JP3288998B2 - Signal multiplex transmission 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 multiplex transmission technique, and more particularly, to a signal multiplex transmission technique in a connection section between a local exchange and a direct terminal equipment.

[0002]

2. Description of the Related Art In a conventional telephone service, when an analog signal is used in a connection section between a subscriber exchange and a direct terminal equipment, one or two pairs of metallic cables are occupied per line, and a digital signal is used. PCM according to the Japanese standard T.G.711
(Pulse Code Modulation)
Occupies a transmission bandwidth of 64 kbps.

FIG. 3 shows a case where signal transmission in a section connecting a subscriber exchange and a terminal equipment is performed by digital signals, that is,
FIG. 3 is an explanatory diagram of a conventional example in the case of using ISDN (Integrated Services Digital Network) (basic), and joins with terminal equipment including a terminal device (telephone) 1 and a line termination device 3 such as a DSU (Digital Service Unit). The connection section with the local exchange 6 is connected by the metallic cable 4, and the transmission line interface adopts the transmission method defined in ITU-T Rec. The metallic cable (communication line) 4 is composed of a pair of cables (information channel 64 kbps × 2 ch = 128 kbps) having a transmission speed of 320 kbps, and enables bidirectional communication.

[0004] In FIG. 3, a voice signal input from a terminal device 1 is PCM voice coded, sent to a cable 4 via a line termination device 3, and sent to a public line network 7 via a subscriber exchange 6. Can be The PCM voice-encoded voice signal (digital signal) transmitted from the public line network 7 to the cable 4 via the subscriber switch 6 is taken into the terminal device 1 via the terminating device 3, and (Analog signal) and output to the outside.

[0005]

In the prior art as shown in FIG. 3, a pair of metallic cables is used as a communication line and assigned to an information channel (64 kbps). Since PCM voice coding is applied, there is a drawback that only two channels (two channels each for up and down) are available, and the communication capacity using ISDN is remarkably increasing due to the popularization of the Internet and the like. There is an urgent need to improve the efficiency of use of communication lines using the existing metallic cables.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks and demands of the prior art, and has as its object to provide a signal multiplex transmission system which realizes efficient use of a connection section between a subscriber exchange and terminal equipment. I do.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a method for controlling a predetermined electric power connected to a public telephone network.
Given a subscriber exchange carriers and a plurality of terminal devices
A signal transmission method in a connection line section connected via a line , wherein both ends of the connection line section are line terminations.
Connected device, the line terminal devices each, when the information signal is input, coded by converting the information signal, the connection line by further multiplexing it and a plurality of sets of encoded information signal And the coded information signal multiplexed from the connection line.
Upon receipt of the item, the said multiplexing encoded information signal is separated to recover a plurality of information signals from the separated plurality of sets of encoded information signal, connect division multiplexer time, the time One of the division multiplexers is one of the line terminators
And the other one of the time-division multiplexing devices is connected to the terminal device via another line termination device, and the two time-division multiplexing devices are connected to the connection line. And transmitting the multiplexed coded information signals from the subscriber exchange or the terminal device to each other via the Internet.

[0008] The second invention is directed to the first invention.
The connection line is a line of another telecommunications carrier.
It is characterized by the following.

[0009]

[0010]

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of a signal multiplex transmission system in a section connecting a subscriber exchange and terminal equipment according to the present invention, and FIG. 2 is an embodiment of a TDM (time division multiplexing device). It is a block diagram which shows the principal part of an example.

In FIG. 1A, the terminal equipment comprises a terminal device (for example, telephone) 1, a time division multiplexing device (TDM) 2, and a line termination device 3 such as a DSU. The equipment comprises a line terminating device 3, a time-division multiplexing device 5, and a subscriber switching system 6. Although only one terminal device 1 is shown for explanation, a plurality of terminal devices are connected to the time-division multiplexing device 2 in practice.

The connection sections between the terminal-side equipment and the subscriber-side exchange-side equipment are connected by cables. The transmission speed of the cable (communication line) 4 is 64 kbps or an integral multiple thereof, and enables bidirectional communication.

As shown in FIG. 2, the time-division multiplexing apparatus 2 has an audio signal encoder 21, a code compressor 22, and a demultiplexing / multiplexing unit 23, and the audio signal encoder 21 The audio signal (analog signal) input from the device 1 is converted to PCM
The voice is coded (converted into a digital signal) by voice coding and output to the code compressor 22. The code compressor 22 compresses the voice code input from the voice signal encoder 21 according to a well-known high efficiency voice signal coding rule, and outputs the compressed data to the separation / multiplexing means 23. The demultiplexing / multiplexing means 23 converts a set of compressed data input from the code compressor 22 (that is, a plurality of sets of voice codes obtained by converting voice information input from a plurality of terminal devices and voice coding) for a predetermined time. The data is switched and multiplexed for each (time slot) and transmitted to the cable 4 via the line terminating device 3. That is, by using the time-division multiplexing device 2, it is possible to switch the data and the voice code corresponding to the cable 4 at a predetermined time (time slot), respectively, and to convert the data and the voice code into a digital signal having a band narrower than 64 kbps.

