JPH02206245A - B channel voice variable rate multiplex control system - Google Patents

Abstract

PURPOSE:To make a secretary magneto telephone equipment efficient by switching voice band compression CODECs with different kinds in an exchange system accommodating a digital communication network (ISDN network) and using them to each B channel in common. CONSTITUTION:Units 64U, 32U, 16U with voice band compressor CODEC mounted by each rate by one octet of B channel are provided and a unit in response to the frequency of use of the user is connected. Since the connector for the units 64U, 32U, 16U is unified, the reconnection of the different unit is attained. One connector of each unit connects to an analog terminal equipment TE via a cross point switch XP2. Moreover, the other connector of the unit is connected to a multiplex converter MUX 1 (or MUX 2) multiplexing and distributing a signal through a B1 channel, a B2 channel. Moreover, the MUX 1 (2) is connected to a network terminator. The converters MUX 1, MUX 2 switches XP1, XP2 are controlled by a control section CONT.

Description

[Detailed Description of the Invention] [Industrial Application Field] A B-channel voice system in which a switching system accommodating a digital communication network is equipped with a plurality of voice band compression CODECs, and multiplex calls are performed by switching the voice band compression CODECs between the switching systems. This invention relates to a variable rate multiplexing control system.

[Prior art] In the conventional transmission system, audio information is transmitted by PCM at 64
The data is converted to Kbit/s and transmitted digitally.

In addition, voice band compression is performed to reduce the bit rate of voice information to 32 bit/s or 16 Kbit/s (and digital transmission is also performed by multiplexing multiple calls. However, conventionally, voice information is A voice band compression CODEC with the same rate for one octet of the B channel was prepared for the B channel, and the call was carried out at a fixed rate on the B channel from which the call was started until the end of the call.In other words, the B channel was 64Kbit/ If you use a 32Kbit/s audio band compression CODEC, 1 octet of the B channel is equivalent to 2 octets at a bit rate of 16Kbit/s.
If you want to use the s audio band compression CODEC, you will need to prepare 4 CODECs.

[Problem to be solved by the invention]

If one octet worth of voice band compression CODECs of the same rate are prepared for each B channel as in the past, the cost of the switching system will increase depending on the frequency of use because the low rate voice band compression codecs are expensive.

In addition, since it is difficult to transmit signals from analog terminals such as facsimiles using low-rate audio band CODECs, if you have a facsimile machine, consider using a regular PCM-CODEC to secure a fixed B channel of 64Kbit. was necessary.

The purpose of the present invention is to solve these conventional problems and to provide a system that improves the efficiency of mutual communication equipment by switching between different types of audio band compression CODECs and sharing them for each B channel. It is to provide.

[Means to solve the problem]

The present invention relates to a digital communication network (Integrated
ServicesDigital NETWORK,
This is a B-channel voice variable rate multiplexing control system that has the following configuration in a switching system that accommodates an I5DN network (hereinafter referred to as an 15DN network).

(1) A unit equipped with a voice band compression CODEC for one octet of the B channel is provided for each rate, and units are connected according to the usage frequency of the user.

(2) In each unit, a CODEC is provided between a crosspoint switch that can be connected to any B channel and a crosspoint switch that can be connected to any telephone/communication terminal.

(3) The type, quantity, and usage status of voice band compression CODECs built into one's own exchange system, as well as outgoing, incoming, and call termination detection information, shall be constantly transferred between exchange systems using the same method. This enabled us to use the B channel more efficiently.

〔Example〕

FIG. 1 is a configuration diagram of a switching system accommodating an 15DN network, which is an embodiment of the present invention.

FIG. 2 is a block diagram showing a plurality of switching systems connected to ISDNm, which is an embodiment of the present invention. FIG. 3 is a diagram showing the control sequence of the exchange system.

