Router board for DIY portable modem

I'm looking for a router board with:

  • M.2 slot for the LTE/4G/5G modem module card.
  • SIM card slot.
  • 12v input (or lower) for powering/charging from electric car plug and using with DYI 12v battery pack.
  • Wi-Fi with antennas: built-in latest version like 11ax or another M.2 or mPCIe slot for module card.
  • OpenWrt support

I want to build a portable modem for car traveling (driving to countryside, offroading, camping, fishing). It will catch low signal from cell towers outside of big cities and share internet access through Wi-Fi to smartphones, laptops. And want to do some experiments with antennas on this router: omni, directional, portable, DIY, specific bands.
What do you think of this kind device? Do you remember oldschool radios? :radio: Those portable boxes with long telescopic antennas? The history repeats itself! Time to bring this fashion back! :grinning:

I'd buy a MiFi device, and attach antennas to it.

Like a Huawei E8278, or something similar with built in battery (they usually don't last very long, though).
The E8278 only have 802.11n 150mbit wifi, but the 4G doesn't go any faster anyway.
It has two TS9 connectors for external antennas.

Obviously no openwrt support, but it works really well.

There are also Huawei and other brand MIFI with 802.11ac radios tho but OP needs to check the supported 3G/4G/5G bands against what the carrier supports before buying anything.

I recently purchased a 4GRouter from Aliexpress for exactly this purpose. i.e. put it in a 4WD for outback touring. see:

I am currently in the UK but intend to holiday and drive in Australia in about 18 months so I'm trying it out before I go. I have the EU 4G card. It will connect to Three and O2 in the UK but does not work well with EE. If you tell me which carrier you want to use I can check if they provide configuration settings to suit. It should I think work with Telstra in AU and supports B28A band to give best range but obviously I'm not able to test that at the moment.

I believe it runs OpenWRT but haven't been able to get CLI connection to confirm. I'm very new to OpenWRT. I'm also playing with various antennas as the box comes standard with stick on patch antennas so I want to try higher gain models both for WiFi and 4G. Happy to discuss further and compare results with whatever you come up with.