Powerline adapters, mesh WiFi, MoCA or a cable: which gets the internet to the far room?

The internet is good next to the modem and poor in the room you need it, and there are four ways to carry it across: the power wiring, the TV coax, the air, or a new cable. Each one depends on something different about your house, which is why the same powerline adapter can be brilliant in one home and useless next door. Here is how each works and what decides it, so you can try the right one first or ask a WiFi technician which one suits your house.

What is a powerline adapter?

A powerline adapter is one of a pair of boxes that plug into power points and send your internet through the house’s power wiring. One plugs in near the modem and connects to it with a network cable; the other plugs in the far room and gives you a network port there, and some models make WiFi as well. You may also see them called Ethernet over power, or by a brand name.

Nothing is installed and no cable is run, which is the whole appeal. The catch is that the signal is travelling through cabling that was built to carry power, not data, so the house decides how well it arrives.

Do powerline adapters work?

Powerline adapters work well in some homes and poorly in others, and you only find out which by trying them. On the calls we take, people describe both: one says the internet in the far room is steady most of the day, another gets half the speed of their plan, and a third finds it swinging up and down every few minutes. Some customers swear by them; plenty give up.

What decides it is the wiring between the two power points:

• The circuit and the board. TP-Link says powerline performs best with both adapters on the same electrical system, that crossing phases reduces the speed, and that separate panels can weaken or block the connection. A granny flat, a garage or a basement on its own sub-board is where it most often disappoints.
• The meter. devolo says an electricity meter weakens the signal, though it does not always block it. That is why two buildings on separate meters are a poor fit.
• The age of the wiring. TP-Link says older or degraded wiring gives slower, less stable connections.
• Power boards and surge protectors. Both makers say to plug the adapters straight into a wall socket, not a power board, an extension lead or a surge protector, which can cut the speed badly.
• What else is plugged in. Phone chargers, lamp dimmers and appliances with motors put electrical noise on the wiring. Keeping them away from the adapters helps.

The speed on the box is not your speed either. TP-Link says the AV rating (AV600, AV1000, AV2000) is the most the powerline link can carry in theory, and that what you actually get is meaningfully lower.

Powerline or mesh WiFi: which is better?

For WiFi through the whole house, mesh is usually the better buy, and it is what our technician suggests on the phone far more often than powerline. A mesh system builds a new WiFi network from several units placed through the house, linked by WiFi or by cable, so it does not depend on your electrical wiring at all.

Powerline has its place. If you need a wired connection in one room, the walls cannot be opened, and both power points are on the same circuit, a pair of adapters is quick to try and easy to return.

Powerline adapters, mesh WiFi, MoCA and a cable compared

Compared on	Powerline adapters	Mesh WiFi	MoCA over coax	A network cable
How the internet travels	Through the power wiring	Through the air, unit to unit, or by cable between units	Through the TV coax	Down its own cable
What it depends on	The circuits, the wiring and what else is plugged in	Where the units sit, and the walls and floors between them	A coax run that really links the two rooms	Getting the cable through the walls, roof or floor
Best at	One wired spot where the walls cannot be opened	WiFi in every room	One wired spot where good coax already runs	Anything that must not drop out
Steadiness	Varies from house to house	Good, and best when the units are cabled	Good on a clean run	The steadiest of the four
Takes it with you when you move	Yes	Yes	Yes	No, it stays in the house
Who sets it up	You	You, from an app	A registered cabler	A registered cabler

Pick a way across

Powerline MoCA Mesh A cable

Modem's room Far room 11 22 22 33 44 44 55 66 66 77

1. 11 Modem
2. 22 Power point
3. 33 Switchboard
4. 44 TV socket
5. 55 Splitter in the roof
6. 66 Mesh unit
7. 77 Data point

Powerline

Through the power wiring. It depends on the circuits, the age of the wiring and what else is plugged in. Best with both adapters on the same circuit, straight into wall sockets.

MoCA

Through the TV coax. It depends on a coax cable that really links the two rooms, and most go back to a splitter first.

Mesh

Through the air, unit to unit. It depends on where the units sit and the walls and floors between them, and it is best with a cable between the units.

A cable

Down its own cable. It depends only on getting the cable through the walls, the roof or the floor. The steadiest of the four.

In a rental, both powerline and mesh can be packed up and taken to the next place, which is a big part of why we point renters to mesh first. For choosing a system and placing the units, see the best mesh WiFi for Australian homes, and for the boxes that only repeat the router’s signal, whether WiFi range extenders really work.

Do powerline adapters work in a unit or apartment?

They can, and a unit is one of the few places where powerline is worth trying before anything else. Concrete walls and floors make a new cable hard, messy and sometimes impossible without cutting channels, and the two rooms are usually close together, which helps the signal.

Where it falls down is distance from the unit’s own wiring. A car space, a storage cage or a lower level fed from another board in the building is the basement-and-sub-board case, where powerline tends to work some of the time at best.

Concrete is hard on WiFi too, so mesh units there go out in the open, one halfway to the far room. If you own the unit and want a cable instead, any run through common property needs the owners corporation’s approval first, and a renter needs the landlord’s yes for anything fixed.

What is a MoCA adapter, and when does it work?

A MoCA adapter sends a network connection over coaxial cable, the round TV antenna or pay TV cable, instead of the power wiring. Like powerline, it comes as a pair: one at the modem end of a coax cable and one at the far end, each with a network port. The MoCA Alliance, the industry body behind it, describes it as home networking over the coax a home already has, including as the link between WiFi units.

