JP2614346B2 - Communication terminal device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a communication terminal device that transmits data using a plurality of data transmission channels.

(Prior Art) In recent years, there are many opportunities to transmit data (data communication) using various communication networks.

Various standardization activities are being carried out at CCITT to establish international standards for data communication. One of the standards is the Integrated Services Digital Network (ISDN). ISDN is one of the communication networks standardized by this CCITT recommendation, and is a comprehensive service network to which telephones, facsimile machines, computer terminals, etc. (hereinafter, these are collectively simply referred to as communication terminal devices) can be connected. It is.

In ISDN, all communications are digital,
The subscriber is provided with a 64 Kbps information channel (hereinafter referred to as B channel) and a 16 Kbps or 64 Kbps signal channel (hereinafter referred to as D channel). For these channels (data transmission channels)
It is defined as an I recommendation of C, C, I, T, T.

The B channel is usually used for data communication such as voice and data, and the D channel is used for transmitting subscriber signal information, for example, information mainly used for controlling a communication network such as call connection. At present, a basic interface consisting of two channels of 64 Kbps, two B channels, one D channel for 16 Kbps transmission, a total of three channels, 23 B channels for 64 Kbps transmission, and 64 B channels.
Two types of ISDN with primary group interface consisting of 24 channels, one D channel for Kbps transmission
Is prepared.

FIG. 2 shows a configuration diagram of a general ISDN network.

The figure shows an example of a basic interface, and communication terminal units (TE) 1a and 1b are connected to ISDN 3 via digital service units (DSU) 2a and 2b and user / network interfaces 4a and 4b.

DSUs 2a and 2b are connected to ISDN3 and user / network interfaces 4a and 4b.
And signal matching (processing such as signal level conversion). User / network interface 4a, 4b
Is composed of a total of three data transmission channels of two B channels (a first B channel and a second B channel) and one D channel.

For example, when the communication terminal device 1a and the communication terminal device 1b perform communication, first, a link with the other communication terminal device is established using the D channel, and after the establishment, data communication is performed using the B channel.

Here, the processing of the ISDN circuit link, that is, the basic control procedure of circuit switching will be described with reference to FIG.

 FIG. 3 is an explanatory diagram of circuit-switched basic call control.

In the figure, first, a call is set from a calling communication terminal device (calling TE) to a called communication terminal device (called TE) via an ISDN (network) (S1, S2). When the called TE receives the call setting, a response of the call setting acceptance is made to the calling TE (S3, S3).
4) In addition, a call instruction indicating that a call is being made is received.
The process is performed from E to TE (S5, S6). If the network connection is taken in response to the call at the destination TE, the destination TE
(S7, S8). When a response confirmation instruction is issued from the originating TE to the destination TE (S9, S10),
Communication using the B channel is performed (S11).

When the communication is completed, an instruction to disconnect the network is issued from the source TE to the destination TE (S12, S13). When an instruction to release the network is issued from the destination TE to the originating TE (S14, S15), an instruction to complete release is issued from the originating TE to the destination TE (S16, S17), and the network is released.

In the above description, all steps except S11 are executed using the D channel.

Now, in S11, two B channels can be used simultaneously. For example, if you take a video call, 1
One B channel is used for audio transmission, and the other is used for image transmission. In this manner, information of two 64 Kbps, that is, information of 128 Kbps, can be transmitted by one user / network interface (transmission path).

Using FIG. 4, 128Kbp using two B channels
The case where s is transmitted will be described.

 FIG. 4 is an explanatory diagram of conventional transmission.

The figure shows communication terminal equipment (TE) 1a to communication terminal equipment (TE).
In this case, six blocks A, B, C, D, E, and F are transmitted toward 1b.

Here, the data (frame) transmitted between the communication terminal device and the DSU will be described with reference to FIG.

 FIG. 5 is an explanatory diagram of the frame format.

FIG. 3A shows a frame transmitted from the communication terminal to the DSU, and FIG. 3B shows a frame transmitted from the DSU to the communication terminal.

As shown in the figure, one frame is 48 bits (250 μs)
And four blocks (first and second B channels Bch1 (B1) and Bch2 (B2)) can be transmitted in one frame. Between each block, data D to be transmitted to the D channel is added one bit at a time.

As shown in FIG. 4, when blocks such as A, B, C, D, E, and F are transmitted, a block is an A block, a block is a B block, a block is a C block, and a block is a The data of the D block is loaded, and thereafter, the same is repeated for a new frame. (Each block is 8-bit information.) Here, returning to FIG. 4, transmission of six blocks will be described. First, in the communication terminal device 1a, six blocks are decomposed, alternately allocated to the first channel Bch1 and the second B channel Bch2, and transmitted to the ISDN3.

(Problem to be Solved by the Invention) Here, it is assumed that the transfer path of the second B channel Bch2 has become long.

