RU2273958C2 - Method and device for determining data transfer resources available for network connections - Google Patents

Abstract

FIELD: systems for determining amount of available data transfer resources.

SUBSTANCE: for determining amount of resources for data transfer and/or speeds of bits transfer for network connection, with known physical length of cable, measurement of energy spectrum is performed depending on transmission frequency for different types of modems by means of power measuring device, weakening is determined for different physical lengths and thicknesses of cable wires, depending on parameter of cross interference, number of sources and correcting coefficient on bass of energetic spectrum noise level is determined, while by means of gauss transformer module on basis of efficient signal levels and appropriate noise levels amount of data transfer resource is determined for different data transfer modulations and/or modulating codes for predetermined bit transfer speed, then available data transfer resource amount is corrected by means of correcting coefficient, including average deviation of stored amounts of data transfer resources from efficiency amounts of resources of data transfer, and on basis of stored efficient recourses for data transfer with utilization of known physical length of determined network connection available data transfer resource for appropriate network connection is determined.

EFFECT: possible determining of amount of available data transfer resources for certain connection.

3 cl, 4 dwg

Description

The present invention relates to a method and system for determining the reserves of data transmission resources for network connections, and in the specified method and system, the physical length of the network connection between the transmitter and receiver is known. In particular, the method relates to networks based on cable connections with copper conductors.

Traditional telephone services, such as POTS (regular telephone network), traditionally connect residential premises and small businesses with the distribution station of the telephone network provider via copper wires, which are twisted together and are called a twisted pair. They were originally intended to provide transmission of analog signals, in particular, tonal and voice transmissions. However, these requirements later with the advent of Internet technology and the associated transfer of data streams have changed and are rapidly changing at present due to the need to provide real-time work and using multimedia applications both at home and at work.

Data networks, such as the intranet and the Internet, rely heavily on so-called shared media, for example, packet-oriented local area network (LAN) or wide area network (WAN) technologies, as for broadband network backbones between switches and gateways, and local network connections with bandwidths of smaller widths. It is common to use packet management systems such as bridges (LAN interface devices) or routers to provide a local area network connection to the Internet. An Internet router should be able to transmit packets based on a wide variety of protocols, such as IP (Internet Protocol), IPX (Internet Packet Exchange), DECNET (DEC Network Architecture Protocol), AppleTALK (Apple Network Protocol Stack), OSI ( open systems interconnection), SNA (IBM system architecture), etc. The integration of such networks in order to route packets globally is a problem for both service providers (providers) and manufacturers of the necessary hardware.

The most common local area network (LAN) systems work relatively well at data rates of the order of 100 Mbps. At transmission speeds above 100 Mbps, in most modern networks, the resources of network administrators, such as packet switches, are insufficient to control bandwidth allocation (assignment) and user access. Of course, the usefulness of packet-oriented networks for the transmission of digital information, especially with short-term impulse transmissions, has long been recognized. Such networks usually have a point-to-point structure (point-to-point connection structure), with the packet going from one single sender to one single recipient, with each packet including at least the destination address (recipient address). A typical example of this is the well-known IP header of an IP data packet. The network responds to the data packet by sending the packet to the address of the corresponding header. Packet-oriented networks can also serve to transmit data types that require a continuous stream of data, such as high-quality tonal and audio transmissions or video transmissions. The commercial use of networks makes it particularly desirable that packet-oriented transmission is simultaneously possible to multiple destinations. An example of this is the so-called packet broadcast for transmitting video and audio data. In this way, pay-TV can be realized, that is, paid broadcasting of video data transmissions over the network.

However, in next-generation applications, such as real-time applications and multimedia applications with their even higher requirements, for the bandwidth that must be guaranteed at every moment of time, packet-oriented networks run into limitations. So, the next generation of networks should be able to dynamically change the configuration of networks so that it can constantly guarantee the user a predefined bandwidth for the required or agreed quality parameters (QoS - quality of service). Such quality parameters include, for example, access guarantee, access performance, error tolerance, data transfer reliability, etc. between all possible end systems. New technologies, such as asynchronous transfer mode (ATM), should at the same time help to create the necessary prerequisites for both the private intranet network and the public Internet access network in the long-term development of networks. These technologies promise a more economical and scalable solution for such high-quality QoS-guaranteed connections.

Changes in future systems will affect, in particular, the flow of data. The data stream is currently based on a server-client model, that is, data from multiple clients is transmitted to one or more or from one or more network servers. Clients usually do not create a direct data connection, but communicate with each other through network servers. This type of connection will be important in the future. Despite this, it should be expected that the amount of data transmitted between peers will increase significantly in the future. Since the ultimate goal of networks to satisfy the requirements will be a truly decentralized structure in which all systems will be able to act as a server and as a client, the data flow over connections between peer nodes will increase. Thus, the network will have to create more direct connections to various peer-to-peer nodes, and, for example, desktop computers will make direct connections via the Internet backbones.

Thus, it is clear that for promising applications, it is becoming increasingly important to ensure that the user can predefined QoS parameters and large bandwidths.

For data transmission to the end user, in particular, a traditional public switched telephone network (PTSN) and / or mobile landline public access network (PLMN) are used, which were originally designed to transmit only tonal signals, and not to transmit such volumes of digital data. Moreover, in determining the QoS parameters that the provider or telephone service provider can guarantee the user, the so-called “last mile” plays a decisive role. This term defines the distance between the last distribution station of the public switched telephone network and the end user. This last mile in some cases is formed by high-performance fiberglass cables, but most often it is based on ordinary cables with copper conductors, such as a cable with a core diameter of 0.4 or 0.6 mm. In addition, cables are not always laid underground in a protected conduit, and there are also sections of their laying above the terrain on telephone poles, etc. The consequence of this is additional interference.

