by R. K. Bloom

TP-Link TL-PA211 – Ethernet from the electrical outlet

TP-Link TL-PA211 – Ethernet from the electrical outlet

Entry

Adapter TP-Link TL-PA211 working on technologies HomePlug AV, which in turn is a variation of Technology PLC. PLC (Power Line Communication) stands for “communication via power lines (power lines).” Many power lines associated with the abbreviation of kilometers thick wires and delicate designs of supports. In fact, ordinary electrical wiring in the apartment is also a power line, only a small, “home” so to speak. Here on this very network wiring and the signal is transmitted. Nothing new in this technology does not. Similar systems have been used for over a century ago. Then the wires between substations transmitted CW signal. With the growing number of high-voltage power lines introduced high-frequency communications system for telephony and telemetry.

Theory

The principle of the PLC in something similar to the familiar to many users, xDSL-connections. And in fact, in both cases are different types of data (tone, voice, network traffic) transmitted by the same wire, but at different frequencies. Each device (telephone, modem, adapter) filters the “wrong” frequency, and receives only what can be processed. The main advantage of PLC, as xDSL, is the lack of need for additional wiring to create another network infrastructure, as well as the relative ease of use and more reliable connection than wireless access. But the disadvantages of these two technologies are similar. For high-quality communication is necessary, first of all, a good wired connection – no twists, cable penetrations of another type, damaged insulation and other electrical delights in haste. Unfortunately, in most Russian homes, except, perhaps, new buildings, the quality of wiring often dismiss poor.

Another feature of PLC is that the total bandwidth is divided among all members of the network. That is, if the same network at once ten PLC-adapters, which are actively exchanging data, the rate for each of them will be about ten times lower than the total bandwidth. Finally, the most important caveat – this is a relatively high sensitivity of PLC to various noise and filters. In the first case, the signal quality can adversely affect even the appliances – the shaver with a hair dryer to the vacuum cleaner and drill. And as a powerful puncher connection or welding machine for sure, “put” network. In the second case it must be remembered that in surge protectors, UPS and stabilizers PLC-adapter will not work. Hence, too, and one more note – all outlets, which will connect the PLC, should be powered from a single location. Roughly speaking, PLC will not operate next door or on another floor of an office building (here all depends on the cabling).

TP-Link TL-PA211 support the standard HomePlug AV, which was introduced already in the summer of 2005. Under this standard, the speed of the network connection can be up to 200 Mbit / s, which should be enough for streaming video and voice. The rate is automatically adjusted depending on the quality of communication. The connection must be encrypted using 128-bit key AES, as well as to maintain the rules of QoS (Quality of Service). The implication is also backward compatible with previous versions of the standard. In theory it all sounds great, but in practice it is not so rosy. Although the results of tests TP-Link TL-PA211 can say that in recent years the technology is well advanced. The fact that five years ago, the author fell into the hands of the same set of two PLC-adapters (will not say what the manufacturer), which according to the specifications had to give speed 85 Mbit / s. Alas, the very first test of this collection of enchanting way failed. When connected to one tee, he gave the rate in the 15-20 Mbit / s. When you turn on one adapter into a socket in the same room rate dropped to 10 Mbit / s, and when you move into the next room and did turn into some kind of vague 2.1 Mbit / s. Thus PLC-network fell at the slightest chihe. In general, hopes to organize a connection through a few walls without drilling the add (Wi-Fi, of course, does not “do”) turned into a wasted 200 dollars with a little. But enough of the lyrics, back to our, um-m devices.

And photo

Set of two TP-Link TL-PA211 is packaged in a box of thin cardboard, decorated in light shades of green. In the box marked image devices and their specifications. Inside the outer box is another – from hard cardboard. In it, in addition to cards, there are two meter patch cord length, brief instructions, warranty card, a few brochures and a CD with the software.

A large part of the case each adapter is made of black matte plastic. On the front cover of the glossy white plastic, there are three green LEDs that signal the presence of power, network connectivity and data transfer. At the bottom is port Ethernet, next to which there is a small knopochka for mating adapters. TP-Link TL-PA211 is quite compact and weighs very little. For mains, it connects with the usual European plug.

Technical characteristics