Last week, the ZigBee Alliance -- the group promoting the ZigBee low-power wireless mesh networking technology that’s a part of many North American utilities’ home energy management plans -- announced a milestone for eventual integration with the “internet of things” writ large.

That milestone is ZigBee IP, the group’s new specification meant to seamlessly integrate into IPv6 mesh networks. While ZigBee’s previous specifications have been aimed at simpler tasks like remote controls for consumer energy, or simpler networks like its ZigBee home automation standards, ZigBee IP is meant to be fully compatible with the newest version (v6) of Internet Protocol, including use of such standards as 6LoWPAN, PANA, RPL, TCP, TLS and UDP, as well as end-to-end security from the IP field.

And while last week’s announcement didn’t make it specific, ZigBee’s newest standard is definitely an outgrowth of one of ZigBee’s other big integration challenges of the past several years, Tobin Richardson, chairman and CEO of the ZigBee Alliance, told me in an interview. That's getting the ZigBee Smart Energy Profile (SEP) spec -- the one that’s being used for connecting smart meters to home area network (HAN) devices across North America -- up and running with Wi-Fi.

“This is really directly linked to utility applications,” Richardson said of the new ZigBee IP spec. In fact, the process of creating it started in 2011, about the same time that the ZigBee and Wi-Fi alliances started working together on Smart Energy (SE) 2.0, he said.

Currently, the industry has two different, yet converging, forms of IP-compatible ZigBee to play with -- even if it lacks a list of commercially available, certified products to buy at present. Last week’s ZigBee IP announcement didn’t come with any named member companies rolling out certified devices, although we’ve seen plenty of testing underway from the likes of Exegin, Silicon Labs and Texas Instruments on the semiconductor side, as well as Cisco, which is working with partners like Exegin and Grid2Home on the ZigBee IP spec.

At the same time, there are plenty of other pathways to creating IPv6-compatible mesh networks. Cisco bought Arch Rock in 2010, and has since built the startup’s IPv6-capable mesh networking technology into its smart grid networking architecture being deployed via such partners as Itron and Alstom. NXP Semiconductor and GreenWave Reality launched a line of light bulbs networked via 6LoWPAN and IPv6 wireless, and Google@Home has set its sights on similar in-home networking.

Likewise, the move to SE 2.0 has been driven both by cooperation and competition in the field of connecting smart meters and other smart grid devices into the low-power, local wireless mesh networks. While ZigBee-only specs like SEP 1.0 and 1.x are now supporting meter-to-HAN connectivity for utilities in Texas, California, Ontario province and other big North American markets, it’s widely expected that broader market adoption will have to wait for SE 2.0.

Opening SEP 1.0 to Wi-Fi wasn’t necessarily ZigBee’s idea at the time, but regulators including the National Institute of Standards and Technology (NIST), the federal agency that coordinated smart grid standards development alongside the Department of Energy’s multi-billion-dollar smart grid stimulus grant program, pretty much insisted on it.

Since then, we’ve seen ZigBee, Wi-Fi and the powerline carrier HomePlug work together via SE 2.0 at interoperability fests and the like. Still, the SE 2.0 development process has been fraught with friction and delays, with the Wi-Fi and ZigBee alliances in particular disagreeing over issues stemming from differences in their networking architectures that could negatively impact one or the other’s performance.

At the same time, we haven’t yet seen much in the way of real-world integration. Some in the smart grid industry are worried that today’s SEP 1.x systems will have trouble upgrading to SE 2.0 when it rolls out over the next couple of years.

Richardson told me that ZigBee and its partners are now connecting multiple devices in home and smart energy environments using SE 2.0, and hope to see things finalized by year’s end.

While Texas has linked up thousands of homes using SE 1.0 technologies, he’s hopeful that California utilities may take things a bit further in terms of marketing their meter-to-HAN plans to customers. We’ve seen the state’s big three utilities open up the ZigBee signals coming from their residential smart meters to a number of devices that consumers can buy at stores or online, including devices from Canadian startup Rainforest Automation and home security player ADT, to name a few options.