Specifically, for example, it is assumed that the communication terminal device 1a is installed in Tokyo and the communication terminal device 1b is installed in Yokohama. The first B channel Bch1 followed a route directly connecting Tokyo and Yokohama, but the second B channel Bch2 followed a route such as Tokyo-Nagoya-Yokohama due to congestion of the route. It shall be assumed.

In this case, in the communication terminal device 1b,
Channel Bch2 has a delay, and the first channel Bch1
And a delay time difference t occurs in the reception timing of each block.

If each block is assembled as it is, the B block is not received from the second B channel Bch2 after the A block, and the C block comes. Thereafter, a similar delay difference continues, and the original data transmitted by the communication terminal device 1a cannot be reproduced.

In the case of data communication such as file transfer, it is only necessary to temporarily accumulate the received data and then rearrange it. However, there is a problem that communication that is restricted by the time system, such as images and audio, cannot be reproduced normally. Had occurred.

For this reason, there has been a problem that it cannot be used while having a transmission capacity of 64 Kbps or more, which is equivalent to one B channel.

The present invention has been made in view of the above points, and provides a communication terminal device that can accurately reproduce data before transmission when data transmission is performed in blocks using a plurality of B channels. It is intended to do so.

(Means for Solving the Problems) A communication terminal device according to the present invention performs data transmission control in blocks using at least two data transmission channels simultaneously.
Specific pattern transmitting means for transmitting a predetermined specific pattern for all the data transmission channels,
A delay time difference detection unit that detects a delay time difference between transmissions of the data transmission channels based on the reception timing of the specific pattern for each of the data transmission channels; and a delay time difference detection unit that is inserted into a transmission path of each of the data transmission channels. The data transmitted on the transmission path is delayed, and the deviation of the reception timing is adjusted by block synchronization.
A delay matching unit; and a delay time setting unit that sets a delay time in the delay matching unit based on the delay time difference.

(Operation) The above device performs data transmission in blocks.
Before actually transmitting desired data, a specific pattern set in advance is transmitted to all data transmission channels.

On the other hand, when the data receiving side receives the specific pattern, it detects a transmission delay time difference between the data transmission channels based on the reception timing for every data transmission channel. Based on this delay time difference, the data transmitted on the transmission path is delayed, and the deviation of the reception timing is matched by block synchronization. That is, a delay is generated for a signal with a fast reception timing so that the reception timings of data received from all data transmission channels match. Thus, data received from each data transmission channel can be obtained at regular timing.

(Embodiment) FIG. 1 shows a configuration diagram of a system according to the present invention.

In the figure, a communication terminal device 1a, 1b has a CPU, respectively.
11,12, memory (MEM) 13,14, layer 1 control unit (L1CTL)
15, 16, serial / parallel interface units (SIU) 17 to 22, and delay matching means 23 to 26 are provided.

The CPU 11, the memory 13, the SIU 19,
Then, delay matching means 23 and 24 are connected. SIU19 is
It is connected to the D channel (Dch) on the layer 1 control unit 15. The delay matching units 23 and 24 are connected to the first and second B channels (Bch1 and Bch2) of the layer 1 control unit 15, respectively. The layer 1 control unit 15 is connected to the user / network interface 4a.

Control signal lines 23a and 24a are provided from the CPU 11 to the delay matching units 23 and 24, respectively.

Note that a similar connection is made to the communication terminal device 1b.

The user / network interfaces 4a and 4b are connected by an ISDN (not shown).

The CPUs 11 and 12 perform control and management of each unit constituting the communication terminal devices 1a and 1b. The memories 13 and 14 are composed of a RAM or the like that stores data and the like to be referenced by the CPU. The layer 1 control units 15 and 16 control layer 1 specified by I430 of CCITT, for example, control of electric signal level setting and the like. The SIUs 17 to 22 perform signal conversion between serial format signals and parallel format signals. The delay matching means 23 to 26 are SIU 17, 18, 20, 21 respectively.
This is to delay the signal output from.

A specific example of the delay matching unit 25 will be described with reference to FIG.

FIG. 6 is a block diagram of the delay matching means according to the present invention.

As shown, delay matching means 25 is composed of n registers (REG (1) ~ (n )) 40 1 ~40 n and the selector 41..

A clock CLK of a predetermined cycle is input to each register. The SIU 20 is connected to the input of the REG (1) 40. Further This input via the signal line 50 ₁ selector 41
It is connected to the. The output of REG ₍₁₎ 40 1 is, REG (2) 4
0 Connected to ₂ . REG (2) 40 ₂ of the input even if the signal line 50 ₂
Is connected to the selector 41 via the. Thereafter, similarly, a signal line is provided, and finally, the output of REG (n) 40 _n is connected to the signal line 50.
It is connected to the selector 41 via _n . The output of the selector 41 is connected to the internal bus 31.

