# Use a cellular connection


> Connect a screen over 4G or 5G with a mobile router, and the data cost and hardware limits to plan around first.
Screens work over cellular, with two constraints worth understanding before you commit to it.

## You need a router, not a modem

You cannot plug a USB modem into a player. Use a 3G, 4G, or 5G router, and connect the player to it over ethernet where possible, or Wi-Fi otherwise.

The reason is the sheer number of modem and carrier combinations, which we cannot test or support. A router turns that problem into an ordinary network connection.

Any router that provides an internet connection over ethernet or Wi-Fi should work. Availability varies by country, and we do not endorse specific models.

## Plan for the data

We cache aggressively, and video and images are still large files. An idle player uses very little, but a playlist of HD video on a metered plan is a different proposition.

See [What the network needs](/docs/screenlyos/networking/overview/what-the-network-needs/) for the traffic figures we have measured, and size the plan against your actual content rather than the idle number.

For fleets, IoT-focused carriers are worth looking at alongside consumer plans.