JP3222671B2 - Notification method during portable device search in private wireless telephone system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing method for an exchange in a private wireless telephone system, and more particularly, to notify a calling portable device that the exchange is searching for a called portable device. How to do it.

[0002]

2. Description of the Related Art For example, a premises mobile telephone system using a low-power wireless system such as a factory / premises work communication, an exhibition hall communication, and a plant or a power plant is composed of a wireless terminal equipped with a private branch exchange and a wired cable connected to the wireless terminal. A plurality of relay connection devices (repeaters) that are connected and distributed in the premises are installed, and a mobile phone (portable apparatus) that moves in a service area constituted by each zone centered on the antenna of each repeater Is configured to communicate with another portable device in the premises or a telephone on the office line via the exchange of the wireless terminal. FIG. 1 is a configuration example diagram of a wireless telephone system to which the present invention is applied. In the figure, 1 is a wireless terminal provided with an exchange, 2 is (1) to (n) repeaters, 3 is a mobile phone (portable device), and 4 is a wired cable. FIG. 2 is a schematic block diagram of an exchange to which the present invention is applied. FIG. 4 is a flowchart of a conventional exchange process in the system of FIG. As shown in this figure, for example, when the telephone or the office line side of the wireless terminal is a calling side and calls a portable device, when the dial is turned, the exchange outputs a calling signal and sequentially operates the n repeaters. Then, a radio wave is transmitted to search for a portable device of a communication partner. The reason why radio waves are not simultaneously transmitted from a plurality of repeaters is to prevent interference from occurring between adjacent zones. For example, when the portable device of the calling party is located in the zone of the n-th repeater, a response signal is returned from the portable device that has received the radio wave from the n-th repeater, and a ringing tone RBT (Ring Back) from the exchange is provided. Tone) is heard by the calling party. If the portable device of the call partner is not in the entire service zone, no response signal is returned, so that the exchange hears a busy tone BT (Busy Tone) from the exchange. That is, during the time T ₁ of the until the responding party by dialing the caller will wait in RBT or silence. The same exchange processing is performed even when the calling side is a portable device.

[0003]

As described above, in the above-described conventional connection processing method, it takes time to search for the portable device on the called side, and furthermore, the exchange uses the power supply of the portable device on the called side. If the search takes longer, because it has been disconnected or is outside the call area, the calling party will
When the BT is heard, there is a problem in that it is thought that the other party has already been called in spite of the search. In addition, when there is no sound, it is considered that the exchange has failed or that the connection has failed. And there is a drawback that the feeling cannot be calmed down, such as starting over again.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and to notify a calling party that a portable machine of a called party is being searched for in a portable telephone searching system in a wireless telephone system. It is to provide a method.

[0005]

According to the present invention, there is provided a method for notifying a portable device in a private wireless telephone system during a search for a portable device, comprising a plurality of repeaters connected to a wireless terminal equipped with a private branch exchange and wired and distributed in the premises. In a private wireless telephone system in which mobile phones in a zone are configured to communicate with each other, after the calling mobile phone dials, the private branch exchange sequentially operates the plurality of repeaters to allow the called party to operate. Until a response signal is returned and a ring back tone is transmitted from the private branch exchange, a sound during the called-side portable device search indicating that the called-side portable telephone is being searched is generated. It is characterized in that it is sent to the calling side.

[0006]

FIG. 3 is a flow chart of an exchange process showing an embodiment of the present invention. The exchange, when dialed from the calling side, notifies the calling side of a portable device searching sound SRT (Search Request T).
one) to perform a portable device search. As shown in the figure, the time T from the time immediately after dialing until it changes to RBT
_{In the case of 0} , an SRT of a preset frequency indicating that the opponent is being searched for is heard, so that the user can wait without annoyance and does not need to call again. When the exchange receives a response from the called portable unit, the exchange sets RB
Switch to T. When there is no response from the called portable device, the device switches to a busy tone (BT).

FIG. 2 is a diagram showing an example of a partial configuration of an exchange provided in a wireless terminal of a system to which the present invention is applied. In the figure, reference numeral 6 denotes an analog switch, which is controlled by a control signal from the control unit of the exchange, and adds the output of a 400 Hz oscillator (OSC) to the BT, RBT, and the present invention by changing the on / off timing of the analog switch. Then, each tone signal of the SRT is generated and output to an audio signal line to a hybrid transformer (HYB).

[0008]

By implementing the present invention, the operator of the calling portable device can accurately recognize the state of the exchange process, so that the user does not get nervous during the call and the reliability of the system is improved. Therefore, the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a block diagram of a system to which the present invention is applied.

FIG. 2 is a partial configuration example diagram of an exchange of a system to which the present invention is applied;

FIG. 3 is a flowchart of an exchange process of the present invention.

FIG. 4 is a flowchart of a conventional exchange process.

[Explanation of symbols]

 1 wireless terminal 2 repeater 3 portable device 4 cable 5 handset 6 switch

Claims (1)

(57) [Claims] 1. A private wireless telephone system in which portable telephones in a plurality of zones are connected to each other by a plurality of repeaters distributed in the premises and connected to a wireless terminal having a private branch exchange by a wire, so as to communicate with each other. In the above, after the calling mobile phone dials, the private branch exchange sequentially operates the plurality of repeaters to search for the called mobile phone and returns a response signal, and the private branch exchange issues a ringback tone. Until the call, the called-side portable device searching sound indicating that the called-side mobile phone is being searched is transmitted to the calling side. Notification method.