An additional problem in determining the maximum QoS parameter is the so-called crosstalk issue. This problem occurs when the signal is modulated in the area, for example, from the end user to the distribution station of the telephone service provider and vice versa. For modulating digital signals in the prior art, for example, xDSL (digital subscriber line) technologies such as ADSL (asymmetric digital subscriber line), SDSL (symmetric digital subscriber line), HDSL (high speed digital subscriber line), or VDSL (ultra high speed digital subscriber line) are known line). Mentioned crosstalk is a physical phenomenon that occurs when modulating data transmitted over a copper cable. Nearby conductors inside one copper cable receive due to electromagnetic interaction the paired components of the signals that are generated by the modem. This leads to the fact that xDSL modems transmitting along adjacent cores of a cable create mutual interference. Distinguish between near-end crosstalk (NEXT), which refers to the unintentional input of transmitter signals at one end into signals at the receiver at the same end, and far-end crosstalk (FEXT), which refers to unintentional input of signals during transmission to the receiver at the other end moreover, the signals during transmission are introduced into the signals of neighboring copper pairs and appear as noise in the receiver.

Although there are currently many studies of xDSL crosstalk, such as Spectral management on metallic access networks; Part 1: Definitions and signal library ”, ETSI (European Telecommunications Standards Institute), TR 101 830, September 2000, due to the complexity of the phenomenon of crosstalk and other noise parameters, there are currently few practical and technically simple to use, as well as cost-effective aids to determine the QoS parameters for a specific end user on the network. In the prior art, remote sensing systems are proposed by various companies, for example, Acterna (WG SLK-11/12/22, Eningen uA, Germany), Trend Communications (LT2000 Line Tester, www.trendcomms.com, Buckinghamshire, Great Britain), etc. .d. At the same time, the maximum data transfer rates at the last mile are determined by direct measurements using remote measurement systems: a digital signal processor is installed on each local distribution station of the telephone network provider (for example, several thousand in Switzerland). By means of a digital signal processor, the so-called "asymmetric measurement" is carried out, since the user does not need to install any devices on the other side of the last mile. But fundamentally, measurements based on the principle of "symmetric measurements" are also possible. But it is necessary to install measuring instruments at both ends of the line.

The disadvantages of this prior art include, among other things, the high costs associated with the necessary installation of remote measurement systems in each local distribution station, inaccurately known uncertainty or unknown measurement error, since measurements are carried out only on one side (asymmetric measurements), and to determine errors would require two-way measurements. Bilateral measurement would be impractical due to labor, time and financial costs. In addition, in the prior art, algorithms with a hardware or software implementation for calculating or predicting the maximum possible bit rates of a network connection are not known. The installation of remote measurement systems on a smaller number of central distribution stations instead of local terminal distribution stations shows that the measurements are characterized by such a high degree of uncertainty that they are not suitable for determining the maximum possible data transfer rate for a particular line to the end user.

The objective of the invention is the creation of a new method, system and computer software product for determining the reserves of data transmission resources for network connections that do not have the above-described disadvantages. In particular, such resource reserves and / or maximum bit rates for a specific user or network connection can be determined quickly and flexibly without requiring disproportionate technical, labor and financial costs.

In accordance with the invention, this problem is solved in particular due to the features of the independent claims. Preferred embodiments follow from the dependent claims and the description.

In particular, these results are achieved in the invention in that for determining the reserves of data transmission resources for network connections, the physical length of the network connection being determined between the transmitter and receiver being known, the energy spectrum is measured depending on the transmission frequency for possible types of modems using a power measuring device and transferred to the data carrier of the computing unit, using the computing unit, the attenuation is determined for various physical lengths and thicknesses of the vein the whiteness of the network connection, and the effective signal levels in the receiver, based on attenuation, as well as the energy spectrum, correlated with the corresponding physical lengths and thicknesses of the cable cores (i.e. cable cores diameters), are stored in the first list on the data carrier of the computing unit, in the second list the noise level associated with the physical lengths and thicknesses of the cores of the network connection cable is stored on the data carrier of the computing device, while the noise level is determined by the computing unit and depending, at least on the crosstalk parameters and the number of interference sources based on the energy spectrum, the computing unit by means of a Gaussian transform module based on the effective signal levels from the first list and the corresponding noise levels from the second list for various modulations of data transmission and / or modulating codes determines the reserves of data transmission resources for a predetermined bit rate and in relation to the corresponding physical lengths and thicknesses of the cores I stores the network connection on the data carrier of the computing unit, the computing unit determines the effective reserves of data transmission resources by at least one or more correction factors based on the stored reserves of data transmission resources and, in relation to the corresponding physical lengths and thicknesses of the core wires of the network connection, saves on the data carrier of the computing unit, and the correction factor includes the average deviation of the stored resource reserves transferring data from the effective reserves of the data transmission resources and / or the coefficient of the correction block to correct the settings of the correction block, and the computing unit based on the stored effective reserves of the data transmission resources using the known physical length of the determined network connection between the transmitter and the receiver determines the reserve of data transmission resources for the corresponding network connection. The advantage of the invention, in particular, is that the method and system for the first time provide a simple and quick determination of the reserves of data transmission resources, without requiring large technical, labor and time costs. In particular, it is possible to correct the uncertainties due to the mentioned correction without requiring, as in the known remote measurement systems for measuring the reserves of data transmission resources and / or bit rates, the adjustment in each local distribution station of a different, definitely unknown uncertainty or unknown error, which, due to one-sided measurements, is difficult to evaluate, since two-sided measurements would be necessary to determine the error. As described above, the costs remain small compared with the prior art. This is true for both measuring and installing the necessary devices.

In one embodiment, the energy spectrum is measured depending on the transmission frequency for the types of ADSL, and / or SDSL, and / or HDSL, and / or VDSL modems. Possible types of SDSL modems may include at least the type of G.991.2 modem, and / or types of ADSL modems, at least the type of G.992.2 modem. Using the Gaussian transform module, the reserves of data transmission resources can be determined, at least for data transmission modulations of the form 2B1Q (2 binary, 1 quaternary), and / or CAP (amplitude / phase modulation without a carrier), and / or DMT (digital multitonal) , and / or PAM (pulse amplitude modulation). Also, through the Gaussian transform module, the reserves of data transmission resources can be determined, at least for coding using trellis code modulation. This embodiment has, among other things, the advantage that, for the types of xDSL modems, the above-mentioned modulations of data transmission and coding using trellis modulation use the usual standard technologies that are readily available on the market and which are widely used as in Europe and in the USA.

