JPH0879829A - Digital cordless telephone system - Google Patents

Abstract

PURPOSE: To allow a home/office to receive the service of a home/office cordless telephone system by setting automatically the home/office mode by an automatic mode set management section when the user uses a mobile station in the home/ office. CONSTITUTION: When a power of a mobile station is applied, or when the standby mobile station detects an out of zone signal, or when the standby mobile station is registered by a public base station adjacent a home/office system, an automatic mode set management section 5 allows a public base station signal detection section 1 and a home/office base station signal detection section 2 to detect the signal from a public and home/office base station and sets the mode to be the home/office mode when a communication available home/office base station is in existence, and sets the mode to the public mode when the home/office base station is not available of communication and a communication available public base station is in existence to make automatic mode setting and position register attended thereto while placing priority on the home/office mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless telephone system, and more particularly to a digital cordless telephone system having a digital cordless telephone handset having a function of operating as a simple portable telephone land mobile station.

[0002]

2. Description of the Related Art A wireless telephone device having a function of operating as a mobile station of a public wireless telephone service network and a function of operating as a mobile station of a home / business cordless telephone system connected to a wired public telephone line is known. , If you want to use the public wireless telephone service, set the mode to public mode,
When using the home / business cordless telephone system, it is necessary to set the mode to the home / business mode. Conventionally, a radiotelephone device having an automatic mode setting function for automatically performing this mode setting functions when the power of the mobile station is turned on or when the mobile station in the standby state performs out-of-range detection.

FIG. 6 is a block diagram of a conventional digital cordless telephone system. In the figure, 21 is a signal detecting unit from a public base station, 22 is a signal detecting unit from a home / business base station, and 23 is a mode switch. Reference numeral 24 is a position registration unit, and reference numeral 25 is a dual mode management unit.

The dual mode management unit 25 activates the signal detecting unit 21 from the public base station, and when the signal detecting unit 21 detects a communicable public base station, notifies the mode switching unit 23 of the signal. Switch the mode to public mode.
The location registration unit 24 performs location registration with a communicable public base station. If no public base station with which communication is possible is detected,
The dual mode management unit 25 activates the signal detection unit 22 from the home / business base station, and when a communicable home / business base station is detected, notifies the mode switching unit 23 to notify the home / business base. Switch to the office mode. The location registration unit 24 performs location registration with a home / business base station with which communication is currently possible. In addition, the dual mode management unit 25
When the power supply of the mobile station is ON or the mobile station in the standby state performs the out-of-range detection, the signal detecting unit 21 from the public base station
It manages the signal detection unit 22 from the home / business base station, the mode switching unit 23, and the position registration unit 24, and performs the automatic mode setting function.

FIG. 7 is a flow chart for explaining the operation of the conventional radiotelephone device having the automatic mode setting function shown in FIG. 6, and when the power of the mobile station is turned on or when the mobile station in the standby state is It is a flowchart which shows the procedure of the automatic mode setting function which operates when out-of-range detection is performed. The steps will be described below in order.

(1) When a public base station with which communication is possible is detected step 1 : First, the dual mode management unit 25 activates the signal detection unit 21 from the public base station, and proceeds to the next step 2. step2 : Next, when a communicable public base station is detected, the process proceeds to the next step5. step5 : Next, the dual mode management section 25 notifies the mode switching section 23 to switch the mode to the public mode, and proceeds to the next step6. step6 : Next, the dual mode management unit 25 notifies the location registration unit 24, and performs location registration to the currently communicable base station.

(2) When a communicable home / business base station is detected step 1 : First, the dual mode management unit 25 activates the signal detection unit 21 from the public base station, and proceeds to the next step 2. step2 : Next, when no communicable public base station is detected, the process proceeds to the next step3. step3 : Next, the dual mode management unit 25 activates the signal detection unit 22 from the home / business base station, and the next step
Go to 4. step4 : Next, when a communicable home / office base station is detected, the process proceeds to the next step5. step5 : Next, the dual mode management unit 25 notifies the mode switching unit 23 to switch the mode to the home / business mode, and proceeds to the next step6. step6 : Next, the dual mode management unit 25 notifies the location registration unit 24, and performs location registration to the currently communicable base station.

(3) When no communicable base station is detected Until the communicable base station is detected, the steps 1 to
Repeat 4. The steps 1 and 2 and steps 3 and 4 are
May be executed first, and in this operation procedure,
As an example, the signal from the public base station is detected first, and then
Signals from home / business base stations are detected, but this order is not fixed.

