In this blog you will find a series of ramblings, product reviews, ideas and projects centered around the topic of Home Automation and Smart Energy. One of my initial aims is to find out the answer to the question… “Which wireless protocol is the future of home automation: Zigbee or Z-Wave (or other)?”.
With ‘the internet of things’ being the latest buzz phrase and an increasing fashion to monitor and automate our lives, there are a number of different technologies and protocols competing for the top spot of Home Automation and, although competition is a good thing, it leaves the consumer confused and the market fragmented.
Two such protocols are Z-Wave and Zigbee, both of which have their strengths and weaknesses, the battle for top spot is reminiscent of the days of the Betamax v’s VHS video war (or in more recent history HD-DVD v’s Blue-Ray), the question is who will be the underdog Betamax? Or is there actually a place for both technologies?
There are various websites which compare the technical differences between Z-Wave and Zigbee detailing radio frequency, modulation techniques and specifications, many of which I can not confess to fully understand. However as was learned from the Betamax v’s VHS war, it is/may not necessarily be the better technology which wins (i.e. although Betamax was technically the superior of the two video formats, in the end it was down to the cheaper and more relaxed licensing of VHS which lead to it becoming more widely adopted by the industry).
Rather than focus on the technical differences, I want to discuss a few industry observations and consumer concerns which I have made…
The eBay and Amazon Test
Although possibly not the most scientific indicators of popularity I occasionally look at eBay and Amazon to gauge the popularity based on the number of devices listed. Without any doubt it would appear that a search for ‘Z-Wave‘ yields the most results. Although a search for ‘Zigbee‘ does also bring back a number of results, the majority of these tend to be XBee, development boards and books rather than actual consumer devices. The same also rings true for the same searches on Amazon. Although I appreciate the development opportunities Zigbee has with the likes of XBee and Arduino, the average consumer will not be interested in this (nor have the coding skills) and will want a more ‘mature’ (out of the box) product with a guarantee that is will be compatible (plug-and-play) with existing devices.
UK Electricity Meters use Zigbee
The UK Smart Meter (SMETS) specification has lent towards Zigbee as its radio and application layer protocol. Driven by UK government policies energy companies like British Gas are currently in the midst of a national roll-out of smart meters, as a result this means that there will be a large number of homes in the UK with Zigbee devices at their heart (even if it is unbeknownst to the homeowner). I have in the past written a couple of blog posts on my experience getting smart meters installed here. It would appear that Smart Energy is one corner of the market which Z-Wave does not seem to have much headway and Zigbee currently possesses the stronghold.
Fragmented and confusing Zigbee Profiles
When purchasing devices bearing the Z-Wave “speaks” logo consumers can with a reasonable level of certainty know that the devices will be compatible with each other and, regardless of manufacturer, sensors, switches and devices can easily be synchronized with controllers. The same unfortunately can not be said of Zigbee due to its fragmented profile standards, to mention a few of these profiles… Smart Energy, Home Automation, Light Link, Healthcare and Building Automation, many of these profiles are not compatible with each other. This means that although a device may bear a Zigbee logo it is not necessarily guaranteed to work with other devices bearing the same logo (the profiles must also match). I myself have 3 Zigbee devices none of which work with each other.
Zigbee Certified Products Register
The Zigbee alliance website has a register of Zigbee certified products which can be used to search for products by type, manufacturer or profile standard. This does assist consumers identify devices which are guaranteed to inter-operate, however there is still a lack of re-sellers selling Zigbee devices. The UKs main reseller for Zigbee products is Vesternet, but there are not many others.
A couple of ‘high profile’ products such as Philips Hue have lifted Zigbee into the spotlight (and there is the Nest thermostat and smoke detectors which apparently host dormant Zigbee chips), but if Zigbee intends to complete with Z-Wave I think it needs to flood the market with more devices which are guaranteed to work with each other. Alternatively it may turn out that the pair co-exist with Z-Wave taking the Home Automation corner and Zigbee the Smart Energy corner.