JPH0548529A - Cordless telephone system and its channel scanning method - Google Patents

Abstract

PURPOSE:To make the scanning efficient by allowing only one unit among plural radio communication units to make scanning when the scanning discriminated the operating state of a speech channel in the cordless telephone system provided with plural mobile stations and a base station having the plural radio communication units. CONSTITUTION:A base station of the cordless telephone system is provided with two radio communication units RF1, RF2. The unit RF1 (RF2) is provided with a reception circuit 13(23), a transmission circuit 14(24), an antenna 11(21), a radio circuit 15(25) connecting them, a reception VCO circuit 17(27), a transmission VCO circuit 18(28) and a PLL circuit 16(26). Then a trunk line connection terminal 1 connecting to the trunk line, a speech circuit 2 between a mobile station and the trunk line, a channel memory 29 storing the result of carrier sense, a control section 30 are used for in common to the RF1, RF2, and the sections select either the RF1 or the RF2 which is idle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless telephone device of a low power type, which is an improved method of channel scanning.

[0002]

2. Description of the Related Art A cordless telephone system includes a base station (base unit) and a mobile station (slave unit), which are connected by a wireless line to move between the base station and the mobile station or via the base station. Station and outside line
A call is made with the (local line).

In the communication between the base station and the mobile station of this cordless telephone device, at the start of communication, call connection request data for calling the base station from the mobile station, call data for calling the mobile station from the base station, etc. "Control data"
Is a "control channel" commonly used in the entire system
“Information data” such as voice, which is transmitted after the communication is established between the base station and the mobile station, is transmitted through the “communication channel” designated by the base station from a plurality of wireless channels.

In the cordless telephone system, 2 channels can be used as control channels and 87 channels can be used as communication channels.

[0005] The base station in reception standby detects the call connection request data from the mobile station while receiving the control channel and the call channel alternately and determines whether the call channel is "busy" or "idle". The judgment is repeated. In the process, when the call connection request data from the mobile station is detected, the channel determined to be "vacant" immediately before (or immediately after) is designated as the communication channel, and "information" between the base station and the mobile station is specified. "Data" communication takes place.

Receiving while changing the channel in this way is called channel scanning, and determining the use state of the communication channel by the carrier wave
I call it Sense.

Conventionally, a cordless telephone apparatus has been implemented in which a plurality of mobile stations are attached to a base station having a plurality of wireless communication units, but in the base station, each wireless communication unit is independent. Channel scan.

Among the devices of this type, the one having two radio communication units (RF1 and RF2) in its base station has a station line connecting terminal 1 connected to a station line as shown in FIG. , A call circuit 2 that forms a call path between a mobile station and a station line
Are commonly provided, and the receiving circuits 13 and 23 and the transmitting circuits 14 and 24 are provided.
, Antennas 11 and 21, receiving circuits 13 and 23, and transmitting circuit
Each of RF1 and RF2 is provided with a call transmission line composed of radio circuits 15 and 25 for connecting 14 and 24 to antennas 11 and 21, and reception VCO (voltage controlled oscillation) circuits 17 and 27 are further provided.
And a circuit for setting a reception / transmission frequency composed of the transmission VCO circuits 18 and 28 and the PLL circuits 16 and 26, channel memories 19 and 29 for storing the results of carrier sense, and a control unit for controlling them. 10 and 20 are also provided separately for each RF1 and RF2.

In this apparatus, RF1 and RF2 perform the channel scan in the same manner. The outline of the procedure of the channel scan will be described with reference to the flowchart shown in FIG. Although only the RF1 is described in the flowchart of FIG.
The same procedure is executed for F2.

Step 1: Send signals from the control units 10 and 20 to control the PLL circuits 16 and 26 and the reception VCO circuits 17 and 27 to match the reception frequency to the communication channel.

Step 2: Call channel carrier
Do a sense.

Step 3; As a result of the carrier sense, the action of Step 4 or Step 5 is taken based on whether or not the user is busy.

Step 4; If the call channel is busy, the information "busy" is stored in the channel memories 19 and 29.

