JPS60165129A - Extension connecting system controlling communication possible range - Google Patents

Abstract

PURPOSE:To expand the talkable range of radio equipment of a slave station by expanding the communicatable range of the radio equipment of each slave station for extension communication by means of the increase of transmission power or the decrease of a threshold value in identification of incoming electric field strength or the like. CONSTITUTION:Each communicatable range of the radio equipments C1, C2 of two slave stations is expanded to twice as shown in a large circle of radius R in the extension talking between the equipments C1 and C2 placed at a range of the communicatable limit point r1 from a master station. Since the two slave stations placed in this way include respectively the extension communication party in their communication range, the extension talking is attained. As the method expanding the communicatable range of the radio equipments in this case, the transmission power is increased or the threshold value of the electric field strength level identifying the presence of an incoming call at its reception section or the S/N detection threshold value of the demodulated output is decreased to 15dB from 35dB to expand its communicatable range easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to communication between slave station radios when mutual extension calls are made between the slave stations in a system such as a cordless telephone system, which is composed of a master station and a large number of slave stations belonging thereto. Regarding possible range control.

In recent years, cordless telephones have come into use, in which a wireless device is added to a telephone connected to a public wired communication station line, which serves as a master station, and calls are made via a portable wireless device that serves as the communication partner. .

As shown in Fig. 1, this is a device that performs wireless communication between the sender and receiver output of a telephone 2 connected to a central office line 1 and a transmitter TL and a slave station radio 3. Since it does not require wires, it is convenient to carry, and its use is increasing.

Furthermore, various methods have been devised in the past to add an extension call function to the above-mentioned slave station radio, but this extension function connection is not done through the master station at all, and for example, only one of the slave station radios transmits/receives. What is the transmitting and receiving channel frequency of the machine? If a system that allows extension calls is created by replacing the lines, the following inconveniences will occur.

FIG. 2 is a diagram showing the status of a cordless telephone equipment station, where P is a master station radio, cl and C2 are slave radios belonging to this, and the circles with radius r centered on these are respectively This assumes the entire communication range of the radio.

As shown in the figure, the slave stations C1 and 02 sandwich the master station P.
If we consider the case where both slave stations C1 and C2 are located, it is possible to talk to the master station P, but extension calls between these stations are not possible, and the distance between the survey stations is r, or less. This becomes possible only when we get close to . Although such a situation frequently occurs, it creates a defect in that the existing extension function cannot be effectively utilized.

The present invention has been made in order to compensate for the deficiencies in the above-mentioned conventional cordless telephone system in which all extension calls can be made, and it provides means for expanding the communication range of the slave station radio. For example, the purpose is to provide a cordless telephone system.

A detailed explanation will be given below based on the illustrated embodiment. FIG. 3 is a station layout diagram exemplifying a cordless telephone to explain the present invention in detail, and similarly to FIG. This figure shows a situation in which when two slave station radios Cs and C2 communicate with each other by extension, their respective communicable distances are doubled to form a great circle with a radius of R. By doing so, the two slave stations located as shown in the figure will be able to make an extension call because the other party will be within their communication range. In this case, methods for expanding the communicable distance of the radio include, for example, increasing the transmission power, or detecting the threshold value of the field strength level at the receiving section to identify an incoming call, or detecting the S/N of the demodulation output. By lowering the threshold value from 35 dB to 15 dB, it is possible to easily extend the entire communicable distance; There will be no inconvenience because it will not be sent.

Further, the method of extending the communication distance need not be limited to the above-mentioned method, and any method may be used as long as it achieves the purpose.

As mentioned above, if it is possible to make internal calls without going through the master station, the slave station will be transmitting and receiving data, and the system will become uncontrollable, making it impossible to respond to outside calls, which is the original purpose of cordless telephones. Therefore, the present invention also provides a communication control method for the master station using the following method.

FIG. 4 is a timing chart diagram illustrating an embodiment of a method that enables control of the master station, in which a is the timing when the master station sends a control signal, and b and C are receptions from the slave station during an extension call. This shows the reception switching timing between the internal call channel and the control channel of the aircraft. It is assumed that the master station radio transmits a slave station control signal on all control channels for a short time t in each cycle T, and each slave station radio normally listens to this control channel and waits for calls, and makes extension calls. If this is to be done, the communication slave station is selectively called via the control channel of the party, one of the many communication channels is determined, all wireless lines of both parties are connected, and an extension call is then made on the communication channel. At this time, as shown in FIG. 2 and C, the communication channel is received in accordance with the timing of the control signal from the master station, and then the switch is made to the control channel reception C. At this cycle, the control signal from the master station is received, and all commands of the signal are deciphered. Due to a forced interruption by the master station or a call from an outside line, extension communication may be temporarily stopped or other information may be transmitted. Furthermore, in the present invention, by receiving and receiving this information, the field strength transmitted from the master station is detected, or the S/Nf of its demodulated output is detected, and extension calls are made only when the base station is located within the control range of the master station. It was designed to continue.

By doing this, even in a wireless system where internal calls are made without going through the master station radio, the slave station can always be under the control of the master station radio, which is useful for cordless telephone systems, for example. If the slave station moves outside the control range of the master station and continues transmission, it can be prevented from interfering with the original purpose of outside line calls.

As explained above, the present invention expands the communicable range of slave station radios when making internal calls to slave station radios without going through the master station radio in a cordless telephone system and the like. This system is extremely effective in enhancing the functionality of a cordless medium telephone system or a similar communication system, since it makes it subordinate to the communication control of the master station radio.

[Brief explanation of the drawing]

FIG. 1 is a block diagram explaining the operating principle of a conventional cordless telephone system, FIG. 2 is a diagram explaining the equipment station status, FIG. 3 is a diagram explaining the present invention in detail, and FIG. 4 is a diagram explaining the present invention. FIG. 3 is a timing chart diagram illustrating how control signals are transmitted and received by a master station and a slave station in the cordless conference telephone system according to the invention. 1...... Office line, 2... Telephone. ３・・・・・・・・・Conventional cordless threat telephone. P...... Master station radio, CI and C2...
......Slave station radio, r, and B...
・・Communication distance of master station or slave station, T・・・・・・・・・
Control signal transmission period of the master station, t...- Control signal transmission time. Patent applicant: Toyo Tsushinki Co., Ltd.

Claims (1)

[Scope of Claims] 1. A wireless communication system consisting of a master station radio and a large number of slave station radios belonging thereto, in which the slave station radios communicate with each other in addition to communication with the master station. In the case of mutual extension communication, the communicable distance of each slave station radio device performing the extension communication can be substantially reduced by, for example, increasing the transmission power or lowering the threshold value for identifying the incoming field strength. An extension connection method characterized by being expanded. 2. Receive the control signal sent by the master station by switching the reception frequency to a predetermined control channel for a short time at predetermined intervals during an extension call, or by providing means such as receiving a reception section dedicated to the control channel. For example, control communication of the master station such as calling an outside line or forcing interruption of the master station, and continuing the internal call only when all the signals sent from the master station can be received, or within the communication control range of the master station. 2. The extension connection system according to claim 1, wherein the extension connection system displays that the extension line is located at