Local Hubs and Backup Power Keep Smart Homes Running When Internet Fails

The report said Wi-Fi accessories often connect directly to cloud servers to fetch instructions and may have no way to store or trigger automations on their own during an outage or router problem. They may not even switch on or off at scheduled times. Whenever possible, Engadget recommended accessories that route through a local hub, which still connects to the internet but can store and process many automations locally as long as power remains. Automations that depend on live data, such as current weather, or involve sharing data remotely are major exceptions. The report said cellular backup is a must for smart security systems if internet outages are a regular issue.

Hubs can take several forms, according to the report. HomePods and Apple TVs can act as home hubs for Apple Home, enabling remote access and local automations. Some security cameras can record to local hub storage even if they need internet access to trigger alerts or perform advanced functions. Matter-enabled smart speakers and displays are capable of executing offline commands, though Amazon and Google do not really exploit this in practice, Engadget said, adding that it discovered this the hard way.

The report described the most bulletproof hubs as those that link local hardware through Thread, Zigbee or Z-Wave radios rather than Wi-Fi. All three are low-power, low-bandwidth mesh standards. A hub can often connect many compatible accessories at once, and the mesh design helps accessories farther from the hub avoid dropping off. Thread is preferable because some Wi-Fi accessories can act as Thread border routers, but Engadget said it has had good experiences with Zigbee-based hubs such as the Philips Hue Bridge. The main limitation is that low bandwidth restricts these technologies to devices such as lights, locks and sensors.

Power redundancy is a separate challenge. Engadget said an ideal setup would pair an entirely hub-based ecosystem with whole-home power backup, but that is unrealistic for most people because some accessories do not exist in hub-compatible form and whole-home battery systems cost thousands or tens of thousands of dollars. Even within budget, the report said the outlay may not be worth it unless a job or safety is at stake, since a soundbar or light panels can be down for 30 minutes. A workable compromise is to look for accessories with their own batteries, backup controls or both. The Philips Hue Go, for example, can connect to a Hue Bridge and includes a battery to operate as a portable lamp; it can keep shining for hours after losing AC power and cycles through basic effects using an onboard button or app-based Bluetooth commands. Smart thermostats will keep operating on their last schedule as long as the HVAC system is powered.

Engadget said users will not be able to secure redundancy for every smart home accessory, but thinking ahead while shopping can keep at least some devices running around the clock. It advised against simply picking the cheapest or slickest options at hand.