4G Router / home network problem

I wondered if anyone could help me with a 4G router home network problem.

Living in a rural area in Wales with poor internet services, I intended to use a 4G router with SIM (TPlink TL-MR6400 Wifi 4 3G/4G LTE Cat 4 Router) together with a Poynting A-XPOL-0002-V”) Antenna for a home network. My mobile gets quite a fast connection (~50MBPS download and ~20 upload).

When the above system is set up using the SIM from my own mobile, to test it, the only device that gets a good connection through the wifi network thus created is my mobile. Other devices have unusably poor internet speed.

I was wondering whether anybody could point me towards what the problem could be here and how it could be resolved? I’d be very grateful for any advice

Which network? If it's Three or one of its MVNOs, that TP-Link box isn't compatible.

I struggled for ages with it before proving the problem to the manufacturer. They gave me my money back and told me to keep the equipment for my trouble.

In reply to a post by richi:

Which network? If it's Three or one of its MVNOs, that TP-Link box isn't compatible.

I struggled for ages with it before proving the problem to the manufacturer. They gave me my money back and told me to keep the equipment for my trouble.

its a cat4 modem so you don't get carrier aggregation - you need a cat 6+ modem based router. And yes the mr6400 doens't support some of the three bands

In reply to a post by jonburt83:

I wondered if anyone could help me with a 4G router home network problem.

Living in a rural area in Wales with poor internet services, I intended to use a 4G router with SIM (TPlink TL-MR6400 Wifi 4 3G/4G LTE Cat 4 Router) together with a Poynting A-XPOL-0002-V”) Antenna for a home network. My mobile gets quite a fast connection (~50MBPS download and ~20 upload).

When the above system is set up using the SIM from my own mobile, to test it, the only device that gets a good connection through the wifi network thus created is my mobile. Other devices have unusably poor internet speed.

I was wondering whether anybody could point me towards what the problem could be here and how it could be resolved? I’d be very grateful for any advice

the mr6400 only supports 300 Mbps Wireless N so some of your devices via wireless struggle with it. Honestly the tp link lte router is really a pile of poo. I hate saying that to somebody has brought something and then being told that

It wasn't a problem with the bands, nor aggregation (the mast I was using only had band 3). It was something that confused Three's traffic management. I forget the symptoms, but it was a problem on all APNs.

In reply to a post by jonburt83:

Living in a rural area in Wales with poor internet services, I intended to use a 4G router with SIM (TPlink TL-MR6400 Wifi 4 3G/4G LTE Cat 4 Router) together with a Poynting A-XPOL-0002-V”) Antenna for a home network. My mobile gets quite a fast connection (~50MBPS download and ~20 upload).

That router is quite an old (circa 2010) technology sadly; and just shows the market for fixed routers with 4GLTE support is tiny. Your antenna is pretty good for UK 4G as it supports 700 MHz to 2700 MHz which in theory should cover bands 1,3, 7, and 20 with ease.

You don't give any postcode, so I would suggest going to cellmapper.net and find your nearest physical mast to your location; and see which networks and what bands the mast is transmitting on. If your personal phone is Android you can use the cellmapper app to update the website, if you install and go for a walk outside around your home, this could usefully update the data set.

When the above system is set up using the SIM from my own mobile, to test it, the only device that gets a good connection through the wifi network thus created is my mobile. Other devices have unusably poor internet speed.

Does the router have ethernet, do you have any laptop or other computer with an ethernet port you could connet, temporarily, to the router to test the speed?

My guess is your router isn't matched to what is being transmitted. An LTE Category 4 device can only use ONE frequency band at a time. If your chosen network is Three and they are transmitting on three different frequencies from the local mast then your router picks one. It may be the most congested!

Three MIGHT be transmitting band 20/5mhz wide, band 3/15mhz wide, band 1/15mhz wide, band 7/20 mhz wide; but you may only have band 3/15mhz as I do living in a town (Three is least good for high speed data in my housing estate, only 25 miles from Heathrow).

It is likely the right combination of network and pointing your antenna at the right mast will get you better speeds, but finding this out will take some research.

The MR600 is cat6 - or at least the later versions are.
I have one and it does CA. I get about 150 down and about 25 up.
Maybe consider an upgrade from the 6400... but I don't think that's the OPs issue ATM.

If I understand correctly the OP says his phone, when on the wifi network created by the 6400, gets ok speed.

I agree with the last post. Test via cable if at all possible to reduce variables in the mix. If cable isn't easy there may be an inbuilt speed test in the router web interface - there is on the 600.


The 600 offers reasonably good diagnostic info in advanced settings
to see what bands it's using. You can also lock to bands which I have found useful in some locations.
Perhaps the same exists in the 6400?

Overall I've found the 600 to be a great router - good enough speeds for most things and v stable.

Edited by Henry8 (Sun 30-Mar-25 20:29:28)

In reply to a post by Henry8:

The 600 offers reasonably good diagnostic info in advanced settings
to see what bands it's using. You can also lock to bands which I have found useful in some locations.

Yes, if you can get diagnostics that can help. If using Three and its sitting on band 20 (800 MHz), there is only 5MHz of capacity so speeds will be low. If the unit allows locking to Band 3 (1800 MHz) where there is 15 MHz capacity can increase speed, or Band 1 (2100 MHz).

But to know which bands to try you need to survey the transmitter.

Is your phone actually connecting via the WiFi or through the native 4G connection?

In reply to a post by jonburt83:

I wondered if anyone could help me with a 4G router home network problem.

Living in a rural area in Wales with poor internet services, I intended to use a 4G router with SIM (TPlink TL-MR6400 Wifi 4 3G/4G LTE Cat 4 Router) together with a Poynting A-XPOL-0002-V”) Antenna for a home network. My mobile gets quite a fast connection (~50MBPS download and ~20 upload).

When the above system is set up using the SIM from my own mobile, to test it, the only device that gets a good connection through the wifi network thus created is my mobile. Other devices have unusably poor internet speed.

I was wondering whether anybody could point me towards what the problem could be here and how it could be resolved? I’d be very grateful for any advice

Your TPlink router only offers 2.4Ghz based WiFi which is prone to interference and is considered a legacy band as far as WiFi throughput and modernity is concerned. Your phone may manage a reasonable connection, but other devices, on a simultaneous access situation may struggle to get a decent connection.

It’s worth checking, as noted, internet throughout using cabled Ethernet connection from your various devices (where they support it) back to the LAN ports on your router to see if speeds improve.

Otherwise I think in your position I’d opt to replace the router with a more updated/ modern design with better WiFi capability (and also cellular 4G/5G reception capability)

Best of luck. 🤞