JPH10336131A - Bulk transmission device and bulk transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently compensate delay time differences between B channels in a bulk transmission device and a bulk transmission method where plural B channels are bound together for transmission. SOLUTION: This bulk transmission device is provided with; a transmitting part 1 which includes a multiplexing part 4 that makes transmission information a multi frame structure with a frame synchronous pattern added, divides each frame of the multi frame structure into the number of B channels to be sent to every B channel and distributedly sends a frame synchronous pattern to every B channel in each multi frame cycle, a transmission switching party 5, etc.; a receiving part which includes a frame synchronous pattern extracting part 6 which extracts a frame synchronous pattern that is distributedly sent to every B channel, a variable delaying part 7, a receiving switching part 8 and a multiplexing separator 9; and a control processor 10 which calculates delay time difference between B channels based on an extracted frame synchronous pattern and controls the part 7 so that the delay time difference may be compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a bulk transmission apparatus and a bulk transmission method for transmitting and receiving a large amount of data by simultaneously using a plurality of channels. ISDN (Integ
The basic configuration of the rated Services Digital Network) method is 2B + D = 144 kbps for a 64 kbps B channel and a 16 kbsp D channel, and 24 B
Alternatively, a B-ISDN system having a 23B + D configuration has been put to practical use as a broadband transmission system. In addition, a bulk transmission system that bundles a plurality of B channels into one to achieve broadband transmission has been put to practical use.

[0002]

2. Description of the Related Art In a bulk transmission system in which a plurality of B channels are bundled into one in the ISDN system to perform broadband transmission, different paths may be set when setting a path for a plurality of B channels. In this case, a delay time difference occurs between the B channels. Therefore, on the transmitting side, the transmission information has a frame configuration corresponding to each B channel, and a frame synchronization pattern is added to each frame and transmitted.
A frame synchronization pattern is detected from a received frame corresponding to each B channel, and a delay time difference between each B channel is obtained.
In order to compensate for this delay time difference, delay processing corresponding to each B channel is performed to restore transmission information.

[0003] However, since the frame synchronization pattern is added for each frame to the transmission information framed for each B channel, there is a problem in transmission efficiency. Therefore, only at the start of communication, the transmitting side transmits a frame synchronization pattern and the like via each B channel, and the receiving side detects the frame synchronization pattern and the like received via each B channel and detects the delay between the B channels. A method has been proposed in which a time difference is obtained, a delay time corresponding to each B channel is set so as to compensate for the delay time difference, and the delay time is continued until the end of communication.

[0004]

In a bulk transmission system in which a plurality of B channels are bundled into one to perform broadband transmission,
The path of each B channel may be different when the path is set, or the path may be changed due to the occurrence of a failure during communication. The above-described method of adding a frame synchronization pattern to each frame can compensate for the delay time difference between the B channels by detecting the frame synchronization pattern even if the route is changed during communication. However, as described above, there is a problem that the transmission efficiency is reduced by adding a frame synchronization pattern other than actual data to each frame.

In the method of transmitting a frame synchronization pattern and the like only at the start of communication and measuring and compensating for a delay time difference between the B channels, the transmission efficiency is reduced by adding the frame synchronization pattern and the like only at the start of communication. However, since there is no need to add a frame synchronization pattern during communication continuation, there is an advantage that the transmission efficiency does not decrease. But,
If a route change occurs during communication, there is a high possibility that a delay time difference different from the delay time difference between the B channels at the start of communication will occur. If such a change in the delay time difference occurs,
Since this delay time difference cannot be measured during communication, transmission information by the bulk transmission method cannot be guaranteed.
Therefore, there is a problem that it is necessary to set a path for bulk transmission again. SUMMARY OF THE INVENTION It is an object of the present invention to reduce a decrease in transmission efficiency and to guarantee transmission information even when a route is changed.