Step 5: If the call channel is an empty channel, the information "empty" is stored in the channel memories 19 and 29.

Step 6: Send signals from the control units 10 and 20 to control the PLL circuits 16 and 26 and the reception VCO circuits 17 and 27 to match the reception frequency to the control channel.

Step 7: When the call connection request data from the mobile station is not received, the process returns to step 1 and the carrier sense of the next communication channel is performed.

Step 8: When the call connection request data is received from the mobile station in step 7, the channel scan is stopped and the communication processing with the mobile station is performed.

Step 9: The channel scanning is stopped until the communication with the mobile station is completed, and when the communication is completed, the procedure returns to step 1 and the channel scanning is restarted.

The measure for stopping the channel scan is also taken in the case other than the case of step 9 when a situation such as a call from the base station or an incoming call of an outside line occurs.

Further, in this example, one call channel is scanned after the control channel is scanned, and the control channel is returned to. However, instead of one call channel, a plurality of call channels may be continuously scanned. it can. Also, in Japanese small power cordless telephone devices, since two control channels are specified,
The two control channels may be scanned alternately.

[0021]

However, the method of channel scanning in such a conventional device is extremely wasteful because all of the plurality of wireless communication units of the base station perform the same operation in duplicate. Many. Not only that, but the PLL circuits 16 and 26 of a plurality of wireless communication units constantly scan 87 communication channels, so that there is a drawback that mutual wireless communication units influence each other.

Further, in a cordless telephone apparatus in which the number of mobile stations exceeds the number of wireless communication units provided in the base station, the mobile station must make a call unless the wireless communication units communicating with each mobile station are determined in advance. There is also a drawback that a plurality of wireless communication units may simultaneously start communication in response to a connection request.

It is an object of the present invention to provide a method for performing efficient channel scanning and a cordless telephone device for implementing the method, which overcomes the drawbacks of such conventional devices.

[0024]

In order to achieve this object, according to the present invention, a call channel is provided in a base station of a cordless telephone apparatus including a base station having a plurality of wireless communication units and a plurality of mobile stations. When performing a channel scan to determine the usage status of a mobile station, even if there are multiple wireless communication units that are not in communication with the mobile station, only one of them should perform a channel scan. I have to.

Further, as a device for carrying out such a method, in a cordless telephone device having a base station having a plurality of wireless communication units and a plurality of mobile stations, a plurality of base stations are provided. A single control unit for controlling all of the wireless communication units is provided, and the control unit has a selecting unit for selecting one of the wireless communication units that are not in communication with the mobile station and a channel scan for the selected wireless communication unit. An instruction means for instructing is provided.

[0026]

Therefore, the channel scan in the base station is performed by one wireless communication unit, and when the mobile station makes a call connection request, communication is started with this wireless communication unit and at the same time, other The wireless communication unit continues channel scanning.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The cordless telephone system shown in the embodiment has two wireless communication units (RF1 and RF2) in a base station. In this base station, as shown in FIG. 1, receiving circuits 13 and 23, transmitting circuits 14 and 24, antennas 11 and 21,
The receiving circuits 13 and 23 and the transmitting circuits 14 and 24 are connected to the antennas 11 and 21.
A call transmission line and reception VCO circuits 17 and 27, which are composed of radio circuits 15 and 25 connected to the PTC, transmission VCO circuits 18 and 28, and P.
The circuits for setting the receiving and transmitting frequencies, which are composed of the LL circuits 16 and 26, are separately provided for each of RF1 and RF2.

On the other hand, a station line connection terminal 1 connected to a station line and a call circuit 2 forming a call path between a mobile station and a station line.
The channel memory 29 for storing the carrier sense result and the control unit 30 for controlling the system are shared by RF1 and RF2. This control unit 30 uses RF1 and R
Both F2 are controlled, and the channel memory 29 does not distinguish between RF1 and RF2 and stores them as information of the entire base station.

A method of channel scanning in this cordless telephone system will be described with reference to the flow chart shown in FIG.

Step 1: The control unit 30 first selects RF1 and determines whether it is in a call with the mobile station. Depending on the result, step 2 or 3 is selected.

