JPS61107897A - Key telephone system - Google Patents

Abstract

PURPOSE:To increase a transmitting channel, to delete a transmitting dead time of a bit code and to improve transmitting efficiency of information quantity economically by forming and transmitting a frame to arrange serially a voice and data respectively to a pair of lines. CONSTITUTION:A key telephone system 10 is linked by a key telephone line 30 respectively composed of two lines of an exchange main device 20, a transmitting line 31 of information and a receiving line 32. At the telephone system 10, a frame forming means 13 to form the frame to send information to the device 20 received from a data bus 12 to the line 31, a frame transmitting means 14 to send the formed frame to the line 31, a frame receiving means 15 to receive the inputted frame from the line 32 and a frame decoding means 16 to decode the bit code of the frame and sent to the bus 12 are installed. For the digital coding constitution transmitted to the line 30, a frame synchronizing signal is arranged to the first four bits, control data are arranged to the next four bits, the data are arranged to the next eight bits and the second voice is arranged to the final eight bits.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention comprises a small-scale exchange or exchange main device that interconnects a multi-function telephone or a button telephone to accommodate it and a communication line connected to another communication network, The present invention relates to a button telephone device having a predetermined information transmission format between the telephone and the switching main device.

(Prior art) A conventional key telephone device connects each of a plurality of key telephones to the switching main device through a total of four wires: a two-wire communication path (conventional subscriber telephone line) and a two-wire data path. has been done. For data transmission and reception on the two-wire data path, a ping-pong method (for example, Paper N, Inoue,
R, Komiya and Yken Inoue, “T
ime-shared two-wire digit
alsubscriber transmission
system andapplicatlon t
o the digital telephone
neset,' IEEE Trans, Corr
mun, , vol, Cαto 29° Nov, 1981
．． ) and an echo prevention method using simultaneous transmission and reception (% vo1.cOR←29. Nov, 1981.). The echo rejection method has a complicated circuit and is not common, so the ping-pong method was widely adopted. In the ping-pong method, the information transmission capacity within a certain period of time is set to H, and transmission and reception are assigned to each. For example, even if prepared information is returned immediately when the transmitted information arrives at the destination, a round trip transmission time occurs as a no-signal zone on the previous transmitting side. Since this transmission delay differs depending on the type and length of the transmission path, the maximum transmission delay is estimated and set, or the transmission path length is limited based on the set amount of transmission delay.

(Problems to be Solved by the Invention) The conventional key telephone device described above is configured such that the data transmission path connecting each key telephone device and the switching main device alternately transmits information in both directions. Because of this, the efficiency of transmitting the amount of information decreases, and when transmitting in both directions at the same time, equipment is expensive, making it less cost effective.

(Means for Solving the Problems) A button telephone device of the present invention includes a plurality of button telephones and a switching main device that controls connections between these button telephones and a communication line coupled to the outside, A pair of two wires is provided as a transmission line and a pair of two lines as a reception line in the communication line connecting the main device, and the information sent to the transmission line for each key telephone is transmitted using a 4-bit frame synchronization code 1,
Frame forming means for arranging a total of 32 bits of information code consisting of 4 bits of control data and 34 channels of PCM voice and data for 8 bits in a predetermined order to form one frame of 125 microseconds; and frame decoding means for detecting a frame synchronization code from the bit string and decoding frame information.

(Example) Next, referring to the drawings regarding the button telephone device of the present invention,
I will explain.

FIG. 1 shows a functional block 1 showing one embodiment of the present invention. The button telephone 10 is connected to the switching main device 20 and the information transmission screen 1
A31 and receiving line 32 are connected by button telephone lines 30 each consisting of 2@. The button telephone 10 receives power from the exchange main device 20 via the button telephone line 30 and includes a power supply means 11 for supplying +5V and -5V power into the button telephone image 10. The button telephone 10 further includes frame forming means 13 for forming a frame for transmitting information received from the data bus 12 to the switching main unit 20 and sent to the line 31. Transmit the formed frame to line 3
Frame transmitting means 14. Frame receiving means 15 receives frames input from the receiving line 32. It also includes a frame decoding means 16 for decoding the bit code of the frame received by the frame receiving means 15 and sending it to the data bus 12. The switching main device 2o is connected to each key telephone 1o via a button telephone line 30, and is connected to other switching devices via a communication line 40.

