NEARFest April 2025

Sat Apr 26, 2025

This is my demo setup for NEARfest April 2025.

You can see my TODO list and my plans for complying with regulations as well as a discussion on the legality of Amateur LTE, as well as how lucky we are that it’s possible in the first place.

This page is all about the demo setup. I’ll have pictures from NEARfest after the fact.

This is also kind of a packing list.

I’ll have a 100 Ah LiFePo4 battery with a 1200 W inverter, along with a 100W solar panel.

I’ll also have a car nearby with a DC-DC charger, and there may be an opportunity to run off standard 110VAC.

EPC, eNBs

  • Mini PC running DragonOS, with Open5GS in docker (Thanks herlesupreeth!)
  • Random tp-link ethernet switch, plus spare
  • GL.INET mini router, USB powered. This will also be a webserver for some basic web pages and files (See demo section)
  • Baicells pBS4100a (50mW). 10MHz, 2390-2400

If possible, one of:

  • Baicells pBS4100a (50mW). 5MHz, 2305-2310

  • Baicells pBS4100 (125mW) 5MHz, 2305-2310

  • Possibly: Limesdr, srsenb with Band 8 into SMA terminators (Probably not to operate, but to show what can be done to experiment)

  • Band 48 (CBRS) Nova227. Probably not running, since I don’t want to set up SAS.

Misc

  • NanoVNA for troubleshooting.
  • HackRF
  • LimeSDR
  • Pluto+

UE

  • Pixel 6A (GrapheneOS), with physical sim card.
  • iPhone 7, physical sim card
  • Moto 5G
  • GL.Inet Spitz AX, physical sim card.

(unproven below:)

  • Anysecu HD6500 (LTE PoC + UHF FM transceiver)(Probably won’t have a PoC compatible server running)
  • Anysecu W6Pro (LTE PoC-oriented android phone with UHF FM+DMR transceiver)

Uplink / Internet

  • Starlink
  • Possible: LTE via Spitz AX

Demo materials

Known working and ready:

  • at least two UE that can make call
  • Live graph of traffic within the EPC (coredump) (and maybe outside of it too?)

Near-definitely:

  • Business cards with links
  • Several different one-sheets available for pickup and perusal, including: Overview, technical details, legal details.
  • Rapid-programming setup for sim cards and esims to allow people to try the network on their phone, RFN.
  • SDR spectrum analyzer showing transmissions, maybe decoding them with LTESniffer if possible

Hopefully:

  • At least two UE that can send/recv texts
  • Laptop uplink through HD6500 modem?
  • Some local-hosted services to demonstrate the value. I’m thinking something like the internal dashboards, some APKs for download (ribbit, …), a local website, a mumble server, openwebrx, takserver, ianrenton/planesailing, dump1090, tarsat, that sort of thing.
  • If I can get kamailio talking with asterisk: conference calls
  • If I can get SMS to all connected devices: dynamic group chats and similar

Misc

  • callsign.cards printout and my card as demo