Bridging the smart-home connectivity divide


The growing popularity of smart-home devices demands equally smart gateways to address interoperability and connectivity issues.

Back in 2010, when the smart-home concept was in its relative infancy, early pioneers proclaimed energy efficiency was the ‘killer app’ that
would drive product development and in turn consumer adoption.

At the time, less than half a percent of homes in North America had a connected device. But fast forward to 2017, and according to analyst IHS, nearly seven percent of households in the region now have at least one connected smart-home device. By 2025, IHS predicts, the figure will reach 10 percent globally. While reducing power bills has indeed proved a catalyst for growth; convenience, security, and entertainment have emerged as equally important drivers.

However, if the adoption of smart home solutions is to meet predictions, then certain hurdles will need to be overcome, not least of which is ironing out some connectivity and interoperability issues. Smart-home device manufactures currently have several low power wireless protocols to choose from when designing a connected product. Bluetooth Low Energy wireless technology, ANT, Thread, Z-Wave, Zigbee, and several proprietary solutions all have their proponents: But regardless of the protocol and application, to make them truly ‘smart’ requires Internet connectivity.

While developments are in hand, most of the commercial low power wireless solutions can’t connect directly to the Internet; to do so means employing a gateway — typically a sophisticated device with its own processor and firmware — to provide that connection.

The smartphone option
Thread and Bluetooth Low Energy wireless technologies are leading the market for smart-home device connectivity. Thread, first released in 2015, is a low-power, easy-to-use, and secure open-standard protocol for wireless home automation networks. Thread gains an advantage over most other protocols targeted at smart-home applications by supporting Internet Protocol (IP), allowing Thread devices to communicate with all other IP-addressable devices without relying on an expensive and complex gateway. Instead, Thread networks employ relatively inexpensive ‘border routers’ to simply relay the short-range WPAN signals to the Internet proper.

Bluetooth Low Energy wireless technology gains market advantage because of its unique interoperability with most of the current generation of smartphones and tablets. These devices can provide a ready-made solution by acting as the gateway between the smart-home device and the Internet. According to analyst, Pew Research Center, roughly three quarters of Americans now own a smartphone, and a similar number have a broadband connection at home, so the mobile solution is effective - but only so far.

Smartphones are expensive, they are also power hungry, but more to the point, they aren’t always in the home. While turning lights on and off from a smartphone or tablet when in the house is one thing, being able to control the lights, or lock or unlock a door remotely, from anywhere, is where the potential of the smart home really comes into its own. And
that requires something other than a smartphone for Internet and
Cloud connectivity, to cater for when the mobile owner is out.

The missing link
Today, proprietary gateways provide the answer. Gateways aggregate data from multiple smart-home sensors, and relay that data directly to
the Internet (via a wired link or Wi-Fi connection), allowing users to retrieve information about their smart appliances from the Cloud wherever they are in the world. Importantly, the connection is bidirectional, allowing for the remote operation of smart- home devices either from their smartphone or tablet, or via a Cloud platform.

Some advanced gateways go a step further by supporting multiple protocols ensuring interoperability between devices employing different wireless technologies. This affords smart-home product developers design flexibility while the smart-home market shakes out, and means end users don’t need to hitch their wagon to a single Wireless Local Area Network (WLAN) technology.

“The smart home will be powered by several wireless technologies including Bluetooth Low Energy,” notes Geir Langeland, Director of Sales
& Marketing with Nordic Semiconductor. “Because of this, the market demands gateways that support multiple WLAN technologies and
Cloud connectivity via Wi-Fi and cellular.”

The recently launched ‘ Gateway’ from Denmark’s Develco Products is a case in point. The gateway is an open Linux platform providing multiple wireless communication technologies to a range of smart home devices and the Cloud. In addition to Bluetooth Low Energy wireless connectivity provided by Nordic’s nRF52832 System-on-Chip (SoC), the Gateway supports cellular 2/3G, Wi-Fi, Wireless M-Bus,
Sub-1GHz proprietary, zigbee, and Z-Wave. The gateway also supports Ethernet wired networking.

“It’s important to include Bluetooth Low Energy in the Gateway because it’s an increasingly popular smart-home wireless technology that’s been adopted by many sensor vendors,” says Henning Mærkedahl, CTO with Develco Products. “But the gateway is modular and can handle many different wireless protocols at the same time, so solution providers are no longer dependent on one vendor.”

For more complex applications — for example mesh-networked smart lighting — networks can use more than one gateway in a single installation. Last year Norwegian wireless network solutions company,
Vitir, launched its ‘MergeRF’ system, a sub-1GHz self-forming and -healing mesh network enabling long-range communication between Bluetooth Low Energy devices. Each Vitir ‘bridge’ includes a Nordic nRF51822 SoC providing Bluetooth Low Energy connectivity between other gateways, Bluetooth Low Energy devices, and Bluetooth 4.0 (and later) smartphones and tablets.

The gateways act as routers for any payload, irrespective of origin in the network, and regardless of the original RF protocol. Together with a Central Unit (CU), interoperability between devices using any RF protocol
is enabled. The CU acts as a gateway to the Cloud with a single RF connection point to the mesh, allowing new gateways or new protocols
to be added to the mesh without the need to recertify the CU.

An eye to the future
While proprietary gateways and bridges provide a perfectly serviceable workaround to the smart-home Internet connectivity and interoperability conundrum, in the longer term better solutions exist.

Wi-Fi presents one option because many homes already employ a gateway in the form of a Wi-Fi router. At present Wi-Fi routers can’t communicate directly with the protocols typically used for smart-home applications. While many enterprise routers already come with Bluetooth Low Energy wireless technology built-in, for example, consumer Wi-Fi router manufacturers have been slow to seize the opportunity. However,
if these makers could also be persuaded to incorporate Bluetooth Low Energy wireless connectivity into omnipresent domestic Wi-Fi routers it would eliminate the need for today’s proprietary solutions in a vast number of homes.

Integrating IPv6 into Bluetooth Low Energy devices so they can connect directly to any other IP-addressable device on the Internet (for example,
a Cloud server) is another solution and would follow the path paved by Thread. As Bluetooth Low Energy wireless technology doesn’t natively communicate using IPv6 the best way to achieve this is by incorporating
a Network Adaption Layer and 6LoWPAN layer into the Bluetooth RF software protocol. This enables “IPv6 over Bluetooth Low Energy” in a similar way to that which the Thread protocol has employed.

Nordic offers developers this option with its nRF5 Software Development Kit (SDK) for IoT, but IPv6 over Bluetooth Low Energy is still some way from mass adoption. When it is, we’ll be much closer to the end goal of
low-power smart-home devices that can communicate directly with
each other, and the Internet, in a standardized way without proprietary gateways or smartphones sitting in the middle. Such technology will form a genuine Internet of Things finally making smart-home products truly intelligent.

The smartphone option

Thread and Bluetooth Low Energy wireless technologies are leading the market for smart-home device connectivity.