-------------- Original message --------------
>
>
> All day yesterday and through the night Team PAD
> (http://www.wifiworldrecord.com) braved rain, lightning and winds over 30
> mph to setup and test their equipment at their mountian top base outside of
> Las Vegas, Nevada.
>
-------------- Original message --------------
>
>
> They had amplifiers for testing, but they were not needed for the 125 mile
> link.
>
> The only time they tried the amps was when the remote group was on a
> mountain in Utah 145 miles away but could not quite reach the desired
> coordinates 2 miles further and hundreds of feet higher, the road ended and
> the terrain was too rough to continue driving. They were a little too low in
> elevation, with a small mountain peak obstructing the two locations, they
> tried unamplified and amplified, and the 802.11b link would not work.
>
> If they made it to the desired location, I'm confident that they would have
> successfully linked up at 145 miles.
>
> Thank you
>
> Frank Keeney
> Pasadena Networks, LLC
> Antennas, Cables and Equipment:
> http://www.wlanparts.com
>
> > -----Original Message-----
> > On Behalf Of Jim Sutton
> >
Jim Thompson wrote:
<snip>
> a) explain how they knocked the side lobes down so they didn't have
> unwanted emissions outside the band. Your answer here very likely
> has the word "filter" in it, but then I'll just ask you for the
> mfg/model # of same, so I can verify its claimed performance.
Under part 97.305, amateur radio stations are allowed to use spread
spectrum in the 13cm band 2390-2450 MHz. The signal has to be 802.11b,
not 802.11g encoded (OFDM is not Spread Spectrum). Amateurs are
allowed to use up to 1 watt without automatic power control and up to
100 watts with APC. There is NO limit on antenna gain. The ARRL
bandplan is a suggestion, not an FCC requirement.
Amateurs can operate on channels 1-6 using part 15 equipment.
Typically hams use channel 5 or 2432 MHz as a center frequency to avoid
interfering with amateur satellite transmissions near channel 1 or
2400-2410 Mhz. Furthermore, by picking channel 5, you have 18 Mhz
above and 42 Mhz below center frequency for the +/- 11 Mhz signal to
fall into. Part 97.307 describes the spurious emissions requirements.
>From what I can tell, their setup could have met these requirements.
> b) explain how they transmitted their HAM call sign (perhaps they set
> the ESSID to it, but this wouldn't fulfill the requirements of Part 97)
Amateur stations using 802.11b must identify every 10 minutes according
to Part 97.119 b(3). ASCII is a recognized code. Setting the SSID to
callsign1-callsign2 in the peer-to-peer mode is enough for ID.
However, it is also acceptable to send identification in the text of
the message, so that anyone with a normal 802.11b card can read the
identities of the transmitting stations. I believe that if they
followed either of these methods, their setup would have met the regs.
> c) send along the call sign(s) used during this experiment, so the
> FCC can pull their tickets.
Please tell me where you think they broke any regulations?
Their setup seems to use the minimum required power required to
maintain the link. The high gain dishes minimize interference with
others using the same band.
But out of curiosity, I too would like to know their callsigns and
would be interested in knowing if they met the part 97 logging rule of
their contact.
<snip>
> They deemed it reliable because they wanted to. Did they put any
> load on the network? Many people will misinterpret the results,
> and clamor for 125 mile links with no other requirements than "line
> of sight" and "big ears". For the reasons I've shown, and others,
> while you might be able to "show" this in a "demo", its both illegal,
> and it doesn't (nee: can't) work correctly.
Give these guys a break. These guys are hackers. Who says it has to
be stock software. They should have been able to hack the retry timer
value in the firmware.
For a valid contact on ham radio, they have to exchange callsigns and a
signal report. There is no requirement to have a network load to make
a contact.
<snip>
73,
Konrad Roeder, WA4OSH
North Bend, WA
What is not FCC compliant?
> Which it probably didn't.
It's heresay on your part as well as theirs. All I am showing you is
that what they are telling you is legally possible under FCC part 97
rules.
> You still have 35 dBi of antenna gain raising the side lobes.
Under part 97 rules, spurious emssions are measured relative to the
input power to the antenna of the fundamental emission. The antenna
gain applies to both the main carrier and the spurs.
97.307(e) "For a transmitter having a mean power of 25 W or less, the
mean power of any spurious emission supplied to the antenna
transmission line must not exceed 25 uW and must be at least 40 dB
below the mean power of the fundamental emission, but need not be
reduced below the power of 10 uW."
> http://www.wlanparts.com/product/XI-325HPPLUS says "up to
> 24.7dBm" (292mW), and since these are Intersil/connexant Prism2-
> based, you can't "tune the power" like you could with an atheros-
> based card.
The Prism 2.5 Chipset can be power controlled under Linux. I have done
it on a Senao 2511, but not this Z-Com card.
>
>
> On Aug 1, 2005, at 9:20 PM, Humphrey Cheung wrote:
>
> >
> > I interviewed the team after the awards ceremony.
> >
> > They dialed down the 300 mw cards to 30 mw.
> >
> > Humphrey Cheung
> > Editor
> >
> > www.tomshardware.com
73, Konrad
With the way the DEFCON contest seems to be run ...
You can set up something to use 12 foot dishes.
Run under part 97
use a BelAir 100 (27.5 dBm and good receiver sensitivity)
get them to sponsor you
and modify their phy and mac slightly to accomodate DX contacts
(wink-wink)
for example, increase the chipping rate and decrease the raw data rate
so that you get much more processing gain...
Maybe even get the first EME contact on Wi-Fi
I really think that DEFCON needs to revisit their contest rules
Konrad Roeder,
North Bend, WA
WA4OSH
If they keep the same rules ... I think I would like to try it next
summer.
Part 97 .. homebrew gear on both ends
Does it have to run in the 13cm / 2400 Mhz band? How about the 902-928
MHz band?
hehe
Konrad