There are a lot of things standards are supposed to do, but their primary role is to create interoperability between vendors. Nowhere is it more apparent that there’s a lack of a standard than in mesh networking using Wi-Fi, where every company has a different way of doing things, whether it’s self-configuration of nodes or traffic signal hopping and routing.
That could all change with the coming of 802.11s. The IEEE’s 802.11 Task Group S was formed to bring some order to mesh networks, and as of the March 2006 meeting, the competing groups with mesh proposals (SEE Mesh and Wi-Mesh Alliance) have merged to create a single proposal that was unanimously confirmed as the starting point for a specification.
Just a month later, and one company, Motorola, is already saying its products will support what’s found in the draft of 802.11s immediately — which might not mean much.
“What you’ve got today is a draft of a standard that does a reasonably good job to get everyone on the same page of what they mean by a mesh,” says Peter Stanforth, Motorola’s Director of Technology in the Mesh Networks Product Group. “It has the industry agreeing in principle… it is a huge step that helps everybody, gives them [the ability to have] apple-to-apples discussions.”
According to Stanforth, as it stands today, 11s covers the infrastructure-based elements of mesh networking using Wi-Fi, the way information is passed around the mesh topology, but not necessarily how it gets to client systems (or even including clients in the mesh).
But will 802.11s even matter when it comes to the big, municipal-sized networks that mesh Wi-Fi is quickly becoming synonymous with?
Phil Belanger doesn’t think so. He helped form the Wi-Fi Alliance in its infancy, and later went on to do marketing and PR for companies like the late Vivato and most recently mesh equipment provider BelAir Networks. Belanger issued a statement posted on Wi-Fi Net News last month regarding 11s progress which said, “this standard will have little impact on that market [citywide Wi-Fi]. The biggest impact of 802.11s will be in your home.”
Belanger contends that 11s “was developed as a single-radio, shared mesh extension of indoor access points.” Most outdoor mesh Wi-Fi equipment has multiple radios that can include Wi-Fi, WiMax and 4.9 GHz for public safety use. Such vendors include Motorola, BelAir, Strix Systems and SkyPilot. (Tropos Networks, which claims the largest deployment base of mesh Wi-Fi hardware, remains single-radio, keeping costs down.)
Belanger feels that the multi-radio mesh guys are part of the 11s standard process because not being there would be marketing suicide. They’d prefer that 802.11s goes away, especially companies with special routing technology that is their big differentiator from the competition.
BelAir’s CTO, Stephen Rayment, is Permanent Secretary of the 802.11s Task Group in the IEEE, and he says things have changed: “The standard is not limited to either indoor or outdoor mesh, or to the number of radios used in the access points… There are two important applications for 802.11s: the first is municipal and citywide networks, and the second is for home networks.”
Motorola’s Stanforth concurs, saying that while the original 11s was indeed limited to 32 indoor nodes at a time, “almost no one had an interest in that limitation. From the beginning, people wanted it to be broader than that and have it extend into wide area deployments.”
Motorola’s plan is to build 11s support into the MeshConnex software that powers the company’s MotoMesh hardware. He says the software is compatible with the 11s draft as written today, but admits it’s “meaningless, since [the specification] will change” as it goes toward a ratification, which is unlikely until 2007 or 2008.
“We just want customers to know that we’re committing to refining and tweaking our software… we’ve developed the ability to do so with over-the-air upgrades,” says Stanforth. “We’ll enhance the products as the specification changes.”
A Strix Systems spokesperson told Wi-Fi Planet today that “generally speaking, Strix is committed to standards,” but didn’t comment on whether Strix would support 11s at all, other than to “see how this one will eventually unfold and what substance it will carry.” BelAir says it will fully support 802.11s, but not until it is finalized.
Even if 11s becomes a finished standard suitable for citywide networks, it might never result in heterogeneous networks using all sorts of vendors. “It’s likely there will be a lowest common denominator on a basic level to allow interoperation between Tropos and Motorola and others,” says Stanforth. He expects different vendors to serve different types of niche markets.
Belanger agrees, saying, “Do not expect to see interoperability between a Tropos and a Strix box… The main end user benefit in this market will be the creation of a mesh portal interface that will allow the big outdoor mesh to talk to your 802.11s-enabled home AP/router in a standardized way. That will bring interoperability between different home routers and the big outdoor mesh infrastructure.”
Motorola recently joined the Wi-Fi Alliance, but it’s unknown at this time if the Alliance will be the group that checks mesh products for interoperability. If not, Stanforth says, “There’s already talk [in 11s meetings] of a group being created to define interoperability procedures.”