A known document describing a conventional digital cordless telephone device is, for example, Japanese Patent Laid-Open No. 6-1.
There is 12893 publication. The frame of this publication is a frame used in communication with a master unit to enable automatic and smooth connection with a specific master unit when shifting from a public system to a home system. Storage means for storing the structure and reception timing in advance, reception information recognition means for recognizing the frame structure and reception timing of the received control channel information, the recognized reception information, and the stored frame structure and reception timing And connecting means for preferentially connecting to the master unit when they match.

Further, according to Japanese Patent Laid-Open No. 5-160784, when an incoming call is received from a portable wireless telephone device by a third party during a call in a cordless telephone mode, the incoming call is prioritized and the cordless telephone is also used. A cordless telephone radio section and a cellular telephone radio section are provided in the portable wireless telephone device so that the cellular telephone mode can be put on hold while the telephone mode is being used and the cellular telephone mode can be received. Above all, when the detection unit that detects the reception of the portable wireless telephone device reception unit detects the reception, the user receives a call by making a sound from the reception unit. By holding a call on the cordless phone with the hold button and prioritizing the call to the mobile wireless telephone device, it becomes possible to make a call in response to an incoming call from the mobile wireless telephone device from a third party. When the hold button is pressed, an incoming call can be made on the cellular telephone according to an instruction from the control unit.

[0011]

However, in the configuration of the conventional radiotelephone device described above, when the home / business cordless telephone system is within the area of the public radiotelephone service network as shown in FIG. The following situations occur. (1) When the power of the mobile station is turned on at home / office,
Alternatively, when a mobile station in the standby state at home / business office detects out-of-range due to some trouble, the automatic mode setting function works and the signal from the public base station is sent before the signal from the home / business base station. If detected, the mobile station used in the home / office is set to the public mode and registered in the public base station. (2) When a user carrying a mobile station in standby mode in public mode moves from off-premises to a home / office, the mobile station exists in the public service area and does not perform out-of-range detection, so the automatic mode setting function Does not work and the mobile station in the home / business is used in the public mode setting.

In both the above (1) and (2), proper mode setting is not realized, and the user uses the mobile station within the service area of the home / business system, but the mobile station is in the public mode. Since it is set and the home / office system is absent from the perspective of the home / office system, the service of the home / office system cannot be received, and the call is made from the public wireless telephone service. Also, there is a problem that uneconomical problems occur.

The present invention has been made in view of the above circumstances, and a home / business cordless telephone system is provided as follows.
Even if you are in the area of a public wireless telephone service network,
It is an object of the present invention to provide a digital cordless telephone system having an automatic mode setting function that realizes an appropriate automatic mode setting and can receive the service of the home / office system in the home / office.

[0014]

In order to solve the above problems, the present invention provides (1) a function of operating as a mobile station of a public wireless telephone service network and a home / business connected to a wired public telephone line. A first signal detection unit having a function of operating as a mobile station of a commercial cordless telephone system, detecting a signal from a public base station, and a second signal detection detecting a signal from a home / business base station. Section, a mode switching section that switches the mode to public or home / business mode, and a location registration section that performs location registration to an appropriate base station. When the power of the mobile station is turned on, or in a standby state. When a mobile station of the above detects an out-of-range signal, it detects a signal from a public base station and a signal from a home / office base station, and if there is a base station that can communicate with the home / office base station, / Switch to office mode Set and set the mode to public mode when there is a base station that cannot communicate with the home / business base station and can communicate with the public base station. Automatic mode setting with priority set to the home / business mode A management unit and a position registration function associated with the automatic mode setting management unit, or (2) a function of operating as a mobile station of a public wireless telephone service network, and a home / business connected to a wired public telephone line. It has the function of operating as a mobile station of a cordless telephone system for local use, and when a mobile station in public mode is attached to a charging unit in the home / office, the mode is automatically changed from public mode to home / office mode. Having an automatic mode setting management unit adapted to perform the above and a position registration function associated with the automatic mode setting management unit, or (3) operating as a mobile station of a public wireless telephone service network. Function, and a function of operating as a mobile station of a home / business cordless telephone system connected to a wired public telephone line, and a first signal detection unit for detecting a signal from a public base station, and a home / business A second signal detecting section for detecting a signal from the base station;
A mode switching unit that performs mode switching to public or home / business mode, a position registration unit that performs position registration to an appropriate base station, and an ID of a public base station having a service area adjacent to the home / business cordless telephone system. When the adjacent base station ID storage unit that records the ID, the current base station ID management unit that manages the ID of the base station in which the mobile station is currently registered, the adjacent base station ID and the current base station ID are collated and they match Consists of a base station ID verification unit that activates the automatic mode setting function,
When the power of the mobile station is turned on, when the mobile station in the standby state performs out-of-range detection, and when the current base station ID and the adjacent base station ID of the mobile station in the standby mode in public mode match,
A signal from a public base station and a signal from a home / business office base station are detected, and if there is a base station that can communicate with the home / business office base station, the mode is set to the home / business office mode, When there is a base station that can communicate with the public base station but cannot communicate with the business base station, an automatic mode setting management unit that sets a priority in the home / business mode that sets the mode to the public mode, It has a position registration function associated with the automatic mode setting management unit, and further, (4) in (3), the adjacent base station ID storage unit detects all signals that can be received by the public base station. It has a function to read and write the base station ID, and by activating this function in the home / office, it registers and stores all public base station IDs that can be received in the home / office. Characterized by A.

