First identify the internet source: fibre or Ethernet, mobile SIM, radio link or another upstream router. The WAN connection determines which router types are compatible.
Estimate coverage and simultaneous users. Walls, floors, interference and long distances reduce signal quality. A large building may require wired access points or mesh nodes rather than one central router.
Check Wi-Fi standard, Ethernet-port speed, SIM bands where relevant, management controls, guest networks, power requirements and installation support. Position and configuration can affect performance as much as the device specification.
