KR100304010B1 - Dedicated line compression concentrator and transmission system using it - Google Patents

Abstract

The present invention compresses and restores transmission data in a transmission system that must guarantee real-time data transmission speed, such as data transmission between a mobile phone base station and an exchange, and distributes and demultiplexes in fewer dedicated lines than the original dedicated line. The present invention relates to a dedicated line compression concentrating device and a transmission system using the same, wherein the dedicated line compression concentrating device of the present invention provides a real-time through a plurality of dedicated lines. A transmission system for transmitting and receiving voice data, comprising: data compression means for compressing voice and additional data of a plurality of channels transmitted from a transmitting end, respectively, and transmitting them through a dedicated line having a smaller capacity than a dedicated leased line during uncompression; And data recovery means for restoring the compressed voice and the additional data received through the dedicated line to the voice and the additional data of the corresponding channel before compression and outputting the compressed voice and the additional data to the receiving end.

Description

Dedicated line compression concentrator and transmission system using same

The present invention relates to a dedicated line compression concentrator and a transmission system using the same. More particularly, the present invention relates to a dedicated line compression concentrator for compressing and restoring data and performing distribution and demultiplexing on fewer dedicated lines than the original dedicated line. And a transmission system using the same.

At present, as the information industry develops, high-speed leased lines (128K ~) are connected to companies and branches distributed nationwide by a specific institution or a specific company, in addition to general communication lines (telephone lines) that can be shared and used freely by all users. 2M bps) continues to increase. The monthly rent for these leased lines is relatively high compared to regular phone lines, and is widely used for data transmission between businesses and devices with a specific purpose.

As such, when a dedicated line is used for communication between devices, a dedicated line having an appropriate communication speed should be selected. In general, the leased line is selected according to the average transmission speed of data within an allowable delay time. However, in the transmission system for data transmission between the mobile telephone base station and the mobile switching center, which must guarantee the data transmission rate in real time, there is no alternative except the method of selecting a dedicated line that can accommodate the maximum data transmission speed.

Accordingly, the present invention was created to solve the above problems, and compresses and restores the transmission data in a transmission system that must guarantee real-time data transmission speed such as data transmission between the mobile phone base station and the switching center. The purpose of the present invention is to provide a leased line compression concentrator and a transmission system using the same to reduce the number of leased lines or to use a low speed leased line by performing distribution and demultiplexing on fewer leased lines. have.

1 shows an example of a transmission system to which a dedicated line compression concentrator according to the present invention is applied,

Figure 2 shows another example of a transmission system to which the dedicated line compression concentrator according to the present invention is applied,

3 is a block diagram of a dedicated circuit compression concentrator according to the present invention;

FIG. 4 is a diagram illustrating the operation of the dedicated line compression concentrator 100 when data is transmitted from the BTS 10 to the dedicated line compression concentrator 200.

FIG. 5 is a view illustrating the operation of the dedicated line compression concentrator 100 when data is transmitted from the dedicated line compression concentrator 100 to the BTS 10.

6 and 7 illustrate an operation in which data is transmitted from the BSC 10 to the dedicated line compression concentrator 100 and a case in which data is transmitted from the dedicated line compression concentrator 100 to the BSC 10, respectively. It is shown to.

※ Explanation of code for main part of drawing

1: mobile phone base station 2: mobile phone switching center

10: base station transceiver system (BTS) 20: switching center system controller (BSC)

100,200: dedicated line compression concentrator 110: system controller

115: clock generator 120,165: E1 line interface

125,160: E1 framer 130,155: HDLC adapter

135: encoder 140: decoder

145: router 150: demux

Dedicated line compression aggregation apparatus according to the present invention for achieving the above object, in a transmission system for transmitting and receiving voice data in real time through a plurality of dedicated lines, the voice and additional data of a plurality of channels transmitted from a transmitting end Data compression means for compressing each data and transmitting the data over a dedicated line having a smaller capacity than a dedicated leased line at the time of uncompression; And data recovery means for restoring the compressed voice and the additional data received through the dedicated line to the voice and the additional data of the corresponding channel before compression and outputting them to the receiver.