The separating / multiplexing means 23 separates the multiplexed digital signal (compressed data) received from the cable 4 via the line terminating device 3 into a plurality of sets of digital signals. Input to the container 22. The code compressor 22 has a function of expanding compressed data input in the reverse direction. The code compressor 22 expands the compressed signal input from the demultiplexing / multiplexing unit 23 and inputs the expanded signal to the audio encoder 21. The audio encoder 21 has a function of converting an audio code (digital signal) input from the opposite direction into an audio signal (analog signal), and converts (restores) the audio code input from the code compressor 22 into an audio signal. And sends it to the destination terminal device (telephone or the like) 1.

The time-division multiplexing device 5 includes the time-division multiplexing device 2
And a set of voice codes obtained by converting voice information received from the public line network 7 through the subscriber exchange 6 into digital signals (that is, converting a plurality of voice information received from the public line network into voice codes). Multiple sets of speech codes
Are multiplexed and transmitted to the cable 4. Also, the multiplexed digital signal received from the terminal device 1 via the metallic cable 4 is separated and restored, and is passed to the local exchange 6.

That is, as shown in FIG. 1B, a speech signal or a PCM speech code inputted from each terminal device (telephone) is converted to a high-efficiency speech coding rule well-known by the time division multiplexer 2. Is converted to a narrow-band digital signal after the high-efficiency voice coding, a plurality of narrow-band digital signals are bundled and multiplexed, and transmitted to the opposing time-division multiplexing device 5 via the communication line 4. You. The opposite-side time-division multiplexing device separates the multiplexed digital signal into each channel and converts the multiplexed digital signal to 64 kb based on the PCM coding method
The digital signal of PS is restored and passed to the local exchange. The same procedure is used for transmission from the local exchange to the terminal equipment.

Thus, the band of 64 kbps in the upward direction is converted into a plurality of narrow bands (16 kbps × 4 channels in the example of FIG. 3).
In the downstream direction, the 64 kbps band is divided into a plurality of narrow bands (16
kbps x 4 channels)
The use efficiency of the transmission path can be significantly improved. Note that the number of narrow bands is not limited to four channels, and may be two channels or more than four channels, and is not limited to a transmission path (communication line). As mentioned above, although one Example of this invention was described, this invention is not limited to the said Example, It cannot be overemphasized that various deformation | transformation implementation is possible.

[0019]

As described above, according to the present invention, the voice information in the connection section connecting the subscriber exchange and the terminal equipment is voice coded with high efficiency to narrow the band required for transmission per unit line. However, since transmission is performed after multiplexing, it is possible to significantly improve the utilization efficiency of the physical line in the connection section as compared with the related art.

In other words, by increasing the multiplicity of the connection section between the subscriber exchange and the terminal equipment, which had a low multiplicity in the prior art, according to the present invention, it has become possible to utilize the transmission with good transmission efficiency (for example, If the transmission section is laid or borrowed from another telecommunications carrier, the cost per channel can be reduced).

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a signal multiplex transmission system in a section connecting a subscriber exchange and terminal equipment according to the present invention.

FIG. 2 is a block diagram showing a main part of an embodiment of the time division multiplexing device.

FIG. 3 is an explanatory diagram of a conventional technique in a case where signal transmission in a section connecting a subscriber exchange and terminal equipment is performed by digital signals.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Terminal device 2, 5 Time-division multiplexing device 3 Line termination device 4 Metallic cable, communication line (connection line) 6 Subscriber exchange 7 Public network 5, 2 Opposing device (opposing device)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiro Ishii 8nd Ichibancho, Chiyoda-ku, Tokyo 2nd Denden Co., Ltd. (72) Inventor Masakatsu Gamo 8nd Ichibancho, Chiyoda-ku, Tokyo 2nd Denden Co., Ltd. (56) References JP-A-10-276163 (JP, A) JP-A-2000-22756 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04J 3/00-3 / 26 H04L 5/22-5/26 H04L 12/00 H04L 13/00 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. Predetermined telecommunications connected to a public line network
Operators subscriber exchange and a plurality of terminal devices and a predetermined times
A signal transmission method in the connection line section formed by connecting through a line, both ends of the connecting line section is connected to the line termination device, respectively
Of the network unit, when the information signal is input, the information
Encoded by converting the broadcast signal, further it a plurality of pairs of marks
Wherein sending the connection line by Goka information signals multiplexed, when receiving multiplexed encoded information signal from the connection line, the said multiplexing encoded information signal is separated and the separated plurality of sets restoring the plurality of information signals from the encoded information signal, connect division multiplexer time, one is one of the line termination instrumentation of said time division multiplexer
Connected to said local switch machine through the location, other one of the time division multiplexer is connected to the terminal device via the other line terminal, the two time-division multiplexer, the connection Over the line
The multiplex from the subscriber exchange or terminal equipment
A signal multiplex transmission method for mutually transmitting encoded information signals . 2. The connection line of another telecommunications carrier.
2. The signal multiplex transmission according to claim 1, wherein the transmission line is a line.
Transmission method.