RU19981U1 - DIGITAL TRANSMISSION SYSTEM FOR TWO CABLE PAIRS WITH ANALOGUE PROCESSING AND SIGNAL CORRECTION - Google Patents

Description

1. Name of utility model

Digital transmission system for two cable pairs with analog processing and signal correction.

Field of technology: Telecommunications. Data transmission systems. IPC heading index: H04J.

2. The level of technology

Systems of high-speed digital data transmission on a copper-cable line, made in accordance with the technology of a digital subscriber line (Digital Subscriber Loop, abbreviated DSL), meeting the standards of the International Telecommunication Union, Telecommunication Standardization Sector (Telecommunications Standartization Sector, abbreviated ITUT), in particular, the G.703 and O.704 standards, as well as the latest G.921.2 (G.shdsl) standard.

The closest analogue is HDSL (High-bit-rate DSL) equipment developed by Paradyne Corporation based on CAP technology with a data transfer rate of up to 2 Mbps (for example, Hotwire 798X TDM HDSL Endpoints. See website: http : //www.paradyne.com/. and the use of CAP technology in HDSL systems is described in Garrick Case, Kevin Mullaney. Performance Technologies to use Paradyne HDSL system. AT&T News Release, JUNE 10.1992)

3. The essence of the utility model

Utility Model Purpose

The purpose of the claimed utility model is to increase the transmission range of digital information on copper-cable lines by increasing noise immunity and improving electromagnetic compatibility with digital and analog transmission systems.

Task and characteristics of utility model

The inventive utility model is a specially selected original combination of technical solutions that allows to realize the goal stated above by solving the following problem: ensuring the transmission of El digital data stream (ITU-T G.703 / G.704) over copper-cable lines with a core diameter of up to 1.2 mm and with a regeneration section length of up to 22 km in one cable with various analog and digital transmission systems.

The original refinement of technology embedded in the utility model

There are many types of DSL-type digital data transmission systems (see, for example, the book by OM Denisiev, DG Miroshnikov. Communications for the “last mile. Third edition. M., Eco-Trends - NTC NATEKS, 2000. 137 s). The most famous of those suitable for solving this problem are HDSL (high-speed DSL), MSDSL (Multi Speed DSL - multi-speed DSL), G.shdsl (DSL using TC-RAM modulation according to the G.921 2 standard).

xDSL standard technologies focused on constructive European solutions where the core diameter is 0.4 mm, and the transmission range at a speed of 2 Mbps and core diameter 1.2 mm does not exceed, as a rule, 8 km.

For HDSL systems using 2B1Q encoding, at a speed of 2 Mbps, the maximum that can be obtained on 1.2 mm conductors is 13 ... 14 km. For HDSL equipment using more advanced ATS modulation, the usual value of the data transmission range at a transmission speed of 2 Mbps (on 1.2 mm cores) is 15 ... 17 km.

MSDSL with CAP modulation transmits a variable-speed stream (from 128 to 2048 kbit / s) in one pair (1.2 mm diameter) over a distance of 13-14 km at a speed of 2 Mbps.

G.shdsl is specifically designed to counteract the electromagnetic interference of different transmission systems when using different pairs in one cable, however, even in the case of using two pairs without special modifications, it is not possible to achieve sufficient distances in the difficult environment of using single cable cores with different systems. The use of solutions based on the TS-RAM linear code allows for reliable operation of one pair at speeds from 192 to 2320 Kbps with a subscriber line length of 2.7 / 6.7 km (with a cross section of 0.5 mm and maximum / minimum speed) .

The most important issue is compatibility with analog and digital systems. Any of the aforementioned xDSL systems, including those using CAP and TS-RAM, will cause interference with analog and digital equipment operating on adjacent pairs. The magnitude of these interference depends on the length of the regeneration sections, the type of cable and the selection of pairs. It is not possible to effectively suppress the influence of interference using standard xDSL solutions.

In the claimed utility model, the use of both HDSL and MSDSL, and G.shdsl technology (and possibly other xDSL systems) is proposed to be supplemented by the use of a special block of analog signal processing and correction (AOKS), which allows the transmission of the E1 stream over two copper-cable pairs so that for each of the pairs information is transmitted in the forward and reverse directions with different speeds (asymmetry), and a total of two pairs implements a symmetric data transmission system (see Figure 1). At the same time, in the AOKS block, it is possible to adjust the optimal transmission asymmetry depth in each pair in real conditions and in a specific noise environment. Equipping the modems of the xDSL-type digital data transmission system with an AOKS unit significantly increases the noise immunity of the systems while simultaneously suppressing the influence of this system on parallel and possibly analogue and digital systems, which makes it possible to increase the range to acceptable values.

As experience in the implementation of such devices shows, they allow E1 stream (2048 kbit / s) to be transmitted reliably over 22 km in cables with a core diameter of 1.2 mm with parallel-acting analog systems with frequency division of channels of type K-60 and digital systems of type IDSL and systems with PCM modulation, which is important for solving the digitalization problems of both trunk lines and the subscriber network.

Figure 1. Schematic diagram of the inclusion of AOKS in xDSL systems

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4. List of figures

5. Information confirming the possibility of useful

The inventive utility model (xDSL with AOKS) is designed for use in manufactured by NTC NATEKS xDSL modems of the FlexGain ™ series (FlexDSL SHDSL, FlexDSL MDSL, MEGATRANS ™). In the MEGATRANS ™ system (DSL based on CAPmodulation), the AOKS unit has already proved its effectiveness.

Thanks to the AOKS unit, the MEGATRANS ™ system has found wide application in Russia and the CIS countries as a digitalization system for trunk lines and long-distance subscriber networks using free pairs in cables of analog communication systems based on K-60 equipment. This equipment, for example, in the performance of MEGATRANS-2 L, is used to organize linear paths with a large number of remotely powered regenerators - from 2 to 6 on each side. A line length of up to 240 km is achieved without intermediate power supply points (cable with a core diameter of 1.2 mm). The certificate of the Ministry of Communications of Russia (No. OS / 1-SP-599) has been issued for the MEGATRANS system for use in all sections of communication networks in Russia.

By including the AOKS unit in modems with linear TS-RAM coding (for example, in FlexDSL SHDSL) by analogy with the MEGATRANS ™ system, you can be sure to achieve an even greater transmission range under the same conditions. By introducing AOKS into 2B1p modulation modems (for example, in FlexDSL MDSL), you can significantly increase the transmission range, while maintaining the low cost advantage for such modems. Thus, modifying any standard xDSL modems using the claimed utility model, as practice confirms, the transmission range increases due to an increase in the noise immunity of the device and an increase in electromagnetic compatibility with other information transfer systems.

models

Claims (1)

A system for digital transmission of streams with speeds of n • 64 kbit / s (where n = 1,2.. 32) over two copper-cable lines, made in accordance with digital subscriber line technology, characterized in that it includes an analog processing unit and signal correction, which allows for the transmission of a stream over two copper-cable pairs so that information is transmitted for each pair in the forward and backward directions at different speeds, but a total of two pairs implements a symmetric data transmission system, while it is possible It is possible to adjust the depth of transmission asymmetry separately for each of the two pairs of wires and adjust the matching parameters with the line, which ensures data transmission with a total data transfer rate of up to 2048 kbit / s with a transmission range of up to 22 km for each of the regeneration sections of the line, effectively solving the task of increasing the range by increasing the noise immunity of digital transmission systems while suppressing the influence of these systems on parallel analog and digital systems operating on the same cable.