6 Jul
2013
6 Jul
'13
4:53 p.m.
On Sat, 6 Jul 2013 12:08:10 -0700, Eric Fort <eric.fort(a)gmail.com>
wrote:
What kind of records need be kept though? It would
seem to me that for
802.11 type stuff the needed records would be minimal such as the KEY and
SSID. Note intent is a major piece here as some would argue that using a
key is cryptography and cryptography is not allowed.
In SS the chip sequence is pseudo-random, usually a LFSR with known
taps. IIRC the FCC specified the register length and taps of
acceptable sequences for amateur use but it's been years since I last
researched it. I was investigating a CDMA scheme for voice UHF
multiplex links in 1992 or so but I abandoned it.
Yes, the chip sequence is related to crypto but it's not crypto for
the purpose of obscuring the meaning of the communications and is
specifically allowed by the rules.
You're looking at the entirety of 97.311(c)(3) "Maintain a record,
convertible to the original information (voice, text, image, etc.) of
all spread spectrum communications transmitted."
IANAL, but I interpret that to mean you must maintain a "record" of
the emitted signal and all the content and methods used to produce
that signal. Which makes it fairly useless for something like TCP/IP
traffic of any volume since you'd have to keep many GB of "record" if
you are doing it full time or automatically. My guess is that when FCC
promulgated the rules they perceived hams to be experimenting with and
researching SS rather than using it for actual traffic or mass
producing devices for it. In that scenario hams would be sending brief
messages in a lab or across town and measuring performance.