When Internet of Things devices debut at this year's CES, one of the biggest questions will be how they'll connect to all the other smart-home gear on display. But anyone who expects a clear answer to that is like a kid who gets up Thanksgiving morning looking for a bunch of gifts under a tree.
The fact is, it's too early to say what standard or protocol will become the glue that can turn a pile of cool gadgets into a system that runs your whole house for you. New systems are just starting to emerge, and though they may eventually work with each other and with older platforms, buying one of each and expecting harmony is still wishful thinking.
Connected homes may make life easier eventually. A thermostat linked to a garage-door opener could tell who's coming home and set the heat or air-conditioning for their preferences. Compatible room lights and an audio system could join in, too.
That vision's starting to catch on. Ownership of connected home devices in the U.S. grew by 50 percent this year, and fully 43 percent of all households in the country will buy one in the next year, research company Parks Associates said last month.
For now, most people only have their eye on one device, said NextMarket analyst Michael Wolf. They may buy a connected thermostat for its features, or buy a networked garage-door opener because their old one broke, but they're not after a whole-home setup yet.
For those who are, there are already ways to tie devices together without giving up a weekend. Many vendors offer hubs to make their own home products work together, and some have opened these systems up to others. Samsung has SmartThings, Belkin has WeMo, retail chains like Lowe's and Staples have their own platforms, and smart-home specialist Insteon has a line of hubs and devices, to name just a few.
Broadband providers like AT&T and Comcast also offer selected products and ensure they work together. These systems may start with home security and expand to include things like lighting and climate control.
But having a vendor or carrier decide which products can understand each other won't be enough in the long run. Some new platforms are designed to offer a broader selection of products that consumers can add on easily.
That's where new buzzwords like AllJoyn, OIC, Brillo, Weave, Thread and HomeKit come in. But there are two things to keep in mind.
First, it's best to think of home IoT in terms of layers. Most of the choices consumers will face involve just two: network and application. One determines how data packets travel through wires or the air, while the other handles how devices understand each other and tell each other what to do.
For two products to work together, they need to speak the same language on both of these layers. If not, you'll need something else, like a hub device or software, that can talk to both.
Second, the future is not yet written for these would-be unifiers. Products certified for the same standard should work just fine, and there are likely to be many more carrying a logo in 2016. But it's too soon to tell if one standard will eventually rule them all. It's also too early to know how well plug-ins and other methods to make them compatible will work.
It will probably be five years before devices from different home IoT ecosystems can carry out complex tasks like setting up the whole house when you arrive home, IDC analyst Michael Palma says.
"I think we're going to see a lot of frustrated people trying to expand whatever they have invested in so far," Palma said.
Several big names working at the application layer are likely to show up on the CES show floor. Another will avoid the noise at a hotel suite nearby.
-- AllJoyn: Based on software developed by Qualcomm, AllJoyn is now an open-source framework administered by the AllSeen Alliance. Members include Microsoft, Cisco Systems, Panasonic and Sony. The group just started certifying products and making sure they work together, and only four are approved so far. Other devices have been using AllJoyn for months, and their makers are working to bring them up to the latest version and get certified, said Philip DesAutels, AllSeen's senior director of IoT.
-- OIC: The Open Interconnect Consortium includes Intel, Samsung, Dell and Cisco. (Some vendors have their fingers in a lot of pies.) It's tested a number of products for interoperability and plans to show them off in a hotel suite near CES. Through an open-source project called IoTivity, people with other technologies, including competing ones like AllJoyn, can introduce plug-ins that let OIC products work with other types of gear, according to OIC Executive Director Michael Richmond.
-- HomeKit: This software framework developed by Apple is designed to let users control home devices directly from an iPhone over Bluetooth or Wi-Fi. It can also tie into an Apple TV for access when your iPhone isn't in the house. Other smart-home platforms can connect with HomeKit through systems like the Insteon Smart Hub Pro. But Apple controls the HomeKit ecosystem and approves the products that can use it.
-- Brillo and Weave: These two software components have been called Google's answer to HomeKit. Brillo is a power-efficient IoT operating system based on Android, and Weave is middleware similar to AllJoyn and OIC that lets devices identify each other and their capabilities. Weave can work with OSes other than Brillo, and it can use at least three different networking protocols: Wi-Fi, Bluetooth Low Energy and Thread, the system spearheaded by sister company Nest.
-- ZigBee: This one's been around a while and is already built into many products. ZigBee standards for all types of devices, both home and enterprise, recently merged in the ZigBee 3.0 specification. ZigBee and Z-Wave are market leaders today because they are full-stack solutions that can ensure devices will work together, though they require hubs, said Parks Associates analyst Tom Kerber. The ZigBee Alliance says there could be bridges built between its platform and AllJoyn or OIC. It has also talked about possible integration with Thread, which would act as the underlying network.
-- Z-Wave: This technology, licensed by chip maker Sigma Designs, is also in a lot of products already. It's a full stack, too, but the Z-Wave Alliance says it's looking at ways to integrate Z-Wave with other platforms like AllJoyn and OIC.
At CES, some vendors will also be talking about the network protocols they use, though consumers are less likely to shop based on networking. Here are some highlights:
-- Wi-Fi: The ubiquitous wireless system will remain at the heart of most home networks, but many small, battery-powered devices won't talk to it directly because of size and power requirements.
-- IEEE 802.11ah: A version of Wi-Fi with lower power consumption, due for approval in 2016.
-- Bluetooth: The familiar personal-area network tackles IoT with the power-efficient Bluetooth Smart (or Low Energy) version and is expected to add longer range and mesh capability in 2016.
-- Z-Wave: A low-power mesh technology licensed by silicon maker Sigma Designs and used in a wide range of connected-home devices.
-- ZigBee: A mesh network based on the IEEE 802.15.4 standard and widely used in low-power home devices.
-- 6LoWPAN: An IPv6-only version of IEEE 802.15.4 mesh networking.
-- Thread: A protocol introduced in 2014 and based on 6LoWPAN, with added features for security, routing, setup and device wakeup.
-- ULE (Ultra Low Energy): A recently introduced low-power version of the DECT cordless-phone network technology.