In another embodiment, the correction coefficient reproduces a non-linear relationship with respect to the physical lengths and / or thicknesses of the cable cores, that is, the correction coefficient can be represented as a non-linear function, for example, a polynomial function of degree greater than 1. This embodiment has, among other things, an advantage consisting in that much more complex dependencies are thereby taken into account and can be corrected than in the case of linear correction coefficients.

Another embodiment includes a computer program product, which can be downloaded directly to the internal memory of a digital computer and includes pieces of software code with which steps are performed according to the above-described embodiments when this product is executed on a computer. This embodiment has the advantage that it provides a technical implementation of the invention, which allows simple handling and use without large hardware costs.

In particular, to determine the bit rates for network connections, the physical length of the network connection between the transmitter and the receiver being known, the energy spectrum is measured depending on the transmission frequency for possible types of modems using a power measuring device and transmitted to the data carrier of the computing unit, with using the computing unit, the attenuation is determined for various physical lengths and thicknesses of the cores of the network connection cable, and the effective signal levels in the receiver based on and attenuation, as well as the energy spectrum, correlated with the corresponding physical lengths and thicknesses of the cable strands, are stored in the first list on the data carrier of the computing unit, and the noise level correlated with the corresponding physical lengths and thicknesses of the cable strands is stored in the second list on the data carrier network connection, while the noise level is determined by the computing unit, depending at least on the crosstalk parameters and the number of interference sources per new energy spectrum, the computing unit through the Gaussian conversion module based on the effective signal levels from the first list and the corresponding noise levels from the second list for various data modulations and / or modulating codes determines the bit rate for a predetermined supply of data transfer resources and saves the transmission speed bits, correlated with the corresponding physical lengths and thicknesses of the cores of the network connection cable, on the data carrier of the computing unit OK, the computing unit determines the effective bit rates using one or more correction factors based on the stored bit rates and saves the effective bit rates, correlated with the corresponding physical lengths and thicknesses of the cores of the network connection cable, to the storage medium of the computing unit, and the correction coefficient includes the average deviation of the stored bit rates from the effective bit rates and / or the coefficient a correction unit for correcting the settings of the correction unit, and a computing unit based on the stored effective bit rates using the known physical length of the determined network connection between the transmitter and the receiver determines the bit rate for the corresponding network connection. The advantage of this embodiment, in particular, is that the method and system for the first time provide a simple and quick determination of the bit rate, without requiring large technical, labor and time costs. In particular, it is possible to correct the uncertainties due to the mentioned correction without requiring, as in the known remote measurement systems for measuring the reserves of data transmission resources and / or bit rates, the adjustment in each local distribution station of different, definitely unknown uncertainties or unknown errors that Due to one-sided measurements, it is difficult to evaluate, since two-sided measurements would be necessary to determine the error.

In one embodiment, the energy spectrum is measured depending on the transmission frequency for the types of ADSL, and / or SDSL, and / or HDSL, and / or VDSL modems. In this case, the possible types of SDSL modems can include at least the type of G.991.2 modem, and / or the types of ADSL modems - at least the type of G.992.2 modem. By means of a Gaussian transform module, data transfer resource reserves can be determined, at least for data transfer modulations of the form 2B1Q, and / or CAP, and / or DMT, and / or PAM. Also, through the Gaussian transform module, the reserves of data transmission resources can be determined, at least for coding using trellis code modulation. This embodiment has, among other things, the advantage that, for the types of xDSL modems, the above-mentioned modulations of data transmission and coding using trellis modulation use the usual standard technologies that are readily available on the market and which are widely used as in Europe and in the USA.

In another embodiment, the correction coefficient includes a non-linear dependence on the physical lengths and / or thicknesses of the cable cores, that is, the correction coefficient can be represented as a non-linear function, for example, a polynomial function of degree higher than 1. This embodiment has, among other things, an advantage , which consists in the fact that much more complex dependencies are taken into account and can be corrected than using linear correction factors.

In yet another embodiment, a bit rate for data transfer resource reserves between 3 and 9 dB is determined by a Gaussian transform module. This embodiment, inter alia, has the advantage that the range between 3 and 9 dB provides reception with a QoS parameter that satisfies most requirements. In particular, the specified range of data transfer resource reserves between 3 and 9 dB provides an optimization of the bit rate with respect to other QoS parameters.

In yet another embodiment, a bit rate for a data transfer resource margin of 6 dB is determined by a Gaussian transform module. This embodiment, among other things, has the same advantages as in the previous described embodiment. In particular, the specified margin of data transfer resources of 6 dB provides optimization of the bit rate in relation to other QoS parameters.

Another embodiment includes a computer program product, which can be downloaded directly to the internal memory of a digital computer and includes pieces of software code with which steps are performed according to the above-described embodiments when this product is executed on a computer. This embodiment has the advantage that it provides a technical implementation of the invention, which allows simple handling and use without large hardware costs.

In addition, it should be noted that the claimed invention, along with the method corresponding to the invention, also relates to a system and a computer program product for implementing this method.

The following examples describe embodiments of the claimed invention. Examples of execution are illustrated by drawings, which show the following:

FIG. 1 is a block diagram showing the architecture of an embodiment of a system of the invention for determining data resource reserves or bit rates for network connection 12 with a specific physical length 13 between transmitter 10 and receiver 11.

Figure 2 is a schematic representation of crosstalk with near-end crosstalk (NEXT) 51, which relates to the unintentional input of signals 50 of transmitter 10 at one end to signals 50 in receiver 11 at the same end, and far-end crosstalk (FEXT) 52 , which relates to the unintentional input of signals 50 during transmission to the receiver 11 at the other end, the signals 50 during transmission being input to the signals 50 of adjacent copper pairs and appear as noise in the receiver 11.

