Ethernet cable is still the best way to connect two points in a home, but it cannot always be run: walls to drill, shared buildings, rented flats. Before resigning yourself to Wi-Fi in every room, it is worth knowing that there are two alternatives that use wires already inside the walls: the electrical wiring and the coaxial cable of the TV aerial.
Powerline: the network over the power socket
Powerline adapters send data over the current of the electrical system, using frequencies much higher than the mains frequency. At least two are needed: one near the router, connected with an Ethernet cable, and one in the room to be served. Many models also include a Wi-Fi access point.
The common technologies are HomePlug AV2 and G.hn. Adapters from different families do not talk to each other, so it is best to buy everything from the same product line.
What to really expect
The speeds printed on the box are theoretical physical link values. In practice the usable speed is often a fraction of the stated figure and depends heavily on the wiring:
- Same circuit and nearby sockets: good, stable performance.
- Different circuits or phases of the same consumer unit: a sharp drop, sometimes no link at all.
- Separate meters: generally it does not work, which is also good for privacy.
In addition, some appliances disturb the signal: cheap power supplies, chargers, LED lamps with poor-quality drivers, appliance motors. The disturbance can vary during the day, for example when the washing machine starts.
Installation rules
- Plug the adapter directly into the wall socket, not into a power strip. Strips with noise filters absorb exactly the powerline signal.
- If you need the socket, choose a model with an integrated pass-through outlet.
- Pair the adapters with the security button: it creates an encrypted network reserved for your devices.
- Check the link speed with the manufacturer's app, trying different sockets in the same room.
MoCA: the network over the aerial cable
MoCA (Multimedia over Coax Alliance) uses coaxial cable, the one behind TV sockets. Coax is shielded and designed to carry high-frequency signals, so the link is much more stable and predictable than powerline. In many countries it is a common solution; in Italy it is less widespread because aerial systems are often shared by the whole building.
Here too at least two adapters are needed. Some critical points:
- Splitters and taps: old models may not pass the frequencies used by MoCA. They may need replacing.
- Shared building systems: the signal could leak towards the riser. A MoCA filter at the entrance of the flat keeps it inside the home and improves performance.
- Coexistence with TV: MoCA uses frequencies different from digital terrestrial and satellite TV, but it is wise to check compatibility with the specific installation, especially if there is an amplifier.
Practical comparison
| Solution | Stability | Ease | Main limits |
|---|---|---|---|
| Ethernet | Excellent | Requires work | Running the cable |
| MoCA | Very good | Medium | Needs suitable coax and filters |
| Powerline | Variable | Very high | Depends on electrical wiring |
| Wi-Fi extender | Variable | High | Often halves capacity |
Using them well
The best use case for both is backhaul: carrying the network from one point to another and connecting an access point or mesh node there by cable. Many mesh systems accept an Ethernet link between nodes, and a powerline or MoCA adapter can act as a virtual cable.
They also work well for fixed devices far from the router: a smart TV in the bedroom, a console, a PC in the attic. For a video call from the sofa, on the other hand, good Wi-Fi remains simpler.
In my work, before buying a pair of powerline adapters, I always ask one question: are the two sockets on the same circuit of the consumer unit? It is enough to check which breaker switches both off. If the answer is no, it is better to have a plan B.
Quick diagnosis
If the link is slow or drops:
- try moving the adapter to another socket in the same room;
- unplug nearby chargers and power supplies one at a time;
- check the physical speed in the app and compare it with the real measured speed;
- for MoCA, check the splitters and whether the entry filter is present.
In short
- Powerline uses the electrical wiring, MoCA the TV coaxial cable.
- Powerline is easy but depends on circuits, phases and electrical noise.
- MoCA is more stable, but needs compatible splitters and an entry filter.
- Always plug powerline adapters into the wall, never into filtered strips.
- Use them mainly as backhaul for an access point or a mesh node.
