I’ve been avoiding this conversation for a long time, but there’s no getting around it. We need to talk about 6LoWPAN. This unwieldly, nested acronym stands for IPv6 over Low-Power Wireless Personal Area Networks and is the lightweight version of traditional internet protocol (IP) designed for the internet of things. Right now, most wireless devices connect to another device — your phone, a hub or a corporate gateway — but for a true internet of things to emerge, these sensors or connected doodads should have the ability to connect directly to a web service.
What is that ungodly collection of numbers and letters?
Instead of device-to-device, it’s device to cloud. And since most of today’s devices use IP to connect to the web, it stands to reason that engineers would like to use IP to connect sensors and activity monitors and whatever else is out there to the web as well. Only IP is a heavy, energy-intensive beast, which is one reason why in 2004, the internet’s standard’s setting organization, the IETF, proposed 6LoWPAN.
The other reason is explained by the numeral “6” in the standard — short for IPv6, the newer addressing scheme for the internet that allows for 340 undecillion (that’s 340 billion billion billion billion ) addresses for connected devices instead of the roughly 4.3 billion total IP addresses allowed by the older IPv4 standard. Clearly if you’re envisioning tens of billions of connected sensors then IPv6 is the way to go. However, supporting the 128-bit numbering system required by IPv6 (IPv4 only required 32 bits) also takes computing and memory overhead that tiny sensors don’t have. It also requires longer packet headers and such that can clog low bit-rate networks.
Solving all of those issues is 6LoWPAN’s raison d’etre. You know, if networking protocols spoke French.
And what about the wireless?
Since the 6 is IPv6 and the Lo references the low-power aspect of the protocol, it’s time to dig into the final acronym in this mother of all acronyms. The WPAN or Wireless Personal Area Network is a nod to the wireless mesh network that the protocol supports. Because this isn’t directly analogous to the traditional network stacks, it’s hard to limit the technology to a particular layer in the network.
Sensors in a connected network can run the gamut from a video camera that’s plugged into a wall to a battery-powered water sensor hiding under the washing machine, so the standard is flexible enough that some nodes might be able to do more than just send information, while others are designed to sleep until an event wakes them for a data transmission. In short, it’s complicated, which makes defining a network stack or standards for the internet of things tough.
While we’re going to have to get used to complexity with multiple radio protocols, 6LoWPAN can work over several radio networks that use the IEEE 802.15.4 standard — the most popular of which is ZigBee. The IETF is also trying to build 6LoWPAN support for the Bluetooth protocol, although it’s not clear if the Bluetooth Special Interest Group is going to support 6LoWPAN.
When asked, Suke Jawanda, Chief Marketing Officer of the Bluetooth SIG, said, “A more direct connection with web services in the cloud that compliments our existing efforts of feeding data securely to apps on a device is an important area for us that we’re spending a lot of time on right now.”
That’s not a no, and the SIG already has taken steps to reduce power consumption to meet the demands of the internet of things, so it clearly is also aware of the need for the IPv6 addressing scheme if someone’s Fitbit (see disclosure) or door lock is ever going to be able to hop online without going over a phone or computer.
Why define 6LoWPAN now?
This whole trip down 6loWPAN lane started with IBM’s news Monday morning that Big Blue is teaming up with with Spanish startup Libelium to offer an Internet of Things Starter Kit that integrates Libelium’s Waspmote wireless sensor platform with IBM’s Mote Runner software and 6LoWPAN. IBM getting behind the standard with this announcement is just one more big name betting on 6LoWPAN as the communications protocol for the internet of things.
A few months ago chip licensing firm ARM purchased Sensinode, a company that has literally written the book about 6LoWPAN. And in 2012 Linear Technology, which also makes chips, bought Dust Networks, another startup that developed 6LoWPAN software. Cisco Systems also has an investment in 6LoWPAN with its 2010 purchase of Arch Rock, for its smart grid initiative.
Platforms such as Electric Imp, Ayla Networks and ThingSquare, all of which offer modules and services to connect devices directly to the internet, are also gaining ground with test programs and early adopters, helping make the case for 6LoWPAN. So as devices start going direct to the cloud and bypassing phones and computers, having a protocol that supports modern addressing at relatively low power and low overhead will become more important. And that’s what this terribly awkward acronym provides.
Disclosure: Fitbit is backed by True Ventures, a venture capital firm that is an investor in the parent company of this blog, Giga Omni Media. Om Malik, founder of Giga Omni Media, is also a venture partner at True.