Transmission of data on electrical wiring: HOMEPLUG AV standard equipment. MGTS will transfer television through a socket what PowerLine adapters

You probably know the situation when some incredible number of wires going to the monitor, a mouse, keyboard, router, and so on, wriggle around the home computer. You can get rid of them in several ways. The easiest thing is to cut, more complicated - go to wireless technologies.

We will not argue about the convenience of wireless mice or keyboards: it all accumulates directly around the computer and therefore it does not interfere especially to live. But Ethernet cables often have to pull across the quarterly. With competent repair, you can take into account all aspects and place an outlet on the house or apartment for connecting to the network. When moving to a removable apartment decide such a question more difficult, there are other nuances.

Wi-Fi? It is not always necessary to hope for it, since the material of the walls is affected by its work, their location. And if we are talking about an apartment building, then there is also an abundance of other wireless access points: the ether is filled with a little more than completely. In the afternoon, it is not so noticeable, in the evening there may begin problems with ping and lags when viewing IPTV or the game "by air".

Options for their solutions - manual settings and regular analysis of the ether, transition to access points with 5 GHz support or return to the sources - wires. The first seems to be time consuming, and it is unlikely that the home user will be constantly digging in dull programs, looking for a free space in the range of 2.4 GHz. Imagine your mother / dad / grandmother / grandfather behind this occupation ... For a start, you would have to teach them using a touch screen smartphone.

Go to 5 GHz? This is an excellent option that we recommend and specialists in the field of communication. However, such routers will cost money, and not all home devices will be able to work on the network. Incredibly, but the fact: this range is incomprehensible to even the current PlayStation 4, which is to talk about inexpensive smartphones and televisions.

Well, the most inconvenient, but a practical way - wires. You can assume a spiderman, decompose them all over the house and with certain skills to achieve aesthetic species. There is another "wired option", which we tested, - PowerLine technology when the Internet enters through the power cable. Slightly scares, honestly ... In a scientific, this is called "communication on the LAP", and it uses the power lines to transmit data on them.

We will not tire a historical certificate, but immediately proceed to business. For testing, we chose an apartment in the house built in the late 70s of the last century. The same ancient aluminum wires are laid in the walls, three automatons are installed in the shield, but the phase is one, as in the overwhelming majority. The operator cable is started in one of the rooms where an inexpensive router with Wi-Fi is installed.

Well, we learn how to cope with aluminum powder with a load. TP-LINK AV1200 TP-LINK AV1200 Testing Adapters "accelerate" to gigabita, but it is possible to utilize all this power, except on the local network in conditions approximate to ideal. Externally, adapters are quite large rectangular boxes with a set of indicators on the side, perforation for ventilation around the perimeter, connector for a data cable and a duplicating socket, that is, the "Through" adapter can still be connected to the technique.

How it works?

The leading adapter needs to receive from somewhere else. We insert the device into the socket and connect the cable from the router to it. Our TP-LINK blinks with light bulbs, and without any settings throughout the apartment when the second adapter is activated, the Internet should appear. Well, isn't Magic?!

Now you can go to any room where there is a socket, and look for a place for the second adapter.

In the adapter models without Wi-Fi, any device will require an Ethernet cable to connect: the same laptop will have to be connected via patch cord. If you want to connect to the Internet "Kitchen" TV, then this option looks more practical.

The range of devices, or rather, their ability to communicate in electrical wiring without loss of packets is 100 meters (for the device being tested). At the same time, it is necessary to take into account the wiring method in the walls that do not go directly from the point A to the point B. If something goes wrong and the second adapter will not see a pair, there is a button forced "pairing". Adapters are looking for each other seconds 10, no user intervention creates a data circuit. The signal can circulate throughout the house, but it all depends on how the wiring is diluted. And remember: just stuck in the plug from the TV or laptop, you will not receive the Internet.

"The 128-bit AES connection is encrypted, the data will not see your neighbor. If the wiring is old, if the contact somewhere is moving, the wires are poorly twisted - it can adversely affect the bandwidth. According to the manufacturer, devices are still, whether copper or aluminum is used in the wiring, " Said Sergey Barisevich, Head of the Client Technical Support Department of Atlant Telecom.

All, no passwords do not need to enter, we also have an ordinary local network with access to the Internet. Now we are interested in speeds.

First, IPTV tested on the TV, running HD channels. No brakes, "lags" and scattering pictures, speed, obviously grabs with more than. "For stable quality, HD content requires 18 Mbps," - Commented on Sergey.

Speedtest turns. The tariff plan allows you to transmit data by 100 Mbps, so we are waiting for the corresponding indicators. Maximum that managed to squeeze out of old wires in the walls - more than 85 Mbps. This is a very decent result with all aspects. At the maximum possible distance in the apartment from the basic outlet, speed dropped to 80 Mbps.

Before the next measurement of speed, load the electrical network to prevent the smooth flow of bits in the wiring. The light includes the light, the TV is working, buzzes the computer fans, tahrates the refrigerator, the microwave and a powerful electric kettle are joined. The next "Speedtest" shows about the same figures, with a minor decline in the region of 5-10%.

Interestingly, Ping practically does not change ("Tankers" will be satisfied), while when connecting through Wi-Fi due to the clog of ether and remoteness from the access point, it jumps to 250-300 ms with a maximum of 30 ms through an electrical outlet. Measurements have shown that wireless communication in an apartment building is less effective in comparison with PowerLine. But still more convenient.

Later, under the conditions of the office, the data transfer rate was 35 Mbit / s at a distance of at least three times more than in the apartment (but it may be even more: the posting schemes did not turn out at hand). In addition, dozens of devices consuming energy are connected here to sockets.

In both cases, there are no complaints about data quality: it is definitely higher than "by air", even with the load on the electrical network.

Why is this technology not used everywhere?

"Question price. Yes, the user can buy a couple of adapters, but the connection price will grow twice. And Wi-Fi is also cheaper, and also provides greater mobility. This solution is convenient for static installed devices. For the same IPTV, you get a stable signal. Even when working through a network filter ", - considers the technical specialist.

