When sourcing 4G routers, the most critical factor is Network Band Compatibility. You must ensure the device supports the specific LTE bands used by carriers in your target country (e.g., B1/B3/B7/B8/B20 for Europe or B2/B4/B5/B12/B17 for North America). Additionally, evaluate the LTE Category (Cat4, Cat6, or higher); Cat4 offers up to 150Mbps, while Cat6 supports Carrier Aggregation for faster speeds. For hardware, prioritize external high-gain antennas to improve signal reception in weak areas and check the WiFi standard (802.11n or 802.11ac) to ensure local wireless distribution meets user needs.