Wireless Standards and the Future of the Smart Home.
For those of you with a long memory the genesis of the Smart Home was born in the late 80s or early 90s when the jargon word was “domotics”. At that time none of the current low power wireless standards had been invented. So progress with home automation was very slow and extremely fragmented in terms of the wired and wireless protocols used.
This article was original published in Electronic Design What Wireless Network Standards Will Rule the Smart Home? | Electronic Design
In a “Smart Home” the difference is that these diverse devices are connected via a common system, and perhaps on via the internet to a remote location. For example, you could turn on your home heating system when you leave work, to warm up your house on your arrival. This saves you heating an empty house unnecessarily.
To do this, and allow different vendors products to be connected, you need common standards. The issue has been not a lack of standards, but too many of them. This article examines the different standards that have been or are being proposed for smart home applications and what might be the future path.
Aging Zigbee
The traditional wireless standard for this kind of application was Zigbee. This is a “mesh” based protocol for linking wireless devices. It has been adopted in various industrial automation applications and gained some traction in the Smart Home domain.
The main issue with Zigbee is that it is showing its age. It originated in a “pre-IP” world. It is proprietary from top to bottom and has a relatively limited installation base. The basic data rate is also low and requires a router device to define paths through the network. The relatively small installed base means it has never been adopted within the Mobile Phone world. In summary, whilst technically Zigbee was a decent solution for its time, the world has moved on.
Ubiquitous Bluetooth
Bluetooth is a technology that has become ubiquitous. There are many Bluetooth controlled devices. For instance smart light bulbs can be controlled by a phone, and various other controls that are now Bluetooth based. So it might seem natural to use Bluetooth as a basis for the Smart Home.
The issue is that Bluetooth was always designed as point to point protocol. Whilst you can have more complex technologies such as a star network or even star of stars, it was never designed to be a peer-to-peer type network. As a solution to this, Bluetooth Mesh was created. It was designed as a peer-to-peer network. The problem is that it only has a passing resemblance to Bluetooth itself. It uses the same physical transport layer at the radio level, but otherwise is a completely different protocol. It also is not particularly efficient or supportive of high data rates.
It has gained some traction for lighting solutions, which arguably it was designed for. However, it isn’t clear if it can support the full range of potential Smart Home needs.
Omnipresent WiFi
WiFi is omnipresent in the home so using WiFi as the backbone of a Smart Home system seems to make sense. There is bandwidth to burn, after all. However, this isn’t really a solution either. WiFi is just a basic data transmission standard. It doesn’t help devices communicate at the application level. More fundamentally, all that bandwidth comes at cost. It isn’t very well adapted to low power devices. Nobody wants to be continually changing batteries or recharging things. It also isn’t well adapted to dense networks as it operates on a limited number of radio channels. As device nodes proliferate in the home it risks grinding to a halt.
The new WiFi 6 standard tackles these issues to some extent. It offers much better support for dense networks of low data rate devices. It has some improved power consumption but nevertheless it isn’t at the Bluetooth Low Energy level of battery efficiency.
Proprietary Smart Home environments
In parallel to the core protocol side, the big device manufacturers have developed their own Smart Home environments – Apple’s Home Kit, Samsung Smart Things, Google Assistant, Philips’ Hue, etc. This is fine if you’re happy to commit to an “Apple Home” or a “Google Residence”. However, many customers don’t want to be tied that way. They fear either backing the wrong standard or being captive to higher prices from a monopoly supplier.
Thread and Matter
One might think that manufacturers would be content with a set of “tied” customers,but not if that inhibits the market. In general terms, there’s enough history to show the value of creating interoperability to grow the size of the market rather than clinging on to a segment of a smaller one.
Hence, enter “Thread” and “Matter” – the industry’s “grand unification” plays in the Smart Home market. What are these protocols and do they offer a solution?
To tackle the wide variety of devices that exist in the home – anything from large mains powered items like a heating unit or kitchen appliance to a battery powered temperature sensor – the aim is to separate this Application Layer from the underlying transport. Thus, devices can communicate Matter based instructions over Bluetooth, WiFi, Ethernet, etc, depending on the data bandwidth requirements and power consumption needs of the device in question.
Matter tackles the interoperability part. In terms of an underlying protocol, as stated above, you can use existing standards like Bluetooth or WiFi. However, Thread is a Mesh protocol specifically designed for this environment. It is Zigbee updated for the 21st Century. Thread is IP based and allows relatively easy internet access if you want to go out of the home. The protocol is designed to operate efficiently in device dense environments. It connects to the Internet via one or more Thread border routers. Unlike Zigbee, you are not limited to a single router device.
In terms of hardware, there are already plenty of chips with Thread protocol stacks running on them. Many devices can run Thread and Bluetooth stacks at the same time, allowing designers to easily implement flexible devices. So, you could, for example, have a device you could interact with locally via a Bluetooth point to point connection, perhaps to set it up in the first place, and then later connect remotely via Thread.
Let’s start with Matter. This is an application layer protocol designed for the Smart Home market. The idea is that you provide a common way of interacting with the different types of device such as lights, entry systems, heating and ventilation. In this sense, it is like the concept of Bluetooth Profiles. Just as a phone can connect to a heart rate monitor from a separate vendor by using a Bluetooth Heart Rate Profile, your Matter enabled device or phone can control your heating system, via a set of command commands and responses.
To tackle the wide variety of devices that exist in the home – anything from large mains powered items like a heating unit or kitchen appliance to a battery powered temperature sensor – the aim is to separate this Application Layer from the underlying transport. Thus, devices can communicate Matter based instructions over Bluetooth, WiFi, Ethernet, etc, depending on the data bandwidth requirements and power consumption needs of the device in question.
Matter tackles the interoperability part. In terms of an underlying protocol, as stated above, you can use existing standards like Bluetooth or WiFi. However, Thread is a Mesh protocol specifically designed for this environment. It is Zigbee updated for the 21st Century. Thread is IP based and allows relatively easy internet access if you want to go out of the home. The protocol is designed to operate efficiently in device dense environments. It connects to the Internet via one or more Thread border routers. Unlike Zigbee, you are not limited to a single router device.
In terms of hardware, there are already plenty of chips with Thread protocol stacks running on them. Many devices can run Thread and Bluetooth stacks at the same time, allowing designers to easily implement flexible devices. So, you could, for example, have a device you could interact with locally via a Bluetooth point to point connection, perhaps to set it up in the first place, and then later connect remotely via Thread.
Future of Smart Home wireless standards
Do Thread and Matter represent the holy grail of Smart Home integration? Flexible, interoperable, interconnected, and resilient? In my view it is a cautious “yes”. They are designed to tackle the problems that exist in previous generations of technology. They are adapted to the modern world of the internet and ubiquitous IP networks.
The caution and the caveats arise from the “interoperable” part. Interoperability is easy to specify, but a lot harder to make seamless in practice. The experience of Bluetooth is that it took many years to get this working. It also needs genuine commitment by the manufacturers to interoperability. This means not merely paying lip service to the idea, whilst keeping certain functions hidden or frequently changing specifications to make it impossible for third parties to engage. There’s also the issue of getting the security aspects right. Whilst opening your home to the internet has some potential physical security benefits, it also carries huge data security risks that could quickly undermine market confidence if not properly addressed.
We are in the early days of this next phase of Smart Home technology. Whilst the ideas seem good, the hard work is doing it, and doing it right. Let’s see!
By Dr Nick Wood, Director, Sales & Marketing, Insight SiP