Direct answer
There is no single speed requirement because local automation traffic is often modest while streaming video, cloud cameras, backups, remote work, gaming, and simultaneous users create most of the internet load. Download and upload capacity both matter; cloud cameras and offsite backups can consume substantial upstream bandwidth. Latency, packet loss, ISP reliability, modem and router capacity, and in-home Wi-Fi can matter as much as the advertised plan.
Inventory concurrent activities and use the current bandwidth requirements published by each service, then add practical headroom. Test with a wired device at the router and compare results throughout the home. Upgrading the ISP plan will not fix weak coverage, interference, bad cabling, or overloaded access points. Critical local lighting and control should also be designed to remain useful when the internet is unavailable.
How this answer was prepared
Camelback Smart Homes publishes this FAQ library for homeowners, design professionals, builders and property teams comparing integrated technology. Answers begin with the practical conclusion, then explain the factors that can change it.
Limitations: This is general educational information, not a site-specific design, quote, code determination or compatibility guarantee. Final requirements depend on the property, construction, infrastructure, equipment versions and project goals.