Figure 3 - schematic representation of the transmission area of the network connection depending on the transmission speed (bit rate) for ADSL modems, as it can be obtained using the system according to the invention. Reference numerals 60 and 61 denote various noise conditions.

4 is a schematic representation of the so-called “last mile” of a public switched telephone network (PSTN), which typically exists between an end user of a home with a network that should be accessible through a public switched telephone network.

Figure 1 presents the architecture that can be used to implement the invention. In this exemplary embodiment, for the method and system for determining the reserves of data transmission resources and / or bit rates for network connections, the physical length 13 of the determined network connection 12 between transmitter 10 and receiver 11 is known. By physical length is meant the effective cable length, and not, for example, the air distance between the transmitter 10 and receiver 11. The network connection 12 may consist of an analog transmission medium, for example, a cable with copper conductors. In this embodiment, for example, copper cables with a core diameter of 0.4 or 0.6 mm were used, as they are typically used for the last mile of a public switched telephone network (PSTN). The last mile is shown schematically in FIG. Reference numeral 70 denotes a router to a network that is connected, for example, via 10BT Ethernet 77 and a public switched telephone network (PSTN) 72 to a server 71 of the modem terminal. The server 71 of the modem terminal may be a DSL access multiplexer (DSLAM). As mentioned, reference numeral 72 denotes a public switched telephone network (PSTN) to which the modem terminal server 71 is connected, for example, with fiberglass cable 78. In addition, the public switched telephone network 79 and, accordingly, the modem terminal server 71 are typically connected via cable 79 with copper conductors through a telephone box 73 are connected to a modem 74 of a personal computer (PC) 75. Reference position 79 here refers to the so-called “last mile” from the distribution station of the telephone network provider End User. The end user 76 can thereby use his PC to directly access the router 70 through the described connection. The most common telephone wires can consist, for example, of a pair of 2-2400 copper wires. But other transmission media can be used, in particular copper cable, for example, with different core diameters. It must be pointed out that the network connections 12 can not only exhibit different diameters or thicknesses 114, 142, 143, 144, respectively, but also that a separate network connection can consist of a combination of cables with different diameters or thicknesses of the cores, that is, that the network connection includes several separate cables with different core thicknesses.

The energy spectrum of the PSD _Modem (f) is measured as a function of the transmission frequency f for the possible types of modems 101, 102, 103, 104 by means of a power measurement device 20 and transmitted to the storage medium of the computing unit 30. The energy spectrum is also denoted by the term “power spectral density” ( PSD) and reproduces for a certain bandwidth a continuous spectrum of frequencies, that is, the total power of a certain bandwidth divided by a specific bandwidth. The division by the bandwidth corresponds to the standardization. Therefore, the power spectral density PSD is a function of frequency f and is usually given in watts per hertz. To measure power by means of the power measuring device 20, a simple analog-to-digital converter can be used in the receiver 11, the voltage being applied to the resistance. To modulate digital signals on line 12, for example, from the end user to the distribution station of the telephone network provider and vice versa, various types of modulation can be applied. In the prior art, for example, xDSL (digital subscriber line) technologies are known, the two main representatives of which are ADSL (asymmetric digital subscriber line) and SDSL (symmetric digital subscriber line). Other representatives of xDSL technology are HDSL (High Speed Digital Subscriber Line) or VDSL (Ultra High Speed Digital Subscriber Line). XDSL technologies are highly developed modulation schemes used to modulate data transmitted in copper wire transmission lines or other analog transmission media. XDSL technologies are sometimes referred to as “last mile technologies”, in particular because they typically serve to connect the last telephone distribution station to an end user in a bureau or at home and are not used for connections between individual telephone distribution stations. XDSL technology is similar to ISDN (Integrated Services Digital Network) in that it can operate on existing copper wire transmission lines, and both require a relatively short distance to the next distribution station of the telephone network provider. XDSL technology provides, however, higher data rates than ISDN. xDSL achieves data rates of up to 32 Mbps for the downstream speed (bit rate when receiving data, i.e. when modulating) and speeds from 32 kbps to 6 Mbps for the upstream speed (bit rate, then there when demodulating), while ISDN supports data transfer rates per channel of about 64 kbit / s. ADSL has recently become a very popular technology for modulating data transmission lines on copper wires. ADSL supports data rates from 0 to 9 Mbit / s for speeds in the downstream direction and from 0 to 800 kbit / s for speeds in the upstream direction. ADSL is called asymmetric DSL, as it supports various bit rates in upstream and downstream. SDSL or symmetric DSL is called, in contrast, symmetric because it supports the same speeds for upstream and downstream data streams. SDSL provides the ability to transfer data at speeds up to 2.3 Mbps. ADSL transmits digital pulses in the high frequency range of a copper cable. Since these high frequencies are not used for normal transmission of tones in the audible range (for example, voices), ADSL can simultaneously act for transferring telephone calls over the same copper cable. ADSL technology is most widely distributed in North America, while SDSL technology is primarily developed in Europe. ADSL and SDSL require specially equipped modems for this. HDSL is representative for Symmetric DSL (SDSL). The standard for symmetric HDSL (SDSL) is currently G.SHDSL, known as G.991.2, developed as an international standard by the CCITT Committee of the International Telecommunication Union (ITU). G.991.2 supports the reception and transmission of a symmetrical data stream over a simple pair of copper wires with transmission rates from 192 kbit / s to 2.31 Mbit / s. The G.991.2 standard was designed in such a way that it includes the properties of ADSL and SDSL and supports standard protocols such as IP (Internet Protocol), in particular modern versions of IPv4 and IPv6 or IPng (Internet Engineering Task Force - IETF ), as well as TCP / IP (Transmission Control Protocol), ATM (Asynchronous Transfer Mode), T1, E1, and ISDN. As the latest xDSL technology, VDSL (Ultra High Speed Digital Subscriber Line) technology is mentioned here. VDSL transmits data in the range of 13-55 Mbit / s over short distances (usually in the range of 300-1500 m) over a twisted pair copper cable. For VDSL, the ratio is true, namely that the shorter the distance, the higher the transmission speed. As the final section of the network, the VDSL connects the user's office or home to neighboring optical network units, called the optical network unit (ONU), which is typically connected to a main fiberglass network (trunk), for example, of a company. VDSL provides the user access to the network with the maximum bandwidth over normal telephone wires. The VDSL standard is not yet fully defined. So there are VDSL technologies that have a line coding scheme based on DMT (discrete multi-tone signal), and DMT is a multi-carrier system, which is very similar to ADSL technology. Other VDSL technologies have a quadrature amplitude modulation (QAM) line coding scheme, which, in contrast to DMT, is more economical and requires less energy. For this embodiment, modem types may include ADSL and / or SDSL and / or HDSL and / or VDSL modem types (101, 102, 103, 104). In particular, possible types of SDSL modems (101, 102, 103, 104) may include at least one type of G.991.2 modem, and / or types of ADSL modems (101, 102, 103, 104) may include at least one type of G.992.2 modem. However, it is understood that this list should in no way be considered limiting the scope of protection of the invention, and, conversely, other types of modems are possible.

