JP3032055B2 - Cordless telephone device 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 low power type cordless telephone apparatus and an improved method of channel scanning.

[0002]

2. Description of the Related Art A cordless telephone device includes a base station (master unit) and a mobile station (slave unit). The base station is connected to the base station by a radio line, and is moved between the base station and the mobile station or via the base station. Stations and outside lines
(Station line).

[0003] In the communication between the base station and the mobile station of the 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, and the like. "Control data"
Is a “control channel” commonly used throughout the system.
The "information data" such as voices 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 among a plurality of wireless channels.

In a cordless telephone device, two channels can be used as a control channel and 87 channels can be used as a communication channel.

[0005] The base station waiting for reception detects the call connection request data from the mobile station while alternately receiving the control channel and the communication channel, and determines whether the communication channel is "busy" or "free". The judgment is repeated. In the process, when the call connection request data from the mobile station is detected, the channel determined to be “free” 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 is performed.

[0006] The reception while changing the channel in this way is called a channel scan, and the determination of the use state of the communication channel by a carrier is called a carrier scan.
We call it sense.

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

[0008] Of the devices of this type, the one having two radio communication units (RF1 and RF2) in its base station has a station line connection terminal 1 connected to a station line as shown in FIG. Communication circuit 2 for forming a communication path between a mobile station and an office line
And receiving circuits 13, 23 and transmitting circuits 14, 24
, Antennas 11, 21, receiving circuits 13, 23, and transmitting circuit
A communication transmission line composed of radio circuits 15 and 25 connecting the antennas 14 and 24 to the antennas 11 and 21 is separately provided for each of the RF1 and the RF2, and further, reception VCO (voltage controlled oscillation) circuits 17 and 27 are provided.
And transmission VCO circuits 18 and 28 and PLL circuits 16 and 26 for setting reception / transmission frequencies, channel memories 19 and 29 for storing the results of carrier sensing, and a control unit for controlling them. 10 and 20 are also provided separately for each of RF1 and RF2.

In this apparatus, RF1 and RF2 perform channel scans in the same manner. The outline of the channel scan procedure will be described with reference to the flowchart shown in FIG. In addition, in the flowchart of FIG. 4, only RF1 is described.
A similar procedure is executed for F2.

Step 1: Signals are sent from the control units 10 and 20 to control the PLL circuits 16 and 26 and the reception VCO circuits 17 and 27 to adjust the reception frequency to the communication channel.

Step 2: Call channel carrier
Do the sense.

Step 3: Steps 4 or 5 are taken based on whether or not the line is busy as a result of the carrier sense.

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 a free channel, information of "free" is stored in the channel memories 19 and 29.

Step 6: Signals are sent from the control units 10 and 20 to control the PLL circuits 16 and 26 and the reception VCO circuits 17 and 27 to adjust the reception frequency to the control channel.

Step 7: If no call connection request data from the mobile station is received, the flow returns to step 1 to perform carrier sense for the next communication channel.

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

Step 9: The channel scan is stopped until the communication with the mobile station is completed. If the communication is completed, the process returns to step 1 and the channel scan is restarted.

It should be noted that, besides the case of step 9, the measure of stopping the channel scan is also taken when a situation such as a call from the base station or an incoming call of an outside line occurs.

In this example, one communication channel is scanned after the control channel is scanned, and the process returns to the control channel. However, a plurality of communication channels may be continuously scanned instead of one communication channel. it can. Also, in Japan's low power cordless telephone, two control channels are specified,
The two control channels may be alternately scanned.

[0021]

However, the method of channel scanning in such a conventional device is extremely wasteful because all of the plurality of radio communication units of the base station perform the same operation in duplicate. Many. In addition, since the PLL circuits 16 and 26 of the plurality of wireless communication units are constantly scanning 87 communication channels, there is a disadvantage that the mutual wireless communication units influence each other.

Further, in a cordless telephone device in which the number of mobile stations exceeds the number of wireless communication units provided in the base station, a call from the mobile station must be made unless a wireless communication unit for communicating with each mobile station is determined in advance. There is also a disadvantage that a plurality of wireless communication units may start communication at the same time in response to a connection request.

An object of the present invention is to provide a method for performing an efficient channel scan and a cordless telephone device for implementing the method, which solves the drawbacks of the conventional device.

[0024]

In order to achieve this object, according to the present invention, a base station is controlled by a plurality of wireless communication units.
Control unit, and the control unit has a
Selecting means for selecting one of the communication units;
To instruct the line communication unit to perform a channel scan
And a wireless communication unit selected by the selecting means.
By instructing channel scanning by the instruction means,
Channel scan at the base station by multiple
Channel scan with only one communication unit
When the mobile station requests a call connection in the process of
Start communication with the wireless communication unit that has been scanning
Channel at the same time by other wireless communication units
・ I keep scanning .

