CNxROOT Two Posts: How to Build an RTL-SDR Server with OpenWRT, Creating a GSM BaseStation with OpenBTS and a USRP
Open Source 3.5G Cellular Developer Programme Announced
Raspberry Pi Used To Replace A 30-Foot GSM Base Station And Create A Working Mobile Network | TechCrunch
GSM, GPRS, GNSS, Bluetooth and RTC HAT for Raspberry Pi | The Pi Hut
Base station
R800C GSM/GPRS HAT for Raspberry Pi | The Pi Hut
The Implementation of YateBTS Based GSM Using Raspberry Pi
Waveshare 4G/3G/2G/GSM/GPRS/GNSS Hat for Raspberry Pi 4 Jetson Nano Based on SIM7600E-H Supports LTE CAT4 for Downlink Data Transfer : Amazon.co.uk: Computers & Accessories
Lime Provides LimeSDR Mini and Raspberry Pi Base Stations for EMF Camp - Lime Microsystems
GSM/GPRS/GNSS/Bluetooth HAT for Raspberry Pi - RobotShop
Engineers use Raspberry Pi to create GSM base station - Blog - Code Exchange - element14 Community