Some weeks back I wrote how old animosities within the committees developing an updated ZigBee specification (Smart Energy Profile 2.0 and associated IP-based protocol stack) were overflowing into public view. In April, a vote on the draft specification unexpectedly failed when a group of participants, nominally aligned with the traditional ZigBee adopters, rebelled against the specification of the widely used, but notoriously inefficient, HTTP/TCP protocol as the transport protocol, instead backing User Datagram Protocol (UDP) plus the new, but less taxing Constrained Application Profile (CoAP) protocol.
Like so many standards development soap operas – and there have been many – this battle was replete with ideological grandstanding, political intrigue, personal recriminations, and Washington-worthy spin doctoring. Most importantly, the stalemate threatened to continue to hold large-scale the Home Area Network (HAN) deployments hostage. Already, most of the large California utilities, who are now approaching critical mass of deployed HAN-enabled smart meter, are waiting for SEP 2.0 before rolling out HAN devices and the energy management programs they will enable.
It turns out that locking everyone in a room in Wuxi, China, in June led to an agreement allowing both solutions, defusing the battle and allowing the process to move forward. The revised specification was released on July 15 for public comment. Since people on both sides of this debate are genuinely smart and passionately committed to strong solutions, I can only assume they all enjoyed some good Chinese beer together afterward.
Normally, resolutions that result in “allow both and let the market decide” end badly, with the market confused and vendors paralyzed. But this is not like VHS vs. Betamax. Without glossing real technical issues, this debate was more over a technicality, as protocol proxies are able to provide interoperability between the approaches transparently. The issue stirred such passion because it served as a kind of proxy for the priorities of the different camps within the group, as described in my previous post.
But perhaps herein lie the risks. Last week I installed an AT&T 3G MicroCell in my home that enables decent in-house cell reception (AT&T has apparently given up providing good coverage in my area, offering this for free). In the “Things to Know” section of the installation guide, it states, “Like many devices, your 3G MicroCell and your 3G phone handset may occasionally need to be “rebooted” to reestablish their connection to each other.” This of course is completely consistent with my PC, smart phone, and Wi-Fi router experience. I was amused by this frank admission – and apparent acceptance – of this condition as normal. It then occurred to me that I will not be so amused if my HAN devices (water heater, HVAC system, smart appliances) will need to be occasionally rebooted.
For all its non-IP inelegance, the ZigBee PRO protocol stack on which the SEP 1.0 version is based, was crafted out of real-world, mission-important (if not mission-critical) applications involving hundreds of network nodes in a variety of commercial applications where reboots are not acceptable. The new IP-based versions still have to prove this level of reliability. It took two to three years for the original SEP 1.0 products to reach “deployment worthiness” (as defined by utility testing in Texas) after being officially certified by the ZigBee Alliance. The SEP 2.0 work will need to happen much faster, though it is not clear how it can.
So perhaps utilities that are waiting for SEP 2.0, comforted by the fact that it is now moving forward, should take a closer look at the updated SEP 1.1 version released this week, which provides some of the application level enhancements of SEP 2.0, but uses the existing, proven (but not IP-based) stacks. This may be a good interim step toward the ultimate SEP 2.0 deployments.
There remains a risk that dual tracks within the ZigBee specifications (SEP 1.x vs. SEP 2.x) will lead to market bifurcation and higher devices costs due to the necessity to support both. Certainly the staunch IP proponents continue to grumble that this is an end run by traditional ZigBee vendors around SEP 2.0. But these vendors generally have SEP 2.0 implementation ready to roll too, and have been testing them for months. They lose only if the stalemate continues. If the IP-ification of ZigBee is truly worth all the market delays that it has caused, then these benefits should quickly become evident in the products and applications it enables. I believe it will, but in the meantime, there are good, robust, standards-based solutions available today to start true HAN deployments.
Then, perhaps, ZigBee will stop being the technology everyone loves to hate.
Tags: Smart Energy Home, Smart Energy Practice, Smart Grid Communications, Smart Meters, Smart Utilities
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