On it's highest settings, the Doorbell Camera requires a dedicated upload speed of at least 2 Mbps at it's mounted location and can connect to either a 2.4 Ghz or 5 Ghz wireless network.
You can visit www.speedtest.net to measure your WiFi internet speed; the speed test should be run at the same location as the camera for accuracy as it can fluctuate depending on your distance from the router.
You can contact your internet service provider to increase your internet speed if needed.