Using the computing unit 30, the attenuation H is determined for various physical lengths 13 and core thicknesses of cables 141, 142, 143, 144, such as, for example, 0.4 mm and 0.6 mm of network connection 12, and effective signal levels S (f) in the receiver 11, based on the attenuation of H (f) and the energy spectrum of PSD (f), correlated with the corresponding physical lengths L13 and core thicknesses of the cables D 141, 142, 143, 144, are stored in the first list on the storage medium of the computing unit 30. Attenuation H (f, L, D), like the effective signal level S (f), is a function depending on the frequency f. The signal sent from transmitter 10 corresponds to PSD _Modem (f), while the effective signal level S (f) = PSD (f) H ² (f, L, D) is received at the receiver. In the second list on the data carrier of the computing unit 30, the noise level N (f) 40 is stored, correlated with the corresponding physical lengths 13 and the thicknesses of the cable cores 141, 142, 143, 144 of the network connection 12, and the noise level N (f) 40 is determined by the computing unit 30 depending on at least the Xtalktype crosstalk parameter and the number A of interference sources based on the PSD energy spectrum. I.e:

where N (f) is the noise level, f is the frequency, i is the index, Xtalktype is the crosstalk parameter, PSD _{Smodem (i)} (f) is the energy spectrum of the interference modulation of the i-th S-modem, Нхр (f, L, Xtalktype , А _i ) - attenuation depending on crosstalk, L - physical cable length, A _i - number.

The sum is taken at index i for all interfering modulations (SModem), depending on their crosstalk parameter Xtalktypes, which operate on parallel connections of a given network connection. As mentioned, the issue of crosstalk is related to the physical phenomenon that occurs when modulating data transmitted over a copper cable. The adjacent copper cable conductors inside the copper cable are obtained due to the electromagnetic interaction of the paired components of the signals produced by the modems. This leads to the fact that xDSL modems that transmit on adjacent wires create mutual interference. Crosstalk as a physical action is negligible for ISDN (frequency range up to 120 kHz), but is significant, for example, for ASDL (frequency range up to 1 M Hz) and is a decisive factor for VDSL (frequency range up to 12 M Hz). As described, the telephone lines used consist of copper cores from 2 to 2400. To, for example, be able to use four pairs, the data stream in the transmitter is divided into many parallel data streams, and it is restored again in the receiver, which increases the effective throughput by 4 times. This would allow the transfer of data at speeds up to 100 Mbit / s. Additionally, in the case of 4 pairs of copper wires, the same wires of four pairs are used in order to transmit the same amount of data in the opposite direction. Two-way data transmission on each copper wire of a pair doubles the information capacity that can be transmitted. In this case, the data transfer rate increases by eight times compared with conventional transmissions, in which two pairs are used respectively for only one direction. For data transmission, as described above, crosstalk noise is a very limiting factor. The types of crosstalk (Xtalktype) are near-end crosstalk (NEXT) 51, which refers to the unintentional input of the 50 signals of the transmitter 10 at one end to the 50 signals at the receiver 10 at the same end, and the far-end crosstalk (FEXT) 52 , which relates to the unintentional input of signals 50 during transmission to the receiver 11 at the other end, the signals 50 during transmission being input to the signals 50 of adjacent copper pairs and appearing in the receiver 11 as noise (see FIG. 1). It is generally assumed that the NEXT 51 interference has only a near-end interference source. The Xtalktype parameter, thus, depends on the location and flow (up / down), that is, this dependence can be written as Xtalktype (flow, location). If there are more than two copper conductors, as is usually the case (in a typical case, there are from 2 to 2400 wires), then the above pairwise connection is no longer valid. For example, for the case when the conductors of four pairs are used simultaneously, then, therefore, there are three unintentional sources of interference that act on signal 50 with their energy. For A in this case, the relation A = 3 is valid. The same is true for crosstalk type FEXT 52.

Computing unit 30 determines the reserves of data transmission resources by means of a Gaussian transform module 31 based on the effective signal levels S (f) from the first list and the corresponding noise levels N (f) from the second list for various data modulations and / or modulating codes for a predetermined speed transmission of bits and saves the reserves of data transmission resources, correlated with the corresponding physical lengths 13 and the thickness of the cores of the cable 141, 142, 143, 144 of the network connection 12, on the data carrier in the computing unit oce 30. Based on the effective signal levels S (f) from the first list and the corresponding noise levels N (f) from the second list, it is possible using computing unit 30 to determine the ratio of signal S to noise N (SNR) in the following form:

where SNR is the signal-to-noise ratio, T is the symbol interval, S (f) is the signal level, N (f) is the noise level, n is the summation index.