An apparatus for performing such a method is provided with a plurality of radio communication units and a control unit in a base station.
Only, the control unit is provided with selecting means for selecting one had wireless communication unit, such a call state with the mobile station, and an instruction means for instructing a channel scan to a wireless communication units selected, and selected by the selection means Channel to wireless communication unit
・ By instructing scanning by instruction means,
Channel scan of multiple wireless communication units
In addition to having only one
If the mobile station requests a call connection during the process,
Communication with the wireless communication unit that
At the same time, select another wireless communication unit
By instructing with the instruction means, other wireless communication units
To continue the channel scan .

[0026]

Therefore, channel scanning in the base station is performed by one wireless communication unit. When a mobile station requests a call connection, communication with this wireless communication unit is started, and at the same time, another wireless communication unit is started. The channel scan is continued by the wireless communication unit.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The cordless telephone device shown in the embodiment has two radio communication units (RF1 and RF2) in a base station. As shown in FIG. 1, the base station includes reception circuits 13 and 23, transmission circuits 14 and 24, antennas 11 and 21,
The receiving circuits 13, 23 and the transmitting circuits 14, 24 are connected to the antennas 11, 21,
, And a transmission VCO circuit 17, 27, a transmission VCO circuit 18, 28,
The circuits for setting the reception and transmission frequencies, which are composed of the LL circuits 16 and 26, are provided separately for each of RF1 and RF2.

On the other hand, an office line connection terminal 1 connected to the office line, and a communication circuit 2 for forming a communication path between the mobile station and the office line.
The channel memory 29 for storing the result of carrier sense and the control unit 30 for controlling the system are shared by RF1 and RF2. The control unit 30 controls RF1 and R
F2 is controlled, and the channel memory 29 stores the information of the entire base station without distinguishing between RF1 and RF2.

A method of channel scanning in the cordless telephone device will be described with reference to a flowchart shown in FIG.

Step 1: The control unit 30 first selects RF1, and determines whether or not RF1 is in communication with the mobile station. Step 2 or 3 is selected according to the result.

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 to set the reception frequency of RF1 to the communication channel.

Step 3: If RF1 is busy, R
Select F2 to determine if it is busy. R
If F2 is also talking, return to step 1
Scanning 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 RF2 reception frequency to the communication channel.

Step 5: Carrier sensing is performed to determine whether the received communication channel is busy.

Step 6: According to the result of the carrier sense, the action of Step 7 or Step 8 is taken based on whether 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 a free channel, the information "free" is stored in the channel memory 29.

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

Step 10: If the call connection request data from the mobile station is not received, the flow returns to step 1 to continue the carrier sense of the next communication channel.

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

As described above, when a channel scan is performed using the apparatus of the embodiment, the channel scan is performed only on one of RF1 and RF2 that is not communicating with the mobile station, and the mobile station is processed in the channel scan process. 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 channel scanning. At that time, if the other RF1 or RF2 is not busy, the channel scan is continued by that RF1 or RF2.

[0042]

As is clear 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 entire control can be improved, and the overall apparatus can be simplified and economical.
In addition, when the number of channel memories is one, the efficiency of memory management can be improved and the device can be formed small.

(2) Since only one of the plurality of wireless communication units of the base station performs channel scanning, a situation in which the plurality of wireless communication units exert unnecessary influences 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 reduced to one, there is no risk of duplicate connection or the like.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a channel scanning method 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 Communication circuit 13, 23 Receiving circuit 14, 24 Transmitting circuit 15, 25 Radio circuit 16, 26 PLL circuit 17, 27 Receiving VCO circuit 18, 28 Transmitting VCO circuit 19, 29 Channel memory 10, 20, 30 Control unit 11, 21 Antenna

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38

Claims (2)

(57) [Claims] A base station controls a plurality of wireless communication units.
And a wireless communication unit that is not in a call state with the mobile station.
Selecting means for selecting one of the wireless communication units,
Instruction means for instructing the unit to perform a channel scan.
Only the channel to the wireless communication unit selected by the selection means
・ By instructing scanning by the instruction means, the base
Channel scan at the station is performed by multiple wireless communication units.
The mobile station makes a call connection request during the channel scan process.
The wireless communication unit that has been scanning the channel.
Communication with the wireless communication unit , and at the same time, channel scanning by another wireless communication unit.
A method for scanning a channel of a cordless telephone device, the method comprising: 2. A method for controlling a plurality of wireless communication units in a base station.
A Department provided in the control unit, selection means for selecting one of the no-<br/> line communication unit not in the communication state with the mobile station, instructing means for instructing the channel scan to a wireless communication units selected the door is provided, the channel to the wireless communication unit selected by the selection means
・ By instructing scanning by the instruction means, the base
Channel scan at the station is performed by multiple wireless communication units.
The mobile station makes a call connection request during the channel scan process.
The wireless communication unit that has been scanning the channel.
Communication with the wireless communication unit , and at the same time another wireless communication unit is selected by the selecting means.
The instruction by the instruction means causes the other wireless communication
Continue channel scan by unit
Cordless telephone apparatus characterized by constituting the.