TECH

Test: Internet transmission through domestic electrical distribution 

Powerline technology makes it possible to use common electrical wiring to network two or more devices. You can connect a laptop to the adapter via cable or via Wi-Fi, for example, while working in the garden gazebo, or other equipment in the house, garage or laundry room, for example a smart washing machine.

Adapters are available that only allow you to connect using an Ethernet cable, or the remote adapter also supports Wi-Fi. Adapters can also be designed with a socket, so after inserting it into the wall socket, you can also connect another home appliance to the adapter. In this case, however, the module must also have a fuse, because the network module can also be destroyed in the event of a short circuit of the connected device. Modules without through sockets are less practical, but there is no need to solve this problem.

In the package, you'll typically find two modules that plug directly into electrical outlets and two Ethernet cables. Installation is very simple. You insert an adapter into a socket near the router and plug it into it. Place the second, larger device in the desired location, for example, near the TV or in the part of the house you want to cover with Wi-Fi signal. You press the pairing button on both devices one after the other and after a few seconds the devices will be connected.

Obviously, transmitting the signal through electrical wiring will only work if the two sockets are in the same phase. In single-family homes, where there is also a three-phase distribution, sockets in different rooms are usually connected to different phases for an even load. If you cannot find a suitable outlet in the desired installation location of the larger module, which would be in the same phase as the outlet on the router, you must ask an electrician to connect the wires from the two outlets to a common phase in the distribution box. Alternatively, an electrician can install a device called a phase coupler in his distribution box, which, for signals above a certain frequency, interconnects all phases of the residential electrical network and makes the signal available at all outlets. Such a device costs approximately 30 euros and must be installed by a qualified professional. As this is a relatively high frequency signal transmission and in domestic distribution the individual phase conductors are led together in some sections, we test that the signal from one phase does not is transferred to the conductor of another phase. In our case, the three phases for the sockets were led by an ordinary cable 4 meters long, by the way, certainly even in the wall, these wires are led close to each other for a certain length. Repeated attempts showed that although there was some indication of signal transfer to another phase and the light occasionally indicated the presence of a signal, we were unable to load a single web page this way.

Of course, we also measure the transmission speed over different distances and compare it with connecting the laptop directly to the router. We tested it in a family home with an optical Internet connection and a 10Gb/s router.

In the second test, I moved the 4K TV to a greenhouse about 40 m from my house, where I have a central with sockets connected by a fixed cable. I connected the second adapter to the router plugged into the house outlet. I connected the stove power to the same phase as the study outlets. Streaming 4K video from a home NAS server worked with an occasional barely noticeable drop in resolution, full HD streaming also worked without issue in this case. Later, I complicated the situation by turning on the vacuum cleaner and the microwave in the house, that is, devices that can be a source of interference. Streaming Full HD video worked just as smoothly and reliably.

Adapters using G.hn wave 2 standard technology reach, depending on the specific domestic environment, a theoretical transmission speed of up to 2400 Mb/s. Common Powerline adapters using the HomePlug AV standard with G.hn have half the transfer speed, ie 1200 Mb/s. As the conductors in the electrical distribution network are made of different materials, conducted in different ways, and at greater distances interference is applied, the actual transmission speed decreases with increasing distance. But even when transferring approximately 25-30 mz from the office upstairs to the workshop on the ground floor, which are on opposite corners of the family home, the transfer speed is approximately 4 Mb/s (megabits per second). For these drives, 1 MB/s = 8 Mb/s or 1 Mb/s = 0.125 MB/s. So when you divide that by eight, the transfer speed is 0.5 megabytes per second. A file such as a 1 GB movie will transfer in 2000 seconds or about 35 minutes under these conditions. To illustrate, when streaming video from services like Netflix in full HD resolution, you need a data rate of 5 Mb/s and a 4K resolution (UHD) data rate of 25 Mb/s. In other words, you can watch full HD video in a room with no more than 25 m of electrical wiring and 4K video in a room with no more than 15-18 m of electrical wiring. It depends, of course, on specific circumstances, mainly interference and the type of adapters.

If you need to connect more devices, you can purchase additional adapters. The maximum distance for power line transmission is 300-500m, so with the help of an adapter in the socket of the same phase, a neighbor can also connect to your network or monitor your network. Adapter designers have taken this into account, so transmissions along electrical distribution lines are encrypted.

by www.nextech.sk