This expression is valid only for modulations of the form CAP, 2B1Q and PAM, but is not applicable for modulation of the form DMT. Modulation of the DMT type is described in more detail below. T may indicate half the inverse of the Nyquist frequency. The Nyquist frequency is the maximum frequency with which a sample can still be accurately taken. The Nyquist frequency is half the value of the sampling frequency, since unintended frequencies are generated when a signal is sampled whose frequency is higher than half the value of the sampling frequency. The summation index n takes values from -1 to +1, which is usually enough in practice. If this is not enough, then additional maximums of 0, ± 1 / T, ± 2 / T, etc. can be used. until the required accuracy is achieved. Resource data transfer resources depend on the modulation of the data transfer and / or modulating codes, as noted above. This embodiment shows the dependency for 2B1Q modulation used for HDSL modems and CAP modulation as an example for ADSL modulation of the DMT type, as well as for modulating codes using trellis coding signals. However, it is understood that the method and system of the invention can also be used for other modulations of data transmission and / or modulating codes, such as PAM (pulse amplitude modulation), etc. Both 2B1Q type modulation and CAP type modulation are used for HDSL modems and are characterized by a predetermined bit rate. Modulation of the form DMT is used for ADSL modems and, in contrast, has a variable bit rate. The types of modulation CAP and DMT use the same underlying modulation technology: quadrature amplitude modulation (QAM), although this technology is used in different ways. QAM provides the possibility that two digital carrier signals have the same transmission bandwidth. In this case, two independent, so-called message signals are used to modulate two carrier signals that have the same carrier frequency, but differ in amplitude and phase. QAM signal receivers can distinguish whether a low or a high number of amplitude and phase states is required to overcome the effects of noise and interference, for example, in a single pair of copper conductors. 2B1Q modulation is also known as 4-level amplitude modulation (PAM). It uses two voltage levels for pulse signals, and not one level, as, for example, in the case of modulation type AMI (coding with alternating polarity of the elements). Since positive and negative differences in levels are applied for this, a 4-level signal is obtained. The bits are then evaluated in pairs, which pair corresponds to a certain voltage level (hence the name 2-bit modulation). Due to this, it is possible to halve the necessary transmission frequency for transmitting at the same bit rate as in the case of bipolar modulation of the AMI type. For an HDSL modem using modulation of the form 2B1Q or CAP, the following dependence of the reserve of data transfer resources on the SNR exists:

M _c = SNR / ξ,

where M _s is the reserve of transmission resources, ξ is a parameter determined depending on the error rate (symbol error rate) ε _s . For local area networks (LAN) of the Internet Protocol (IP), the error rate ε _s = 10 ^{-7 is} usually sufficient, that is, every 10 ⁷ bits is transmitted on average with distortion. Firms typically require ε _s = 10 ^-12 for their branded networks. If the value of ε _s becomes of the order of magnitude of the transmitted data packet (for example, 10 ^-3 ), then this, on the contrary, would mean that each packet should be transmitted on average twice, until it is received correctly. For modulation of the form 2B1Q for the parameter ε _s , for example, the following is true:

для некодированных сигналов

for non-encoded signals

для сигналов решетчатого кодирования,

for trellis coding signals,

while for the modulation of the form CAP the following relations are true:

для некодированных сигналов

for non-encoded signals

для сигналов решетчатого кодирования,

for trellis coding signals,

where ε _s is the error rate, M is the moment number / grouping quantity, G _c is the complementary Gaussian function.

The parameter G _c for both types of coding is a complementary Gaussian function of the form

M denotes a moment number for modulation of the form 2B1Q, and M = 4 for 2B1Q, while for modulation of the CAP type, the grouping parameter is M × M. T denotes, as indicated above, the symbol spacing or half the inverse of the Nyquist frequency. For ADSL modems using modulation of the form DMT, the dependence is different. As noted above, ADSL has a variable bit rate. This is also manifested in the determination of the parameter M _s . In this case, the following relation holds:

where ξ (f) is the signal-to-noise ratio S (f) / N (f), x _ref is the standard reserve of resources, which in this embodiment was typically chosen to be 6 dB, i.e., x _ref = 10 ^0.6 although other values may be chosen as reference resource stocks; Δf is the entire frequency band or frequency band that is used for transmission; D is the bit rate, for example, in bits per second (bps); G - correction factor. In this embodiment, G has a value, for example, of 9.55. The integration in this example is performed over the frequency f. Similarly, it can, however, be carried out in time or other physical quantity, moreover, the above expression should be accordingly consistent.

In the general case, the reserves of data transmission resources obtained above do not coincide with the experiment. Therefore, the computing unit 30 determines the effective reserves of data transmission resources by means of at least one correction coefficient based on the stored reserves of data transmission resources. A correction factor was chosen for this embodiment in such a way that sufficient consistency is achieved between the received data transfer resource reserves and the effective data transfer resource reserves. As a sufficient value in this case, it was taken, for example, +/- 3 dB, and other values can be used. To obtain this maximum deviation of +/- 3 dB, two parameters are defined. M _imp takes into account the good or poor implementation of the modem by the manufacturer. The parameter M _imp was introduced on the basis of the fact that the same modems with comparable hardware and the same modulation of data transfer and / or modulating codes, however, issued by different manufacturers, when converting an analog signal to a digital signal and vice versa, gave different results, which influenced their maximum data transfer rate or their maximum range for a particular network connection. This should be adjusted in relation to the stock of data transfer resources. The parameter N _int was introduced as the second parameter. The parameter N _int takes into account the quantization noise in the modem (analog-to-digital conversion), as well as the possible poor adjustment of the correction block during transmission. If there is a transfer between the transmitter 10 and receiver 11, then the correction unit in the modem will coordinate the data transfer rate with the conditions of the network connection, for example, attenuation in the line, phase distortion, etc. through a test sequence that is sent between both leading modem information exchanges in both directions. Poor coordination due to the correction block leads to distortion of the results and should be adjusted. For a linear correction block, for example, the following expression can be used:

Where

where SNR _LinearEq is the signal-to-noise ratio, S _e is the signal received by the correction unit, N _e are the noises, f is the frequency, T is the symbol interval.

For a correction block with adaptive decision feedback (DFE), for example, the following expression can be used:

where SNR _DFE is the signal-to-noise ratio, S _e is the signal received by the correction unit, N _e are the noises, f is the frequency, T is the symbol interval. The computing unit 30 for determining the SNR _DFE may use, for example, the following approximation:

where SNR _DFE is the signal-to-noise ratio, S _e is the signal received by the correction unit, N _e are the noises, f is the frequency, T is the symbol interval.

