File:Mainboards of UMTS Router Surf@home II, o2. Incl. Option PC Card-8329.jpg - Wikimedia Commons
UMTS - Wikipedia
Installation of LTE modem into Turris Omnia router [Turris wiki]
File:Mainboards of UMTS Router Surf@home II, o2. Incl. Option PC Card-8331.jpg - Wikimedia Commons
Amazon.com: Teltonika RUTX11100400 Model RUTX11 Dual SIM Router 4G LTE Cat6 DL Up to 300Mbps, 3G Up to 42 Mbps, 4x1GB Ethernet Ports, Dual-Band AC WiFi, Bluetooth LE and USB Interfaces :
R311 4G WiFi Router External Antennas 4G LTE Router Internet Connection for Home | eBay
WNA – TA Wiki
RM500U-CN 5G HAT - Waveshare Wiki
VoIP gateway - How to set 2N® NetStar as a VoIP gateway - FAQ_Telco_private