[0006]

The bulk transmission apparatus of the present invention is: (1) A bulk transmission apparatus for transmitting and receiving transmission information by simultaneously using a plurality of B channels, wherein the transmission information is added with a frame synchronization pattern. Multi-frame configuration,
A transmitting unit 1 that divides each frame constituting the multi-frame into the number of B channels, distributes and transmits the divided frames to each B channel, and sequentially switches the frame synchronization pattern every multi-frame period to distribute and transmit the B channels; A frame synchronization pattern extraction unit 6 for extracting a synchronization pattern, and a variable delay unit 7 for controlling a delay time corresponding to a plurality of B channels
And a reception switching unit 8 that combines the reception information corresponding to each B channel in which the delay time difference between the B channels is compensated by the variable delay unit 7 and restores the transmission information of the multi-frame configuration.
And a control processor that determines a delay time difference between the B channels based on the frame synchronization pattern extracted by the frame synchronization pattern extraction unit 6 and controls the variable delay unit 7 to compensate for the delay time difference. 10 is provided.

[0007] (2) The transmitting section 1 includes a frame synchronizing pattern generating section 12 for generating a frame synchronizing pattern, a transmission frame of a plurality of terminals being multiplexed to form a multi-frame configuration, and A multiplexing unit 4 for adding the frame synchronization pattern of the above, dividing each frame of the multi-frame multiplexed by the multiplexing unit 4 into the number of B channels, distributing and transmitting the divided frames to each B channel, and And a transmission switching unit 5 for sequentially switching and transmitting to the B channel by switching every cycle of the multiframe.

[0008] (3) The receiving section 2 can be provided with a demultiplexing section 9 for demultiplexing the transmission information of the multi-frame configuration restored by the reception switching section 8 to a plurality of terminals and transmitting the demultiplexed information.

The bulk transmission method according to the present invention is: (4) A bulk transmission method for transmitting and receiving transmission information by simultaneously using a plurality of B channels. Add a pattern,
Each frame constituting the multi-frame is divided into the number of B channels and distributed and transmitted to the B channels. In addition, the frame synchronization pattern is sequentially switched at a multi-frame cycle and distributed and transmitted to the B channels. The information is received by the receiving unit 2 and the B
The frame synchronization pattern distributed to the channels is extracted, the delay time difference between the respective B channels is obtained, and the delay time corresponding to the B channel is controlled so as to compensate for the delay time difference. It includes the process of restoring.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of a first embodiment of the present invention, wherein 1 is a transmitting section, 2 is a receiving section, 3 is a line interface section, 4 is a multiplexing section, and 5 is a transmitting section. A switching unit, 6 is a frame synchronization pattern extraction unit, 7 is a variable delay unit, 8 is a reception switching unit, 9 is a demultiplexing unit, 10 is a control processor,
1 is an LAPD processing unit, 12 is a frame synchronization pattern generation unit, and 13 is an ISDN line.

The transmitting section 1 includes a multiplexing section 4, a transmission switching section 5, and a frame synchronization pattern generating section 12, and a receiving section 2
Includes a frame synchronization pattern extraction unit 6, a variable delay unit 7, a reception switching unit 8, and a demultiplexing unit 9. Further, the control processor 10 controls each unit, calculates the delay time difference between the B channels based on the frame synchronization pattern corresponding to each B channel extracted by the frame synchronization pattern extraction unit 6, and compensates for the delay time difference. The delay time corresponding to the B channel of the variable delay unit 7 is controlled. The variable delay unit 7 can be configured, for example, by a shift register that can control the number of stages, and can switch the delay time by switching the number of stages in units of a cycle of a shift clock signal (not shown).

The line interface section 3 is an interface with the ISDN line 13 and separates and multiplexes the D channel together with the B channel. LAPD processing unit 11 controlled by control processor 10
Thus, transmission and reception of various information messages via the D channel are performed.

