Open 802.11b wireless access points and remailers

[Sampo Syreeni]

On Fri, 27 Jul 2001, Steve Schear wrote:

>>You could triangulate ultrabroadband with an antenna array, but in real
>>life the reflexion and multipath will make it difficult.
>
>In particular see :
>http://www.aetherwire.com/Aether_Wire/Integrated_CMOS_Ultra-Wideband_Localizers.pdf

True, but even that application requires cooperation on behalf of the sender
-- like most such architectures, it uses sliding correlation and agreed upon
pseudorandom sequences to get a considerable process gain in the detection
stage. Asynch UWB pulses should be considerably more difficult to deal with,
although I don't think that multipath will be the reason: UWB pulses are
time-localized enough to make direct separation of the directly propagated
one from the echoes feasible. Rather I'd think that the asynchrony and the
low power requirements for short-range hops would make remote detection
troublesome.

Still, I'm more a fan of direct sequence spread-spectrum. How easy is it to
detect and/or triangulate that when the spreading sequence is not known, is
secure, and we can assume the widest bandwidths to date achieved for DSSS?

Sampo Syreeni, aka decoy, mailto:decoy at iki.fi, gsm: +358-50-5756111
student/math+cs/helsinki university, http://www.iki.fi/~decoy/front