[Freedombox-discuss] Serval is getting involved in the 802.11ah standards process
paul at servalproject.org
Wed Sep 14 00:21:34 UTC 2011
Serval is getting involved in the IEEE 802.11ah (WiFi on ISM bands
below 1GHz) to try to make sure that it is well suited to
infrastructure-independent ad-hoc and mesh networking at the IEEE
meeting in Okinawa next week.
Here is our submission:
Basically we are asking for two things:
1. Improvements to ad-hoc mode (or provision of a new "packet radio"
mode) that remove some of the problems currently faced when creating
wifi-based ad-hoc mesh networks.
2. That the 802.11ah standard consider speeds below 1mbit and using
cell phone baseband radios as a supported transport so that even cheap
cell phones can form relatively long range mesh networks without any
This second point is really important, because compared with 2.4GHz
WiFi a mesh running in the ISM 915MHz band gains about +9db just from
the change in frequency, which alone improves range by almost 3x. If
it supports lower bit rates, then further significant gains are
possible, e.g., allowing 100kbit communications gives another +10db,
for a total of 8x range versus WiFi.
There are some significant protocol challenges to be addressed, but if
the standard doesn't support the use-case, then there will be no
hardware and no chance.
These measures have the potential to push the indoor range up from
WiFi's "about one house wide" to "about a block wide" and clear
line-of-sight range up to a few km, which suddenly makes the formation
of suburban ad-hoc mesh networks possible, which has profound impact
for creating resilient infrastructure-independent communications
solutions, for example for sustaining communications during disaster
or enabling communications for rural and remote or developing
We admit that we are very green to this process which we frankly find
to be daunting.
But we feel compelled to try, regardless of what we perceive to be the
odds of success.
We invite any comment, advice or questions on our proposal that anyone
Dr Paul Gardner-Stephen.
Shuttleworth Telecommunications Fellow,
Rural, Remote & Humanitarian Telecommunications Research Fellow,
Founder, Serval Project.
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