[0015]

The automatic mode setting device configured as described above is used for the public base station and the home / business office base when the power of the mobile station is turned on or when the mobile station in the standby state detects the out-of-service area. By detecting both signals from the station, it is determined whether there is a home / business base station with which communication is possible. When there is a public base station with which communication is possible when there is no business base station, automatic mode setting is realized in the public mode. Further, when the mobile station is attached to the charging unit in the home / business office, the automatic mode setting is realized in the home / business office mode. When a mobile station in standby mode in public mode is registered in a public base station adjacent to the home / business office system, in addition to normal signal detection from the public base station, Signal detection is also performed, and it is determined whether or not there is a communicable home / office base station, and if there is, a mode switch to the home / office mode is performed to realize automatic mode setting.

[0016]

Embodiments will be described below with reference to the drawings. First, a first embodiment of the present invention will be described. FIG.
FIG. 1 is a configuration diagram for explaining an embodiment of an automatic mode setting device in a digital cordless telephone system according to the present invention, in which 1 is a signal detecting unit from a public base station (first signal detecting unit), 2 Is a signal detection unit (second signal detection unit) from the home / business base station, 3 is a mode switching unit, 4 is a position registration unit, and 5 is an automatic mode setting management unit.

The function of operating as a mobile station of the public wireless telephone service network and the home / home connected to the wired public telephone line.
It has a function of operating as a mobile station of a cordless telephone system for business establishments, and a signal detecting unit 1 from a public base station and home /
The signal detection unit 2 from the office base station detects the signal from each base station and records the signal level of each base station. The mode switching unit 3 automatically sets the mode to the public or home / office. The position registration unit 4 registers the position with the most appropriate base station. The automatic mode setting management unit 5 activates the automatic mode setting function when the power of the mobile station is turned on and when the mobile station in the standby state detects the out-of-service area, and is a base that can communicate with the home / business system. When the station is detected, the mode is set to the home / business mode, the communicable base station is not detected in the home / business system, and the communicable base station is detected in the public base station. The mode is set to the public mode, and the location is registered to each appropriate base station.

FIG. 2 is a flow chart for explaining the operation of the digital cordless telephone system according to the present invention, which is automatic when the power of the mobile station is turned on or when the mobile station in the stand-by state performs out-of-range detection. It is a flowchart which shows the procedure of a mode setting function. The steps will be described below in order.

(1) When a home / business base station with which communication is possible is detected step 1 : First, the signal detection unit 1 from the public base station detects a signal from each base station of the public system, and then The step
Go to 2. step2 : Next, the signal detection unit 1 from the public base station records the detected signal level from each base station, and the next step3
Proceed to. step3 : Next, the signal detection unit 2 from the home / business base station
Detects the signal from each base station of the home / business system and proceeds to the next step 4.

[0020] step4: Then, the signal detection unit 2 from the home / office records the signal level from each base station is detected, proceed to the next step5. step5 : Next, the automatic mode setting management unit 5 determines whether or not there is a base station of a communicable home / business office system, and if there is, the process proceeds to the next step7. step7 : Next, the mode switching unit 3 sets the mode to the home / business mode, and proceeds to the next step8. step8 : Next, the location registration unit 4 performs location registration to the home / business base station having the highest reception level.