In addition, the transmission system using the dedicated line compression aggregation method according to the present invention, in the transmission system for performing data transmission in real time between one mobile switching center and one or more base stations, N (N) Compresses transmission data transmitted through a dedicated line of an integer greater than or equal to 2, distributes and allocates the data to a dedicated line of less than N, and restores the compressed transmission data transmitted through a dedicated line of less than N. First compression aggregation means for transmitting to the mobile telephone switching center through the N dedicated lines; And compressing transmission data transmitted through the N dedicated lines by the one or more base stations, allocating the distributed data to fewer dedicated lines and outputting the same to the first compression converging means, and transmitting the data to the first compression converging means. And second compression concentrating means for restoring compressed transmission data and transmitting the same to the one or more base stations through the N dedicated lines.

Hereinafter, a preferred embodiment of a dedicated line compression concentrating device and a transmission system using the same according to the present invention will be described in detail with reference to the accompanying drawings.

A base station transceiver system (BTS) in a mobile phone base station and a base station system controller (BSC) in an exchange station are directly connected through a dedicated line. As a result, three to four leased lines are used in areas with high call volume, such as downtown areas, and one to two leased lines in areas with relatively low call volumes.

In the present invention, between the BTS 10 of the mobile telephone base station 1 and the BSC 20 of the switching center 2, a dedicated line compression condenser 100,200 is provided, and between the dedicated line compression condenser 100,200. The private line is to be installed at In an area using four dedicated lines between the BTS 10 and the BSC 20, the dedicated line compression concentrator 100,200 of the present invention, as shown in FIG. 1, uses three or less dedicated lines. Can be reduced. In addition, in the area where two dedicated lines are used between the BTS 10A or 10B and the BSC 20, as shown in FIG. 2, the four dedicated lines of the BSC 20 of the switching center 2 are shown in the present invention. A dedicated line between the dedicated line compression concentrators 100 and 200 by connecting to the BTSs 10A and 10B of adjacent base stations 1A and 1B using two dedicated lines through the dedicated line compression concentrators 200 and 100 Can be reduced to 3 or less. Here, the dedicated line compression condenser 100 may be provided on either of the base stations 1A and 1B.

In the present invention, a dedicated line lower than the maximum transmission rate may be used without reducing the number of dedicated lines between the dedicated line compression concentrators 100 and 200.

Next, a detailed configuration and operation of an embodiment of the dedicated line compression concentrator 100 and 200 according to the present invention shown in FIGS. 1 and 2 will be described with reference to FIGS. 3 to 7. This embodiment is applied to the E1 system, a European digital transmission system formed by the European Telegraph Commission (CEPT).

Dedicated line compression concentrator 100,200 according to the present invention, as shown in Figure 3, the system controller 110, clock generator 115, E1 line interface 120, E1 framer 125, HDLC adapter ( 130), code / decoder (135,140), router / demultiplexer (145,150), high-level data link control (HDLC) adapter 155, E1 framer 160, E1 line interface 165 It is configured to include.

The system controller 110 stores or changes operation information necessary for the operation of the entire system, performs initialization of the entire hardware, monitors the state of the system, and outputs an alarm in the event of an abnormal state of the system. The controller 115 recovers the received clock from the input signal received at the E1 line interface and supplies the received clock to the E1 framer, and generates and transmits a transmit clock signal to the E1 framer and the E1 line interface.

The other components 120 to 165 receive data at the E1 line interface 120 and transmit data at the E1 line interface 165, and receive data at the E1 line interface 165 and E1. The functions of transmitting data through the line interface 120 are different from each other, and the above two cases will be described with reference to FIGS. 4 and 5.

First, a case in which data is received at the E1 line interface 120 and data is transmitted at the E1 line interface 165 will be described with reference to FIG. 4 when the data is transmitted from the BTS to the compression concentrator 200. .

When the E1 signal is input to the compression concentrator 100 from the BTS, which is an E1 transmitter, the E1 line interface 120 extracts a clock from the input E1 signal and A / D converts the E1 signal to digital digital pulse modulation (PCM). Outputs the E1 signal. At this time, the clock generator 115 generates a reference clock in synchronization with the extracted clock.