Transmission data SD1 to SD from a plurality of terminals
n is multiplexed by the multiplexing unit 4 and the received data RD1 to RDn separated by the multiplexing / demultiplexing unit 9 are transferred to the terminal in a bulk transmission apparatus in which two B channels are bundled into one for bulk transmission. , The multiplexing unit 4 transmits the transmission data S
D1 to SDn are multiplexed to form a multi-frame configuration, and a frame synchronization pattern from the frame synchronization pattern generation unit 12 is added to generate 128 kbps transmission information. This transmission information is divided into 64 kbps for the B1 and B2 channels. Is transmitted as transmission information of the speed.

In this case, since two B channels are used, each frame constituting a multi-frame is
The signal is divided into two parts corresponding to one channel and the B2 channel and transmitted to the B1 channel and the B2 channel, respectively. B that transmits a frame synchronization pattern at a multi-frame cycle
It switches between channel 1 and channel B2. That is, each frame is divided into two and the time slots TS1, T1
If S2, the frame synchronization pattern of the multi-frame is included in the time slot TS1, and the time slot TS1 is set to B1 for the first multi-frame.
The transmission switching unit 5 operates so as to transmit to the channel and transmit the next time slot TS2 to the B2 channel. For the next multiframe, the time slot TS1 including the frame synchronization pattern of the multiframe is changed to the B2 channel. The transmission switching unit 5 operates to transmit the next time slot TS2 to the B1 channel. Therefore, the frame synchronization pattern is sequentially transmitted to the B1 and B2 channels.

The frame synchronization pattern is extracted from the 64 kbps transmission information received from the ISDN line 13 via the B1 and B2 channels by the frame synchronization pattern extraction unit 6 and transferred to the control processor 10. The control processor 10 determines that the delay time difference between the B1 and B2 channels is zero when the frame synchronization pattern can be received in the multi-frame cycle, and when the frame synchronization pattern is not in the multi-frame cycle, the control processor 10 compares the frame synchronization pattern detected in the B1 channel with the B2 channel. Due to the magnitude relationship between the time with the frame synchronization pattern detected in the channel and the multi-frame period, B
The delay time difference between the 1 and B2 channels can be obtained.

The control processor 10 calculates the calculated B1, B2
Variable delay unit 7 to compensate for the delay time difference between channels
Control. For example, when the B2 channel is delayed with respect to the B1 channel, the B1 channel is delayed according to the delay time difference. As a result, frame synchronization between the B1 and B2 channels can be achieved. Then, the reception switching unit 8 combines the frames of the B1 and B2 channels to restore the 128 kbps transmission information of the multi-frame configuration, and the demultiplexing unit 9 outputs the reception data RD1 to RD1 corresponding to the terminal.
RDn is demultiplexed.

As described above, when transmitting transmission information of a multi-frame structure to which a frame synchronization pattern is added while a plurality of B channels are bundled into one, the frame synchronization pattern is sequentially distributed to each B channel and transmitted. By doing so, it is possible to obtain the delay time difference between the B channels without compromising the transmission efficiency even if the number of B channels is increased, and to compensate for the delay time difference.

FIG. 2 is an explanatory diagram of a multi-frame structure. When B1 and B2 channels of 64 kbps are bundled, 1
28 kbps information can be transmitted. In this case, if one frame is 125 μs and one multi-frame is 2.5 ms, one frame is constituted by 16 bits, and one multi-frame is constituted by 20 frames. A frame synchronization pattern F including a frame synchronization bit and a frame number is added to the multiframe. Further, one frame is divided into two and the time slots TS1, TS2
And

In the first multi-frame MF1, the time slot TS1 is distributed to the B1 channel and the time slot TS2 is distributed to the B2 channel, and transmitted. In the next multi-frame MF2, the time slot TS1 is distributed to the B2 channel.
The time slot TS2 is distributed to the channel and transmitted to the B1 channel. Similarly, the time slots TS1 and TS2 are switched to the B1 and B2 channels in a multiframe cycle and transmitted. As a result, the frame synchronization pattern is distributed and transmitted to the B1 channel in the first multiframe MF1 and to the B2 channel in the next multiframe MF2.

