MoCA: Ethernet over the TV coax you already have

Running new cable through finished walls is a pain. Many homes already have one in most rooms: the coax for the TV. MoCA turns it into a network.

Published · 2 min read

In this guide
  1. What MoCA does
  2. When MoCA is a great fit
  3. What to check before buying
  4. Outside North America
  5. Where to put the Wi-Fi at the far end
  6. Measure the room, not the adapter

The best fix for a weak room is almost always a cable: a wired access point or mesh node puts full-strength Wi-Fi exactly where it's needed. The problem is getting that cable there. In many American homes, it's already there, hidden behind the TV outlet.

What MoCA does

MoCA (Multimedia over Coax Alliance) adapters send network data over the coaxial cable used for cable TV. You put one adapter near the router, connected to it by Ethernet and to a coax outlet, and another in the far room, connected to that room's coax outlet. The far adapter gives you an Ethernet port.

Current adapters (MoCA 2.5) are rated up to 2.5 Gbps on paper. Real-world speed is lower, but what matters more is that it's stable: coax is shielded, so it doesn't suffer from the interference and wiring noise that trouble powerline.

When MoCA is a great fit

  • Coax outlets in the rooms you need, and ideally one near the router.
  • You want to wire mesh nodes without drilling. MoCA makes excellent wired backhaul; see wired backhaul for mesh.
  • Powerline was disappointing. MoCA is usually faster and much steadier.

What to check before buying

  • Splitters. MoCA needs splitters rated for its frequency range (up to 1675 MHz). Old splitters labeled for lower frequencies can weaken or block it.
  • A point-of-entry filter. A small filter where the coax enters the house keeps your MoCA signal inside your home and improves performance. Many kits include one.
  • Your provider's equipment. Some cable and TV boxes use MoCA themselves. That's usually compatible, but it's worth checking which channel each device uses.
  • Satellite TV coax carries signals in some of the same range. Check the adapter's compatibility before mixing the two.

Outside North America

Coax TV outlets are common in European and Latin American homes too, usually for the antenna. MoCA adapters are less common there, but G.hn coax adapters do the same job over antenna coax. The same rules apply: the right splitters, and an outlet near the router.

Where to put the Wi-Fi at the far end

The adapter gives you Ethernet; the Wi-Fi still has to come from somewhere. Plug an access point or wired mesh node into it and place that unit high and in the open, not on the floor behind the TV where the coax outlet usually is. See where to put a mesh node.

Measure the room, not the adapter

The adapter's lights say the coax link is up. WiFi Heatmap shows whether the room itself improved: map it before the new access point, map it after, and compare the two. Compare the result with powerline if you're choosing between the two.