A recent article on Stacey-on-IoT brought up Smart Home Hubs, a topic that is very near and dear to my heart and was actually a subject of engineering projects here at Afero. (Scroll down to see the link to the article.)
The main discussion was about adding hub capabilities to Wi-Fi routers to eliminate some clutter. This means not only the software to interact with IoT devices, but also the communication protocols that such devices might demand, like Bluetooth and BLE for sure, but other protocols like Zigbee have also been mentioned. And therein lies the challenge.
Here’s an updated version of the comment I added to that discussion which summarizes our experiences here:
I’ve worked on this precise problem and it’s a tough one because there’s a conflict between Wi-Fi and Bluetooth, BLE or Zigbee that also operate in the same radio band (2.4GHz). This problem is called Coex – short for “coexistence” and basically means the Wi-Fi needs to stop while the other radios do their stuff. Wi-Fi is is “loud” compared to these low power radios and drowns them out easily. Now, this is a solved problem – its done all the time on your smartphone because you can stream over Wi-Fi and listen on your Bluetooth earbuds, but the conflict comes in the effect it has on Wi-Fi performance when it is done in an access point/router (AP).
The best way to service IoT devices would be to listen all the time, because they often blerp out data unpredictably. But if your AP listened all the time, Wi-Fi transmissions in the 2.4GHz band would drop to zero. That is a bad thing for Wi-Fi devices because although some use 5GHz, a lot still use 2.4GHz, especially when range is required. Also, Wi-Fi access point vendors are ranked and rated on their throughput so there’s a disincentive to sacrifice a band just on the off-chance IoT devices might be around.
There are other issues too – such as the fact that IoT innovation is occurring a lot faster than Wi-Fi and there are nowhere near the standards in place yet (or ever?) so AP vendors would be making a big gamble by trying to fit something in there. Today’s hot IoT system could be dead in a year and then all those AP’s are out of date. There are also competitive issues – for example, why would Google ever put HomeKit support into their box?
Some AP vendors have put Bluetooth in, but it’s often used just for setting up and then disabled, or as a fallback if something goes wrong. Others use clever Coex to try to mitigate the issue or shift as many devices onto the 5GHz band as possible. But there’s no getting away from physics unfortunately.
There are far too many makers reinventing the wheel out there in this regard. Hub software can also be put into smartphones and other devices, like fridges so that dedicated devices are not required. Further, with appropriate security (end-to-end, hardware root-of-trust), hubs could service any IoT device, even your neighbor’s if they are in range. Think like Comcast’s Xfinity Wi-Fi – a similar coverage for IoT devices could be available.
One result is that we have IoT hubs. They are placed away from the main Wi-Fi access point (ideally 6 feet or more) to avoid interference and they do the job for their bit of kit. The best long term solution in my mind is that IoT gadget makers get out of the hub business and adopt an open or de facto standard for low-power device connectivity so there could be just one hub for all devices! We have taken this approach with our partner D-Link which produces a delightful little IoT Hub. Powered by Afero, it comes with all the ease of onboarding, security, and speed that the Afero Platform is known for
What do you think?