FIG. 2 is a frame configuration diagram showing an example of a digital code configuration transmitted to the button telephone line 30.・In order, the first 4 bits are signals for frame synchronization, the next 4 bits are control data, such as lamp lighting commands, button press information, etc., and the next 8 bits are audio (PCM)
, the next 8 pits are for data, and the last 8 pits are for second audio (PCM), and the -frame consists of a total of 32 bits. This frame is 125 based on PCM audio.
The length is μsec (8kHz), and one channel is 8kHz.
At least 256 Kbp for 4 channels in bits
The code is transmitted at a rate of s. The second audio channel is, for example, dedicated to calls that are directly connected to the speaker, and when the first audio channel is in use for a normal call, it automatically answers an incoming telephone call and transmits the audio from the caller through the speaker. You can receive it.

Next, the functional aspect of the present invention will be explained with reference to FIG.

FIG. 3 is a functional block diagram showing a detailed embodiment of FIG. 1. In FIG. 3, the same components as in FIG. 1 are given the same numbers and symbols, and their explanations will be omitted. A processor 17 is connected to the data center 12 of the button telephone 10,
Processor 17 that sends and receives information via data bus 12
controls the execution of each function of the button telephone 10. The switching main device 20 includes a channel connecting means (CHI~) 21 connected to the button telephone 10, and a channel selecting means 2 connected via a PCM path 22 for transmitting and receiving PCM audio.
4 and a process 25 connected via a data bus 23 for transmitting and receiving data. The channel connection means (CH1~) 21 has the same configuration as the frame transmitting/receiving section of the button telephone 10, and inputs data and voice (PCM) via the data bus 23 to form the frame configuration shown in FIG. A frame forming means 211 for forming a frame, and a frame transmitting means 212 for sending the formed frame to the receiving line 32 of the button telephone 10. and button telephone 10
A frame receiving means 213 receives frames via the transmission line 31 of the frame receiving means 213, decodes the received frames and sends audio (PCM) to the channel selection means 24 via the PCM path 22, and data to the channel selection means 24 via the data bus 23. ,
Frame decoding means 214 that sends each frame to
Equipped with The frame forming means 13/211 receives the clock signal and receives the frame synchronization code, control data, audio (PCM),
Transmission data is encoded and arranged in the configuration shown in FIG. The frame transmitting means 14/212 transmits a frame formed by pulse driving to the transmission line 31 or 32. Frame receiving means 15/213 and frame decoding means 16
- Execute the reverse procedure of H.214 frame formation and transmission. The channel selection means 24 connects the communication line 40 connected to the outside to the channel connection means 21 corresponding to the selected button telephone 10 under the control of the processor 25. The power supply for the key telephone 10 is 48 V at the receiving end of the transmitting line 31 of the key telephone line 3o in the switching main device 20.
On the other hand, Ov is supplied to the transmitting end of the receiving line 32, the button telephone line 3o is formed as a Shigenobu line, and the transmitting end of the transmitting line 31 and the receiving end of the receiving circuit 32 in the button telephone 10 are connected and input. +5V and -5V are formed.

In the above embodiment, the frame structure is illustrated in FIG. 2, but the arrangement positions of audio and data are not limited to this figure. For example, even if the second audio is the second data, or even if the audio and data are arranged in a large number, the same function can be achieved. Although the channel connection means of the switching main device is explained in FIG. 3 as being configured by the same means as the button telephone set, it is also possible to use the illustrated method as long as the frame transmitted to the button telephone line is unified into a predetermined configuration. Even if the content is different, it can perform the same function.