Why don't operators use PowerLine?

At one time, the operators studied the possibility of applying such technology to provide Internet access for homes. "Roughly speaking, one switch is put on the house, connected to optics, and the subscriber receives his adapter in the apartment. No additional wiring was required. " - told Sergey. But in fact, it would be a significant waste: operators cannot guarantee the quality of wiring laid 5-10, 30 or more years ago. "Something like this happens with ADSL technology, when all operators depend on the Beltell phone line and cannot control the quality of the connection," - he added.

conclusions

In a small apartment, if there is a Wi-Fi, the practicality of PowerLine adapters is not obvious. The exception is only stationary installed technique: smart TV or console. Models with wireless modules are more expensive, but allow you to ensure uninterrupted Wi-Fi coating in apartments, where the walls interfere with the signal. Similarly, for a private house, when, for example, you need to spend the Internet into the basement.

Good afternoon friends! Greetings to our learning Internet portal "With a computer on" you ".

In the previous article we talked about, disassembled the most popular. But sometimes it happens that the usual connection methods (Ethernet network cable or wireless connection Wi-Fi) cannot be used.

Reasons for that recently renovated renovation and not a desire to make extra holes in the walls for laying the cable; Steel fittings in the walls and overlap of monolithic structures that impede radio wave penetration and much more.

If you hit this situation, then your choice is. In this case, the role of a computer local network will perform a regular wiring at home. The most common technology providing the liner between the 220-volt socket and the Ethernet port is the HomePlugav standard.

Providing Internet access by electrical network is possible due to the development of PLC technology (Power Line Communication - transmission of data on the electrical outlet). PLC in terms of its capabilities is no different from other technologies, only does not require a special cable or wireless channel with dedicated frequent. Data is transmitted by home power grid.

To create such a network, you will need two adapters: one is inserted into the socket and commutes a twisted pair with a computer or a router that provides Internet access. To provide other computers Internet through a socket You need to connect an additional homeplugav adapter in the same etherprove itself.

The principle of operation of such adapters is quite simple. As you know, the current on the wires of the home power grid is transmitted with a frequency of 50 Hz. The adapters convert computer data into an electrical signal with a higher frequency (2 - 32 MHz) and impose it to an alternating current of the power grid. On the receiving side there is a reverse transformation.

types HomePlugav Adapters

1. With the Ethernet port. In this case, the transfer of data between the computer and the adapter is carried out using a conventional twisted pair.

2. With the presence of a WLAN module. Computer connection is installed on a wireless network. In addition, adapters, as a rule, are additionally completed with the Ethernet port.

3. With the connector for connecting the satellite antenna. This type of adapters can include the latest and new models that use a home power grid to transmit a signal from the satellite antenna to a computer or TV receiver.

Advantages of the technology "Internet through a socket"

Lack of additional wires. No need to lay the network cables, it is enough to insert the adapter into the rosette of the appropriate room.
Large range. Since in modern apartments and houses outlets are present in each room, the Internet is available in any corner of the apartment. What can not be said about the Wi-Fi network: the signal is already weakening when passing through two walls. If the house is 2-storey, then without a repeater signal can not do.
The possibility of rapid expansion. It is enough to purchase an additional adapter.

disadvantages of the technology "Internet through a socket"

HomePlugav Adapters can serve as a source of interference for radiophers and short-wave radio transmitters. The reason is that the adapters convert computer data into the signal range of short waves and transmit them together with an electrical signal of the power grid. Because The wiring, unlike coaxial wiring, is not shielded, it is similar to the transmitting antenna, radiates a shortwall radio signal. Many manufacturers equip their adapters with special filters in order to exclude radio interference.
Other electrical appliances (washing machines, computers or TV) can be added to the data channel. As a result of the influence of such devices, the data rate on the network drops very sharply.
Modern apartments are usually equipped with three-phase electrolyones, i.e. There is no power grid in the apartment, and three. In this case, it is necessary to establish a phase pairing device to carry out the transfer data on the electrical network in the electrical panel (on the staircase).

data security in PLC networks

Because The power grid is not limited to one apartment and even by one building, the probability of connecting to your network is very high. However, the HOMEPLUGAV standard has not only a high data transfer rate (about 200 Mbps), but also a high data reliability (an AES encryption algorithm is used with a 128 bit key). And if you consider that there is no widespread equipment of digital devices in this technology (as in the case of Wi-Fi), we can say that "Internet through a socket" has sufficient security and reliability.

prospects for the development of technology

Despite the widespread development of the wireless network, the PLC technology (in particular the HomePlugav standard) will also get its popularity. Large distances, the need for high bandwidth, radio absorbing obstacles - all this makes "Internet through a socket" in demand from users.

This technology has its drawbacks, as in any other technology. But progress does not stand still, the standard is improved, the speed and noise of the channel is growing.

Among other things, the spread of PLC networks is promoted by the popularity of another technology of the near future - intelligent home networks ("smart" house). No one will argue that the future for a single monitoring and management of all household appliances and all life support systems is from the light bulb to the door lock. And the technology transfer technology PLC is suitable for this, as it is impossible.

D-Link DHP-P308AV is a PowerLine network adapter. It allows you to connect the device to the local network using the power supply network.

The development of Power Line Communications (PLC) specification is engaged in HomePlug Alliance. At the moment, such specifications have already been developed by several:

HomePlug 1.0.

up to 14 Mbps

HomePlug AV.

AV 200 (up to 200 Mbps)
AV 500 (up to 500 Mbps)

HomePlug Av2.

Up to 1200 Mbps

But it is necessary to understand that the values \u200b\u200bof the values \u200b\u200bare physical speeds. The actual data transfer rate will always be less. In addition, the real speed will depend on the quality of electrical wiring in the house.

The disadvantages of PLC technology include the impossibility of the operation of devices in the shared network if they are connected to electrical outlets at different phases. But this can be circumvented in two ways:

Turn on one device for each phase and connect them through the switch;
Put an interfacial repeater, such as MRC-1 (Russian production).