Therefore, in the frame synchronization pattern extraction unit 6 on the receiving side, B is used in the first multi-frame MF1.
A frame synchronization pattern can be extracted from one channel, and in the next multi-frame MF2, a frame synchronization pattern can be extracted from the B2 channel. The control processor 10 determines whether or not the frame synchronization pattern has been detected in a multi-frame cycle based on the time t1 when the frame synchronization pattern is extracted from the B1 channel and the time t2 when the frame synchronization pattern is extracted from the B2 channel.

As described above, the multi-frame period MFT
, The detection cycle is t1-t2 = MFT, and in the next detection cycle, t2-t1 = MFT,
The delay time difference between the B1 and B2 channels is zero. Further, the detection cycle is t1-t2> MFT, and the next detection cycle is t
When 2-t1 <MFT, the delay time of the B2 channel is longer than that of the B1 channel. In this case, the variable delay unit 7 is controlled to set the delay time τ for the B1 channel to [ By giving (t1−t2) −MFT] = τ, the delay time difference can be compensated.

FIG. 3 is a diagram for explaining the operation of the first embodiment of the present invention, wherein a on the transmitting side indicates transmission information of a multi-frame configuration multiplexed by the multiplexing unit 4, and each frame is represented by a time slot. With respect to the multiframe divided into TS1 and TS2, data F1, F2, F3,... Of the time slot TS1 to which the frame synchronization pattern is added and data a1, a2, a3 of the time slot TS2 to which the frame synchronization pattern is not added. ... is shown.

The transmission side b transmits the transmission information of the multi-frame configuration by the transmission switching unit 5 to the time slots TS1 and TS1.
The first multi-frame of the data F1 and a1 indicates that the data F1 of the time slot TS1 is transmitted to the B1 channel, and the data a1 of the time slot TS2 is transmitted to the B2 channel. In the next multiframe, the data F2 of the time slot TS1 is transmitted to the B2 channel, and the data a2 of the time slot TS2 is transmitted to the B1 channel. Similarly,
The frame synchronization pattern is B1, B
The transmission is sequentially switched to two channels.

On the receiving side, c is the data of the B1 and B2 channels received via the line interface unit 3, and d is the variable delay unit 7 in which the delay time difference is compensated, and the reception switching unit 8 restores the multi-frame configuration. Indicates transmission information.
In this case, B2 channel is 2MF for B1 channel.
Assuming that there is a delay time difference of T, when data F3 is received via the B1 channel, data a1 is received via the B2 channel, and as described above, the delay time difference is determined by detecting the frame synchronization pattern. In this case, the variable delay unit 7 is controlled to give a delay time of 2 MFT to the B1 channel. Then, by combining the data into a multi-frame configuration by the reception switching unit 8, the transmission information indicated by d on the receiving side can be restored.

FIG. 4 is an explanatory view of a main part of the second embodiment of the present invention, wherein 24 is a multiplexing unit, 25 is a transmission switching unit, and 26 is a transmission switching unit.
Is a line interface unit, 27 is an ISDN line, 28 is a reception switching unit, 29 is a demultiplexing unit, and a frame synchronization pattern generation unit, a frame synchronization pattern extraction unit, a variable delay unit, a control processor, and the like are not shown.

In this embodiment, B1, B2, B3, B
The figure shows a case in which four channels are bundled into one and bulk transmission is performed. Transmission information of a multi-frame configuration multiplexed by the multiplexing unit 24 and having a frame synchronization pattern added thereto is transmitted by the transmission switching unit 25 to B1, B2, B3, and B4. The signal is distributed to channels and transmitted to the ISDN line 27 via the line interface unit 26.

