It’s been an odd month for Smart Energy, or at least for the wireless standards that are tackling connectivity around the home. If you were to go back six months, then, at least in the U.S., the general consensus would have been that ZigBee had the market tied up. It had the only profile with “Smart Energy” in its name and was winning the PR battle hands down.
Within the major working groups, things weren’t quite so clear. NIST, which has been trying to herd the wireless cats into some semblance of order started a more thorough analysis of just what existed, which saw an increased emphasis on other members of the IEEE 802 standards family, bolstering the fortunes of Wi-Fi (in its 802.11 incarnation) and Bluetooth (in its 802.15.1-2005 form). And it made its preferences clear about a need for IP support. But the status quo didn’t seem to shift very much as a result.
Then, last month, Bluetooth emerged from its normal mode of PR silence to announce the formation of a Smart Energy Study Group. The fact that Emerson, one of the world’s leading manufacturers of home HVAC devices was one of the sponsors for the group caused some noticeable shivers in the Smart Energy marketplace.
This week, there were more ripples, when Wi-Fi and ZigBee announced their Alliance of Alliances to jointly provide an in-home solution for Smart Energy. The Twitterati thought it significant, but what was behind it? Is it deadly rivals joining forces against a common enemy, or is there more going on?
On the surface it’s a bizarre alliance, as much has been written about the interference issues of using both ZigBee and Wi-Fi in close proximity to each other. Some of that has been promoted by rival standards, but as both are fixed channel devices in the 2.4GHz spectrum with limited agility, it is a real issue.
Despite its high PR visibility and initial success, ZigBee has been having to trim its cloth to accommodate some of the industry’s requirements. NIST’s Smart Grid Interoperability Project (SGIP) has indicated its preference for an IP based protocol for Smart Energy devices. ZigBee’s first version of Smart Energy profile didn’t support that, which left them in a quandary. So they scurried away to some of their former members who had deserted them in favour of 6LowPAN to attempt to bring the work they’d been doing on that back into the ZigBee fold. They still have a vision of releasing a future version of their Smart Energy Profile as an IEC specification, but quite what that will be is becoming more opaque by the day. To get there, they’re reportedly looking for input from IEC members to continue to evolve the profile.
Wi-Fi doesn’t have any problems with support for IP protocols, as that’s what it’s made of. Where it has had a problem with Smart Energy devices is in its power consumption. Wi-Fi is not a lightweight wireless protocol – the way it works and the volume of data that goes over the air, even for a small piece of information, means that it’s power hungry. Or at least, it has been. In recent years a number of new silicon vendors have emerged producing some innovative Wi-Fi (or to be more correct 802.11) chipsets that substantially reduce the power, to the point that they can be used for small battery powered devices. Foremost amongst these are G2 Microsystems, Gainspan, Redpine Signals and Ozmo Devices. Most of these vendors already target the Smart Energy market and must have felt as sick as a parrot when they heard that the Wi-Fi Alliance was having a public affair with their arch-rival.
The cynical may say it doesn’t matter, at least for Wi-Fi. Its volume shipments are so much larger than ZigBee’s (over two orders of magnitude larger), that it can use the announcement as political leverage to improve their position and then dispose of their new-found child bride as soon as the market takes off.
The announcement does raise the question of where Wi-Fi Direct has disappeared to? Touted as a low power PAN solution for Wi-Fi, some of these vendors have been instrumental in driving it forward. It seems strange that the Wi-Fi Alliance saw an alliance with ZigBee as a better alternative to promoting their own low power solution.
Which adds credence to the theory that this was a knee jerk reaction about the arrival of Bluetooth on the Smart Energy scene. Bluetooth has been used in Smart Energy devices for many years, but most have been built using proprietary protocols. (That’s actually been a deliberate choice from many appliance vendors, who in the past have not wanted interoperability, as they prefer to owner the entire ecosystem.) The announcement that Bluetooth was working on an interoperable Smart Energy profile, alongside the release of Bluetooth low energy, which is even lower power than ZigBee, seems to have induced a mild panic, where a known enemy seems a lot safer than an unknown one.
However, all of these announcements detract from the real question, which is “what is required for local connectivity in Smart Energy?” Rather than pandering to the rival screams of “I do it best”, the Smart Energy industry needs to come together with a requirement of what it actually needs. Is it IP to a device, or just to a home gateway? What level of security is needed? What range? What battery life? What robustness to interference is required, and for how many years must it maintain that robustness?
Hopefully the SGIP group may answer these and other important questions, so it can direct the industry to develop a standard that is fit for purpose. It is clear that industry leaders like Emerson consider it far too early to put all of their eggs into one basket. So we should probably take announcements like the Wi-Fi / ZigBee alliance with a pinch of salt, as being just one more distraction on the bumpy road to a reliable, interoperable solution.