JPH0795874B2 - Multiplex transmission system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention multiplexes and transmits data of a plurality of terminals to the same destination from a private branch exchange via a communication network such as an ISDN network in the same channel. The present invention relates to a multiplex transmission system that

[Conventional technology]

FIG. 8 is a conceptual diagram showing a conventional example according to a speed matching method to a 64 Kbps channel (hereinafter referred to as B channel) specified in CCITT Recommendation I.460 when transmitting data via an ISDN network. 1a) to (1d) are data terminals with existing interfaces, and (2) are terminal adapters for accommodating terminals with existing interfaces in the ISDN interface, and protocol conversion and speed conversion to match the communication speed of terminals. There is a function of. (3) is a speed converter in the terminal adapter (2). (4a) and (4b) are private branch exchanges, and (5) is an ISDN network.

Next, the operation will be described. For ease of explanation, the communication speeds of the data terminals (1a) to (1c) are set to 1.
2Kbps, 2.4kbps and 9.6Kbps are assumed, and the case where the data terminal (1d) is a computer and a plurality of data terminals and the computer perform n: 1 communication will be described.

ISDN uses the information channel 64
The method of speed conversion in units of 8 Kbps on the B channel of Kbps is standardized. For example, the speed of 4.8 Kbps and below is converted to 8 Kbps, the speed of 9.6 Kbps to 16 Kbps, and the speed of 19.2 Kbps to 32 Kbps. These speed converted 8Kbp
The speed of s, 16Kbps, 32Kbps is called the subrate, and the signal is called the subrate signal.

As a method of accommodating a terminal in a private branch exchange, a method of directly accommodating a terminal having a speed conversion function to a subrate, a method of accommodating it through a data interface module such as a digital telephone, and an existing interface terminal are available. There is a method of accommodating via an ISDN terminal adapter (hereinafter referred to as a terminal adapter).

In FIG. 8, the terminal (1a) is a computer (1d)
When communicating with the other party, a call is set up via the signal channel (hereinafter referred to as the D channel) in response to a call request from the terminal (1a), and the B channel communication is performed between the terminal (1a) and the terminal (1d). The path is established and data exchange is performed. Next,
When the terminal (1b) sends a call request to the terminal (1d) while the terminal (1a) and the terminal (1d) are communicating, the terminal (1a)
A B channel different from the B channel between the terminal and the terminal (1d) is set and data is exchanged.

[Problems to be Solved by the Invention]

Since the conventional data transmission is configured as follows,
When multiple terminals exchange data with the same party's terminal, it is necessary to set the B channel communication channel separately, and when the communication speed of the terminals is low, it is compared to the transmission capacity of the B channel. Since the amount of information is small, the transmission efficiency is low and the cost is economically high.

The present invention has been made to solve the above problems, and an object thereof is to obtain a multiplex transmission system capable of transmitting a plurality of data having the same transmission destination through the public network in the same channel.

In this regard, CCITT Recommendation I.460 defines a format for time division multiplexing to 64 Kbps B channel, but the present invention relates to an implementation method according to this concept.

[Means for Solving the Problems]

A speed converter for matching the communication speed of the transmission data from the terminals, a private branch exchange for transmitting the transmission data of the matched communication speeds from a plurality of terminals through the network, and a transmission channel provided for the network. , A common trunk that stores transmission data from each terminal to the same transmission destination, and stores the multiplex position of the transmission data within a predetermined time slot corresponding to a matched communication speed, Each time there is a call request from the terminal, the transmission data and the multiplexing position are sequentially stored in the common trunk of the same transmission destination, and the stored transmission data is read out within a predetermined time slot of the same channel and is multiplexed and transmitted. And a call processor.