That is, each frame of the multi-frame configuration is divided into four timeslots TS1, TS2, TS3, T
S4, the frame synchronization pattern is the time slot TS
1, so for the first multiframe,
TS1 → B1, TS2 → B2, TS3 → B3, TS4 →
It is distributed to B1 to B4 channels so as to be B4, and for the next multiframe, TS1 → B2, TS2 → B
B1 to B3 so that 3, TS3 → B4, TS4 → B1
Distribute to 4 channels. Similarly, the time slot TS1 including the frame synchronization pattern can be distributed and transmitted to each B channel.

On the receiving side, the data of the B1 to B4 channels transmitted via the ISDN line 27 is received by the line interface unit 26, and a delay time difference between the B1 to B4 channels is obtained by detecting a frame synchronization pattern.
The delay amount corresponding to the B1 to B4 channels is controlled so as to compensate for the delay time difference, the transmission switching unit 25 restores the multi-frame configuration transmission information by the reverse operation of the transmission switching unit 25, and the demultiplexing unit 29 Demultiplex.

FIG. 5 is a diagram for explaining the operation of the second embodiment of the present invention, wherein a on the transmitting side indicates transmission information of a multi-frame configuration multiplexed by the multiplexing unit 24, and each frame is represented by B1 to B1. Time slot TS corresponding to B4 channel
A multi-frame divided into 1 to TS4, F1,
F2, F3,... Indicate that a frame synchronization pattern is added, as in the case shown in FIG.

The transmission side b distributes the transmission information of the multi-frame configuration to the B1 to B4 channels by the transmission switching unit 25, and transmits the information to the ISDN line 2 from the line interface unit 26.
7 indicates the transmission status, and the time slots TS1 to TS
4 and B1 to B4 channels in the first multiframe, TS1 → B1, TS2 → B2, TS3
As B3, TS4, and B4, data including the frame synchronization pattern is transmitted to the B1 channel, and in the next multiframe, TS1.fwdarw.B2, TS2.fwdarw.B3, TS3.fwdarw.B
4, TS4 → B1, the data including the frame synchronization pattern is transmitted to the B2 channel, and in the next multiframe, TS1 → B3, TS2 → B4, TS3 → B1,
As TS4 → B2, data including the frame synchronization pattern is transmitted to the B3 channel, and in the next multiframe, TS1 → B4, TS2 → B1, TS3 → B2, TS
As 4 → B3, data including the frame synchronization pattern is transmitted to the B4 channel. Therefore, the frame synchronization pattern is periodically distributed and transmitted to each B channel.

On the receiving side, c indicates transmission information of a multi-frame structure received at the line interface unit 26 via the ISDN line 27, and the B2 and B3 channels have a delay time difference of 1 MFT with respect to the B1 and B4 channels. Since the delay time difference of each B channel can be obtained based on the detection time of the received frame synchronization pattern corresponding to the B1 to B4 channels as described above, the variable delay units (not shown) use B1 and B4. 1M for channel
After the FT delay, the reception switching unit 28 sequentially sets B1 to B4
By selecting a channel, transmission information having a multi-frame configuration can be restored as shown by d on the receiving side.

Each of the above-described embodiments shows a case where the time slots to which the frame synchronization pattern of the multi-frame is added are sequentially distributed to each of the B channels. However, the frame of the multi-frame is divided into the number of B channels. It is also possible to adopt a configuration in which the time slots are fixedly distributed and transmitted to the B channels, and only the frame synchronization pattern is sequentially distributed to each B channel in a multi-frame cycle. In this case, for example, the multiplexing unit 4 sequentially switches the position to which the frame synchronization pattern is added from the frame synchronization pattern generation unit 12 so that the transmission switching unit 5
Is that only the transmission information of 128 kbps multiplexed by the multiplexing unit 4 is divided into 64 kbps and transmitted to the B1 and B2 channels, and the frame synchronization pattern is sequentially distributed and transmitted to the B1 and B2 channels in a multi-frame cycle. become.