D-Link DHP-P308AV is the HOMEPLUG AV 500 adapter. The adapter is equipped with a built-in "Passthrough" socket through which other electrical devices can be connected to the main outlet. In this case, the adapter filters electrical interference from the connected device, which may affect the PowerLine connection.

D-Link has similar devices:

DHP-308AV - HOMEPLUG AV 500 adapter without built-in socket "Passthrough";
DHP-P309AV - set (Starter Kit) of two DHP-P308AV adapters;
DHP-309AV - set (Starter Kit) of two DHP-308AV adapters.

The D-LINK DHP-308AV adapter looks like this:

The DHP-P308AV adapter differs from DHP-308AV the presence of a built-in socket, the rest of the device is identical.

Data transfer in PLC network is provided by using AES 128 encryption. And this means that encryption keys should be generated. This is the configuration of adapters.

Everything is configured very simple.

1. Connect the adapters to electrical outlets. For resetting settings to the default settings, click the SIMPLE CONNECT button and keep it pressed for 10 seconds.

2. Then on the first adapter, click the SIMPLE CONNECT button. Pressing time - no more than 3 seconds. After the button is released, the power indicator (Power LED) will flash.

3. No later than 2 minutes, you need to press the SIMPLE CONNECT button on the second adapter. Pressing time - no more than 3 seconds. Release the SIMPLE CONNECT button, the Power LED indicator will flash.

Adapters configure encryption keys. The settings will be remembered before they are disconnected from the network.

If you need to connect more than two adapters, then on subsequent adapters you need to press the SIMPLE CONNECT button (no more than 3 seconds) and then press the SIMPLE CONNECT button on any of the adapters of the existing PLC network. The Simple Connect button on the second adapter must be pressed no later than 2 minutes after pressing the button on the first adapter.

If you quickly press the SIMPLE CONNECT button twice, the adapter will switch to energy-saving mode. To "awaken" the device, you need to click on the SIMPLE CONNECT button again. And be careful, because the adapters cannot be configured while they are in energy-saving mode.

The fact that the Poweline connection is set to signal the 18 Powerline LED indicator (PowerLine LED).

Now we can connect network devices to the Ethernet ports of the adapters and our local network will work through the wiring.

After familiarization with the next material, the joke about the "Ethernet killer", which represents patch cord with the RJ-45 plug at one end and a plug of connection to the network 220 V - on the other, no longer seem so witty. True, the gap of this wire will need to include the corresponding Powerline adapter ...

The famous joke that the majority of inventions comes from human laziness, applies very well to data networks. Since the presence of communication between computers in the office has become mandatory, and Ethernet has become a de facto standard, attempts have not ceased to make this relationship even easier - for example, getting rid of the need to lay additional cables.

On the various technologies that allow "save" on the wiring of a separate network infrastructure, we have already written more than once - for example about HomePNA, involving use, or about wireless networks. The technology that will be discussed today uses to build local networks ... the usual wiring existing in any building.

PowerLine technology has a complex and changeable fate. Several times she was kept a central place in the development of home information networks. Then "Forgotten" about it, so that as the technological base improves the technological base, it will return to return and proclaim it almost a panacea. They did not induce attention this sector of the market. Nor research agencies, nor IT-publications (as it turned out, there are only a couple of more or less serious publications on this topic, but in Uanet - and less).

Partly want to fill out the established informational vacuum, in part in connection with the next wave of commercial interest in this democratic and, at first glance, an extremely simple idea, we decided to continue the conversation started in the review "", adding his story about what efforts are achieved sustainable Work via the power supply. The readers are offered a detailed overview of Powerline technology, as well as tests and our impressions of the operation of devices that are already actually present in the domestic market.

You really do not hold us away for fools.
You are here in the project indicated 70 meters of cable and 10 network sockets.
And we have that, in your opinion, computers are still from solar
Energy harvested? Can you, maybe new drilling holes gathered? ...
(From the discussion of the Calculation on the Network, 1996)

Of this sufficiently comical history, when I had to prove a small company for a long time and reasoned, that the information cable and sockets really need to be installed, because the network of the power supply is one, and the information network is absolutely different, the final question is remembered, symbolizing farewell from The last hope: "So, according to the same wires it is impossible?". If you close your eyes to some "non-technical" formulation of the question itself, this person is quite easy to understand. Only ended the chic repair of the mansion, and the need to work with the Organization with a well-established floculation system, located just in four rooms on three floors, was dictated in a single network with more considerations of prestige, rather than an urgent need.

Is it possible in those days to answer this question in the affirmative? Back in 1996 - no. Wireless networks are expensive and unstable. As a long-standing technologies and transmission protocols for Energy Setails (X-10, Cebus, LonWorks) and many others, with advertising bands promising to "saturate our intelligence our dwelling" and subsequently without a trading in the summer, were more exotic in the domestic market. They were characterized either low exchange rate, or a weak noise immunity, or the first and second at the same time, and scared the unnecessarily high cost of the terminal devices.

PowerLine: childhood, adolescence, youth

... and experience, son of difficult mistakes ...

Meanwhile, the story has kept many attempts to use as a physical environment for the exchange of data "unsuitable" wires. It is easier, of course, operated with telephone "copper pairs" - their parameters were standardized, and the rules of the gasket were presented quite rigid, unified in a number of countries, requirements. Therefore, therefore, the technology proposed by TUT Systems (mid-90s) has become the first viable technology of transmission technology on alternative wires. As it is known, on its basis, the standard of transferring data on telephone wiring, HOMEPNA 1.0, was soon adopted. Let the first version of this standard were not very "advanced", but on the network by homepna 1.0, numbering up to 7-10 computers, as a whole, it was possible to obtain 1 Mbps with a range between them about 100-150 m.

Although home network wiring for a number of reasons to which we will return later, the environment is even less grateful, the idea to use one transport to power the devices and transmission of control signals goes to its roots almost to the beginning of the electricity era. In patent annals of the 20s of the 20th century, it was possible to detect an offer based on "... using the tones of several voice [sound band. - approx. The author] frequencies to enable and disable the wires on the wires for which it is powered. " Moreover, as a control signal in an extended patent formula, an enterprising author "docked" use ... whistle and microphone with amplifier.