Thus, for effective reserves of data transfer resources, we obtain: S (f) = PSD _Modem (f) H ² (f, L, D), as before. Noises are adjusted as follows:

where N (f) are the noise, PSD _Smodem (i) (f) is the energy spectrum of the interference modulation of the i-th S-modem, Нхр ² (f, L, D, xtalktype _i , n _i ) is the attenuation depending on the crosstalk . N _int - correction.

Correction can be implemented in the computing unit 30 by hardware or software in a single module. It should be noted that with the help of such a module, based on the correction N _{int, a} variable noise factor is introduced, which, for example, can take into account the setting of the correction block, etc. This solution is not known from the prior art and belongs, among other things, to the essential advantages of the invention.

The effective data transfer resource reserves M _eff are taken into account by the relation M _eff = M _c -M _imp , which is taken into account in addition to N _int , as mentioned above. Correct values for M _c and N _int can be obtained by computing unit 30 in comparison with experimental data. In a typical case, the computing unit 30 should then have access to the data of various experiments in order to be able to correctly determine the parameters within the desired deviations. By means of correction factors, which, therefore, include the average deviation of the stored reserves of data transmission resources with respect to the effective reserves of data transmission resources, the effective reserves of data transmission resources are determined, as well as in comparison with the corresponding physical lengths L 13 and thicknesses D cores of cables 141, 142, 143, 144 of network connection 12 are stored on a storage medium of computing unit 30. It should be noted that correction factors are not necessarily linear coefficients, that is, they must be constant, but with the same success they can include correction functions with a nonlinear dependence. Thus, depending on the application, more complex deviations of experimental data can be taken into account. Using the stored data arrays with data transfer resource reserves, the computing unit 30 determines, based on the stored effective data transfer resource reserves, using the known physical length 13 of the network connection 12 between the transmitter 10 and the receiver 11, the data transfer resource reserve for a particular network connection 12. Data transfer resource reserves are indicated, as was repeatedly mentioned above, in decibels. For values> 0, the modem operates in a typical way, while for values <0 it does not work. To guarantee reliable quality operation, it may be appropriate to choose, for example, 6 dB as the lower limit. However, in general, other values of data transfer resource reserves for the lower boundary are suitable for use, for example, values ranging from 3 dB to 9 dB. Due to a similar configuration for ADSL modems, it is also possible, as follows from the above data, instead of data arrays with data transfer resource reserves, data arrays with bit rates for various network connections, for example, for data transfer resource reserves of 6 dB, can be respectively determined. Thus, to determine data arrays with bit rates of 6 dB = M _eff . For HDSL modems, this does not make sense in this regard, since in the case of HDSL, encodings are used, for example, of the form 2B1Q or CAP with a constant data rate, in this case 2.048 Mbps. The reason for this difference with respect to ADSL modems lies in the fact that HDSL systems were designed only for connection with a higher bit rate, and only transmission reliability (SNR ratio) is of interest to them.

Figure 3 shows the transmission section of the network connection depending on the bit rate for ADSL modems. Reference numerals 60 and 61 denote various noise conditions. Bit rates, as described above, are based on stored data arrays or lists.

Claims (15)