The E1 framer 125 restores the A / D-converted PCM E1 signal to the reference clock from the clock generator 115 to the E1 synchronization signal and TLC level high-level data link control (HDLC) data. The HDLC adapter 130 checks a flag for the HDLC data, performs error correction using an error correction code, and outputs a data packet in a frame form. Here, the transmission data frame of the base station and the switching center is composed of additional data such as header data and voice data. The voice data is variable from 1Kbps to 8Kbps or fixed at 9.6Kbps.

The encoder 135 compressively encodes a data frame of each line output from the HDLC adapter 130. Here, the data frame should be compressed in real time within the maximum allowable delay time, and the compression rate is preferably at least 50% or more. Such compression coding preferably uses reversible compression, which is lossless compression due to the characteristics of a communication system. In the present invention, an encoder and a decoder are constructed by using the "Lempel-Ziv" method which can optimize a processing speed and a data compression rate by registering in a codebook and transmitting only a corresponding code to a transmission data sequence with high frequency.

The distributor 145 distributes and allocates the compressed data encoded by the encoder 135 to the line to actually transmit. Here, if one line can accommodate 80 to 100 call channels, if three lines are operated in the BTS and the BSC, approximately 240 to 300 call channels are compressed by the encoder 135 in units of frame packets, thereby distributing the divider 145. The divider 145 is allocated to the transmission line in units of input frame packets and adds and outputs line allocation information of the frame packet.

The HDLC adapter 155 adds a flag and an error correction code to the frame packet data input from the distributor 145 and converts the HDLC data into HDLC data, and the E1 framer 160 converts the input HDLC data into a clock generator. The E1 line interface 165 converts the analog E1 frame data obtained by D / A conversion of the E1 frame data and the clock for transmitting the E1 data onto a dedicated line in synchronization with the transmission clock from 115). Output Accordingly, the E1 transmission data output from the E1 line interface 165 is input to the E1 interface 165 of the compression concentrator 200 as shown in FIG. 7, and performed by the compression concentrator 200. The process is the same as the operation of the compression concentrator 100 described later with reference to FIG.

Next, an example of transmitting data from the compression concentrator 200 to the BTS in the case of receiving data at the E1 line interface 165 and transmitting data at the E1 line interface 120 will be described with reference to FIG. 5. .

When the compressed E1 signal is input to the compression concentrator 100 as in FIG. 4 in the compression concentrator 200 that is the E1 transmitter, the E1 line interface 165 extracts a clock from the input E1 signal and E1. A / D conversion of signal to output digital PCM (Pulse Code Modulation) E1 signal. At this time, the clock generator 115 generates a reference clock in synchronization with the extracted clock.

The E1 framer 160 restores the A / D-converted PCM E1 signal to the reference clock from the clock generator 115 to the E1 synchronization signal and TLC level high-level Data Link Control (HDLC) data. The HDLC adapter 155 checks a flag for the HDLC data and performs error correction using an error correction code to output a data packet in a frame form.

The demultiplexer 150 separates and outputs the original line so that the order of the frames is not changed using the line allocation information of the input data packet, and the decoder 135 is a frame form separated from the demultiplexer 150. Data packets are decrypted using the "Lempel-Ziv" decoding scheme.

The HDLC adapter 130 adds a flag and an error correction code to the recovered frame packet data input from the decoder 140 to convert the HDLC data, and the E1 framer 125 clocks the input HDLC data. In synchronization with the transmission clock from the generator 115, the E1 frame data is converted and outputted, and the E1 interface 120 converts the E1 frame data, the analog E1 frame data obtained by D / A conversion, and the clock for E1 data transmission. Will print Accordingly, the E1 transmission data output from the E1 interface 120 is transmitted to the BTS.

As described above, in the dedicated line compression concentrating device according to the present invention, by compressing the transmission data at the transmitting end and restoring the compressed data at the receiving end, the transmission speed of the dedicated line is maintained but reduced by the bandwidth reduced by compression. It is possible to reduce the number of lines used to 3: 2 or 2: 1.

In addition, since the present invention compresses and transmits transmission data, the number of leased lines is maintained, but a dedicated communication between devices is possible even if a leased line is lower than the maximum transmission speed of the transmission data.

Meanwhile, as shown in FIG. 6, the compression concentrator 200 operates in the same manner as the compression concentrator 100 described with reference to FIG. 4 when transmitting data from the BSC to the compression concentrator 100, as shown in FIG. 7. As described above, when data is transmitted from the compression concentrator 100 to the BSC, it operates in the same manner as the compression concentrator 100 described with reference to FIG. 5, and thus description thereof will be omitted.