TE is an analog terminal, FAX is a facsimile, XPI,
XP2 is a cross point switch, 64U, 32U, 1
6LJ is COD E (::(7)Y='7),
, MUX is a multiplex conversion device, and C0NT is a control unit.

The unit 64U is equipped with one CODEC of 64 Kbtt/s. Unit 32. U is equipped with two audio band compression CODECs with a bit rate of 32 Kbit/s, and the two outputs from these are converted into a bit rate of 64 Kbit/s.
It is equipped with a multiplex conversion device 32MUX that multiplexes it into 8 and also distributes it conversely. Unit 16U has 4 audio band compression CODECs with a bit rate of 16Kbit/s.
4 outputs from these at a bit rate of 64 Kb
It is equipped with a multiplex conversion device 16MUX for multiplexing into IT/s and distributing it vice versa. Since the connectors of the above three types of units 64U, 32U, and 16U are unified, different units can be replaced.

One connector of each unit is connected to an analog terminal TE via a crosspoint switch XP2. In addition, the other connector of the unit is connected to the B1 channel, B2 channel and D via the crosspoint switch XPI.
A multiplex conversion device M that multiplexes channels and also distributes them.
Connected to UXI (or MLJX 2). Furthermore, a multiplex conversion device MUXI (2) is connected to the network termination device.

The polymorphic conversion devices MUX1, MUX2 and crosspoint switches XPI, XP2 shown in FIG. 1 are controlled by a control unit C0NT.

FIG. 2 is a block diagram showing a plurality of switching systems connected to 15DN%, which is an embodiment of the present invention. E is the exchange system at the head office, F is the exchange system at the factory, and G is the exchange system at the branch office.

The operation will be explained below based on the control sequence shown in FIG.

In the call state shown in FIG. 2(a), two calls are multiplexed using one unit (32U) between the head office (E) and the factory (F) on the same ground, and are carried out on one B channel. That is, the 32 Kbit/s voice band compression CO in the unit 32U
Analog terminal 782 at head office (E) using two DECs
The machine and 782 analog terminals at the factory are communicating on one B channel.

Also, between the head office (E) and branch office (G), unit 6
A call is being made using 4U.

From state (a), a call request is made from the head office (E) to the factory (F). Then, the head office exchange system E
The control unit C0NT searches for a B channel connected to the factory (F). When it is detected that there is a B channel in use and the unit 32U is being used, it is then detected whether there is any CODEC that is not being used in the unit 32tJ. In state (a), there are two CODECs.
Since the unit is being used and there is no free space, the control unit C0NT searches for another empty unit. As a result, it is detected that the unit 16U, which has a lower bit rate than the unit 32U, is empty.

Then, a call request and a request to make a call using the unit 16U are transmitted to the control unit C0NT of the factory exchange system F. When the control unit C0NT of the exchange system F detects an unused unit 16U, it returns an acknowledgment signal. Under the control of the control unit C0NT of the head office exchange system E that received the acknowledgment signal, the head office (E) and the factory (F) Now, make two calls at the same time from unit 32U to unit 16U.
Switch to . Furthermore, the unit 16U is an audio band compression C
Since there are four ODECs, there are still two spaces left.

Therefore, newly occurring calls between the head office and the factory are made using one of the available voice band compression CODECs. This state is shown in FIG. 2(b).

Next, when there is a request to send a facsimile fax from the factory (F) to the head office (E), the control unit C0NT of the exchange system of the factory (F) transmits the request to send a facsimile fax to the exchange system of the head office E.

The control unit C0NT of the exchange system E at the head office searches for a unit 64U having a 64 Kbit/s CODEC necessary for facsimile reception. Unit 1-64U is in use, the unit in use is a telephone call, and 64B is
When it is detected that it can be done using a unit using an audio band compression CODEC for 8 or more, a vacant unit is searched. As a result, after detecting that the unit 16U is vacant, the control unit C0NT of the switching system E of the head office is sent from the branch office to the exchange system G of the branch office that is using the unit 64U to detect whether the unit 16U is vacant. When a response signal acknowledging the transfer is received, the call is transferred to unit 16U, and at the same time, the call is transferred to unit 16U in the branch exchange system as well.

