communicating condition of the channel is determined to be bad based on a result of the measurement, grades the channel as an inferior channel and notifies the base unit of the value of the field strength together with the channel number, and said base unit i) stores the channel number and the field strength in said storing unit of said base unit, and, ii) when the number of the inferior channels has become not less than a predetermined number and when notified by said handset unit of information about a further inferior channel, compares field strength of the inferior channel with the field strength value of the stored inferior channel, determines the channel of better communicating condition as the channel to be used, and sends said handset unit a notice to switch the channel for use in communication to the channel to be used. - View Dependent Claims (2, 3, 4, 6, 7)
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5. A cordless telephone on Frequency Hopping Spread Spectrum (FHSS) system comprising:
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a handset unit; and
a base unit communicating with said handset unit, wherein, in a channel setting stage preceding a conversation stage, notification of information about a channel, communicating condition thereof is determined to be bad by said handset unit based on field strength, is given to said base unit, and said base unit sends said handset unit a notice that switching should be made to the channel to be used, and in the conversation stage, said handset unit determines communication error condition of a channel selected from the channels determined to be used in the channel setting stage, and said base unit, based on communication error condition determined by said handset unit, selects the channel, field strength thereof is the smallest of the channels graded as inferior channels in the channel setting stage, as a new channel to be used and sends said handset unit a notice that switching should be made to the new channel to be used. - View Dependent Claims (8)
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9. A method of channel setting for setting channels of good communicating condition in a cordless telephone on FHSS system including a handset unit and a base unit comprising the steps of:
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a) setting the channels of good communicating condition in said handset unit; and
b) setting the channels of good communicating condition in said base unit;
whereinsaid step a) includes the steps of;
a-1) selecting a channel as an object of determination;
a-2) measuring field strength on the selected channel;
a-3) determining whether the selected channel should be graded as inferior channel based on the field strength;
a-4) notifying said base unit of the measured field strength together with channel number of the determined inferior channel; and
a-5) exchanging the inferior channel for a good channel responsive to a request for exchanging from said base unit; and
said step b) includes the steps of;
b-1) storing the inferior channel number and the field strength;
b-2) counting number of the inferior channels;
b-3) determining whether the counted number of the inferior channels is greater than a predetermined number inclusive;
b-4) determining, when the counted number of the inferior channels is determined to be not less than the predetermined number, whether a further inferior channel should be exchanged for an inferior channel of the stored channels;
b-5) sending, when the exchanging is determined to be made in said step b-4), a request to said handset unit for perfuming the exchange; and
b-6) performing, when the exchanging for the inferior channel is determined to be made in said step b-4), the exchange. - View Dependent Claims (10, 12)
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11. A method, in a cordless telephone on FHSS system including a handset unit and a base unit, of channel setting for carrying on a conversation over a channel of good communication error condition comprising the steps of:
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a) discriminating, before the conversation is started, channels of good communicating condition and channels of bad communicating condition;
b) selecting further, at the handset unit, channels for conversation from the good channels; and
c) selecting further, at the base unit, channels for conversation from the good channels;
whereinsaid step b) includes the steps of;
b-1) sequentially selecting channels for conversation;
b-2) determining whether good or bad communication error condition of the selected channels for conversation is;
b-3) grading a channel as an inferior channel when the communication error condition thereof is determined to be bad in said step b-2), and notifying said base unit of the channel number of the selected channel for conversation and error information indicating that the communication error condition thereof is bad; and
b-4) making channel exchanging responsive to a request from said base unit; and
said step c) includes the steps of;
c-1) determining whether notification of the error information is received;
c-2) determining, upon receipt of the error information, whether the number of the inferior channels exceed a predetermined number;
c-3) storing, when the number of inferior channels is determined to be smaller than the predetermined number, the channel for conversation specified in the error information as the inferior channel;
c-4) incrementing, when the number of inferior channels is determined to be smaller than the predetermined number, the number of inferior channels by one;
c-5) selecting, when the number of the inferior channels is determined to be not less than the predetermined number, a channel electric field strength thereof is the smallest of the channels graded as inferior channels in step a), as a new good channel;
c-6) sending said handset unit a request for exchanging the channel for conversation specified in the error information for the new good channel; and
c-7) exchanging the channel for conversation specified in the error information for the new good channel. - View Dependent Claims (13)
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Specification