JPH02241127A - Cordless telephone system - Google Patents

Abstract

PURPOSE:To prevent collision of signals for reply and call or the like by sending a signal such as reply call through the detection of an electric field of a control channel in the case of sending the signal such as reply call to a slave set and retarding the time of detecting the electric field for each master set sequentially. CONSTITUTION:In the case of call from slave sets 11-1N, master sets 21-2M receiving the call detect an electric field of a master set control channel. The master sets 21-2M detect the electric field with a prescribed time delay sequentially in this case and only the master set detecting first the electric field replies the slave set. Then master sets detecting the electric field after the first master set do not reply the call because the reply is already implemented. Thus, since no reply comes from the plural master sets 21-2M in the call from the slave sets 11-1N, collision of transmission signals does not exist and destruction of the transmission data is not caused.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cordless telephone used within a fixed call area such as a golf course, construction site, or factory. The present invention relates to a callless telephone system which prevents a plurality of base units from responding to a call made by a slave unit.

[Conventional example] In recent years, cordless telephones have been proposed by various manufacturers as new home appliance products. A two-to-one-less telephone consists of a connecting device (base unit) that is connected to the telephone line and a pan 1-set (slave unit).
Between them, signals such as calls, ID codes, voice communications, etc. are transmitted and received by radio waves. Therefore, the connection device is equipped with a radio wave transmitting and receiving function, and the handset also has a built-in radio wave transmitter and receiver. In other words, the other party's voice is converted from an electrical signal to a radio wave signal by the connecting device and sent to the handset. Conversely, a voice signal transmitted by radio waves from a handset is converted from a radio wave signal to an electrical signal by the connecting device, and then transmitted to the other party via a line.

[Problem to be solved by the invention] By the way, the above-mentioned cordless telephones come in two types: a weak type for home use and a low power type for business use, but both have come to have a one-to-one correspondence between a base unit and a slave unit. and cannot use multiple handsets. Therefore, there is a demand for a cordless phone with one base unit and N (any number) handsets, or a cordless phone with M (any number) base units and N handsets. In particular, there is a demand for devices that allow handsets to communicate with each other within a golf course, construction site, or factory in a predetermined area.

On the other hand, when a call is made by the handset and a call request is sent, the base device must accept the call request. In other words, since the call request is sent on the control channel for the handset device determined by the regulations, the base device always detects the electric field of the control channel for the handset device, and based on the electric field detection, the call request is sent from the handset device. It is now receiving requests. Therefore, as shown in FIG.
...ylN and base unit 2□, 2□, ...+2M, for example, cordless phone 1□
When making a call from multiple base units 21122? ...,
2M will receive the call request, and those base units 2
A response call is transmitted from 112212M on the same base unit control channel. Then, the signals of the response calls will collide with each other, causing a problem that the transmitted data will be destroyed.

This invention was made in view of the above problems, and its purpose is to transmit a signal such as a response call to a handset,
A cordless telephone system that transmits the signal by detecting the electric field on the control channel and sequentially delays the time to detect the electric field for each base unit to prevent collisions of signals such as answering calls. It is about providing.

[Means for Solving the Problems] In order to achieve the above object, the cordless telephone system of the present invention is capable of sending and receiving signals such as calling, ID code, voice communication, etc. between a plurality of handsets and the handsets. It consists of a plurality of base units, and an exchange that connects the base units and extension telephones (or system representatives) or outside lines by wire. , each has a function of detecting the electric field of the control channel for the base unit by delaying the time, so that any one of the multiple base units makes a response call to the slave unit making the call request. The summary is what was done.

[Function] With the above configuration, when a call is made from the slave unit,
Each base unit that receives the call performs electric field detection on the base unit control channel. At this time, each base unit sequentially detects the electric field after a predetermined time delay, and only the base unit that first detected the electric field makes a response call to the slave unit.

Then, in the base unit that performs electric field detection after the base unit, the response call is not made because the response call has already been made. Therefore, when the slave unit makes a call, there is no response call by a plurality of base units, so there is no collision of transmitted signals and no destruction of transmitted data.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, parts that are the same as those in FIG. 4 are given the same reference numerals, and redundant explanation will be omitted.

In FIG. 1, a plurality of base units 2□, 2□ of cordless telephones are located in a predetermined area (for example, the grounds of a golf course, etc.).