Next, the control unit C0NT transmits to the factory exchange system F that the unit 64U has become vacant.

Between the exchange systems on the other side, facsimile transmission is performed from the factory to the head office using the unit 64U. This state is shown in FIG. 2(C).

FIG. 4 is a diagram showing another control sequence.

Two calls are made between exchange system E at the head office and exchange system F at the factory using one unit 32U and one call using unit 64U. 32Kbit/s voice band compression CO from factory switching system F
When there is a request to disconnect one of the two calls being made using the DEC, the control unit C0NT of the factory exchange system F searches to see if the call with the head office exchange system E can be made more efficient. In this case, it detects that one call is being made using unit 64U, and transfers the call from unit 64U to exchange system E at the head office, compressing the voice band of 32 Kbit/s to the free one of unit 32U, which is already in use. COD
A request to transfer the call using EC is communicated to the central office switching system. Control unit C0N of factory exchange system F
When the acknowledgment response signal arrives from the exchange system E at the head office, T sends out a switching control signal and also sends a switching control signal to its own exchange system F.
Calls using the PCM and CODEC of unit 64U are transferred to the free 32 of unit 32U.
Moving on to a call using a Kbit/s voice band compression CODEC.

At the same time, the control unit C0NT of the switching system E at the head office also shifts to a call using the 32 Kbit voice band compression CODEC on the free one side of the unit 32U. After that, the exchange system at the head office and factory was connected to Unit 64U.
Open the channel.

Note that since it is not possible to communicate between exchange systems without passing through units equipped with audio band compression CODECs with the same bit rate, the installation design of the units should be designed to match the volume of calls between exchange systems.

In the above-described embodiment, one unit is combined with the same voice band compression CODEC, but it may be used in a mixed manner, such as when a special use is made between two exchange systems. That is, one unit has a configuration of two 16 kbit/s units and one 32 Kbit/s unit.

As for the configuration of the exchange system shown in Figure 1, it is necessary to prepare as many crosspoints as the number of multiplexed CODEC units for the crosspoint switch Band pressure! It is much cheaper than ICODEC.

〔Effect of the invention〕

As described in detail above, since the exchange system can be constructed by replacing units according to the usage frequency between the exchange systems, the design standardization of the exchange system can be achieved. Furthermore, since multiplexing can be performed using a voice band compression CODEC, call charges can be reduced.

For audio, use a low bit rate CODEC; for analog data terminals such as facsimile, use a high bit rate C.
By recombining the ODEC to an appropriate path, the call loss rate is reduced and efficient communication becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a switching system accommodating an 15DN network, which is an embodiment of the present invention. FIG. 2 is a block diagram showing a plurality of switching systems connected to an 15DNI, which is an embodiment of the present invention. FIG. 3 is a diagram showing the control sequence of the exchange system. FIG. 4 is a diagram showing the control sequence of the exchange system. 64 U, 32 U, 16 U---CODE
Unit with C, 32MUX, 16MUX, - multiplex converter, MUXI, 2-1 multiplex converter, X P
1, 2 ---- Cross point switch C0NT
...-Control unit, TE----Analog terminal FAX
−−, −−・−・ Facsimile. Patent applicant: Kanda Tsushin Kogyo Co., Ltd. Nippon Telegraph and Telephone Co., Ltd.

Claims (1)

[Claims] In a system that accommodates a digital communication network and performs multiple calls/communications between switching systems equipped with voice band compression CODECs, the calling side and receiving side switching systems are equipped with rate-specific units composed of the same type of voice band compression CODECs, B, characterized in that the audio band compression CODECs in the rate-specific units are collectively switched and connected to any B channel.
Channel audio variable rate multiplexing control system.