Building an LTE Access Point with OpenWRT Rooter

If you want none of the fun, a rooted dual SIM smartphone does all that. I've not had trouble finding prepaid SIMs that would not work via Hotspot.

Having played with all of this before I have some opinions on a few of these things.

I have half a dozen of those TP-Link routers in a drawer, they're fun to play with and ok for on the go. For traveling I'd stick with one off those over a Raspberry Pi, or better yet, for a nice little upgrade I'd go with one of the GL.INet routers, I have a few of those too and they all support OpenWRT/LEDE. They come with it out of the box (albeit with their GUI on top).

RPi is sensitive to power fluctuations and note great for travelling because pulling the plug a couple of times will likely destroy your micro SD. If you were to use one for travel I'd suggest mounting your microSD read-only for maximum safety. I've been through a dozen or so cards in a static Pi before I switched to ramdisks and read-only root.

Currently I only use my mobile as a hotspot because it's inconvenient and extra cost to have additional SIM/data when my mobile contract offers plenty.

Another more powerful device is the NanoPI R1 which packs WiFi, BT and two Ethernet ports (one through USB) in a form factor comparable to that small TP-Link router. The second Ethernet and bigger hardware specs could be handy to set up a VPN to a safe network when connecting from untrusted places. https://www.friendlyarm.com/index.php?route=product/product&... Currently not listed among Rooter compatible devices, but the Orange PI zero plus is (both use Allwinner CPUs), so porting shouldn't be that hard.

If you have time to spare this is a nice option to have. However,I didn't so after looking up reviews online I got a TPLink Archer MR200 LTE/4G router that you can simply plug a sim card in and it provides both wired and 2.4/5GHz WiFi. As the thing sits in the attic next to a diy dual biquad lte antenna its Wifi doesn't cover lower floors of the house so I have two of Fritz Wlan Repeater 1750E.

Now the TPLink router is not cheap. The US price is around $300, but in my opinion is well worth it as it gives me the ability to connect my DIY antennas and up to now it has been working almost flawlessly (barring a restart every few months) for 3 years. There are probably other routers that are equally good, but my experience is with this one.

Regarding the WLAN repeater, it is also an expensive one at around $100, but it is the only reliable WLAN repeater I found. I started with a cheap D-Link, returned it to the store after a day, tried another one etc. I went through 5 or 6 repeaters until I found this model that actually works with multiple devices, is fast etc.

Also, on the subject of LTE, I had real trouble finding a directional antenna I could purchase that would have at least 10dB gain at 800MHz (that's the LTE frequency my local tower uses) and wouldn't cost more than the router itself. So I ended up making two of them(as the router supports multi paths). At the end of the day it is only a bit of sheet steel and wire. I don't get why good lte antennas costs as much as they do.