[OpenWireless Tech] Mesh Networking

[Seamus Tuohy]

Sorry to jump into this conversation a bit late.

The concerns about mesh networking are well founded. Any last-mile use
above three hops reduces user experience dramatically if multiple users
are using the same gateway. Luckily, in many of the bigger community
networks (Ninux, funkfeuer, freifunk, Athens Wifi, etc. which are
operating in the thousands of nodes) there are many gateways and local
services that allow a user's device to connect to services over a
shorter hop count. When you add in a backbone (set of nodes that are on
a different channel than the user network, but pass data across the
mesh) that allows for a shortening of hops between any router and a
gateway, and multiple radios within a device a mesh can allow for a
larger area to be better covered by free wireless access than otherwise
possible.

It should be noted that the larger networks also encourage, and require,
a level of community participation and viability in the network than
simply loading a mesh enabled firmware. Truly ad-hoc networks simply
cannot scale to metropolitan levels. It takes community advocates to
plan a network that will provide access where access is needed, and to
recruit gateways and strategic (tall) locations for backbone placement.
Maintenance also becomes a vital concern with mesh networks. When you
have bottlenecks that connect a part of the network to a gateway there
needs to be technically capable members of the community that can repair
those nodes if they go down, and to upgrade them when it is time. Many
of the larger community network maintainers are working to track down
derelict wireless routers running firmware from years ago that were
installed by an old tenant or a property owner who is long gone. There
are projects that are trying to make this process more transparent and
easy to implement and maintain without requiring a bevy of
technologists, but we are still a ways off.

If we are looking to make individuals who load the open-wireless
software able to share their gateways bandwidth when their neighbor is
getting overloaded by traffic, the addition of mesh routing can do that
with only a little training and software modification. But, the
difficulties with mesh currently require that communities who implement
it on a larger scale require some level of expertise to create a fully
functional metro-scale mesh.

Seamus Tuohy
Commotion Wireless