JPH0479444A - Subrate exchange system - Google Patents

Abstract

PURPOSE:To perform subrate exchange and to reduce the transmission delay for tandem connection by transmitting a multiplexed time slot to a counter station by a time division digital exchange and demultiplexing the time slot from the counter station to transfer it to plural low-speed data terminals by this exchange. CONSTITUTION:Data of channels (a) to (d) are multiplexed to a 8-bit time slot in a subrate trunk 14. Multiplexed data is converted to a transmission line signal again through a network 13 and a data trunk 15 and is transmitted to the counter station. The multiplexed time slot is transmitted to the counter station and the time slot from the counter station is separated to transfer it to plural low-speed data terminals. Thus, subrate exchange is possible in the time division digital exchange 13 where only exchange with prescribed bits as the unit is possible, and the data transmission delay is reduced at the time of tandem connection.

Description

[Detailed Description of the Invention] [Summary] Regarding a subrate exchange method, the purpose is to enable subrate exchange in a time-division digital exchange that exchanges in fixed bit units, and to exchange data from multiple low-speed data terminals. In a time-division digital exchange of a system that transmits data by inserting it into a time slot consisting of a predetermined number of bits in a high-speed format, only effective bits are extracted from a plurality of low-speed data converted to the high-speed format and are then transmitted from the predetermined number of bits. A subrate exchange trunk is provided for multiplexing in one channel time slot and performing reverse processing to separate the subrates.
The time division digital switch transmits the multiplexed time slots to the players, and separates and transmits the multiplexed time slots from the players to a plurality of low-speed data terminals.

[Industrial Application Field] The present invention relates to a method for subrate exchange, and in particular, by providing a trunk for subrate exchange that performs flexible bit-by-bit exchange, it improves line utilization efficiency of a digital communication network and also improves tandem connection. However, it is related to a subrate exchange method that can reduce transmission delays.

In a time division digital switch, data is generally exchanged in units of 8 bits, but not all bits in such data may be valid.

In such cases, it is desirable to multiplex only valid data among the 8 bits for transmission and reception, and to perform bit-by-bit exchange, that is, subrate exchange, at the exchange to improve line utilization efficiency. . Furthermore, the trunk for subrate exchange in this case is required to be capable of reducing transmission delays even in tandem connections.

[Prior art] With the development of the integrated public data network (ISDN) and high-speed digital communication networks between companies, and with the spread of data terminals such as personal computers, private branch exchanges (PBXs) are now capable of not only voice communication but also host communication. Data communication with computers is increasing.

In this case, the data communication mode has a communication speed of 64
Using only one channel of kbps line, 6
Transmit and receive at 4kbps, or use multiple channels of a 64kbps line at the same time, such as 6 channels, 24 channels, 30 channels, etc., to transmit and receive data at 384kbps,
There is a demand for higher speed data transmission and reception, such as 1536 kbps, 1920 kbps, etc.

On the other hand, contrary to the demand for faster communication, 120
0bps, 2400bps, 4800bps, 9600
There may be cases where low-speed data transfers at speeds below 64 kbps, such as 19.2 kbps, 19.2 kbps, etc., are required;
10 formats.

In such a case, the effective data in the 8-bit data to be transmitted will be in units of 1 bit, 2 bits, 4 bits, etc., and it is inevitable that the line efficiency will decrease.

Figures 6 (1) and (2) conceptually illustrate the conventional switching system, where (1) shows a multiplexing configuration, and (2)
) indicates the bit configuration of each channel.

That is, as shown in (1), the terminal 11. ．． 11b1
1200 bps from 1c and 11d, respectively.

1200bps, 2400bps, 1200bpS data (a), (b), (C), (d) are multiplexed by multiplexer (MPX) 12 to generate 64kbps data (e
).

In this case, channels (a) to (d) are 64kb as is.
When converted to ps data, only the least significant bit B0 of the 8-bit data B, -B contains valid data, as shown in (2).

As described above, in the conventional exchange system, when low-speed data is exchanged, a decrease in line efficiency cannot be avoided.

[Problem to be solved by the invention] Therefore, as shown in Fig. 6 (1) (e), data from such multiple terminals is multiplexed in bit units into one channel and transmitted and exchanged. , a subrate exchange is requested.

By doing so, it becomes possible to effectively utilize the lines of the digital communication network.

However, in general, time division digital exchanges are based on CCI
According to TT Recommendation G, 711, audio is sampled at 8kHz and encoded into a μ-law PCM signal or A-law PCM signal, converting it into numbers from 00H to FF, and exchanging in that unit. ing. That is,
It is based on a 64 kbps exchange operation in 8-bit units. Therefore, as mentioned above, 1 bit, 2 bit, 4
It was not possible to easily exchange subrates in units of bits.