But objectively asserting who exactly made the next decisive step "into the outlet", it is quite difficult - the development of technology was a long chain from tactical research victories and strategic market lesions. The conducted search engines were characterized by an explanation and differed in directions: some companies set themselves the task of getting rid of additional wires in the transmission of audio signals, as a result of their work already in the 40s there were various "beabyphones" and "intercoms". Others (this is already applied by the end of the 70s) threatened forces on noise-protective control systems for the supply network, which did not require high metabolism. Third ways of various sophistications were trying to "squeeze" a band, occupied by a video signal (it constitutes megahertz units), in a conventional power cable. True, in practice it often turned out that the economic efficiency of using these decisions was usually imaginary.

It became obvious that the embodiment of albeit, but, in fact, the analog or quasiciferous approaches to the formation, encoding and transmission of information and being connected existing technological restrictions (such as: high cost DAC, ADC and other digital processing path components signals), commercial versions of "serious" devices do not create. This, in the end, cooled the fervor of the skeners, and a good ten years old, the idea slowly "was cooked in its own juice." However, still on the market you can find connected network wires (intercoms, mini-PBX) and uncomplicated control devices (for example, ignitioning several chandeliers), produced by serial, and in the Internet - to meet a description of the original projects and various interesting designs: From amateur (usually using for the formation of a set of commands for the sound or ultrasonic frequency range) to sensors, decoders and commanders for the needs of industrial electronics.

And as if, in childish, it was primitive to these devices with the heights of technological development today, it is thanks to a number of conceptual decisions of those years, we can tell today about the information transfer devices on the wires of the supply network, which in practice proved that they are able to provide high speed and observance of the process Exchange and have a sufficient resource to address device devices. The last fact is especially important when mass distribution, as it determines the ability to unambiguously identify, to whom the information is directed. For those who consider this requirement not so critical, we remind the American joke, telling about how to press the button of the network remote control of the coffee maker (apparently working on the principles close to the aforementioned patent!) He led to the execution of a team to defrost the refrigerator and the inclusion of irrigation of lawns on the neighbor's site.

The period of adolescence in the development of technology is usually associated with a number of conducted in 1997-2000. Experiments on data transfer and votes in the framework of pilot projects of leading research laboratories. In addition to those who are little known at that time of the companies, such giants of the telecommunications industry, like Siemens, Nortel and several service providers of German and Great Britain participated in them. And although the plans were built by Truly Napoleonic (Norweb Telecom managed to conclude agreements with a dozen leading energy companies of Eurasia) and the promises were distributed generously (1.5 Pfenniga in a minute of work on the Internet), the idea of \u200b\u200blarge-scale electrical wiring is once again "not lucky".

Explanations and reasons for this can be given by many: and high level of side emission of devices, and their cost, comparable with the price of DSL and cable modems, and the structural imperfection of the terminal devices, and an unstable working to them, and hard pressing from large telecommunication companies ... All this is the case, but, according to the author, not the last role played by marketing errors related to the peculiarities of the perception of solutions to those addressed to. Recall that it was for these years a victorious procession "Twisted Pair" under the slogans "Fast Ethernet in every office". And those responsible for small office networks, the specialists who have impaired with BNC connectors and end terminators were obviously not prone to experiments with the new and more and more and more sufficiently crude technology that did not promise high speeds and the inheritance topology of the "coaxial" ethernet age. As for cautious ordinary burghers involved in experiments ... Calculation that they will defend a technological decision, let it even be very promising, to the detriment of their current needs and financial interests, as repeatedly evidenced by the history of the development of technology, is doomed in advance - "... Copper Ground and do what you want with him. "

Let the first attempts to put on the commercial basis, the organization of home networks and the "distribution" of the Internet did not lead to the expected coup in the market of telematic services, already in 2001, serially produced devices with a modest inscription "HomePlug 1.0" proved during operational tests conducted in 500 homes, That effective work through the power supply network is possible in 98% of cases.

Fig. 1. Prospects drawn by analysts inspire optimism

Reliability laid in the standard, vitality and quite a high speed, according to analysts, forced to think about telephone companies how hard they hold "their piece of cake", which served as one of the factors of further decline in prices for network connection services.

The provision of access services in the Internet is the most attractive, although not the only scope of application of information transfer technologies for power wires. Today, all the well-known directions, within which the development of such systems seems as a basis for sharing information through the network, can be considered to be conditionally divided into three groups.

The first group. Wednesday for information exchange between control and management of home automation systems

The house, full electrical appliances and welcoming its owners, appeared in the fantastic novels of Ray Bradbury back in the 60s. And still most of us these ideas are perceived as popular science fiction, is not cheaper and not vital. But in the original idea - to link the controller (control unit), computer, printer, phone, climate control sensors and various actuators (like: managed switches, air conditioning, heaters, kitchen household appliances, aquarium and lawn irrigation system) - Nothing suzelic and supernatural is not contained. Moreover, its individual elements available for sale today can and should be considered as a basis for creating a comfortable, autonomous, safe and energy-saving (for some estimates - up to 20-25% of expenses) of the future management system. It can be assumed that as the cost of energy and electricity is further growth, its payback period will decrease. And I want to believe that in the near future, significant initial investments are pleasing to be a serious obstacle to their introduction ...

It is clear that such a single environment, including PC, and computer peripherals, and household devices, can function only if there is a local information network, the main requirement of which is a high and guaranteed level of reliability due to, primarily, the degree of excellence of the technology of exchange data. Obviously, the appearance of interface jacks for connecting USB, FireWire or Ethernet on the kettle, vacuum cleaner, or lamp-shed is unlikely to be perceived by the buyer with joy. Although we will not shut down - surely there is a manufacturer who will manage not only integrate all this in his coffee maker, but also convince the client that he dreamed of all his life.