[Action]

In the multiplex transmission system according to the present invention, the call processor provided in the private branch exchange sequentially stores the transmission data and the multiplex position in the common trunk of the same transmission destination every time there is a call request from each terminal, and this storage is performed. The transmitted data is read out within a predetermined time slot of the same channel, multiplexed, and transmitted.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. First
The figure shows the concept of this embodiment. In the figure,
(6) is a common trunk, and a plurality of trunks are provided corresponding to the lines. (7) and (8) are highways that connect the common trunk (6) to the private branch exchanges (4a) and (4b).
Further, the same symbols as those in FIG. 8 indicate the same or corresponding portions.
FIG. 2 is a block diagram showing the structure of the common trunk (6). In the figure, (61) is the first for recording the destination number.
Memory, (62) a second memory for designating the position of a bit for multiplexing data into a time slot of the same channel, (63) a bit multiplexer, (64) a bit multiplexer (6
Control units that perform control in 3), (65) and (66) are highway interface units that interface the highway with the exchange, and (67) is a highway in the common trunk. (9) is a call processing processor of the private branch exchanges (4a), (4b), a control unit (64), a first memory (61) for recording a destination number and a second memory (62) for designating a multiplexing position. ) And the bus (10) to manage the common trunk (6).

FIG. 3 is a diagram showing in detail the relationship between the bit multiplexing unit (63) and the control unit (64), and (631) is a third memory for temporarily storing data from each terminal at each time slot, (63
2) is a write circuit, (633) is a read circuit from the third memory (631), (641) is an address memory for recording the read address of the third memory (631), (642),
(643) is a counter. FIG. 4 is a diagram showing a memory configuration of the first memory (61) for recording the destination number and the second memory (62) for recording the bit position to be multiplexed. FIG. 5 is a diagram showing how data of a plurality of terminals are multiplexed.

FIG. 6 is a flow chart.

Next, the operation will be described with reference to the drawings.

First, when one of the terminals (1a) to (1c), for example, the terminal (1a), makes a call request to the terminal (1d), the call processing processor (9) of the private branch exchange (4a) The communication speed and the destination number of the terminal (1a) are received via the D channel which is a signal channel, a connection request is made to the network, the destination number is recorded in the first memory (61), and then the second A bit number flag corresponding to the communication speed of the terminal (1a) is set in the memory (62). When the call setup procedure on the D channel is completed, the call processing processor (9) establishes a path to the private branch exchange (4a) and the common trunk B channel network. The data of the terminal (1a) is sequentially written in the third memory (631) of the bit multiplexing unit (63) through the writing circuit (632) in accordance with the address generated by the counter (643) in time slot units. Here, the time slot is explained with a unit of 8 bit sequence, and since the communication speed of the terminal (1a) is 1.2 Kbps, the 1st bit in the time slot is the data bit and the 2nd bit ~.
The 8th bit is not used (CCITT Recommendation I.460 stipulates that an unused bit is set to a binary value of "1"). Reading from the third memory (631) of the bit multiplexing unit (63) reads the third memory (631) into the address memory (641) based on the information recorded in the bit position recording memory (62). Record address A. If the third memory (631) is read through the read circuit (633) by this address information, the data bit of the terminal (1a) can be read.

Next, when the terminal (1b) makes a call request with the same party as the other party, the call processing processor (9) causes the first memory (6
When you search 1), you know that the destination number of the terminal (1d) is already recorded, and you search the second memory (62) to see if there is a bit margin corresponding to the communication speed of the terminal (1b). Find out. There is still room for 7 bits here, and the terminal (1b)
, The second bit in the time slot is designated and a flag is set at the second bit in the area next to the second memory (62). Based on this information, the third memory address B where the data bit of the terminal (1b) is recorded is written in the second area in the reading order of the address memory (641).
Next, if the third memory (641) is randomly read in order using the address information recorded in the address memory (641), at the first bit in the time slot, the terminal (1
The data bit of a) and the data bit of the terminal (1b) are read out at the second bit, and the terminal (1b) is read within the same time slot.
The data of a) and the terminal (1b) are multiplexed and transmitted to the terminal (1d) in the same B channel.

