Review: Three 5G Router – Zyxel NR5103Ev2

Quick Review: A well spec’d 5G router with all the features a home user needs. The router is unlocked, so it works with SIM cards from other UK mobile networks. The router is a bit bulky

Overall Rating

When I moved home, I needed a temporary internet solution while my Virgin broadband connection was processed and set up. Initially, I used a 4G modem connected to my WiFi router for internet access, but I found that the 4G connection often slowed considerably in the evenings. I looked at getting a 5G modem to replace the 4G modem, but they don’t seem to exist. So I ended up buying a Three 5G router, the cheapest way I found of getting 5G mobile broadband.

What Is A 5G Router

A 5G router is a networking device that uses 5G mobile broadband technology to provide high-speed internet access to home devices, such as game consoles, PC, mobile phones and tablets. It’s similar to traditional Wi-Fi routers but instead of connecting to the internet via a cable or DSL (telephone line) connection, it connects to a 5G cellular network.

What 5G Router Does Three Use

The latest 5G router that Three uses is the Zyxel NR5103Ev2. The router was first released in early 2024. The router replaces the old Zyxel NR5103E.

Where Can I Buy a Three 5G Router

Obviously, you can buy a Three 5G router directly from Three. However, you can’t just buy the 5G router; you have to sign up for a contract, which you probably won’t want to do if you are going to use other mobile networks.

The cheapest place I found to buy a Three 5G router was on eBay. I found a ‘new’ router for £130, plus £5 delivery.

The Three routers are also available to buy from CEX, which specialises in pre-owned consumer electronics. CEX shops can be found on many UK high streets and they also have an online shop. 

Three 5G router ports

Pros: Three 5G Router (Zyxel NR5103Ev2)


Mobile network operators often lock devices they supply so they only work with their network.  Fortunately, the Three 5G router is supplied unlocked, which means it will work with any UK mobile network operator.


The 5G router is capable of incredibly fast internet speeds of 4.67 Gbps download and 2.5 Gbps upload. The bad news is that those crazy-fast speeds will probably never be achievable in the real world.

There is 5G coverage from Vodafone in the area where I live. The best internet speeds I get are 80Mbps download and 23Mbps upload. Which isn’t too bad. It’s easily fast enough for all the streaming, game playing and web browsing that goes on in my house hold.


The Three 5G router has all the features you typically get with a router supplied by an Internet Service Provider, like Virgin, BT and TalkTalk. 

Most home users are mainly only concerned with WiFi settings, which are all fully configurable. There are more advanced features like NAT and Firewall which will appeal to the more technically minded users

Sometimes mobile network operators disable features on purpose, but as far as I can tell, the Three 5G router has all features enabled.

Easy Setup

Setting up the 5G router is super simple: insert a data SIM card into the router and turn it on. The default WiFi name and password are all printed on the side of the router. Details on setting up the router can be found on the Three website.

TIP: Changing the default WiFi name and password is good practice to improve network security.

Cons: Three 5G Router (Zyxel NR5103Ev2)

Router Placement

The router should be located by a window pointing towards the mobile cell tower. I found that slightly changing the direction the router is facing made quite a difference to the signal strength.

Ideally, I’d have the router tucked away out of sight, not sat on the window sill.

Internet Speed Fluctuation

Sometimes the internet speed can drop quite a bit. I think this problem is more related to the mobile network than the 5G router. 

Three 5G Router Firmware Update

The firmware for the Three Zyxel NR5103Ev2 is updated automatically Over The Air (OTA). The latest (March 2024) version is V1.00(ACIR.0)C0

To get the latest firmware, the router needs (I think) to have a Three SIM card inserted or a SIM card from a virtual network operator (e.g. Smarty) that uses the Three network inserted.

I had a Vodafone SIM card inserted in the router for a week and the firmware never updated. When I inserted a Smarty SIM card the firmware updated within 24 hours. The firmware automatically updated at about 5:00am.

The router has the ability to upload the latest firmware manually. But as far as I’m aware, neither Three nor Zyxel publish the firmware files for manual update.

 Conclusion: Three 5G router – Zyxel NR5103Ev2

Using a Three 5G router purchased from eBay was the cheapest way I found of getting 5G mobile broadband access. Fortunately, the current 5G router supplied by Three is pretty good. It has all the features that home users need, it’s unlocked to work with all UK mobile networks, and it is reliable. 

The only negatives I found relate to mobile broadband signal strength. Which are really more related to the mobile network operator than the router.

If you’re looking to get a temporary internet connection or even permanently move from a fixed line connection to mobile broadband, then I think the Three 5G router is a very good option.


Frequently Asked Questions: Three 5G Router

How much is a Three 5G router?

The Three 5G router can be purchased for about £130 from eBay or CEX. 

Will a smartphone SIM card work in the Three router?

Yes, a smartphone SIM card will work in a router as long as your SIM card has data, which all do these days.

How to improve 5G router signal?

There are a number of things that can be done to improve the 5G signal:

  1. Locate the router next to the window
  2. Locate the router as high up in your house as possible
  3. Use a smartphone app to locate your nearest mobile cell tower. point the router in the direction of the cell tower
  4. Keep the router away from other electronic devices to reduce interference
  5. The Three 5G router has ports for external antennas, which may improve the signal.

Is the Three 5G router backwards compatible with 4G?

Yes, the Three 5G router will work with 4G mobile broadband. The router will automatically detect and connect to the best available 5G or 4G network 

Three 5G router external antenna

The Three 5G router (Zyxel NR5103Ev2) has two TS9 connectors for an external antenna. Selecting the best antenna for the router requires some research to make sure the correct antenna is selected for your situation.

For most people, the built-in internal antennas should be sufficient.

Changing the Three 5G router  APN setting

The APN settings are instructions for the router on how to establish a connection to the mobile network operator’s infrastructure. 

The default setting on the Three 5G router is to detect the APN settings automatically. Which I found works for all the SIM cards I tried, apart from Vodafone, which I had to set manually.

To find the APN settings for the network operator you are using can easily be found by doing a search on Google e.g. ‘Vodafone APN settings’.

Note: The APN settings may be different depending if the SIM card you’re using is pre-pay or contact

 Three 5G router bridge mode

The Three 5G router has a bridge mode setting

Bridge mode is often used in situations where you have another device performing routing functions, such as a separate router, and you want the 5G router to act purely as a modem or bridge to connect to the 5G mobile broadband network. This setup allows for more flexibility and control over the network configuration.

Bridge mode is for advanced users.

Are 3 5G routers unlocked?

Yes, 3 5G routers are unlocked. Three do not lock the Zyxel NR5103v2 5G router. This means that the router will work with data SIM cards from any mobile network operator


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