By the way, it is with the emergence of new versions of information transmission technologies that the process of rethinking the concept of a home security system is associated with a wide range of sensors (firefighters, movements, glass, etc.), monitoring subsystems (including tracking chambers), fire extinguishing and access controls objects. Here, however, emphasis should be placed. While we can talk about "security", used as auxiliary (or additions to already existing, or autonomous), because to connect to a centralized security or fire system, a corresponding certificate may be required both on the sensor and in general on the technology of transmitting this information . For a number of preliminary estimates, the technical parameters of such solutions of security systems (first of all - on the criteria for the reliability and protectedness of the transmission channel) are comparable or even better than that of existing wireless.

The second group. PowerLine Phones & Media

In principle, in the telephone solutions market there are original devices. So, in the summer of 2002, Ascom from Bern reported that he began to release a new series built on the company PLC adapter. At the heart of the Voice Over Powerline solution offered by the company, are small cute boxes, each of which can be connected from one to four voice (or facsimile) terminals and organize up to two pairs of telephone conversations at the same time. The press release emphasizes that the use of new type products does not impair the parameters of the "computer" exchange in the network on the electrical wiring.

Otherwise, telephony solutions are based on standard classic Voice Over IP, and PowerLine adapters assigned the role of Ethernet-to-PowerLine environmental converters, the network connector of which the telephone IP apparatus is connected.

The first experiment on the transmission of music in the framework of the idea of \u200b\u200bcombining household electronic devices into a single home infrastructure is associated with the demonstration of Motorola, Phoenix Broadband and SonicBlue companies, when the computer connected to the power out of the network has sent files loaded from the Internet to the SONICBLUE Rio MP3 player.

The basic requirements for such systems are to ensure a certain QoS and, in the second case, also satisfying the growing "appetites" of streaming audio and video and video information with high quality. They are tougher if there are several such streams or data transmission in parallel with other types of applications. Almost when using the HOMEPLUG 1.0 standard devices, it was proved to transmit two MPEG-1/2 streams without tangible delays while maintaining network activity (some averaged standard "streaming") between the five-six other subscribers. A significant demonstration was a significant demonstration on the last 2003 of the Consumer Electronics Show of the first transmission at the beginning of 2003 with a speed of 30 FPS high-quality video along the Powerline network stand. Wested by VIXS Systems companies (chip developer and video) and COGENCY SEMICONDUCTOR (Piranhat chipset manufacturer). By the way, it is reported that the experiment was duplicated by broadcasting through the WLAN channel, and the difference between the first and second transmission methods could not be detected.

Group third. PowerLine Networking and Powerline Internet

The tendency to increase the number of computers in the house continues to gain momentum, which requires the appearance of cheap and convenient means to combine computers and peripheral devices into a single network, when the laying of new wires is invalid or inexpedient (Fig. 2).

Fig. 2. Powerline home network structure. Connect to Intranet / Internet

However, the discussion of only one case is to connect multiple devices within one apartment or a private house - the possibilities of using PowerLine are not limited.

The second aspect of the application of the technology "network over power" is the solution of the problem of the "last mile" and "last feet" when connected to the network. Moreover, in 1999, such a solution to the problem was considered so economically correct that the project was "disclosed" a project with a dual abbreviation of Palas - Powerline for Alternative Local Access, designed in every way to contribute to the introduction of technology to the European market. The calculation of his participants was based on the fact that the power supply networks covers up to 95% of the territory hidden by man. The cells of such infrastructure are quite regular, and, and, according to preliminary estimates, the number of potential users, to cover which there is no need to create a new cable infrastructure, exceeds the number of telephone subscribers in 1.5-5 times (depending on the level of the region's telephonization). Experts reasonably believed that where telephone communication was not developed enough, the demand for the Internet connection through the electrical network would be an order of magnitude higher. True, as for the Palas itself, then, judging by the state of Palas.regiocom.net, the work of its members does not differ in particular activity.

The structure of such an informational education may be similar to those shown in Fig. 2. The design maximum strip in terms of one subscriber is usually reduced to 300-500 kbps. At the same time, however, the requirements for the minimum level of information security (mechanisms of user authentication and data streams) - after all, the topology of the educated network is similar to the topology of the coaxial Ethernet and allows you to "listen to everyone".

For those who have the opportunity to Powerline "at the reception" will be still insufficient, it is possible to offer to take advantage of the already tested solutions for asymmetric access to information. For example, from a satellite, the user receives incoming traffic at speeds to units of MBPs, and ground communication lines send a small outgoing traffic. Such a solution to the task of the "last mile" easily fits into the elevated structure and is primarily focused on small companies and discerning private users.

However, and here we will have to make a slight retreat, reminding the differences in foreign power supply systems from domestic. If in most countries of the world, it is customary to bring two phases and protective "zero", then almost all apartments of Ukrainian energy consolments are content with the connection to one of the three phases of the network 380 V and "zero", i.e., if we consider the task of building a unified network based on an apartment building (And the maximum range of homeplug devices allows), then to combine all users to the "total bus" between the "phases" it will be necessary to include the appropriate bridges. Without going into the particular schemery of this simple device, we note that the task of creating an infrastructure can go beyond the simple installation of ready-made, tested and certified solutions in the West. Although with a large number of clients may be appropriate to combine three groups (subnets) into a single network using the corresponding switch already immediately before entering the external channel to the house.

Finishing this small analysis, we will once again discuss that the attempt to delimit services is more than conditional - in the development of modern network technologies as a trend in the development of a trend after an increase in speed is the desire to combine various types of traffic in a single network stream (data, telephony, video). Another thing is that the required bandwidth with all the desired services simultaneously (and it, as it turned out, for PowerLine devices - even less than 10 Mbps) may not be enough (Fig. 3).

Fig. 3. The tendency to combine all groups of devices. Will the strip enough?

