JPH01220556A - Howler tone sending system in radio telephone system - Google Patents

Abstract

PURPOSE:To send a howler tone with sufficient sound volume to a general subscriber telephone set and to effectively use a time slot for speech by providing a howler tone detecting means at a central station and a howler tone generating means at a slave station. CONSTITUTION:At the central station 12, a howler tone detector 15 detects the generation of the howler tone when an existing exchange 11 generates the howler tone, and sends the detection information to the slave station 28 with the time slot for control. In other words, information representing the fact that the howler tone is generated at the existing exchange to the slave station, not sending the howler tone as in an on-going system. At the slave station 28 receiving the detection information of the howler tone, a howler oscillator 25 generates the howler tone, and sets it at a prescribed level, and sends a howler signal to the general subscriber telephone set 27, and also, releases the time slot for speech occupied at the time of off-hooking the telephone set 27.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a howler sound transmission system in a time division multiplex multiple access wireless telephone system.

(Prior Art) FIG. 3 shows an example of a system configuration of a time division multiple access wireless telephone system. A central station 32 connected to the existing exchange 31, colts 33-1 to 33-N and slave stations 33-1 to 3 connected to the central station 32 via wireless lines.
General subscriber telephones 34-1 to 34-1 connected by wire to 3-N
It is composed of 34-N.

FIG. 4 shows the time-divided time slots (TSi,i
=O to N). T.S.

is a control time slot for transmitting control signals between the central station 32 and the slave stations 33-1 to 33-N. T.S.
˜T S N is a time slot for a telephone call that transmits a voice signal.

Now, when the general subscriber telephone 34-n goes off-hook, the off-hook information is sent from the slave station 33-n to the central office 32 in the control time slot TS, and the telephone A time slot TS is assigned and a line with the existing exchange 31 is connected. A dial tone is sent from the existing exchange 31 to the general subscriber telephone 34.
I can hear it from -n. Generally, when a subscriber hears a dial tone, he or she sends a dial signal to establish a line with the other subscriber and begin a call. However, if the off-hook state continues inadvertently, the existing exchange 31 will send out a dial tone for a certain period of time, then send out a busy tone for a certain period of time, and then send out a howler tone and hook the general subscriber telephone 34-n. The 0 dial tone, busy tone, and howler tone warning that the call is off are sent to the general subscriber telephone 34-n via the encoder using the time slot TS for communication.

(Problems to be Solved by the Invention) However, the above-mentioned conventional time division multiplex multiple access radio telephone system has the following problems.

Since the aforementioned howler sound is a warning sound when the hook is off-hook for a long time, its level is required to be extremely high.

However, when the level of the howler sound is raised, the encoder's operation cannot keep up with this, and the howler sound level cannot be faithfully encoded, which limits the level of howler sound on general subscriber telephones and reduces the volume. There are drawbacks. In addition, in order to transmit the howler sound, it occupies a time slot for a call for a long time even when the call is not in progress.
This method has the disadvantage of being wasteful in terms of effective use of radio waves and effective use of time slots for calls.

In view of the problems of the prior art described above, an object of the present invention is not to transmit howler sounds from the central office, but to use a control slot from the central office to transmit only information that an existing exchange is emitting howler sounds. The howler sound generation means is separately provided in the slave station, and when the information of howler sound generation arrives from the central station, a howler sound signal of sufficient level is generated and sent to the general subscriber telephone. At the same time, by releasing the call time slot that was occupied until the howler sound was generated in the existing exchange, the howler sound can be heard with a high volume on general telephones and the howler sound is transmitted without occupying the call time slot unnecessarily. The aim is to provide a method.

(Means for Solving the Problems) The present invention has the following means configuration to achieve the above object.

That is, the howler sound transmission system in the wireless telephone system of the present invention has one central station connected to an existing exchange and a plurality of slave stations scattered around the central station, and the central station always communicates with the slave stations. In a time division multiplex multiple access wireless telephone system having one control time slot and a plurality of call time slots, the central office includes a howler sound detection means for detecting a howler sound transmitted from an existing exchange; means for transmitting howler sound detection information to the slave station using a control time slot; means for the slave station to generate a howler sound within itself when the howler sound detection information is obtained; Means for transmitting this howler sound to general subscriber telephones; Means for releasing a communication time slot used between the central station and the slave stations in conjunction with the transmission of the howler sound; It is characterized by:

(Function) Hereinafter, the function of the howler sound transmission system of the present invention having the above-mentioned means configuration will be explained.

In the central station, when an existing exchange generates a howler sound, the howler sound detection means detects the occurrence of the howler sound, and sends the detection information to the slave stations in a control time slot. That is, instead of sending a howler sound signal to the slave station as in the past, information indicating that the howler sound is being generated in the existing exchange is sent. When the slave station receives this howler sound detection information, the howler sound generating means generates a howler sound to a predetermined level and sends this howler sound signal to the general subscriber telephone, and when the general subscriber telephone goes off-hook. Frees the call time slot occupied by

As explained above, in the howler sound transmission system of the present invention, the howler sound to be sent to the general subscriber telephone is generated at the slave station, so it is possible to send the necessary and sufficient level of howler sound to the general subscriber telephone. At the same time, the time slot occupied by the off-hook telephone until the exchange generates the howler tone is freed up and can be used for other subscribers' calls. This eliminates the waste of occupying time slots for calls during calls.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a central office 12 connected to an existing exchange 11. As shown in FIG. The central office 12 includes a subscriber line interface section 13 having an interface with the existing exchange 11, a band limiting filter 14, a howler sound detector 15, a control section 16, a transceiver 17, and a central office antenna 18.