The delay matching means 25 having the above configuration holds data that each register inputs at the timing of CLK. That is, REG
(1) 40 ₁ contents, REG (2) When CLK is inputted to the input 40 ₂ is sent successively REG (n) to 40 _n.

In addition, the selector 41 switches a signal line connected to the internal bus 31 to a signal line 50 by a selection signal input through the control line 25a.
Select from ₁ to 50 _n .

Returning to FIG. 1, the CPU 12 is provided with a specific pattern transmitting means 55, a delay time difference detecting means 56, and a delay time setting means 57.

Specific pattern transmitting unit 55, predetermined specific pattern before performing data transmission, for example, _{"00 H" ~ "FF H} "
Increment information up to this point is generated and transmitted to the first B channel Bch1 and the second B channel Bch2.

The delay time difference detecting means 56 is provided for the first B channel Bch1
And the specific pattern input from the second B channel Bch2, and based on the specific pattern input from one side,
The time until the same specific pattern is input from the other side, that is, the delay time difference is detected. Delay time setting means
57 outputs a selection signal for selecting the input of the selector 41 to the control lines 25a and 26a based on the delay time difference detected by the delay time difference detection means 56.

 Note that the CPU 1 has the same configuration.

Here, the operation according to the present invention will be described with reference to FIG.

 FIG. 7 is a time chart according to the present invention.

Here, a case will be described as an example where data is transmitted from the communication terminal device 1a to the communication terminal device 1b using the first and second B channels Bch1 and Bch2.

First, the specific pattern transmitting unit of the CPU 11 is activated and transmits a specific pattern to the communication terminal device 1b (S3
1). In the communication terminal device 1b receiving this, the delay time difference detection means 56 is activated, and the first and second B channels Bch1,
Compare the specific pattern output from Bch2 (S3
2). As a result, for example, it is assumed that a delay time difference of one block has occurred in the second B channel Bch2. Therefore, if the received data of the first B channel Bch1 is delayed by one block, the first and second B channels Bch1 and Bch1 are delayed.
A state can be created as if the data from 2 were received at the same time. The information of the delay time difference is notified to the delay time setting means 57. The delay time setting unit 57 transmits a control signal via the signal line 25a. The contents of the control signal is one in which the selector 41 is the input to the signal line 50 ₂ (S33). That is, the internal bus 31, so that the signal delayed by the REG ₍₁₎ 40 1 is input.

When the selection of the input of the selector 41 is completed, the CPU 12
Respond via channel Dch (S34). When the CPU 11 confirms the response (S35), the transmission of the data originally intended to be transmitted, that is, the valid data is started (S36). In the communication terminal device 1b, the first B channel Bch1 is output (received) from the internal bus 31 with a delay of one block from the actually input timing (S37). That is, a state similar to the case where the reception timings of the first and second B channels Bch1 and Bch2 match can be created.

As described above, since the data from the other B channels is intentionally delayed and received in accordance with the B channel in which the delay time difference has occurred, the reception timing of the data from each B channel must be finally matched. Can be.

 The present invention is not limited to the above embodiments.

In the embodiment, the basic interface has been described, but the present invention can also be applied to a primary group interface. Further, the present invention is not limited to ISDN, and the present invention can be applied as long as data transmission is performed using a plurality of transmission lines that may have different paths at the same time.

(Effect of the Invention) The communication terminal device of the present invention having the above configuration detects a delay time difference between the B channels, and intentionally delays data from each B channel in accordance with the delay time difference.
Because of block synchronization, it is possible to create a state where data is received from all the B channels at the same timing. Therefore, higher-speed communication using a plurality of B channels can be realized, and reduction in communication cost can be expected.

[Brief description of the drawings]

FIG. 1 is a block diagram of a system according to the present invention, FIG. 2 is a diagram of a general ISDN network, FIG. 3 is an explanatory diagram of circuit-switched basic call control, FIG. FIG. 5 is an explanatory diagram of the frame format, FIG. 6 is a block diagram of the delay control means according to the present invention, and FIG. 7 is a time chart according to the present invention. 23 to 26: delay matching means, 55: specific pattern transmitting means, 56: delay time difference detecting means, 57: delay time setting means.

Claims (1)

(57) [Claims] 1. A method for controlling data transmission in blocks by simultaneously using at least two data transmission channels, wherein a predetermined specific pattern is set for all of the data transmission channels prior to transmitting valid data. Specific pattern transmitting means for transmitting; delay time difference detecting means for detecting a delay time difference between transmissions of the data transmission channels based on the reception timing of the specific pattern for each of the data transmission channels; and each of the data transmission channels A delay matching unit that is inserted into the transmission line and delays data transmitted on the transmission line, and performs block synchronization of the shift of the reception timing to match the delay time. Communication terminal, comprising: a delay time setting means for setting. Location.