(2) When no communicable home / business base station is detected step 1 : First, the signal detection unit 1 from the public base station detects a signal from each base station of the public system, Next step
Go to 2. step2 : Next, the signal detection unit 1 from the public base station records the detected signal level from each base station, and the next step3
Proceed to. step3 : Next, the signal detection unit 2 from the home / business base station
Detects the signal from each base station of the home / business system and proceeds to the next step 4. step4 : Next, the signal detecting unit 2 from the home / office records the detected signal level from each base station, and the next step
Go to 5.

[0022]step5: Next, the automatic mode setting management unit 5
Exists a home / business system base station that can communicate
It is judged whether or not it exists, and if it does not exist, the next step 6
Proceed to. step6 : Next, the automatic mode setting management unit 5 can communicate.
Determine if there is a public system base station and
If so, go to the next step 7. If it does not exist
Return to step 1 above.step7 : Next, the mode switching unit 3 switches to the public mode.
After setting, proceed to the next step 8.step8 : Next, the position registration unit 4 has the highest reception level.
Register location with public base station.

As described above, when the power of the mobile station is turned on, or when the mobile station in the stand-by state performs out-of-range detection, both signals from the public and home / business base stations are detected to / If a base station that can communicate with the business system is detected, set the mode to home / business mode,
If no communicable public base station is detected, set the mode to public mode and
The automatic mode setting is implemented with priority given to the office mode.

Next, a second embodiment of the present invention will be described. A mobile station of a digital cordless telephone system having a function of operating as a mobile station of a public wireless telephone service network and a function of operating as a mobile station of a home / business cordless telephone system connected to a wired public telephone line is a mobile station. It is necessary to charge the mobile station using a time that does not require the time, which is usually realized by installing the charging unit in the home / business cordless telephone system and mounting the mobile station on the charging unit. The automatic mode setting management unit recognizes that the mobile station is attached to the charging unit, confirms the current mode, and if it is currently in the public mode, performs automatic mode switching to the home / business mode and selects the appropriate mode. Register location with home / business base station.

The mobile station registered in the public base station B in FIG. 5 has the function of automatically setting the mode to the home / office mode when the mobile station is attached to the charging unit in the home / office. When the station moves into the home / office, it remains in the public mode as long as it is in the service area of the public base station B, but this function is activated when the mobile station in the standby state is attached to the charging unit, Automatically set the mode to home / business mode. Therefore, all the mobile stations attached to the charging unit in the home / office by this function are in the standby state in the home / office mode.

Next, a third embodiment of the present invention will be described. FIG. 3 is a configuration diagram for explaining another embodiment of the automatic mode setting device in the digital cordless telephone system according to the present invention. In the figure, 11 is a signal detecting unit from a public base station, and 12 is a home / office. Signal detection unit from base station, 13 mode switching unit, 14 position registration unit, 15 automatic mode setting management unit, 16 adjacent base station ID storage unit, 1
Reference numeral 7 is a base station ID collation unit, and 18 is a current base station ID management unit.

The function of operating as a mobile station of the public wireless telephone service network and the home / home connected to the wired public telephone line.
It has a function of operating as a mobile station of a business cordless telephone system, and a signal detecting unit 11 from a public base station and a signal detecting unit 12 from a home / business base station detect signals from the respective base stations. , Record the signal level of each base station. The mode switching unit 13 automatically sets the mode to the public or home / business office. The location registration unit 14 performs location registration with an appropriate base station. The adjacent base station ID storage unit 16
Record the ID of the public base station that has a service area adjacent to the home / business system.

The base station ID collating unit 17 collates the current base station ID with the adjacent base station ID, and if they match, activates the automatic mode setting function. The current base station ID management unit 18 manages the ID of the currently registered base station. The automatic mode setting management unit 15 is arranged such that when the power of the mobile station is turned on, when the mobile station in the stand-by state performs out-of-range detection, or when the mobile station in the stand-by state in the public mode is adjacent to the home / business system. When registered to a public base station, the automatic mode setting function is activated, and when a base station that can communicate with the home / business system is detected, the mode is set to home / business mode and location registration is performed. To do.

When no communicable base station is detected in the home / business office system, and when a communicable base station is detected in the public base station, the mode is set to the public mode and a new position registration is required. If not, register the location with an appropriate base station. Further, the adjacent base station ID storage unit 16 has a function of detecting a signal from the public base station and reading and writing all receivable base station IDs, and activates this function in the home / office. By doing so, registration and storage of all public base station IDs that can be received in the home / office are performed.

FIG. 4 is a flow chart for explaining the operation of the digital cordless telephone system according to the present invention shown in FIG. 3. When the power of the mobile station is turned on, the mobile station in the standby state performs out-of-range detection. 6 is a flowchart showing a procedure of an automatic mode setting function which is activated when a mobile station in a standby state in public mode is registered in a public base station adjacent to a home / business system. The steps will be described below in order.