FIG. 2 shows a slave station 28 connected to a general subscriber telephone 27.
It is. The slave station 28 includes a slave station antenna 21 and a transceiver 22.
, a control section 23 , a subscriber line interface section 24 , a Howler oscillator 25 , and an amplifier 26 for amplifying the Howler signal generated by the Howler oscillator 25 .

It is now assumed that the general subscriber telephone 27 has been accidentally disconnected from the hook. Since the slave station 28 is disconnected from the hook, it is considered to be off-hook, and the slave station 28 and the central station 12 are connected by radio line in the call time slot TS, and a line with the existing exchange 11 is established.

Next, the existing exchange 11 sends a dial tone back to the general subscriber telephone 27. Since the existing exchange 11 cannot receive a dial signal while transmitting the dial tone, the dial tone changes to a busy tone and then changes to a howler tone.

In the central office 12, the howler sound sent from the existing exchange 11 passes through a band-limiting filter 14 and enters a howler sound detector 15 adjusted to a howler sound detection level, where the howler sound is detected.

The information detected by the howler sound detector 15 is transmitted to the control unit 16
is input. Since the control unit 16 must encode the howler sound detection information and send the howler sound detection information only to a specific slave station, an individual number assigned to each slave station as shown in FIG. 53 and howler sound detection information are placed on a control signal 54, which is sent to the transceiver 17 at the timing of the control time slot TSo, and sent to the slave station 28 through the central station antenna 18.

In the slave station 28 , the TSo sent from the central station 12 passes through the slave station antenna 21 and is sent to the control unit 23 via the transceiver 22 . The control unit 23 processes the TSo information, and if it matches the individual number of the own station, it recognizes that the information is for the own station, and if the howler sound detection information is detected in the TSO information, the control unit 23 activates the howler oscillator. 25, the signal from the Howler oscillator is amplified to the required level by the amplifier 26, and is sent to the general subscriber telephone 27. At the same time, the time slot TS used until now is released, and the signal from the Howler oscillator is amplified to the required level by the amplifier 26. be made available for use against persons.

(Effects of the Invention) As explained above, the present invention provides a detector for howler sounds sent from the existing exchange in the central office, and transmits howler sound detection information to the slave stations at the control time slot □TS0. Since the howler sound is generated within the slave station by the transmission, it is possible to send out a sufficient volume of the howler sound to the general subscriber telephone. It is also effective in terms of effective use of the time slot for calls, as it frees up the time slot for calls that was occupied until the howler sound occurs at the exchange and allows it to be used by other subscribers due to the continued off-hook state of the telephone. There is.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an existing exchange and the central office according to the embodiment of the present invention connected thereto, Fig. 2 is a block diagram showing the composition of the slave station according to the embodiment of the present invention, and Fig. 3 is a block diagram showing the configuration of the central office according to the embodiment of the present invention. FIG. 4 is a block diagram showing the system configuration of the multi-access wireless telephone system, FIG. 4 is a diagram showing the configuration of time-divided time slots, and FIG. 5 is a diagram showing the information configuration in the control time slots. 11...Existing exchange, 12...Central office, 13...Additional line interface unit,
14...Band limiting filter, 15...
...Howler sound detector, 16...Control unit,
17...Transmitter/receiver, 18...Central station antenna, 21...Slave station antenna, 22
......transmitter/receiver, 23...control section,
24...Subscriber line interface section,
25...Howler oscillator, 26...
Amplifier, 27... General subscriber telephone, 28
...Slave station, 31...Existing exchange,
32...Central office, 33-1 to 33-N...
...Slave station, 34-1 to 34-N... General subscriber telephone, 41... IIJ time slot, 42... Call time slot, 51...
...Preamble signal, 52...Frame synchronization signal, 53...Individual number, 54.
...Control signal, 55...Dummy signal. Agent Patent Attorney Yoshi Yahata Takahiro Hiroshi Akibun 0 Central Bureau /) Lecture 2 bu V, design / illustration missing example /) Child station 0 force 2 Glock map 2 design - / ~ 34-N------General access electrician Asafuto Nashida Emperor 72 Rena access curtain disaster news magazine ♂go 0 system 僑烑 0-appreciate it 3 confrontation itto Liu chain da time, K117 tuto Purchase jV figure rate 4 figure interest m tie A slot inclination J1 fan formation half δ figure

Claims (1)

[Claims] It has one central office connected to an existing exchange and a plurality of slave stations scattered around the central office, one control time slot that the central office always transmits to the slave stations, and a plurality of telephone calls. In a time division multiplex multiple access wireless telephone system having time slots for control, the central station has a howler sound detection means for detecting howler sounds transmitted from the existing exchange; means for transmitting information; and the slave station has means for generating a howler sound within itself when the howler sound detection information is obtained; means for transmitting the howler sound to a general subscriber telephone; ;In conjunction with howler sound transmission,
A method for transmitting a howler sound in a wireless telephone system, comprising: means for releasing a communication time slot used between a central station and a slave station.