Step 2: If RF1 is not busy
The control unit 30 controls the reception VCO circuit 17 of RF1 through the PLL circuit 16 of RF1 and sets the reception frequency of RF1 to the communication channel.

Step 3: R1 if RF1 is busy
Select F2 to determine if it is busy. R
If F2 is also talking, go back to step 1
The scan is stopped.

Step 4; If RF2 is not busy
The control unit 30 controls the RF2 reception VCO circuit 27 through the RF2 PLL circuit 26 to set the reception frequency of RF2 to the communication channel.

Step 5: Perform carrier sense to judge whether the received communication channel is busy.

Step 6; As a result of the carrier sense, the action of Step 7 or Step 8 is taken based on whether or not the communication channel is busy.

Step 7: If the call channel is busy, the information "busy" is stored in the channel memory 29.

Step 8: If the call channel is an empty channel, the channel memory 29 is made to store the information "idle".

Step 9: A signal is sent from the control unit 30 to control the RF1 or RF2 PLL circuits 16 and 26 and the receiving VCO circuits 17 and 27 during channel scanning to match the receiving frequency to the control channel.

Step 10: When the call connection request data from the mobile station is not received, the process returns to step 1 and the carrier sense of the next communication channel is continuously performed.

Step 11; When the call connection request data is received in Step 10, RF1 or RF2
The channel scan of is stopped and communication processing with the mobile station is performed. At the same time, the process returns to step 1 to restart the channel scan using RF1 or RF2 which is not in a call.

As described above, when performing the channel scan using the apparatus of the embodiment, the channel scan is performed by only one of RF1 and RF2 which is not in a call with the mobile station, and the mobile station is in the process of the channel scan. When a call connection request from the mobile station is detected, communication is started between the mobile station and RF1 or RF2 that has performed the channel scan. At that time, if the other RF1 or RF2 is not busy, the channel scan is continued by the RF1 or RF2.

[0042]

As is apparent from the above description of the embodiments, the present invention has the following effects.

(1) Since a plurality of wireless communication units are controlled by one control unit, the efficiency of the whole control can be improved, and the whole device can be simplified and made economical.
In addition, when the number of channel memories is one, the efficiency of memory management can be improved and the device can be made compact.

(2) Since only one of the plurality of wireless communication units of the base station performs the channel scan, a situation in which the plurality of wireless communication units do not have an unnecessary influence on each other does not occur.

(3) Since the number of wireless communication units that start communication in response to a call connection request from the mobile station is automatically limited to one, there is no possibility of duplicate connection.

[Brief description of drawings]

FIG. 1 is a block diagram of a base station in an embodiment of a cordless telephone device of the present invention,

FIG. 2 is a flowchart showing a method of channel scanning according to the present invention,

FIG. 3 is a block diagram showing an example of a base station in a conventional cordless telephone device,

FIG. 4 is a flowchart showing a conventional channel scanning method.

[Explanation of symbols]

 1 Station line connection terminal 2 Call circuit 13, 23 Reception circuit 14, 24 Transmission circuit 15, 25 Radio circuit 16, 26 PLL circuit 17, 27 Reception VCO circuit 18, 28 Transmission VCO circuit 19, 29 Channel memory 10, 20, 30 Control unit 11, 21 Antenna

Claims (2)

[Claims] 1. A cordless telephone apparatus comprising a base station having a plurality of wireless communication units and a plurality of mobile stations, wherein the base station performs a channel scan for determining a usage state of a communication channel. When there are a plurality of wireless communication units that are not in communication with the mobile station, only one of them can
A method of scanning a channel in a cordless telephone device, characterized by performing scanning. 2. A cordless telephone apparatus comprising a base station having a plurality of wireless communication units and a plurality of mobile stations, wherein the base station has a single unit for controlling all of the plurality of wireless communication units. A controller for selecting one of the wireless communication units that are not in communication with the mobile station, and an instruction unit for instructing the selected wireless communication unit to perform channel scanning. A cordless telephone device characterized by being provided.