The present invention aims to solve the problems of the prior art, and is to provide a trunk for subrate exchange in the position of a common trunk for a time-division digital exchange that can only exchange in units of 8 bits. The purpose of this is to enable such subrate exchange and to reduce transmission delays during tandem connections.

[Means for Solving the Problems] As shown in the principle configuration of FIG. 1, the present invention transmits data by inserting data from a plurality of low-speed data terminals 11 into time slots consisting of a predetermined number of bits in a high-speed format. In the time-division digital exchange 13 of the system, only valid bits are extracted from a plurality of low-speed data converted into a high-speed format by the sub-rate exchange trunk 14, and multiplexed into one channel time slot consisting of a predetermined number of bits, Also perform the reverse process to separate
The time division digital switch 3 transmits the multiplexed time slots to the opposing station, and also separates the multiplexed time slots from the opposing station and transfers them to a plurality of low-speed data terminals 11.

Further, the present invention provides subrate replacement trunk 1 in this case.
4 writes data from each terminal serially using the communication path memory 16, reads it out, performs multiple processing, performs separation processing by reverse operation, and reads data in the communication path memory 16 using the control memory 17. The writing order is specified, and the processor 18 writes the reading and writing order of data in the communication path memory 16 to the control memory 17 based on the bit exchange information from the call processing section.

[Effect]

In a time-division digital switch for a system that transmits data from multiple low-speed data terminals by inserting it into time slots with a predetermined number of focus points in a high-speed format, only valid bits are extracted from the multiple low-speed data converted to a high-speed format. The multiplexed time slots are multiplexed into l-channel time slots consisting of a predetermined number of bits, and the reverse processing is performed to separate the multiplexed time slots, and the multiplexed time slots are transmitted to the player, and the multiplexed time slots from the player are separated. Since the data is transferred to a plurality of low-speed data terminals, subrate exchange can be performed in a time division digital exchange that can only exchange in units of predetermined bits.

In this case, in the trunk for subrate exchange, the communication path memory serially writes data from each terminal based on the bit exchange information from the call processing unit, reads it out and performs multiple processing, and performs separation processing by reverse operation. It may also be something that does this.

(Embodiment) FIG. 2 shows a system configuration of an embodiment of the present invention, illustrating a subrate switching system switching center, and 1
1. ．． 11. , IL, 11a is a data terminal, 13 is a network, 14 is a subrate trunk, and 15 is a digital trunk.

Low speed data channels (a), (bL (C), (d) for each terminal 11-, 1 lb, 11c, 11d)
is connected via the network 13 to the subrate drink 14 for subrate exchange. In the subrate drink 14, each channel (a), (bL (C), (
The data of d) is multiplexed into an 8-bit time slot I. The multiplexed data is again connected to the digital trunk 15 via the network 13, converted to a transmission path signal via the data trunk 5, and transmitted to the opponent station.

In this case, the function of the subrate drunk is to extract only the valid bits from the data from multiple terminals connected via the network, and store these valid data in a time slot of one channel consisting of 8 bits. It multiplexes only the data and sends it to the opponent. In a game, conversely, 8-bit data, in which only valid data has been multiplexed, is separated bit by bit for each opposing data terminal using the subrate exchange trunk.

In this case, the system communicates the information of each data terminal, such as information such as communication speed, and the bit position where the data is multiplexed, using a common line signaling system such as the D channel, and uses this information to determine the subrate. The switching trunks perform multiplexing/demultiplexing to enable communication between each data terminal.

FIG. 3 shows an example of the configuration of a subrate switching trunk, in which 16 is a speech path memory (SPM), 17 is a control memory (CM), and 1B is a CPU.

The 32 time slot 8-bit data, that is, the 256-bit serial data, which consists of data from each terminal and multiplexed data from the game, from the highway (HW) in a time-division digital exchange (not shown) is SPMI6 written serially.

On the other hand, based on bit exchange information from a call processing processor (CPR) (not shown), the CPU 18 creates information on the order in which each bit of 256 bits of data should be read, and writes it to 0M17. . SPM16
The data written in 0M17 is read out in the order written in 0M17 to form multiplexed data for the game, and is sent to the time division exchange via the HW.

Conversely, the multiplexed data from the game is written to the SPM 16 based on the designation of 0M17, and is read out to form 256-bit serial data to be separated to each terminal. At this time, the CPU
1B is the SPM in which order the multiplexed data is
Create information on whether to write to 0M16 and write it to 0M17.