..., 2a are provided, and in that area there are multiple cordless telephone handsets 1□, 1□, . . .ylN. In addition, the plural base units 21', 22 . ...+2M is connected to an exchange 3, and to this exchange 3, an extension telephone (or system representative of extension number 200) 4 and an outside line (telephone line) 5 are connected, as in the past.

Note that the above-mentioned cordless telephone system employs a duplex method, and is capable of voice communication including various data transmissions within the voice band. In addition, ID for IL to prevent incorrect charges and incorrect connections.
Regarding the coat, when the line is connected, the ID code is checked, and if there is a mismatch, the line is not set. In addition, base unit 2□, 22. ...+2M is housed in a case that cannot be opened easily.

Next, we will explain the operation of the cordless telephone system with the above configuration in a second manner.
This will be explained based on the diagram and the time chart in FIG.

First, when calling another handset using the handset (IDI) 1□ and making a call, the call button of the handset 1□ is pressed, that is, an off-hook operation is performed. Then, the handset 12 transmits a call request signal through the handset control channel. At this time, each base unit 21°2□, . . . , 2M is detecting the electric field of the control channel for the slave unit, so that the call request can be received. At this time, each base unit 2□, 2゜, ・
- In +2M, when transmitting a response call, for example, a call on an empty channel, to the handset 12, the electric field detection of the base unit control channel for transmitting the response call signal is performed sequentially with a predetermined time delay. . That is, for example, in FIG.
) and (b), first the base unit 21 detects the electric field, and then the base unit 2□, base unit 23,
. . . The electric field is detected in the base unit 2M with a sequential delay. At this time, base unit 2□, which uses the base unit control channel for the first time, makes a response call to slave unit 1□.

Then, base unit 2□, which detects the electric field after a predetermined time delay, does not make a response call because it knows that a response call has already been made. In addition, the following base unit 23,...
, the base unit 2M also does not make a response call. As a result, only the base unit 21 makes a call in response to a call made by the slave unit 1□, so there is a reliable link between them.
) state.

On the other hand, as shown in FIGS. 3(a) and 3(b), when signals such as voice communication are being sent and received by the base unit 21 and the base unit 2□, the slave unit 1□ When a call is made, the electric field detection of the control channel for the base unit is first performed by the base unit
is performed, and then, after a predetermined time delay, the base unit 24 is performed,
Furthermore, the base unit 25, . Therefore, only the base unit 23 that first detected the electric field transmits a response call signal through the base unit control channel, and the other base units 24, . . . , base unit 2M do not make a response call.

In this way, when a call is made by a handset, it is possible to prevent multiple bases from making a response call at the same time. etc. will not be destroyed. In other words, the calling handset and the second base unit are reliably linked, and subsequent signals such as ID codes and voice communications can be transmitted and received.

[Effects of the Invention] As explained above, according to the present invention, a plurality of slave units, a plurality of base units that exchange signals such as calling, ID codes, voice communication, etc. with the slave units, and A cordless telephone system consisting of a base unit and an extension telephone (or system representative) or an exchange that connects an outside line by wire. In addition to detecting the electric field of the channel, each device detects the electric field sequentially with a delay of a predetermined time, so that the base device that first detects the electric field of the control channel for the base device makes a response call, and then If the base unit detects an electric field, no response call will be made,
It is possible to prevent simultaneous response calls by multiple base units, and it is also possible to prevent collisions of signals transmitted on the base unit control channel and destruction of transmitted data.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a cordless telephone system showing an embodiment of the present invention, FIGS. 2 and 3 are time charts for explaining the operation of the cordless telephone system, and FIG. 4 is a cordless telephone system. FIG. 2 is a schematic block diagram for explaining problems in the system. In the figure, 11, 1□, ...+IN are child units, 2□, 22.
..., 2M is a base unit, 3 is an exchange, 4 is an extension telephone (or system representative), and 5 is an outside line (telephone line). Patent applicant: Fujitsu General Co., Ltd. Agent: Patent attorney: Takuya Ohara

Claims (1)

[Claims] (1) Calling between multiple handsets and those handsets, I
It is composed of a plurality of base units that transmit and receive signals such as D-code and voice communication, and an exchange that connects these base units and an extension telephone (or system representative) or an outside line by wire, and the multiple base units are When receiving a call request from a slave unit, the controller has a function of delaying the time and detecting the electric field of a control channel for the base unit, and transmits a call request to any one of the plurality of base units to the slave unit making the call request. A cordless telephone system characterized in that a base unit makes a response call.