[137034] in North American Network Operators' Group
Re: US Warships jamming Lebanon Internet
daemon@ATHENA.MIT.EDU (Denys Fedoryshchenko)
Tue Feb 8 08:52:57 2011
From: Denys Fedoryshchenko <denys@visp.net.lb>
To: TR Shaw <tshaw@oitc.com>
Date: Tue, 8 Feb 2011 15:41:23 +0200
In-Reply-To: <052C3BF4-13C9-4AE1-BF5E-DC5AF16179C7@oitc.com>
Cc: North American Network Operators Group <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Tuesday 08 February 2011 15:46:31 TR Shaw wrote:
> On Feb 8, 2011, at 7:34 AM, Denys Fedoryshchenko wrote:
> > On Tuesday 08 February 2011 14:41:29 Adrian Chadd wrote:
> >> On Tue, Feb 08, 2011, Denys Fedoryshchenko wrote:
> >>> On Tuesday 08 February 2011 14:18:59 Adrian Chadd wrote:
> >>>> On Tue, Feb 08, 2011, Denys Fedoryshchenko wrote:
> >>>>> I try to install C-Band bandpass filter, no effect at all, so it is
> >>>>> in-band
> >>>>>=20
> >>>>> interference. Putting foil (yes i try almost everything) near LNB
> >>>>> doesn't affect interference level too.
> >>>>=20
> >>>> Can you get access to some kind of spectrum analyser kit to see what
> >>>> the kind of interference is?
> >>>>=20
> >>>>=20
> >>>>=20
> >>>> Adrian
> >>>=20
> >>> Yes, on short (few minutes) sweeps it is clean. During long time run,
> >>> with 100 Khz resolution, if we run few hours we can catch anomalies on
> >>> the carrier. Important note: this snapshot done on spectrum analyser =
in
> >>> Europe, same transponder, and results similar, so it looks like
> >>> interference is on transponder. Issue start to affect us at same time
> >>> when people in Lebanon got local interference issues.
> >>>=20
> >>> Here is snapshot of carrier spectrum with anomaly:
> >>> http//www.nuclearcat.com/PICTURES/interference.jpg
> >>=20
> >> And does this interference similarly screw up being able to RX data fr=
om
> >> the transponder whilst in Europe?
> >>=20
> >> (eg, if you stick a modem on RX-only in Europe (ie, no uplink) and then
> >> just lock onto the signal and decode whatever happens, do you suffer
> >> the same problem?)
> >=20
> > Difficult, in Europe EIRP of transponder is too low, to try.
> > By the way interference almost disappeared yesterday, and it's much
> > better today.
>=20
> BTW, here is some comments on the pict from my office mate...
>=20
> It doesn't show what the sweep span is ... If it's the full transponder,
> could be narrow band carriers ... The gain slope across the pass band
> looks like CRAP ... He must have a funky LNB ... If this is one carrier,
> then obviously there=E2=80=99s interference =E2=80=A6 If the spikes are t=
here, it could be
> radar or it could be some type of burst TDMA junk ... I have articles
> talking about C Band inband interference in Europe somewhere ... Brian
It is PLL LNB, one carrier, we are using full transponder 36 Mhz. There is=
=20
almost no other users on this satellite (inclined more than 1.5 degree), an=
d=20
other carriers center frequency 100Mhz away.
