IEEE Starts Weaving Mesh Network Standard

Proposals for standardizing wireless mesh networks, which can link many wireless LANs to cover a city or campus, are being presented this week to a working group of the Institute of Electrical and Electronics Engineers.

There are 15 separate proposals for the standard, which will be called IEEE 802.11s, said Bilel Jamoussi, director of strategic standards at the Chief Research Office of Nortel Networks. The 802.11s working group is getting together as part of a weeklong meeting of the IEEE 802 committee in San Francisco.

Proposals for the standard are being delivered for the first time, Jamoussi said. Those plans will be whittled down through compromises and consolidations until there is a single draft, which could happen as soon as next May, he said. Once that draft is available, vendors can confidently start developing products that will meet the standard, he said.

Cutting Wires, Costs

Mesh networks reduce the need for wired connections in wireless LANs by letting multiple access points carry each others' traffic. Whereas a conventional wireless access point needs its own wired link to a backbone network, with a wireless mesh there can be just one wire for many access points. Traffic that is destined for the Internet can hop from one access point to another until it reaches the one wired connection. Though each access point still needs a power source, the mesh can reduce the need for leased lines, thus reducing costs, Jamoussi said.

When a new access point is added to the mesh, it can be automatically configured for characteristics such as security and quality of service. As decisions are made about routing packets across the mesh, the network can take into consideration congestion and other factors and route around busy access points, Jamoussi said.

Nortel Networks and other vendors already sell wireless mesh networks, but an access point from one vendor can't necessarily join in a mesh with gear from other makers, he said. A standard would give customers a choice of mesh vendors, ease the work of product developers and lower product prices, Jamoussi said.

Nortel's mesh equipment is being used in a wireless mesh network that is expected to cover much of Taipei with an estimated 10,000 wireless LAN access points by the end of this year. Users will be able to access the network via Wi-Fi client devices.

Multiple Proposals

The Wi-Mesh Alliance, which includes Nortel, is presenting a proposal that makes use of Nortel's lessons in creating mesh networks for the city of Taipei as well as other governments and universities, Jamoussi said. The group also includes vendors Accton Technology, NextHop Technologies, Koninklijke Philips Electronics NV, Thomson SA, InterDigital Communications and The Mitre Corporation, plus ComNets RWTH Aachen University, a department of a university in Germany that is researching mobile communications.

The group's proposal for 802.11s is designed to work for all three major applications of mesh technology, Jamoussi said: Consumer and small business, metropolitan, and military.

Another major proposal is from a group called SEEMesh (Simple, Efficient and Extensible Mesh), which includes heavy hitters such as Intel, Texas Instruments, Nokia, Motorola, and mesh network vendor Firetide, as well as Japanese mobile operator NTT DoCoMo.

"We do see a lot of commonality between the proposals that are being presented this week, which we see as really encouraging," said Anuj Batra, a member of the group technical staff in Texas Instruments' research and development organization.