[0033]

As described above, according to the present invention, the transmission information is formed into a multi-frame structure, and a frame synchronization pattern is added.
The frame synchronization pattern is divided and transmitted to the B channels while being divided into the number of channels, and the frame synchronization pattern is sequentially switched at the multi-frame period and distributed and transmitted to the B channels. On the receiving side, the frame synchronization pattern is sequentially distributed to the B channels at the multi-frame period. , The delay time difference between the B channels is obtained, the delay time corresponding to the B channel is controlled so as to compensate for the delay time difference, the frame synchronization between the B channels is obtained, and the transmission information of the multi-frame configuration is obtained. Since only a frame synchronization pattern of a multi-frame configuration is added, there is no reduction in transmission efficiency as compared with a case where a frame synchronization pattern is transmitted at a frame period for each B channel. Since the pattern is periodically distributed and transmitted to each B channel, the delay time due to the route change during communication Even if the change of, since it is possible to compensate for changes in automatic delay time difference, there is an advantage that can continue stable bulk transmission.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a multi-frame configuration.

FIG. 3 is an operation explanatory diagram of the first embodiment of the present invention.

FIG. 4 is an explanatory view of a main part of a second embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmitting part 2 Receiving part 3 Line interface part 4 Multiplexing part 5 Transmission switching part 6 Frame synchronization pattern extraction part 7 Variable delay part 8 Reception switching part 9 Demultiplexing part 10 Control processor 11 LAPD processing part 12 Frame synchronization pattern generation part 13 ISDN line B1, B2 B channel

Claims (4)

[Claims] 1. A bulk transmission apparatus for transmitting and receiving transmission information by simultaneously using a plurality of B channels, wherein the transmission information has a multi-frame configuration to which a frame synchronization pattern is added, and each frame constituting the multi-frame is A transmitting unit that divides the number of B channels, distributes and transmits the B channels, and sequentially switches the frame synchronization pattern every cycle of the multiframe to distribute and transmit the B channels; and a frame that extracts the frame synchronization pattern. A pattern extracting unit, a variable delay unit for controlling a delay time corresponding to the plurality of B channels, and receiving information corresponding to each B channel in which a delay time difference between each B channel is compensated by the variable delay unit, and A reception unit including a reception switching unit for restoring transmission information of a frame configuration, and a frame synchronization pattern extraction unit A bulk transmission apparatus comprising: a control processor that obtains a delay time difference between B channels based on the issued frame synchronization pattern and controls the variable delay unit to compensate for the delay time difference. 2. The transmission section includes: a frame synchronization pattern generation section for generating a frame synchronization pattern; and a transmission frame from a plurality of terminals, multiplexed to form a multi-frame configuration, and a frame synchronization pattern from the frame synchronization pattern generation section. A multiplexing unit that divides each frame of the multi-frame multiplexed by the multiplexing unit into the number of B channels, distributes and transmits the divided frames to each B channel, and sets the frame synchronization pattern to the cycle of the multi-frame. 2. The bulk transmission apparatus according to claim 1, further comprising: a transmission switching unit that sequentially switches each time and distributes and transmits the B channel. 3. The reception unit according to claim 1, wherein the reception unit includes a demultiplexing unit that demultiplexes transmission information of a multi-frame configuration restored by the reception switching unit to a plurality of terminals and transmits the demultiplexed transmission information. Bulk transmission equipment. 4. In a bulk transmission method for transmitting and receiving transmission information by simultaneously using a plurality of B channels, a transmission section adds a frame synchronization pattern to the transmission information as a multi-frame configuration to form the multi-frame. Each frame to be divided into the number of B channels, distributed and transmitted to the B channels, the frame synchronization pattern is sequentially switched in the multi-frame cycle, distributed and transmitted to the B channels, and the receiving unit is transmitted via the plurality of B channels. Receive information at
By extracting the frame synchronization pattern sequentially distributed to the B channels in a multi-frame cycle, calculating a delay time difference between the B channels, and controlling a delay time corresponding to the B channel so as to compensate for the delay time difference, A bulk transmission method comprising a step of restoring transmission information having a multi-frame structure.