Much like how it joined the Wireless Power Consortium, the standards group behind the Qi specification, Apple has very quietly signed up to the Thread Group, the body pushing the 802.15.4-based low-power mesh personal area network (PAN) protocol. It comes in the same week as Thread’s rival, and sometimes good friend, Zigbee passed 500mn sales, with projections to hit 3.8bn by 2023. However, the Zigbee Alliance is claiming that it will account for 85% of 802.15.4 shipments, which leaves very little room for Thread.
Spotted by IHS, analyst Lee Ratliff said that this could be huge news for Thread, especially if Apple incorporates it into HomeKit. However, both Apple and Thread are well behind Riot’s expectations for smart home progress – although in their defense, the entire smart home sector seems quite delayed, especially so from the smartphone giants.
However, Apple only really has two devices that make sense as homes for Thread radios – the new HomePod smart speakers (of which Apple’s is not particularly smart compared to Amazon’s and Google’s), and the Apple TV. Given the generally slow pace of Thread device certification, we don’t expect Apple to be announcing much in the way of Thread compatibility at its WWDC event in a few months, and we would estimate that its involvement in Thread will be mostly from its HomeKit software framework – which governs how smart home devices interact with its iOS and Mac OS platforms.
Adding Thread would also be a notable departure for Apple, which until now has stuck solely to WiFi and Bluetooth, despite the option of the long-tenured Z-Wave and Zigbee protocols. Bluetooth 5.0 has introduced its own mesh networking feature, Bluetooth Mesh, which might prove a useful tool for the likes of Apple, and Bluetooth’s main benefit over the rivals is that it directly links smartphones and smart home devices – although a bridge or gateway would admittedly solve that particular problem.
Apple has recently exited the WiFi router market, and so it seems unlikely that it’s going to bother launching a new AirPort with Thread support. However, Apple should definitely consider the mileage it would get from its own brand of smart home devices, such as cameras, environmental sensors, and perhaps even a thermostat. It has a pretty dedicated group of core enthusiasts, as well as a strong brand that could go toe-to-toe with the likes of Nest – and what better way to ensnare people inside its ecosystem than to turn their house into a churn-cutter itself.
But again, to reiterate, Apple has been very slow in pushing HomeKit out. Its recent iOS 12 update only made minor tweaks to the Home app, and HomeKit has only just added support for third-party remote controls, and still limits cameras to mains-powered only.
The new HomeKit Made For iPhone (MFi) developer kit won’t do much to smooth over the developers that are jaded by Apple’s shift from mandated hardware-based security, on specified approved chips, to a software-based approach. Apple does say that the new dev kit has removed a lot of the burden from developers, and claims that prototypes only take a week to create, with full releases possible in just three months.
If developers are able to hit those speeds, then perhaps Apple might be able to significantly ramp HomeKit adoption. So far, a trickle of devices have arrived on the market, which leaves Apple in something of a catch-22 – why bother investing resources in HomeKit if almost none of its customers are using it?
Well, if the Zigbee Alliance’s proclamation is true, then there will be a whole heap more smart home devices in the world, which might eventually change Apple’s mind. According to figures from ON World, some 500mn Zigbee chipsets have been sold to date, and by 2023, that figure is expected to hit 3.8bn. That’s some 85% of the total 4.5bn IEEE 802.15.4 chips that the forecast predicts, the family that includes Wi-SUN, and of course, Thread.
Thread and Zigbee use the same 802.15.4 MAC layer, and to this end, that does mean that some chips can support both protocols, meaning that they can share the same PHY layer. However, above the MAC, they are pretty different. Thread uses 6LoWPAN for the networking layer, whereas Zigbee has its own IP-compatible implementation, and then Thread also uses the Zigbee application layer. As you can see, it’s currently a bit messy, and things would be a lot easier if they could just merge already and iron out their differences.
Riot broached that topic back in 2016, noting that Zigbee and Thread had moved closer. The following December, in the run-up to CES 2018, the pair announced that Zigbee’s Dotdot application layer had been successfully ported to Thread, and that this joint stack constituted the first interoperable IoT language running over an IP-based network. Notably, Dotdot would also work as an option for things like WiFi, Bluetooth, or NB-IoT, should you be that way inclined.
Essentially, Dotdot defines how devices connect to networks and how they speak to other devices once they have joined. As long as a device is using Dotdot, it should be able to communicate with all other Dotdot devices on a shared network. While the Zigbee Cluster Library manages this for Zigbee, Dotdot is providing a way to do the same for other protocols – which has obvious benefits when it comes to IoT environments, as it means that WiFi devices should be able to communicate natively with Thread or Zigbee units.
In theory, Dotdot should enable all those devices to stay connected to all other Dotdot units, preventing them from completely losing their network connections. For developers, it means not having to hire the skills to support multiple protocols or devices, and for those looking to build or sell ecosystems, picking Dotdot should mean that your gateways, thermostats, or lightbulbs will all play nicely together – again, in theory.
So without being to Ross-and-Rachel about the chances of a merger, now that Thread-advocate Nest has been rolled back inside Google, we might see something of a more united front from the smartphone platforms. Chiefly, if Thread becomes the option of choice for both Android and iOS, then we might see some unification from the two camps, settling on a common approach that then might help the collective market grow.
As for the rest of ON World’s numbers, it says that Zigbee accounts for over a third of the current smart home Wireless Sensor Network (WSN) chipset market. The Z-Wave Alliance recently announced its 100 millionth chip shipment, for some perspective, although it’s worth noting that a lot of Zigbee chips are being used in things like TV remote controls, and not really smart home devices. By 2023, the figures project that Zigbee will be hitting a billion annual shipments.