(1) When a communicable home / business base station is detected step 1 : First, the signal detecting unit 11 from the public base station detects a signal from each base station of the public system, and then The st
Proceed to ep2. step2 : Next, the signal detection unit 11 from the public base station records the detected signal level from each base station, and the next step
Go to 3. step3 : Next, the signal detection unit 1 from the home / business base station
2 detects the signal from each base station of the home / office system, and proceeds to the next step 4.

[0032]step4: Next, signal detection from home / business
The output unit 12 records the detected signal level from each base station.
And proceed to the next step 5.step5 : Next, the automatic mode setting management unit 15 can communicate.
Whether there is a base station for a home / business system
It is determined, and if it exists, the process proceeds to the next step 6. step6 : Next, the mode switching unit 13
Set the mode to the mode and proceed to the next step 7.step7 : Next, the location registration unit 14 is a home / business base station.
Location registration to the base station with the highest reception level among
U

As described above, when the power of the mobile station is turned on, when the mobile station in the stand-by state performs out-of-range detection, or when the mobile station in the stand-by state in the public mode is adjacent to the home / business system. When a home / business system base station with which communication is possible is detected when registered as a public base station,
The home / business mode is automatically set and the location is registered.

(2) When no communicable home / business base station is detected step 1 : First, the signal detection unit 11 from the public base station detects a signal from each base station of the public system, Next st
Proceed to ep2. step2 : Next, the signal detection unit 11 from the public base station records the detected signal level from each base station, and the next step
Go to 3. step3 : Next, the signal detection unit 1 from the home / business base station
2 detects the signal from each base station of the home / office system, and proceeds to the next step 4. step4 : Next, the signal detection unit 12 from the home / business office
Record the detected signal level from each base station and
Proceed to ep5. step5 : Next, the automatic mode setting management unit 15 determines whether or not there is a base station of a communicable home / business office system, and if not, the process proceeds to the next step8.

[0035] step8: Next, the automatic mode setting management unit 15
Judges whether or not there is a base station of a public system with which communication is possible, and if there is, it proceeds to the next step 9. If it does not exist, the process returns to step 1. step9 : Next, the mode switching unit 13 sets the mode to the public mode, and proceeds to the next step10. step10 : Next, the automatic mode setting management unit 15 determines whether or not new location registration is necessary, and if it is necessary, the next st
ep11, and proceeds to next step 12 if not necessary. step11 : Next, the location registration unit 14 performs location registration to the base station having the highest reception level among the public base stations. step12 : Next, the current base station ID storage unit 18 notifies the base station ID collation unit 17 of the ID of the currently registered base station, and the base station ID collation unit 17 that has received it notifies the current base station ID.
And adjacent base station ID are collated, and if they match, the automatic mode setting function is activated, and the process returns to step 1. If they do not match, the process ends.

As described above, when the power of the mobile station is turned on, when the mobile station in the stand-by state performs out-of-range detection, or when the mobile station in the stand-by state in the public mode is adjacent to the home / business system. If a communicable home / business system base station is not detected when registered as a public base station and a communicable public system base station is detected, the mode is set to public mode and a new location registration is performed. If necessary, the location is registered, and each time, the location is checked against the adjacent base station ID. Therefore, even if the communicable home / business base station cannot be detected due to some trouble in the home / business office service area and it is registered in the adjacent public base station, the automatic mode setting function is activated again.

As can be seen from the above-mentioned third embodiment, in the automatic mode setting management unit in the digital cordless telephone system according to the present invention, when the power of the mobile station is turned on, the mobile station in the standby state detects the out-of-range. When the mobile station in standby mode in public mode is registered in the public base station adjacent to the home / business system, the automatic mode setting function is activated, and the service area of the home / business system is the public service. Not only when it is not in contact with the area but also when the service area of the home / office system is located in the public service area as shown in Fig. 5, the automatic mode is set to the home / office mode in the home / office. Has been realized.