Finally, those who intend to organize the provision of network access services will have to return to the issue of developing a software kit for remote administration and monitoring with advanced features due to the specifics of this technology. Such a kit, except for the standard network capabilities for this case, should allow:

detect all devices that are online and define their type (Ethernet, USB or PCI card) and a MAC address assigned to the manufacturer, and also provide the administrator to determine and assign the IP address of the device;
conduct constant network monitoring and create graphs of the workload of one or another area, as well as collect traffic statistics on each of the protocols used, to quickly monitor and check the quality of the connection with each of the devices on the network (at the level of the physical connection);
remotely manage customer access rights to the service (to connect / disconnect the user), change the password to create a custom network with your security settings. It will be worthwhile to provide the capabilities to the operator to assign, which of the specific devices (if one client has several) allow access to the service. Thus, it will be possible, for example, to block the installation by the user of any PowerLine adapter acquired by them without negotiation with the service provider.

Running forward, we note that today from all the considered software packages on functionality to these requirements are closer to all the Open Powerline Management set from Corinex. It includes the PowerNet Setup Tool utility, which allows you to find all MAC addresses available PowerNet devices. However, in practice it turned out that it is necessary for her work the presence in the network at least one "native" device.

We still stop at this, providing economists with the opportunity to carry out a deeper analysis. Obviously, the potential laid in Powerline is huge, and as of today, the use of technology can be the subject of business, in particular, for energy supply companies. As an example, the Mosenergo program, conducted in Zelenograd, the former "silicon capital" of Russia, can be given. At the first stage, it is planned to resolve pressing problems associated with the consumption of electricity and the management of the power supply system. The following is planned to provide access services in the Internet, IP telephony, teleconferencing organizations and others.

Technologies for transmitting control signals and network wiring information

PowerLine - Definition and Classification

PowerLine, Powerline Communications (PLC) - a family of communication technology, which are based on the use of an existing power supply network (120 V, 220 V, etc.) as a physical environmental distribution environment.

As existing research on these technologies, the devices already implemented "in the hardware" can be differentiated by the exchange rate.

Low Baud Rate (Low Baud Rate, sometimes below 0.05 kbps) with transmission ranges up to tens of kilometers. Such PLC systems are already used in the energy sector at high-voltage trunk systems for the transfer of service telemetry information.
MEDIUM BAUD RATE, usually in the range from 0.05 to 50 kbps) for medium distances not exceeding several kilometers. Such PLC systems allow you to implement simple controlling applications and are focused on existing network power supply infrastructures (home automation, lighting control systems, organization of automatic measurements, monitoring via the Internet, etc.). Information is transmitted in the frequency band 50-535 kHz.
High Speed \u200b\u200bExchange (High Baud Rate, from 100 Kbps). The main purpose is "Computer" local data exchange. Classic for such systems usually include tasks of combining into the shared access resources of existing printers, scanners and other devices, as well as the organization of the home or computer network SOHO. This class would fairly be included the solution of the entire spectrum of multimedia tasks. Devices due to a number of contradictory requirements are forced to occupy a sufficiently wide frequency band (ranging from 1.7 to 30 MHz) and ensure work at a distance of up to several hundred meters. This category includes HomePlug Powerline devices.

Problems associated with the transmission medium or
Is it really so difficult?

Actually, if you deepen into technical problems, you can try to explain why the PowerLine adapter cannot be compared with an Ethernet card. Do not forget that the latter is designed to use in combination with a designed transmitted medium specifically for it, and it allows it to be simple, affordable and cheap. But it is worth taking the transmission to "non-specialized" wires - and the design becomes complex and notable: it is forced to compensate for its complexity and high costs to compensate for work with the surrogate of network cables.

Consider in more detail. We will be interested in the following frequency band in several dozen megahertz, its minimum value is determined by the informational band that must be ensured, in our case - up to a tent of the MBPS. So, in the network cable with increasing frequency (as, however, in any other feeder), the value of the pursuit of the attenuation is growing (Fig. 4).

Fig. 4. The feeding electrocabel itself is not the best environment for distributing high-frequency signals.

In practice, this means that, wishing on the other end of the cable to accept and process the entire spectrum of the source signal, we will have to transmit its high-frequency components to dozens of tens of time than in the low-frequency part. There are sufficiently rigid restrictions both on the frequency range that can occupy the signals in the cable and for their maximum levels, which forces the use of special techniques to reduce the spectral density of the signal power and at the same time use incessic methods for the economical representation (encoding) of the original digital signals .

The next problem inherent in the apartment network wiring is reflections from the inhomogeneities of its structure. Each number of wiring, the contact group, parallel inclusion and branch of the wires lead to multiple interference of direct / delayed signals and to the frequency-selective weakening. Ignoring light, including something and disconnecting from the network using the extension cords, we constantly change the parameters of this structure, and not only in yourself, but also, to some extent, the neighbor is driven from the same "phase". It leads to this to a fairly well known in wireless radio systems and multimode fiber-optic communication lines with an effect called intersomol interference (ISI). There, it is determined by the multipath propagation of radio waves (i.e., the arrival at the receiver simultaneously several signals shifted by a certain amount proportional to the difference in distances traveled by each of them). As a result, the short pulse "blurs" and turns into a wider or even in a sequence of several, i.e. the transmitter was emitted by one pulse corresponding to the symbol (or several characters in a row corresponding to the information group), a whole series detects on the receiver, which leads To the wrong interpretation and, as a result, - to errors in the transmission session and limit the maximum bandwidth of the channel.

But the total number of different terminal devices that actively affect the parameters of the power network, even in a small house, cannot be given any account. Moreover, many of the household appliances (vacuum cleaners, mixers, PCs with cheap power supplies, fluorescent lamps, etc.) are not just "noisy", but are capable of generating long series of pulses with amplitudes, an order of magnitude exceeding the expected in the outlet 220 V . It remains to add several burnt contacts on the shield and the legendary "Uncle Vanya with welding" to this "electrochat". For completeness, the picture is also recommended that the wires of the network are not only emitted, but they also cope with radio wave reception (radio stations of at least three broadcasting and four amateur wave ranges fall into the bands) to understand that tangle problems over which device developers Powerline beat more than a dozen years.

Oreke hard, but still ...