On the other hand, the present invention is not limited to the above specific embodiments, it can be carried out by variously modified and modified within the scope not departing from the gist of the present invention. For example, in the above specific embodiment, the present invention has been described as an example where the present invention is applied between a base station transmission / reception system (BTS) and a switching center system control apparatus (BSC) in a switching center. It is also applicable to other transmission systems that perform data transmission.

According to the present invention made as described above, by using the compression and recovery apparatus at the transmitting and receiving end, the transmission line of the dedicated line is maintained, but the number of lines used can be reduced by the band reduced by compression, or a dedicated line lower than the maximum transmission rate can be used. have. Accordingly, when the dedicated line compression aggregation apparatus according to the present invention is installed between the base station transceiver system (BTS) in the mobile telephone base station and the switching center system control device (BSC) in the switching center, the number of leased lines is reduced or low transmission speed is achieved. Since a dedicated line can be used, the installation cost of the dedicated line can be significantly reduced.

Claims (10)

In a transmission system for transmitting and receiving voice data in real time through a plurality of dedicated lines, First data extracting means for extracting a frame data packet from a plurality of channels of transmission data transmitted from a transmitting end, an incubation means for compressing and encoding the extracted frame data packet, and the compressed and encoded frame packet to a corresponding dedicated line. Circuit allocation means for allocating and allocating, and first data output means for converting the compressed coded frame data packet to which the dedicated line is allocated into transmission data and outputting the transmission data. A data compression device for compressing each of the data and transmitting the compressed data over a dedicated line having a smaller capacity than a dedicated dedicated line at the time of uncompression; And Second data extracting means for extracting a frame data packet from transmission data received through the dedicated line, data separating means for separating the extracted frame data packet for each line of the dedicated line, and the separated frame data packet. And a second data output means for converting the decoded frame data packet for each dedicated line into transmission data and outputting the decoded voice data and the additional data received through the dedicated line. And a data recovery device for restoring the voice and additional data of the corresponding channel before and outputting the same to the receiver. The method of claim 1, The dedicated line compression condensing device, characterized in that the number of the small capacity dedicated lines is smaller than the number of dedicated lines used in the non-compression. The method of claim 1, The dedicated line compression concentrating device, wherein the small capacity dedicated line has a transmission speed lower than that of the dedicated line at the time of uncompression. The method of claim 1, The first data extraction means, Data separating means for separating the synchronization signal and the frame data sequence by using a clock included in the input transmission data; And And a frame packet output means for outputting a frame data packet after performing flag inspection and error correction of the frame data sequence. The method of claim 1, And said encoding means performs reversible compression coding using the Lempel-Ziv method. The method of claim 1, The first data output means, Code adding means for adding a flag and an error correction code to the frame packet data input from the line assignment means; And And a conversion output means for converting output data of the code adding means into transmission data in synchronization with a transmission clock. The method of claim 1, The second data extracting means, Data separation means for separating the synchronization signal and the frame data sequence by using a clock included in the input transmission data; And And a frame packet output means for outputting a frame data packet after performing flag inspection and error correction of the frame data sequence. The method of claim 1, And the decoding means performs reversible compression decoding using the Lempel-Ziv method. The method of claim 1, The second data output means, Code adding means for adding a flag and an error correction code to the decoded frame packet data; And And a conversion output means for converting the output data of the code adding means into transmission data in synchronization with a transmission clock. A transmission system for performing data transmission in real time between one mobile switching center and one or more base stations, The mobile telephone switching center compresses and transmits the transmission data transmitted through N dedicated lines (N is an integer of 2 or more), distributes them to fewer dedicated lines than N, and outputs them. First compression concentrating means for restoring the compressed transmission data transmitted through the first transmission line and transmitting the recovered transmission data to the mobile switching center through the N dedicated lines; And Compress the transmission data transmitted through the N dedicated lines in the at least one base station, distribute the allocation data to fewer dedicated lines than N and output the same to the first compression converging means, and the compression transmitted from the first compression converging means. And a second compression aggregation means for restoring the transmitted data and transmitting the received data to the at least one base station through the N dedicated lines.