[0038]

As is apparent from the above description, the present invention has the following effects. (1) When the power of the mobile station is turned on at home / office,
Or, due to some kind of failure, when the mobile station in the standby state in the home / business office performs out-of-range detection, the automatic mode setting function is activated, and preferentially detects a communicable base station in the home / business system. , Home / business mode is set in the home / business. (2) The mobile station attached to the charging unit in the home / office is in the standby state in the home / office mode. (3) When a user carrying a mobile station in a standby state moves from outside the house to the home / office, for example, in FIG.
The mobile station registered in the public base station B exists in the service area of the public B even in the home / business office, and does not perform the out-of-range detection, but moves from the ID of the public base station B adjacent to the home / business office. The home / business system recognizes that the station is located near the service area of the home / business system, activates the automatic mode setting function, and preferentially detects a communicable base station in the home / business system. In the office, it is set to home / business mode. (4) Even if the home / business cordless telephone system is located in the public wireless telephone service area as described in (1), (2), and (3) above, the
Since it is set to the office mode, it is possible to prevent uneconomical situations such as making calls from the home / office with public service charges.
Home / business cordless telephone system services are available in the home / business.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a digital cordless telephone system according to the present invention.

FIG. 2 is a flow chart for explaining the operation of one embodiment of the digital cordless telephone system according to the present invention.

FIG. 3 is a configuration diagram for explaining another embodiment of the digital cordless telephone system according to the present invention.

FIG. 4 is a flow chart for explaining the operation of another embodiment of the digital cordless telephone system according to the present invention.

FIG. 5 is a configuration diagram of a service area in the digital cordless telephone system.

FIG. 6 is a block diagram of a conventional digital cordless telephone system.

FIG. 7 is a flow chart for explaining the operation of the conventional digital cordless telephone system.

[Explanation of symbols]

1, 11 ... Signal detection unit from public base station, 2, 12 ... Signal detection unit from home / business base station, 3, 13 ... Mode switching unit, 4, 14 ... Position registration unit, 5, 15 ... Automatic Mode setting management unit, 16 ... Adjacent base station ID storage unit, 17 ... Base station ID collation unit, 18 ... Current base station ID management unit.

Claims (4)

[Claims] 1. A public base station having a function of operating as a mobile station of a public wireless telephone service network and a function of operating as a mobile station of a home / business cordless telephone system connected to a wired public telephone line. A first signal detecting section for detecting a signal from the base station, a second signal detecting section for detecting a signal from the home / business office base station, and a mode switching section for performing mode switching to public or home / business mode. , A location registration unit that performs location registration to an appropriate base station, and when a mobile station is powered on or a mobile station in a standby state detects out-of-range detection, signals from a public base station and home /
If a signal from the business base station is detected and the home / business base station has a communicable base station, the mode is set to home / business mode, and the home / business base station cannot communicate. When there is a base station that can communicate with the public base station, an automatic mode setting management unit that sets priority to the home / business mode that sets the mode to the public mode, and location registration accompanying the automatic mode setting management unit A digital cordless telephone system having a function. 2. A public mode telephone having a function of operating as a mobile station of a public wireless telephone service network and a function of operating as a mobile station of a home / business cordless telephone system connected to a wired public telephone line. The automatic mode setting management unit that automatically changes the mode from the public mode to the home / business mode when the mobile station is attached to the charging unit in the home / business office, and the automatic mode setting management unit A digital cordless telephone system having a position registration function. 3. A public base station having a function of operating as a mobile station of a public wireless telephone service network and a function of operating as a mobile station of a home / business cordless telephone system connected to a wired public telephone line. A first signal detecting section for detecting a signal from the base station, a second signal detecting section for detecting a signal from the home / business office base station, and a mode switching section for performing mode switching to public or home / business mode. , A location registration unit that performs location registration to an appropriate base station, an adjacent base station ID storage unit that records the ID of a public base station having a service area adjacent to the home / business cordless telephone system, and the mobile station is currently registered The current base station ID management unit that manages the ID of the existing base station, and the base station ID matching unit that checks the adjacent base station ID and the current base station ID and, if they match, activates the automatic mode setting function. When the power of the mobile station is turned on, when the mobile station in the standby state performs out-of-range detection, when the current base station ID and the adjacent base station ID of the mobile station in the standby mode in public mode match, A signal from a public base station and a signal from a home / business office base station are detected, and if there is a base station that can communicate with the home / business office base station,
Set the mode to business mode, and if the home / business base station cannot communicate and the public base station has a communicable base station, set the mode to public mode. A digital cordless telephone system comprising an automatic mode setting management section provided and a position registration function associated with the automatic mode setting management section. 4. The adjacent base station ID storage unit detects all signals from a public base station, and all the receivable base station IDs.
It has a function of reading and writing of, and by activating this function in the home / office, it registers and stores all public base station IDs that can be received in the home / office. The digital cordless telephone system according to claim 3.