Work continues and on improving software products. In the joint statement of Intellon and Corinex, I am already promised to a software based on the MIB Open Standard (Management Base). Its use will make it possible to make the installation process more "transparent" and expand the possibilities of local and remote network administration devices based on Intellon chips (Specification HomePlug 1.0.1). Note that since the standard HomePlug 1.0.1 is still implemented by "in the gland" only in the development of the "pocket" company Intellon Alliance, at the moment we can put the sign between its chipsets and the standard itself. In the meantime, on the Corinex website, the contents of the installation CD containing drivers, by PowerNet Setup Tool and the SNMP agent for PowerNet, operating only with their own, branded devices.

conclusions

Let us summarize the foregoing. HOMEPLUG 1.0's PowerLine Device Market from different manufacturers, quite easily finding "Common Language", suggests that finally the technology "cleared" from serious hereditary compatibility issues and came out of the discharge of exotic on the level of commercial operation. It is possible only to be surprised that such a logical invention in the style of "Gol on the fiction of the cunning" did not appear in the post-Soviet space. Although, on the other hand, such a decision due to the "accidents" of the transmission environment requires implementation in the "hardware" of fairly difficult principles and suggests the developer of all production elements of the technological cycle, which allow you to bring the idea to a stage of commercial exploitation.

Although the claimed maximum theoretical bandwidth of POWERLINE networks - 14 Mbps, the actual average data transfer rate was equal to 5-6 Mbps. These indicators are comparable to HOMEPNA characteristics and wireless networks (WLAN) for IEEE 802.11b and HOMERF 2.0. The technology is more simple for implementation than telephone networks, because if the telephone socket is not found in each room, then there is a power outlet everywhere, and even more so next to the computer or printer. For it, there are no "dead zones" characteristic of wireless solutions (when it is not possible to take a signal at certain points of the room), and its organization can do cheaper than the gasket "from scratch" wired Ethernet. Although the current cost of POWERLINE devices in terms of the user is comparable or even exceeds the price of the WLAN kit (Wi-Fi, without taking into account the value of the license), there are all chances that, as the device's release is mastered, it will gradually decline.

For each of the main parameters, HOMEPLUG technology has a decent competitor. But in fact, despite a number of promises to "cheap all" with other technologies, a unambiguous universal solution that combines acceptable quality and simplicity with minimal initial and proportional subsequent investments for the infrastructure of the scale, such as the middle city house, not. In contrast to the already mastered, transmission technology on the supply wires is characterized by a relatively low level of initial investment by saving investments on the creation of a physical transmission medium. Powerline networks are well scalable, i.e. provide stable operation when connecting new customers, the speed of work is sufficient for most practical applications, proportionally decreasing with increasing distance (up to 200-300 m).

A number of experiments we spent shows that high resistance to interference and non-criticism of the transmission medium laid out in the HomePlug standards allow you to consider ready-made devices and as a semi-finished product for developing your own home and industrial wired solutions.

In the meantime, we want to believe that the device announced to CEBIT (combined access points WLAN / POWERLINE, routers and ISDN / DSL-to-PowerLine modems, multimedia players, camcorders with built-in support for this technology, new Voice Over Powerline, as well as kits for combining In the home network of computers, WEB-tablets and MP3 players) are already on the way to our buyer. Let these devices are not so common so much - this is how much it is possible to judge the results of trial operation, just a matter of time ...

Electrical Wiring Technologies for PLC (Powerline Communication) or DPL (DIGITAL POWERLINE) began to be developed for quite a long time (even in Russia in the 30s of the last century on the Kashira power line conducted studies of data exchange on ordinary power supply wires), but engineers For a long time could not overcome the problem of attenuation of the signal caused by interference on the line (any electrical wiring is characterized by a high level of noise and rapidly attenuation of the high-frequency signal, as well as a significant change in the communication parameters of the line, depending on the current load). Later, these problems were successfully solved through the use of broadband signal modulation algorithms (for example, PLC technology has long been used to transmit information and technical data in power systems and on railways), however, equipment for transmitting data on electrical networks remained quite expensive, so the data is widely distributed Technologies have not received for a long time. After all, a decisive role in the success of any technology is played by an economic factor - for the commercial success of development it is necessary that the equipment is reliable and multifunctional, ensuring a sufficiently high transmission rate and remained relatively inexpensive.

And today, in the market, inexpensive equipment, which meets all these requirements, and consider that the number of electrical outlets is still significantly superior to the number of telephone (especially in our country, where telephonization is still not a necessary attribute in the construction of houses), That PLC technology receives almost unlimited development opportunities. It is these considerations that the developers of the equipment for transmitting data over the lines of electrical wiring were guided. The power supply lines are everywhere, even in the most remote corners of the globe, so that this technology does not require the laying of additional communications (and in some places of new cables at all undesirable or simply impossible), which significantly reduces its cost and increases functionality.

Obviously, in the new millennium, the technology of transmission technology of digital traffic on the lines of electrical network becomes one of the most promising areas of development in the provision of communication services - a wide prevalence of electrical networks, their availability and multifunctionality opens up rich opportunities for using PLC.

Homemade wireless networks

If there are several network devices in the house (desktop, laptop, media server, game console, photo frame, etc.), naturally, the need to exchange data between them arises, while the traditional solution is to combine such devices to the local network, as it opens The possibility is not only data exchange (which could be done with the help of external media), but also accessing the Internet, watching video or network games. Moreover, it is desirable that the local network is easily scaled to be easily scaled, that is, in the future new devices can connect to it, and its configuration could be changed without additional investments. Traditionally, home networks are organized by the installation of Ethernet cables (twisted pairs) or by using wireless networks based on the 802.11 b / g protocol. However, each of these approaches has their own as indisputable advantages and substantial disadvantages.

Yes, when combining computers in the home network using a twisted pair based on the Ethernet protocol, we get a speed-based reliable network with a high level of noise immunity. And financial costs seem to be small - taking into account the availability of almost all modern computers of the network controller, we must acquire only a network switch and cable. However, the gas cable laying creates serious inconveniences in any house, and sometimes it is in general a difficult problem. After all, a rare hostess in the modern house favorably reaches the emergence of new wires. In addition, in the case of a wired local network laying, each workplace is "tied" to a power outlet and in case of redevelopment of the room, you need to lay the local network almost again. And this is impossible without carrying out repair and construction works of a scale, so the problem of laying a wired network is exacerbated by the year from year to year, especially due to the steady increase in prices for building materials.