MoCA only works where a coax cable really does link the two rooms, and that is the part to check before you buy:

• Most TV coax goes back to a splitter. The antenna or pay TV cable comes into the house, goes to a splitter, and the splitter feeds each room. The socket in the far room may not lead where you think.
• An ordinary TV splitter can weaken the MoCA signal. Makers of MoCA adapters recommend splitters rated for the frequencies MoCA uses.
• A clean run is the good case. If you know one cable runs end to end from the modem’s room to the far room, with nothing in between, MoCA can work well.

It is not a plug-in job like powerline. The ACMA’s rules on what cabling work is regulated (opens in a new tab) give an Ethernet over coax adapter as the example of re-purposing existing cabling, which turns it into network cabling and has to be done by a registered cabler or under one’s supervision.

On HFC, the NBN’s coax comes in to the NBN box through the wall box outside. Leave that coax and the box as they are: it carries your internet, and it is not the cable to experiment on.

When does a network cable beat all of them?

A network cable beats powerline, mesh and MoCA every time it can be run, because it depends on nothing but itself. It gives the far room the full speed of the connection, it does not drop out when the kettle goes on, and nobody has to place or pair anything.

• For anything that must not drop out: a home office, gaming, a TV that streams in 4K.
• To make a mesh work properly: one cable to the far mesh unit turns its link from the air into a wire, the biggest single upgrade a mesh can get.
• To move the router: where the NBN box sits in the garage or a front corner, a cable to the middle of the house fixes the cause rather than working around it.
• For a granny flat or a studio: a cable in conduit is the dependable link, or a wireless bridge between the two buildings where digging is not possible.

Running fixed cable through walls, ceilings and under floors in Australia is a registered cabler’s job, because it connects to the network and shares the building with mains power. How to set up a wired network at home covers what is possible in a unit, a single storey and a two storey, and the data cabling cost estimator gives a price range for the run before anyone visits.

How to test the powerline adapters you already have

Test with a laptop on a cable, first at the modem and then through the adapters, and compare the two results. If the adapters give you close to the modem’s result, they are doing their job; if they give you half or less, try the fixes below before you give up on them.

1. 1

   Test at the modem

   Plug a laptop straight into a yellow port on the modem with a network cable and run a speed test. That is the speed coming into the house.

2. 2

   Test through the adapters

   Plug the same laptop into the far adapter with a cable and test again. Do it a few times through the day, because powerline can swing.

3. 3

   Take out the power boards

   Plug both adapters straight into wall sockets, not a power board, double adapter or surge protector, and move chargers and appliances off the sockets next to them.

4. 4

   Try another power point

   A socket on the same circuit as the one near the modem usually does better. Try a couple in the far room and keep the best.

5. 5

   Decide

   Close to the modem's result: keep them. Still half or less, or it drops out: mesh for WiFi, or a cable for that room.

Check your speed first Run it on a laptop plugged into the modem, then on the same laptop through the powerline adapters. The gap between the two numbers is what the power wiring is costing you.

If the speed is poor even on a cable at the modem, the adapters are not the problem, and a home internet technician tests the line and the gear in turn.

Which one should you choose?

Choose by what your house has and what you need in the far room. In order of what we usually suggest first:

1. WiFi in several rooms, or a rental: a mesh system.
2. One wired spot, walls that cannot be opened, and both power points on the same circuit: powerline is worth a try.
3. One wired spot, and a coax cable you know runs straight there: MoCA is worth asking a registered cabler about.
4. A granny flat, a basement or a garage on its own sub-board: not powerline. A cable, or a wireless bridge.
5. Anything that must not drop out, a mesh that needs a wired link, or a building job under way: a network cable.

If powerline suits the house, buy a kit with a pass-through power point so the wall socket is not lost. If mesh is the better fit, a three-pack covers most homes.

We earn a small commission if you buy through our Amazon links, at no extra cost to you. As an Amazon Associate we earn from qualifying purchases.

Gear mentioned here, on Amazon Australia

Product	What it is for	Link
TP-Link TL-PA8033P KIT	Keeps the power point free	View on Amazon for the TP-Link TL-PA8033P KIT (opens in a new tab)
TP-Link TL-PA9020P KIT	Faster, two ports each end	View on Amazon for the TP-Link TL-PA9020P KIT (opens in a new tab)
TP-Link TL-WPA4220 KIT	WiFi from the far adapter	View on Amazon for the TP-Link TL-WPA4220 KIT (opens in a new tab)
TP-Link Deco X55, 3-pack	WiFi 6 mesh for most homes	View on Amazon for the TP-Link Deco X55, 3-pack (opens in a new tab)

When to call a technician, and when you don’t need one

You do not need us to try powerline adapters or set up a mesh system. Both are made to be plugged in at home, and if the far room is now fast and steady, you are done. We can set them up for you when a cable run isn’t practical, and a cable is always better where one can be run. MoCA and a new cable are different: both are a registered cabler’s work. Check the shop’s returns policy before you test, in case the wiring does not suit them.

Call a technician when you have tried the adapters and a mesh and the far room is still poor, when the house has concrete floors or several levels, or when you want a cable run through the walls. On a visit our technician tests what you have and tells you plainly which of the four suits the house. A cable run is quoted as data cabling, and if you would rather someone set up the mesh and the devices on it, that is home tech support.