Hey everyone, I wanted to share something that I've been working on. I bought a Fibocom 850GL from eBay (the HP version) for about $30. My original intention was to create a DIY Portable Mobile Hotspot with a Raspberry Pi acting as the router and a TP Link WR902ac for a fast WiFi AP. I got two Cradlepoint antennas (I didn't trust any cheap ones on eBay/Amazon) that is rated to pickup 2.5 GHz and put the modem in an enclosure that converts from M.2 to USB 3.0 with a SIM slot.
You can see it all together held by rubber bands (there is also a 20,000 mAh battery underneath it all):
It worked great! I installed OpenWRT on the RPi and configured it to get a cellular data connection. I used it for a few weeks taking it around town and it was stable. However data speeds weren't as fast as it should be (about 42 Mbps). I initially thought it was the antennas but after some digging around I figured out a way to fix it. To keep it brief, abrasive on GitHub figured out how to change USB modes with an AT command. I tried changing the USB mode to 7 which allows it to work in Windows using CDC MBIM (before it wouldn't work in Windows). To my surprise it worked, and without any drivers! Best of all, I'm seeing much better data speeds almost upwards of 120 Mbps download. The modem supports 3xCA on B41.
From here, I haven't gotten much further. I'd like to put this modem in a real router using PCIe instead of USB but I'm unsure about compatibility and drivers when looking some up. Now why this modem? You can activate it on Sprint as a "tablet" which costs $15/month after auto pay (the HP version only) for unlimited data.
Also as a side note, right now I deactivated it. Should I reactivate it again because of the merger and the plan not being available? I don't need this but it's pretty cool to have.