Of course, more convenient to use wireless technology to build a home network, because then we can get rid of us from bringing us to a certain place of wires and get much more mobility, but this approach is not deprived of serious flaws. For example, if in the Ethernet wired network, the distance between nodes can reach 100 m, then Wi-Fi wireless networks work on much smaller distances. At the same time, the radius of the wireless networks strongly depends on the obstacles occurring on the path, for example, reinforced concrete structures, which absolutely do not let the waves of the range of 2.4 GHz. So modern houses are far from the best place to establish record ranges of this kind of devices. And if within one apartment, 802.11 b / g wireless networks can be considered a very effective solution, then the connection with friends living even in the next apartment for the capital wall may well be unstable or even at all impossible. In addition, to receive IP-television and high-definition video at an arbitrary point of the house Wireless standards of the 802.11 family and even the new version of 802.11n are not adapted - transfer of broadcast video content (Multicast) provided by IPTV operators, it is not provided for them.

Electricity high permission

But, for example, the range of the network of electrical wires in the HomePlug AV standard, which refers to the PLC technique family using the most common wiring as a network medium, reaches 300 m and does not depend on the number and thickness of the flooring indoors. Even in distressed cases, the HOMEPLUG AV technology provides a real speed of not lower than 40 Mbps. Moreover, the main advantage of such a solution is the absence of the need to lay additional cables to connect network equipment - enough so that the room has electrical wiring (network 220 V). Thus, digital networks on telecommunication lines can be the only alternative to direct Ethernet connection when viewing, for example, digital video without delays and loss of quality simultaneously with data transfer.

Moreover, under the conditions of modern dwelling, building a home local network on PLC technologies may be more preferable than alternative options. The last one is the third version of the homeplug AV home networks in the HOMEPLUG electrophores provides data transmission at a speed of up to 200 Mbps and can be used as a convenient channel to transmit high definition television signal (HDTV), IPTV, Internet and IP telephony (VoIP ). Abbreviation AV indicates a multimedia orientation - the specialization of the transmission over the electrical wires of the audio and video content in real time.

Equipment for transmitting data on electrical wiring

One of the main manufacturers of HOMEPLUG AV is ZyXEL. The device line in which the idea of \u200b\u200btransmitting data on the HOMEPLUG AV electroplux is implemented, consists of the P660HWP Internet Center and the HOMEPLUG AV POWERLINE adapters and PLA470. The P660HWP Internet Center is a universal device that serves to connect to the Internet and IP television over the dedicated ADSL channel with the ability to create a home network not only by Ethernet and Wi-Fi, but also through the usual electrical wiring using HomePlug AV technology. Having a built-in HOMEPLUG AV adapter, the P660HWP Internet Center is the connected element of the electrical wiring network, and the PLA400 and PLA470 adapters allow you to dilute the local network in the apartment, while ensuring quite high speed and allow you to connect a personal computer with any other network devices in other rooms. Using adapters, you can transmit audio and video signals, IP telephony and data on conventional electrical pipelines and create inexpensive home local networks. Thus, you can combine various devices in the house into a single multimedia space, and without making any additional communications.

The PLA400 model is equipped with a single port of Ethernet, and the PLA470 is a built-in 4-port switch, which allows you to connect multiple network devices through one electrical outlet, such as a computer and a gaming console.

HomePlug AV Adapter PLA400 (with one Ethernet port) Sale in Russia for 2000-2200 rubles. (less than 100 dollars), PLA470 (with a 4-port Ethernet switch) is now in retail, about 2500-2700 rubles. (up to $ 110), and the P660HWP Internet Center with the built-in HOMEPLUG AV adapter, the 4-port Ethernet switch and Wi-Fi 802.11g access point for sale at 4,400-5000 rubles.

Following the testing of this equipment in the conditions of the usual Moscow wiring, it was not possible to achieve 200 Mbit / s, of course, it was not possible (the connection was set at 50 Mbps with minor drops when domestic electrical appliances), but high resolution video was transmitted by electrical circuit without failures and distortion. That is, until the speed of 100 megabit ethernet network, this technology does not reach, but WiFi 802.11g wireless network is significantly ahead.

It is especially important that all homeplug AV adapters have built-in QUALITY OF SERVICE support mechanisms (QoS), which provides a guaranteed bandwidth required when transmitting voice, sound, video and data encryption for secure information transmission (information is reliably protected from listening and intercepting the protocol AES with a 128-bit key). All this works great and no complaints cause, and the influence of interference created by various household appliances on the communication line established between the two PCs using the HOMEPLUG AV adapters, in practice it turned out minimal (as it turned out, neither a working drill, nor luminescent lamps with pulsed converters substantially The impact on the quality of data transmission does not provide). The process of installing the above-mentioned devices is extremely simple and will not cause questions even from unprepared users. Setting up the P660HWP Internet Center and HomePlug AV adapters to connect to the Internet and IP television is made using the ZyXEL NetFriend program. To configure the equipment with the help of a "network friend", you will need a minimum skill and about 10 minutes of time. It will only be necessary to choose your city, provider and a tariff plan. The remaining settings such as Wi-Fi and IPTV are already at will.

When using IPTV services to the ZyXEL P660HWP Internet center, you must connect the television console, select the desired tariff and specify the program to the port to which you have connected the prefix. And if the prefix connects to the PLA400 or PLA470 adapter through the wiring, then with the help of the same program you need to select HomePlug AV. Adapters also do not require the user any special knowledge for installation and settings - on the household level HOMEPLUG AV can be represented simply as an Ethernet network extension.

Thus, this technology and its implementation in the devices from ZyXEL can be recommended as an alternative to traditional technologies where the latter disadvantages listed above becomes difficult, costly or simply inconvenient.