When the terminal (1c) makes a call to the terminal (1d) in this state, the call processing processor similarly searches the destination number recording memory (61) and recognizes that there is the same address, and the bit The number of bits corresponding to the communication speed of the terminal (1c) and a flag indicating the multiplex position are recorded in the third area of the position recording memory (62). Here, the communication speed of the terminal (1c) is
Since it is set to 9.6 Kbps, it occupies 2 bits in the time slot. Therefore, since the flag of the terminal (1a) and the terminal (1b) have already been set in the bit position recording memory (62) for the first bit and the second bit, the flag for the terminal (1c) is set to 3 bits. Hit the eyes and the 4th bit. With this information, the addresses C and D to which the data bit of the terminal (1c) of the memory (631) of the bit multiplexing unit (63) is written are the address memory (641).
Write in the 3rd and 4th. Then, the third memory (631) of the bit multiplexing unit (63) can be read out in order from the addresses A, B, C and D recorded in the address memory (641) by one in the time slot. Bit 1 is the data bit of terminal (1a), Bit 2 is the data bit of terminal (1b), Bit 3 is the data bit of terminal (1c), Bit 3 is the data bit of terminal (1c), 3 terminals (1a), (1b) The data of (1c) and (1c) are multiplexed in the same B channel and transmitted to the terminal (1d).

Similarly, the data of a plurality of terminals can be multiplexed until the data bit in the time slot is full.

On the other hand, the call processing processor (9) sends to the other party's private branch exchange (4b) via the D channel, information about which terminal data is multiplexed at which bit position of the time slot each time there is a call request from the terminal. In the private branch exchange (4b) and the common trunk (6), the call processing processor (9) performs the procedure opposite to the above-mentioned operation based on the information, and thus the data of the plurality of terminals multiplexed in the B channel is acquired. Is decomposed into the data of each terminal and sent to the computer (1d). The computer (1d) processes the data of each terminal and sends it to the private branch exchange (4b). The data guided from the private branch exchange (4b) to the common trunk (6) are multiplexed here based on the information of the time slot position and transmitted to the private branch exchange (4a) on the calling side via the network (5).

In the above embodiment, multiplexing of ISDN to 64 Kbps B channel was described, but the transmission speed is not limited to this.
Also, a transmission speed other than ISDN may be used. Further, in the description of the multiplex operation, writing to the memory is performed sequentially and reading is performed at random, but the same effect can be obtained even if this is reversed.

Further, although the common trunk is provided outside the private branch exchange in the description, it may be provided inside the private branch exchange.

FIG. 7 shows another embodiment, in which a speed converter is provided on the incoming highway of the common trunk.

〔The invention's effect〕

As described above, according to the present invention, each time there is a call request from each terminal, the transmission data and the multiplexing position are sequentially stored in the common trunk of the same transmission destination, and the stored transmission data are stored in the same transmission channel. Since it is configured so that the data is read out within the time slot and multiplexed, the data transmission efficiency of the transmission channel can be improved and the economical efficiency can be obtained.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a multiplex transmission system according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a multiple common trunk, and FIG. 3 is a detailed diagram of a multiplex unit and a control unit. Four
FIG. 5 is a diagram showing the structure of the memory, FIG. 5 is a diagram showing how data is multiplexed, and FIG. 6 is a flow chart. FIG. 7 is a diagram showing another embodiment. FIG. 8 is a conceptual diagram showing a conventional transmission method. (1a) to (1d) are terminals, (2) is an ISDN terminal adapter, (3) is a speed converter, (4a) to (4b) are private branch exchanges, (5) is a network, and (6) is a common trunk. (61), (6
2) is memory, (63) is multiplexing section, (631) is memory, (63
2) write circuit, (633) read circuit, (64) control unit, (641) memory, (642) and (643) counter, (9) bus, (10) private branch exchange call The processing processor is shown. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A speed converter for matching the communication speed of transmission data from a terminal, a private branch exchange for transmitting the transmission data of the matched communication speed from a plurality of terminals through a network, and a private branch exchange of the network. It is provided corresponding to the transmission channel, stores the transmission data from each of the terminals to the same transmission destination, and stores the multiplex position of the transmission data within a predetermined time slot corresponding to the matched communication speed. The common trunk and the private branch exchange are provided, and each time there is a call request from each of the terminals, the transmission data and the multiplexing position are sequentially stored in the common trunk of the same transmission destination, and the stored transmission data is stored. A multiplex transmission system comprising: a call processor that reads out, multiplexes, and transmits the data in the predetermined time slot of the same channel.