1. A method for determining the reserves of data transmission resources for network connections, the physical length (13) of the determined network connection (12) between the transmitter (10) and receiver (11) being known, characterized in that the energy spectrum is measured depending on the transmission frequency for possible types of modems (101, 102, 103, 104) using a power measurement device (20) and transferring the data to the data storage unit of the computing unit (30), using the computing unit (30) determine the attenuation for various physical lengths (13) and core thicknesses cable (141, 142, 143, 144) of the network connection (12) and the effective signal levels in the receiver (11), based on attenuation, as well as the energy spectrum, correlated with the corresponding physical lengths (13) and cable core thicknesses (141, 142, 143, 144), are stored in the first list on the storage medium of the computing unit (30), in the second list on the storage medium of the computing device, the noise level (40) is correlated with the corresponding physical lengths (13) and thicknesses of the cable conductors (141, 142, 143, 144) of the network connection ( 12), while the noise level (40) is determined by m of the computing unit (30) depending on at least the crosstalk parameter and the number of interference sources based on the energy spectrum, the computing unit (30) by means of the Gaussian conversion module (31) based on the effective signal levels from the first list and the corresponding noise levels from the second list for various modulations of data transmission and / or modulating codes determines the reserves of data transmission resources for a predetermined bit rate and with correlation with the corresponding physical With the lengths (13) and thicknesses of the cable conductors (141, 142, 143, 144), the network connection (12) stores on the data carrier of the computing unit (30), the computing unit (30) determines the effective reserves of data transmission resources by at least one correction factor based on the stored reserves of data transmission resources and correlating with the corresponding physical lengths (13) and thicknesses of the cable veins (141, 142, 143, 144) of the network connection (12) is stored on the data carrier of the computing unit (30), and the correction VK coefficient includes the average deviation of the stored reserves of data transmission resources from the effective reserves of data transmission resources and / or the coefficient of the correction block for the correction adjustment of the correction block, and the computing unit (30) based on the stored effective reserves of data transmission resources using a known physical length (13) the determined network connection (12) between the transmitter (10) and the receiver (11) determines the reserve of data transmission resources for the corresponding network connection (12). 2. The method according to claim 1, characterized in that the correction coefficient reflects a non-linear dependence on the physical lengths (13) and / or thickness of the cable strands (141, 142, 143, 144). 3. The method according to claim 1, characterized in that the energy spectrum is measured depending on the transmission frequency for the types of modems ADSL (asymmetric digital subscriber line), and / or SSDL (symmetric digital subscriber line), and / or HDSL (high speed digital subscriber line line), and / or VDSL (Ultra High Speed Digital Subscriber Line) (101, 102, 103, 104). 4. The method according to claim 3, characterized in that the possible types of SDSL modems (101, 102, 103, 104) include at least the type of modem G.991.2, and / or the types of modem ADSL (101, 102, 103, 104) - at least the type of modem G.992.2. 5. The method according to claim 1, characterized in that through the module (31) of the Gaussian transform determine the reserves of data transmission resources, at least for modulations of data transmission of the form 2B1Q (2 binary, 1 quadruple), and / or CAP (amplitude / carrierless phase modulation), and / or DMT (digital multi-tone), and / or PAM (pulse amplitude modulation). 6. The method according to any one of claims 1 to 5, characterized in that through the module (31) of the Gaussian transform determine the reserves of data transmission resources, at least for coding using modulation trellis code. 7. A method for determining bit rates for network connections, the physical length (13) of the network connection (12) between the transmitter (10) and receiver (11) being known, characterized in that the energy spectrum is measured depending on the transmission frequency for possible types of modems (101, 102, 103, 104) using a device (20) for measuring power and transferring it to the data carrier of the computing unit (30), using the computing unit (30) determine the attenuation for various physical lengths (13) and cable core thicknesses (141, 142, 143, 144) network connected I (12), and the effective signal levels in the receiver (11), based on attenuation as well as the energy spectrum, correlated with the corresponding physical lengths (13) and cable core thicknesses (141, 142, 143, 144), are stored in the first list on the data carrier of the computing unit (30), in the second list on the data carrier of the computing unit, the noise level (40) is stored, correlated with the corresponding physical lengths (13) and thicknesses of the cable cores (141, 142, 143, 144) of the network connection (12) while the noise level (40) is determined by the computing unit (30 ) depending on at least the crosstalk parameters and the number of interference sources based on the energy spectrum, the computing unit (30), through the Gaussian transform module (31), based on the effective signal levels from the first list and the corresponding noise levels from the second list for different modulation of data transmission and / or modulating codes determines the bit rate for a predetermined supply of data transmission resources and saves the bit rate associated with the corresponding With the physical lengths (13) and thicknesses of the cable conductors (141, 142, 143, 144) of the network connection (12), on the data carrier of the computing unit (30), the computing unit (30) determines the effective bit rates by means of a correction coefficient based on the stored speeds transmission of bits and saves effective bit rates, correlated with the corresponding physical lengths (13) and thicknesses of the cable veins (141, 142, 143, 144) of the network connection (12), on the data carrier of the computing unit (30), and the correction factor includes includes the average deviation of the stored bit rates from the effective bit rates and / or the coefficient of the correction block for correcting the settings of the correction block, and the computing unit (30) based on the stored effective bit rates using the known physical length (13) of the determined network connection ( 12) between the transmitter (10) and the receiver (11) determines the bit rate for the corresponding network connection (12). 8. The method according to claim 7, characterized in that through the module (31) Gaussian transform determine the bit rate for stocks of data transfer resources between 3 and 9 dB. 9. The method according to claim 7, characterized in that through the module (31) Gaussian transform determine the bit rate for the reserve of data transfer resources of 6 dB. 10. The method according to claim 7, characterized in that the correction coefficient reflects a non-linear dependence on the physical lengths (13) and / or thickness of the cable strands (141, 142, 143, 144). 11. The method according to claim 7, characterized in that the energy spectrum is measured depending on the transmission frequency for the types of modems ADSL, and / or SDSL, and / or HDSL, and / or VDSL (101, 102, 103, 104). 12. The method according to claim 11, characterized in that the possible types of SDSL modems (101, 102, 103, 104) include at least the type of modem G.991.2, and / or the types of modem ADSL (101, 102, 103, 104) - at least the type of modem G.992.2. 13. The method according to claim 7, characterized in that through the module (31) of the Gaussian transform determine the reserves of data transmission resources, at least for modulations of data transmission of the form 2B1Q, and / or CAP, and / or DMT, and / or RAM . 14. The method according to any one of claims 7 to 13, characterized in that through the module (31) of the Gaussian transform determine the reserves of data transmission resources, at least for coding using modulation trellis code. 15. A system for determining the reserve of data transmission resources for network connections, the physical length (13) of the determined network connection (12) between the transmitter (10) and receiver (11) being known, characterized in that the system includes a measuring device (20) for measuring the energy spectrum depending on the transmission frequency for possible types of modems (101, 102, 103, 104), as well as a storage medium of the computing unit (30), on which the energy spectrum can be stored, the computing unit (30) contains means for determining I attenuation for various physical lengths (13) and thicknesses of the cable conductors (141, 142, 143, 144) of the network connection (12), and the effective signal levels in the receiver (11) based on the attenuation, as well as the energy spectrum, are correlated with the corresponding physical lengths (13) and thicknesses of cable cores (141, 142, 143, 144) are stored in the first list on the data carrier of the computing unit (30), the computing device (30) contains means for determining the noise level (40) depending on at least from the crosstalk parameter, the number of interference sources n based on the energy spectrum, and the noise level (40), correlated with the corresponding physical lengths (13) and thicknesses of the cable cores (141, 142, 143, 144) of the network connection (12), is stored in the second list on the data carrier of the computing unit, the computing unit (30) comprises a Gaussian transform module (31) for determining data resource reserves for a predetermined bit rate based on the effective signal levels from the first list and the corresponding noise levels from the second list for different modes data transmission and / or modulating codes, moreover, the reserves of data transmission resources correlated with the corresponding physical lengths (13) and thicknesses of cable cores (141, 142, 143, 144) of the network connection (12) are stored on the storage medium of the computing unit (30 ), the computing unit (30) contains a correction module that determines the effective reserves of data transmission resources by means of at least one correction coefficient based on the stored reserves of data transmission resources and correlated with the corresponding physical the lengths (13) and thicknesses of the cable conductors (141, 142, 143, 144) of the network connection (12) are stored on the data carrier of the computing unit (30), and the correction factor includes the average deviation of the stored reserves of data transmission resources from the effective reserves of resources data transmission and / or coefficient of the correction block for correcting the adjustment of the correction block.

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