In this way, a 256-bit bitwise switch is constructed.

FIG. 4 shows a specific example of the configuration of a bit-by-bit switch, in which the same components as in FIG. 3 are designated by the same numbers, and 19 and 20 are sequential counters that operate at different phases.

Dual port RA for SPM16 and 0M17 each
Using M, the manual order of bit readout to 0M17 is:
This is done by giving an address and data from the CPU 18. By giving the output of the sequential counter 19 as an address, the HW
By writing 256-bit serial data from 0M17 and giving the output of sequential counter 20 as an address, data of 0M17 is read. And 0M
By giving the data read from SPM 17 as an address, the data of SPM 16 is read. In this way, the configuration shown in FIG. 4 constitutes a switch that performs bit-by-bit exchange.

FIG. 5 shows an example of a digital communication network in which switching stations of the subrate switching system are connected in tandem.
B1. CI, Dl, A2. B2C2D2 and El,C
2 is the terminal, 21.2223 is the switching center, 24,, 24□
, 243. '244 is a digital trunk, 25. ．． 2
5□, 253 is a sub-rate drunk.

Now terminals A1 and A2. Terminals B1 and B2. Terminals C1 and C2
Terminals DI and D2. When the terminals E1 and B2 communicate, the data of the terminals At, Bl, and CI Di are sent to the subrate drunk 25. Subrate multiplexing via . The subrate multiplexed data is transferred to the digital trunk 241.
The signal is transmitted via the transmission path. The exchange 22 receives this via the digital trunk 24°. In the switching center 22, which is a tandem station, the data of the terminals At, Bl, and Di are passed through, and the data of the terminal CI is separated at the subrate drunk 25°, and the data of the terminal El is transmitted to the terminals Al, Bl, and DI. The data is multiplexed and sent out to the transmission path via the digital trunk 243. At the exchange 23, a digital trunk 244
The subrate drunk 253 separates the data of terminals Al, Bl, Di, and El, and sends them to terminals A2 . B2', D2. Transfer to B2.

By doing this, the exchange 22, which is a tandem station, does not need to temporarily separate all the multiplexed data and then re-multiplex it.

Therefore, according to the configuration shown in FIG.
The transmission delay of Bl and Di data can be reduced.

[Effects of the Invention] As explained above, according to the present invention, 64-bit data according to CCITT V, 110 Formats I, from a plurality of terminals
In data communication at kbps or less, only the valid focus among the 8 bits is multiplexed for transmission and reception, making it possible to effectively utilize the lines of the data communication network.

Furthermore, since the subrate exchange trunk is configured with a switch that can flexibly exchange bits, when tandem connections are made in a digital communication network, there is no need to temporarily separate all of the data multiplexed at the tandem station and then re-multiplex it. , data transmission delay can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic configuration of the present invention, FIG. 2 is a diagram showing the system configuration of an embodiment of the present invention, FIG. 3 is a diagram showing an example of the configuration of a subrate exchange trunk, and FIG. 4 is a diagram showing the configuration of a subrate switching trunk. Figure 5 is a diagram showing a specific configuration example of a unit switch, Figure 5 is a diagram illustrating a digital communication network in which switching stations using the subrate switching system are connected in tandem, and Figures 6 (1) and (2) are diagrams showing an example of a conventional switching system. It is a diagram conceptually shown. 11 is a low-speed data terminal, 13 is a time division digital exchange, 14 is a trunk for replacing plates, 16 is a speech path memory, 17 is a control memory, and 18 is a processor.

Claims (2)

[Claims] (1) In a time division digital exchange (13) of a system that transmits data by inserting data from a plurality of low-speed data terminals (11) into time slots consisting of a predetermined number of bits in a high-speed format, multiple data are converted to the high-speed format. A subrate exchange trunk (14) is provided for extracting only valid bits from the low-speed data of the data, multiplexing it into a time slot of one channel consisting of the predetermined number of bits, and performing reverse processing to separate the data, A subrate switching system characterized in that an exchange (13) transmits the multiplexed time slots to the opposing station, and separates the multiplexed time slots from the opposing station and transfers them to a plurality of low-speed data terminals (11). . (2) The subrate exchange trunk (14) serially writes data from each terminal, reads it out, performs the multiplex processing, and performs the reverse operation to perform separation processing, and Call path memory (16)
a control memory (17) for specifying the order of reading and writing data in the communication channel memory (16) based on bit exchange information from the call processing unit; Writing processor (18)
2. The subrate exchange system according to claim 1, further comprising: