Bandwidth adsl line. How to increase the speed of data transfer via ADSL. Setting up ADSL equipment for maximum performance

ADSL2 and ADSL2 + technologies and standards

ADSL2 and ADSL2 + technologies enabling true solutions. New video applications such as IPTV and VoD require high bit rates (over 10 Mbps) towards the user, and ADSL2 + can provide them. ADSL2 + transmission speeds are up to 24 Mbps.

Benefits

ADSL2 + technology also has a number of new features and benefits over the older version of ADSL. The most important features, such as increased range and transmission speed, line diagnostics, transmission power control, fast connection establishment and improved interoperability, are already integrated into new subscription fees BAN, mBAN and ipBAN nodes. ADSL2 + technology is also excellent for replacing VDSL in home subscribers with more demanding access requirements. With ADSL2 +, video service providers will be able to offer users even 3 simultaneous video programs on a single broadband port.

The main distinctive features and benefits

Improved parameters of speed and transmission distance

ADSL2 and ADSL2 + use improved modulation to provide reduced framing overhead, higher coding gain, and improved initialization mechanisms and signal processing algorithms. ADSL2 allows for faster speeds data transmission towards the user up to over 12 Mbps, compared to about 8 Mbps in the case of ADSL. ADSL2 can extend the loop length by about 200 m, or increase the data rate by about 50 kbps over the same distance for long subscriber lines.

ADSL2 + standard allows to double the maximum frequency used for data transmission towards the user - 2.2 MHz instead of 1.1 MHz. This allows the maximum downstream transmission rate to be increased to 25 Mbps on telephone lines up to 1500 m.

Diagnostics and automatic adjustment

Real-time monitoring functions provide real-time information on line quality and noise at both ends of the line. Service providers can use this data to monitor the quality of the ADSL connection and prevent service degradation. In addition, this data will help providers determine if a particular user can be provided with higher bit rate services. SELT (line test with no remote end connected) and DELT (line test with remote end connected) provide the ability to determine before use the length of the line, the presence of short-circuited and open circuits, the size of the wires and the expected throughput... If conditions change in the channel, use new opportunity, which is called seamless rate adaptation (SRA). This capability allows the ADSL2 system to change the data rate of a connection without service interruption or bit error.

Advanced power management capabilities

Dual power management modes can reduce power consumption while maintaining a constant aDSL connections for users. L2 power mode is for low bit rate mode that does not require full bandwidth, while L3 power mode is for standby or sleep mode. This feature reduces energy consumption by more than 50% for each line.

Quick start

Quick Start Mode reduces the initialization time from about 10 seconds to less than 3 seconds.

Fully digital mode

This additional option allocates "telephone" frequency band for data transmission. In this case, the data transfer rate in the upstream direction (from the user to the network) increases by 256 kbps, which can be an attractive solution for enterprises in which voice services are provided over different telephone lines and for which the possibility of increasing the upstream data flow rate is special interest. This opportunity may also be of interest to service providers who can lease subscriber lines from telecommunications companies on a subscriber line division (LLU) basis.

Improved hardware interoperability

New modem initialization procedures address hardware compatibility issues and provide better performance when interconnecting ADSL transceivers from different chip vendors.

Other features and capabilities

Channeling

The channelization capabilities of ADSL2 provide support for coded voice over DSL (CVoDSL) technology, a method for transparently transporting TDM voice traffic over DSL lines. CVoDSL transports voice traffic at the physical layer, allowing analog telephone "lines" to be inserted into a DSL channel and carried in parallel with data traffic, supporting both analog telephone network (POTS) and high-speed Internet access.

Combining multiple lines for higher transfer rates

The new standards support inverse multiplexing for ATM (IMA) developed by the ATM Forum for networks with traditional ATM architecture. Thanks to IMA, ADSL2 ICs can combine multiple copper pairs into a single ADSL link. As a result, data transfer rates are provided over existing copper lines, comparable to fiber-optic lines.

Packet service support

Packet network services (eg Ethernet) can be carried over ADSL2 as a complement to ATM.

ADSL is an unbalanced Internet access technology. It is an asymmetric system by its structure and allows working with connections at speeds up to 8 Mbps. ADSL technology, the transmission rate of which is calculated up to 1 Mbit / s, operates on average over a distance of more than 5 km. Today we will look at what this type of connection is and how it works.

History of appearance

Before answering the question: "What is ADSL?", We offer you some historical data. For the first time they started talking about the creation in the late 80s, when even the Internet in its modern guise was only its main task in 1989 was to improve and modernize the technology for transmitting data over copper telephone wires. Analog-to-digital conversion was created mainly for the rapid transfer of information between various interactive services, video games, video files, as well as for instant remote access to LANs and other network systems.

Modern ADSL technology: how it works

The operation of the network is based on the subscriber's digital line, which provides access to the Internet via telephone channels. But telephone lines use an analog signal to carry voice messages. An ADSL connection is designed to convert an analog signal to digital and send it directly to a computer. At the same time, unlike the outdated Dial-up modems, devices based on ADSL do not block the telephone line and allow the use of digital and analog signals simultaneously.

The essence of the technology (asymmetry) is that the subscriber receives a huge amount of data - incoming traffic, and transfers a minimum of information from himself - downstream traffic. All kinds of content are meant as input: video and media files, applications, objects. Downstream sends only important technical information - various commands and requests, emails and other secondary elements. Asymmetry means that the speed from the network to the subscriber is several times higher than the speed from the user.

The most important advantage that ADSL technology has is its budget and cost effectiveness. The fact is that the same copper is used for the operation of the system.The number in them, of course, significantly exceeds the number of similar elements in cable modems... But at the same time, no modernization of switching equipment and complex reconstruction is necessary. ADSL connects quickly, and modern types of modems are intuitive to operate and configure.

What equipment is used for this connection?

In order for the technology to work, special types of modems are used, which differ in their structure, design, type of connection:

• PCI modems (internal computer devices).
• External modems with USB connection type.
• Devices with interface type of Ethernet.
• with Ethernet circuit.
• Profile types of modems (for security companies, private telephone lines).
• A router with internal Wi-Fi hotspots.

Additional equipment: splitters and microfilters

Do not forget that to connect a gadget such as an ADSL modem, you need splitters and microfilters. Devices are selected in accordance with the design of the telephone cable. In the situation when the cable outlet is made (or it can be done), a splitter is used to separate the channel of the modem and the telephone. In another case, the purchase of a microfilter is required, which is installed on each telephone present in the room.

The main task of the splitter is the separation of frequencies - voice (0.3-3.4 KHz) and used directly by the modem itself (25 KHz-1.5 MHz). It is in this way that the simultaneous operation of the modem and the telephone is ensured, which do not interfere with each other and do not interfere. Splitters are compact and will not cause unnecessary inconvenience. The miniature box is equipped with three connectors and is lightweight.

ADSL - what is it? High-speed Internet connection stages

1. Choosing a provider. Each provider offers to use this technology at the moment. Different kinds and tariffs depend on the region, as well as on technical capabilities company whose coverage area may be limited.
2. Purchase of equipment. Nowadays, it is not necessary to buy a modem, splitters and microfilters. When concluding a connection agreement, the provider offers to rent the necessary equipment, including an ADSL modem. In the future, upon termination of the document, the equipment is returned back. The client pays exclusively for the Internet connection. Modern Internet ADSL - what is it? It is a fast, cheap and high quality connection method.
3. Account activation. The provider reserves an account for each client, which can take up to 12 days to activate. However, in most cases, with normal network coverage, the procedure does not take more than a few hours. The provider first checks the phone number for ADSL connectivity. If the technology access zone is not enough, then high-speed Internet will not work.
4. Equipment setup. At this stage, the devices are connected to the telephone line, the splitters and microfilters are installed, the modem drivers are installed on the computer, and the modem's network parameters are set in the Internet browser.

pros

What are the advantages of ADSL technology? Here are a few of them:

• High ADSL allows you to easily transfer files of any size without long waiting times. The technology is constantly being improved, and the speeds are growing, significantly expanding the capabilities of the subscriber.
• Wireless connection. To use an ADSL system, there is no need to lay a cable to the subscriber and install a large amount of equipment. The reliability, quality and functionality of the network are improved.
• No interference on the telephone line. The ADSL router operates in an independent mode and does not create any problems for the phone. You can make calls and travel around the virtual space completely free.
• Constant ADSL Internet access. What it is? This means that the network will not fail during operation. The technology does not require reconnection. The user gets access to the Internet constantly and can be online around the clock.
• Reliability and stability. ADSL is the most reliable type of Internet connection today.
• Profitability. The cost of connecting ADSL and installing a modem with a router is minimal and will not hit the family budget.

disadvantages

1. No cross talk protection. If several dozen clients are connected to one channel, you will not have to rely on high speed. The more subscribers on one ADSL, the lower the quality of data transmission.
2. Although ADSL technology has disadvantages, they are few. This can also include the minimum speed from the subscriber. The asymmetry of ADSL has an obvious disadvantage - the file transfer from the subscriber will be long and inconvenient. But the technology is intended primarily for quick access to the Internet, for surfing. In addition, the information transmitted from the subscriber takes up a minimum of space and does not require a large resource.

Speed \u200b\u200band factors affecting it

ADSL is a high-speed Internet technology, but there is no universal meaning and formula. For each individual subscriber, the speed is individual and is determined by a whole set of factors. Including some of them can affect the reliability and quality of equipment. Therefore, it is best for professionals to install modems and routers.

The main reason for the slow speed of ADSL connections is the quality of the subscriber line. We are talking about the presence of cable branches, their condition, wire diameter and length. Signal attenuation is a direct consequence of increasing the length of the subscriber line, and interference can be reduced by expanding the wire diameter. The standard length of an ADSL channel does not exceed 5 km - the optimal range for high-speed data transmission.

Speed \u200b\u200bcharacteristics

Compared to other Internet connection technologies, ADSL is significantly faster in speed. An analog modem will give a maximum of 56 Kbit / s, while ADSL at the dawn of its appearance already allowed information to be transmitted at a speed of up to 144 Kbit / s.

ADSL technology, the maximum speed of which is also determined by the characteristics of the modem and can reach 2048 Mbit / s, optimizes the information transfer process. Digital lines greatly increase the user's capabilities, pushing him beyond the limits even with several connected computers, mobile phones, tablets and other gadgets.

Technology Perspective

Opportunities and Resources aDSL technology are still far from exhausted. Even the ADSL2 and ADSL2 + standards, introduced in the mid-2000s, still retain their relevance and capabilities. It is, in fact, the only technology that can provide broad Internet access without glitches and software problems, and therefore competes with many other methods of connecting to the Internet.

Minimum technical equipment complemented by modern views modems. Manufacturers annually release new devices designed for continuous operation without the need for maintenance and service. Moreover, ADSL speed is constantly increasing and is not limited to megabits. Connection becomes relevant both for home and for an entire office company with several dozen computer clients.

Conclusion

So, we found out what ADSL technology is, what is its essence and how it works. As you can see, this is one of those technologies that practically does not fail during operation (even if several dozen users are connected to the network). At the same time, she does not need constant reconnections and speed limits.

There are several ways to access the Internet using a regular telephone cable, and ADSL technology is one of them. The purpose of this article is to tell the reader, what is ADSL modemhow data is exchanged, and what is the advantage of this way of organizing the transfer of information

What is ADSL and how does it work

Digital Subscriber Line, or DSL (Digital Subscriber Line) for short, is a way of organizing the exchange of data by creating a high-speed connection to transfer it between two or more computers. To connect computers to a computer local network or to access the Internet, special DSL modems are used on the client's side, and switches on the provider's side.

The technology appeared in the late 80s of the last century and combines several technologies under the general name xDSL:

• ADSL - Unbalanced Digital Subscriber Line or Asymmetric DSL. The data transfer rate reaches 8 Mbps for receiving, and up to 1 Mbps for sending data from the subscriber;
• HDSL - high-speed digital subscriber line or High Data Rate DSL, where the transmission speed is up to 2 Mbit / s in two directions;
• VDSL - Ultra High Speed \u200b\u200bDigital Subscriber Line or Very High Data Rate DSL when the highest speed is reached at 52 Mbps.

When used by private subscribers, asymmetric data transmission technology has become the most popular. This allows you to use one telephone line for Internet access and for regular calls. A high connection speed is achieved by using a higher frequency than that used by a conventional dial-up modem.

The principle of asynchronous data transfer is quite simple:

• Frequencies up to 4 kHz are used directly for communication by telephone or for sending fax messages.
• When creating a connection between the client modem and the provider's modem, frequencies from 4 to 140 kHz are used. At these frequencies, data is transferred from the client to the Internet provider. Because relatively little data is sent from the client, then there is no need to use higher frequencies, and, accordingly, a higher speed. The speed rarely exceeds 1 Mbps.
• Frequencies from 1.1 to 4.4 MHz are used for inbound traffic. The connection speed here reaches 8 Mbps.

What is ADSL modem

When connecting to the Internet via an ADSL line, the user does not need to perform any additional actions, for example, make a call to the provider, as in a dial-up connection. Everything necessary work the modem will do it for the client. So, what is adsl modem? It is a high-tech device that is designed to convert an incoming or outgoing signal from analog to digital and vice versa. The modem creates a permanent broadband connection and monitors its stability.

Constantly improving ADSL technology has undergone several evolutionary transitions, which affected the proposed acquisition of ADSL modems, which are now of the following types:

• internal modem for connection to PCI slot;
• external version with USB or Ethernet connectors;
• external routers with Ethernet ports;
• external routers with built-in WiFi access point.

Now that it has become a little clearer how it works adsl modem what is it and about the technology in general, we can conclude about the advantages and disadvantages of using the described technology to access the Internet.

Advantages and Disadvantages of ADSL Connection

The most obvious advantages of ADSL technology are very high data rates and connection stability. But there are a few more important points that speak in favor of ADSL:

• permanent connection and Internet access;
• there is no need to lay additional cables, because the telephone line has already been installed in almost every apartment, office or house;
• use of both the telephone and the Internet on the same telephone line;
• relatively low price for equipment and provider services.

The disadvantages of this type of connection mainly include the poor quality of telephone lines, which can significantly reduce the data transfer rate and the rather low speed of outgoing traffic. But the technology is evolving and these problems must be solved in the near future.

The modern world is ripe for the use of DSL technologies. The increase in the flow of information transmitted over the Internet by companies and private users, as well as the need to organize remote access to corporate networks, gave rise to the need to create inexpensive technologies for digital high-speed data transmission through the "bottleneck" of the digital network - the subscriber telephone line. DSL technologies can significantly increase the speed of data transmission over copper pairs of telephone wires without the need to upgrade subscriber telephone lines. It is the ability to transform existing telephone lines into high-speed data transmission channels that is the main advantage of DSL technologies.

So what exactly is DSL technology?

DSL stands for Digital Subscriber Line. DSL is enough new technology, allowing to significantly expand the bandwidth of old copper telephone lines connecting telephone exchanges with individual subscribers. Any subscriber currently using a regular telephone connection can use DSL technology to significantly increase the speed of his connection, for example, to the Internet. It should be remembered that it is the existing telephone lines that are used to organize the DSL line; This technology is so good that it does not require laying additional telephone cables. As a result, you get round-the-clock access to the Internet while maintaining the normal operation of regular telephone communications. None of your friends will no longer complain that they can't call you for hours. Thanks to the variety of DSL technologies, the user can choose the data transfer rate suitable for him - from 32 Kbps to more than 50 Mbps. These technologies also allow the use of the regular telephone line for broadband systems such as video on demand or distance learning. Modern DSL technologies bring the possibility of organizing high-speed Internet access to every home or to every medium-sized and small businessconverting ordinary telephone cables into high-speed digital channels. Moreover, the data transfer rate depends only on the quality and length of the line connecting the user and the provider. At the same time, providers usually give the user the opportunity to choose the transmission speed that best suits his individual needs.

How DSL works

The telephone set at your home or office is connected to the telephone exchange equipment using a twisted pair of copper wires. Traditional telephone communication is intended for ordinary telephone conversations with other subscribers of the telephone network. In this case, analog signals are transmitted over the network. The telephone set picks up acoustic vibrations (which are a natural analog signal) and converts them into an electrical signal, the amplitude and frequency of which is constantly changing. Since the entire operation of the telephone network is based on the transmission of analog signals, the easiest way, of course, is to use this method to transfer information between subscribers or a subscriber and a provider. That is why you had to buy, in addition to your computer, a modem, which allows you to demodulate an analog signal and turn it into a sequence of zeros and ones of digital information perceived by a computer.

Analog signal transmission uses only a small portion of the bandwidth of the twisted-pair copper telephone wires; the maximum transmission speed that can be achieved with a conventional modem is about 56 kbps. DSL is a technology that eliminates the need to convert a signal from analog to digital and vice versa. Digital data is transmitted to your computer exactly as digital data, which allows for much wider telephone line bandwidth. At the same time, it is possible to simultaneously use both analog telephone communication and digital high-speed data transmission on the same line, separating the spectra of these signals.

Different types of DSL technologies and a brief description of how they work
DSL is a collection of different technologies that make it possible to organize a digital subscriber line. In order to understand these technologies and determine their areas of practical application, it is necessary to understand how these technologies differ. First of all, you should always keep in mind the relationship between the distance over which the signal is transmitted and the data rate, as well as the difference in the transmission rates of the “downstream” (from the network to the user) and “up” (from the user to the network) data stream.
DSL integrates the following technologies under its roof.

ADSL (Asymmetric Digital Subscriber Line - asymmetric digital subscriber line)

This technology is asymmetric, that is, the data transfer rate from the network to the user is much higher than the data transfer rate from the user to the network. This asymmetry, combined with the "always-on" state (which eliminates the need to dial a phone number each time and wait for a connection to be established), makes ADSL technology ideal for organizing Internet access, access to local area networks (LANs), etc. When establishing such connections, users usually receive much more information than they transmit. ADSL technology provides downstream data rates ranging from 1.5 Mbps to 8 Mbps and upstream data rates from 640 Kbps to 1.5 Mbps. ADSL allows data transmission at a speed of 1.54 Mbps over a distance of 5.5 km over a single twisted pair of wires. The transmission speed of the order of 6 - 8 Mbit / s can be achieved when transferring data over a distance of no more than 3.5 km over wires with a diameter of 0.5 mm.

R-ADSL(Rate-Adaptive Digital Subscriber Line - speed adaptive digital subscriber line)

R-ADSL technology provides the same data transfer rate as ADSL technology, but at the same time allows the transfer rate to be adapted to the length and condition of the twisted pair wires used. Using r-ADSL technologies the connection on different phone lines will have different data rates. The baud rate can be selected when synchronizing the line, during a call, or on a signal from the station.

G.Lite (ADSL.Lite) is a cheaper and easier-to-install ADSL technology offering up to 1.5 Mbps downstream and 512 kbps upstream or 256 kbps both directions.

IDSL (ISDN Digital Subscriber Line - IDSN digital subscriber line)
IDSL technology provides full duplex data transmission at speeds up to 144 kbps. Unlike ADSL, IDSL's capabilities are limited to data transmission only. Despite the fact that IDSL, like ISDN, uses 2B1Q modulation, there are a number of differences between the two. Unlike ISDN, the IDSL line is a nonswitched line that does not increase the load on the provider's switching equipment. Also, the IDSL line is "always on" (like any line organized using DSL technology), while ISDN requires a connection.

HDSL (High Bit-Rate Digital Subscriber Line - high speed digital subscriber line)

HDSL technology provides for the organization of a symmetrical data transmission line, that is, the data transfer rates from the user to the network and from the network to the user are equal. With data rates of 1.544 Mbps over two wire pairs and 2.048 Mbps over three wire pairs, telcos are using HDSL technology as an alternative to T1 / E1 lines. (T1 lines are used in North America and provide a data rate of 1.544 Mbps, while E1 lines are used in Europe and provide a data transfer rate of 2.048 Mbps.) Although the distance over which the HDSL system transmits data (which is about 3.5 - 4.5 km), less than ADSL technology, telcos can install dedicated repeaters to extend HDSL line lengths inexpensively but effectively. The use of two or three twisted pairs of telephone wires for the organization of the HDSL line makes this system an ideal solution for connecting PBXs, Internet servers, local networks, etc. HDSL2 technology is the logical result of the development of HDSL technology. This technology provides similar performance to HDSL technology, but uses only one pair of wires.

SDSL (Single Line Digital Subscriber Line - single line digital subscriber line)

As well as HDSL technology, SDSL technology provides symmetric data transfer at speeds corresponding to the speeds of the T1 / E1 line, but the SDSL technology has two important differences. Firstly, only one twisted pair of wires is used, and secondly, the maximum transmission distance is limited to 3 km. Within this distance, SDSL technology provides, for example, the operation of a video conferencing system, when it is necessary to maintain the same data transfer streams in both directions. In a sense, SDSL technology is the predecessor to HDSL2 technology.

VDSL (Very High Bit-Rate Digital Subscriber Line - ultra high speed digital subscriber line)

VDSL technology is the fastest xDSL technology. It provides downstream data rates ranging from 13 to 52 Mbit / s, and upstream data rates ranging from 1.5 to 2.3 Mbit / s, with one twisted pair of telephone wires. In symmetric mode, speeds up to 26 Mbps are supported. VDSL can be seen as a cost-effective alternative to routing fiber to the end user. However, the maximum transmission distance for this technology is from 300 meters to 1300 meters. That is, either the length of the subscriber line should not exceed this value, or the fiber-optic cable should be brought closer to the user (for example, brought into a building with many potential users). VDSL technology can be used for the same purposes as ADSL; in addition, it can be used to transmit high definition television (HDTV) signals, video on demand, etc.

First, DSL technologies provide high-speed data transfer. Different options for DSL technologies provide different data rates, but in any case, this rate is much higher than the speed of the fastest analog modem.
Secondly, DSL technologies leave you the opportunity to use a regular telephone connection, despite the fact that they use a subscriber telephone line for their work. With DSL technology, you no longer need to worry that you will not receive an important news in time, or that for a regular phone call you first need to go out of the Internet.

Finally, the DSL line always works. The connection is always established, and you no longer need to dial the phone number and wait for the connection to be established every time you want to connect. You no longer have to worry about an accidental disconnection in the network, and you will lose connection at the very moment when you download data from the network that you simply vital. Email you will receive at the time of admission, and not when you decide to check it. In general, the line will always work, and you will always be on the line.