(Effects of the Invention) As explained above, the key telephone device of the present invention connects the switching main device and each key telephone device using four wires, two wires are paired as a transmitting line, and the remaining two wires are paired as a receiving line. By forming and transmitting a frame in which voice and data are arranged serially on each line, the number of channels to be transmitted is increased, and the bit code transmission pause time is eliminated. This has the effect of improving the transmission efficiency of the amount.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing an embodiment of the button telephone device of the present invention, FIG. 2 is a frame configuration diagram showing an embodiment of the transmission frame of FIG. 1, and FIG. 3 is a detailed explanation of FIG. 1. It is a functional block diagram showing an example of a nodame. lO...button telephone, 11...power supply means, 12.23...data bus, 13,
211... Frame forming means, 14, 212.
...Frame transmission means, 15,213...
・Frame receiving means, 16°214... Frame decoding means, 17.25... Processor, 2
0... Exchange main device, 21... Channel connection means, 22... PCM path, 24...
...Channel selection means. 7.Pa) Agent: Susumu Uchihara, patent attorney /'E. \''・, 7' N--2/ Figure 2 Procedural amendment (method) ': i0.3.22 Showa year, month, day 1, case description 1982 41F patent application No. 228
624 No. 2, Title of the invention: Button telephone device 3, Relationship with the person making the amendment: Applicant: 5-33-1 Shiba, Minato-ku, Tokyo (Contact address: NEC Corporation Patent Department) 5. Date of amendment order February 26, 1985 (shipment date) 6. Column L of "Detailed Description of the Invention" of the specification subject to amendment Contents of amendment (1) Description, page 3, lines 5 to 10 [Paper N, 1noue, R, Komiya and Y
, Inoue. @Time-shared two-wire dig
ital snb-5criber transmi
ssion system and ap-plic
ation to the digital
telephoneset,” IEEE Tra
ns,Commun,,volCOM-29,N
ov, 1981. ” to “IEEE Transactions and Communications Expansion, published in November 1981.
ions and Communi-cat 1on
s), Volume 29, N., Inouuni, R., Komya and Y.
, Inouuni et al.'s paper "Time-division two-line subscriber transmitter and its application to digital telephones (Time-5hared
two-wire digital sub-5c
river transmission system
and ap-plication to th
e digital telephone set)
JJ corrects. (2) Same page, lines 11 to 14 “Thesis” 1.
Holte and 8.5tuflotten,
”A new digital echo cacel
er for two-wire subscciber
1ines,” IEEE Trans. Commu, vol, C0M-29, Nov.
, 1981.4 “Published in November 1981
IEEE Transactions and Communications (IEEE Transacti)
onsand Communications), Volume 29, H. Holte and S.
``2-A new digital echo canceler for subscriber lines'' by Tuflloten et al.
anceler for two-wire 5ub
scriber jines) J J to correct. -65;

Claims (1)

[Scope of Claims] A button telephone device comprising a plurality of button telephones and a switching main device for accommodating and connecting these and controlling the connection between the button telephones or to a communication line that connects them to the outside, each button telephone having: The pair of two wires is connected to the main switching device by a button telephone line consisting of four wires, which is used as an information transmission line and the remaining two wires are used as an information reception line, and the transmission line and reception line are connected to a heavy trust line. A power supply means that receives power from the exchange main device and supplies power internally, and a 4-bit frame synchronization code, 4-bit control data, and 3-channel 8-bit information to be sent to the transmission line. Time-division multiplexing frame forming means for arranging information codes of a total of 32 bits consisting of PCM voice and data in a predetermined order and forming one frame for 125 microseconds, and receiving bit codes from this frame forming means at a speed of 256 Kbps. frame transmitting means for transmitting to the transmitting line; frame receiving means for receiving the bit code via the receiving line; detecting a 4-bit frame synchronization code from the bit code received by the frame receiving means to form the frame; A button telephone device comprising frame decoding means for identifying a frame having the same configuration as a frame formed by the means and decoding voice and data.