This blog has already explored the multitude of standards currently being used as the basis for connecting sensors, object and all sorts of things to the Internet and to each other. Nowhere is this problem more acute than in the area of home automation, where the lack of widely adopted standards results in systems that don’t talk to each other, and worse, in systems that quickly become obsolete and cease to be supported by their manufacturers. The situation where the home heating, lighting and security solutions all run on different incompatible technologies clearly doesn’t do much for consumer confidence in this space.
Whilst WiFi is the undisputed champion of home wireless connectivity, its cost and complexity rule it out from more mundane applications as connecting a light bulb. Instead, there are two technologies vying for success in this space, Bluetooth and Thread / 802.15.4.
Bluetooth Smart
A couple of weeks ago the Bluetooth Special Interest Group (SIG) released version 4.2 of the Bluetooth specifications. Already, in its ‘Bluetooth Smart’ or ‘Bluetooth Low Energy’ variant, a technology that was initially designed to connect wireless headsets to phones had been transformed into something a lot more useful. Widely supported by all major smartphone and tablet platforms, Bluetooth Smart introduced a lower rate, though much more power-efficient configuration that can be used in battery-powered devices for several months. Applications include connecting wearable devices such as fitness bands and medical devices, providing micro-location services in retail outlets as well as connecting to devices in the home. The latest evolution of the specification will allow smart products such as light bulbs and door sensors to connect directly to the Internet over IPv6 without use of an intermediary device such as a gateway or smartphone. Bluetooth received a further shot in the arm in October, when mobile chip giant Qualcomm announced its intention to buy CSR, a leading Cambridge company providing Bluetooth chipsets.
Thread / 802.15.4
The other principal contender for providing Smart Home connectivity is Thread. Based on an open radio standard called 802.15.4, it is the result of a partnership between, amongst others, Nest (owned by Google), ARM, Samsung and Silicon Labs. It is effectively an upgrade on the Zigbee standard which is being used currently smart meters. The aim is to provide a simple protocol for connected devices in the home that is secure and power efficient. In other words, exactly the same objectives as Bluetooth Smart .
The power of mesh networks
So how do these two standards square up? On many fronts, Bluetooth 4.2 and Thread are pretty similar. They offer similar levels of security, support for IPv6 and have not dissimilar low-power configurations. Additionally, they both have heavy-weight technology backers. To me, the key difference is that Bluetooth is already pervasively supported across smartphones and tablets, and device vendors will be very reluctant to have to integrate yet another wireless standard into their devices.
On the other hand, Thread, supports Mesh networking, a system whereby communication messages can hop on across different devices, rather than be routed via a central hub. This provides a number of advantages, including increasing the effective range of the network, lowering the per-unit cost of the network, and creating a more resilient, self-healing network, as it reduces dependencies upon a single point of failure. Mesh networks are already beginning to provide resilient networks in Smart Cities and to connect smart meters back to the energy companies. For example, Telefonica is rolling out a wireless mesh network provided by a Swedish company called Connode to in the South and Central UK regions to provide smart meter connectivity to areas without cellular coverage. Moreover, where it is necessary to connect a large number of sensors such as street lights, traffic monitors, rubbish bins, parking meters and parking spaces across a city’s large footprint, mesh networks can provide a cost-effective and more reliable alternative to mobile, fixed or wifi connectivity.
The advantages that make mesh networks a good solution across cities also apply to the smart home, and this is something that the Bluetooth camp has recognised. CSR has already demonstrated a Bluetooth-based mesh network solution, but has clearly been unsuccessful so far in bringing together support of the rest of the Bluetooth community. Despite Google’s support of Nest, I believe that in the long term, the fact that Bluetooth is already supported so pervasively billions smartphones makes it likely that this will become the defacto standard for the Smart Home.