mobile (cell) phone jamming

"Jon S Green" <jonsg@deadspam.com> wrote:
futureworlds <nobody@mail.futureworlds.it> wrote:

Even if they complained, would the police or even the UK
equivalent of the FCC be interested in expending the resources to
track down and prosecute a nut with a few mW transmitter?

Oh, yeah. Big time.

Operating a low-power illegal "normal" transmitter (like an unlicensed
CB set) is one thing - a minor offence under Part I (s.1) of the
Wireless Telegraphy Act; they'll just get the kit seized, and a Police
caution. Perhaps a small fine if it's worth a prosecution. Maybe even
a suspended jail sentence if it was shown to be interfering with
licensed equipment (by accident).
Click to expand...
Speaking from personal experience many years ago this just didn't happen.

Yes the DTI did go round in their detector vans when the problem got out
of hand. Found out the people using, say, 500W 27MHz amps and hi-gain
antennas with SSB rigs.

Then normally told them to stop using it & get rid of it. Took gear off
them if it was causing interference to phones/TVs/radio.

I've never heard anyone get a fine. Never heard police involved. Police
didn't want to know if people reported severe interference to them.
Suspended jail sentence? Never heard of any.

Deliberate jamming, on the other hand, is a Part II (s.13) offence, and
a whole different order of magnitude. The Radiocommunications Agency
(www.radio.gov.uk) will rain Hellfire on offenders: expect a jail term
and/or (probably 'and') a stiff fine. And seizure of anything, not just
txing equipment, that could be argued to be relevant to the offence.
Click to expand...
Have you ever seen this happen? Seisure I can see, but nothing else. The
RA/DTI are/were a bunch of lazy sods :)



frag
 
Hello,

The RIS tend to go out at nights and weekends and can take months finding a
station. It depends on the amount of overtime.

"Richard Wood" <news1@ukrm.co.uk> wrote in message
news:bs10uu$nv2$1@server.localdomain...
"Jon S Green" <jonsg@deadspam.com> wrote:
futureworlds <nobody@mail.futureworlds.it> wrote:

Even if they complained, would the police or even the UK
equivalent of the FCC be interested in expending the resources to
track down and prosecute a nut with a few mW transmitter?

Oh, yeah. Big time.

Operating a low-power illegal "normal" transmitter (like an unlicensed
CB set) is one thing - a minor offence under Part I (s.1) of the
Wireless Telegraphy Act; they'll just get the kit seized, and a Police
caution. Perhaps a small fine if it's worth a prosecution. Maybe even
a suspended jail sentence if it was shown to be interfering with
licensed equipment (by accident).

Speaking from personal experience many years ago this just didn't happen.

Yes the DTI did go round in their detector vans when the problem got out
of hand. Found out the people using, say, 500W 27MHz amps and hi-gain
antennas with SSB rigs.

Then normally told them to stop using it & get rid of it. Took gear off
them if it was causing interference to phones/TVs/radio.

I've never heard anyone get a fine. Never heard police involved. Police
didn't want to know if people reported severe interference to them.
Suspended jail sentence? Never heard of any.

Deliberate jamming, on the other hand, is a Part II (s.13) offence, and
a whole different order of magnitude. The Radiocommunications Agency
(www.radio.gov.uk) will rain Hellfire on offenders: expect a jail term
and/or (probably 'and') a stiff fine. And seizure of anything, not just
txing equipment, that could be argued to be relevant to the offence.

Have you ever seen this happen? Seisure I can see, but nothing else. The
RA/DTI are/were a bunch of lazy sods :)



frag
Click to expand...
 
On Sat, 20 Dec 2003 07:46:24 -0000, Jon <spam@unlockingshop.co.uk>
wrote:

If Mr bush said "would you mind turning
off your network for a few hours" and the network said "yeah, OK"
Click to expand...
I think you'll find that what would have happened is that Mr Bush asks
them to turn the networks off, and the networks respond "Off? Piss
off!"


--

Iain
the out-of-date hairydog guide to mobile phones
http://www.hairydog.co.uk/cell1.html
Browse now while stocks last!
 
<hairydog@despammed.com> wrote in message
news:2899uvodo6873aqrpaovann5bemr45h1tr@4ax.com...
On Sat, 20 Dec 2003 07:46:24 -0000, Jon <spam@unlockingshop.co.uk
wrote:

If Mr bush said "would you mind turning
off your network for a few hours" and the network said "yeah, OK"

I think you'll find that what would have happened is that Mr Bush asks
them to turn the networks off, and the networks respond "Off? Piss
off!"
Iain

Didn't Tony give himself powers to turn off GSM networks after the fuel strike.
Click to expand...

Steve Terry
 
On Sat, 20 Dec 2003 20:18:07 -0000, "Steve Terry"
<g4wwk@despammed.com> wrote:

Didn't Tony give himself powers to turn off GSM networks after the fuel strike.
Click to expand...
There have been those powers for a very long time.

--

Iain
the out-of-date hairydog guide to mobile phones
http://www.hairydog.co.uk/cell1.html
Browse now while stocks last!
 
default <R75/5@defaulter.net> wrote:

There are holes in the present systems. Cell phone users are used to
encountering areas where the phone won't work or momentary glitches.
They may not notice a jammer.

If they do, it is still a pretty daunting task to pin it to one person
unless he keeps transmitting for a prolonged period and stays in one
place.

Then the jammer can't be depended on to be stupid, unadaptable or
ignorant either . . . he could switch to directional antennas, use his
device in a vehicle, take advantage of the terrain, keep to short
bursts from one location, switch off when he sees the people with
directional antennas homing in. It is a cat and mouse scenario - the
cat teaches the mouse; the mouse teaches the cat.
Click to expand...
I think the OP would count on factors like these. He (possibly she)
said he wanted a range of up to 5 yards, for use in a bus, with short
directional bursts. He just wants to disconnect specific loud phone
users, not disrupt phone use on the bus in general.

So:

* The "victims" wouldn't know why their calls were cut off (bear in
mind, they are used to momentary glitches.
* The OP would be using it on a moving vehicle; even if he uses the
same bus route every day, he wouldn't be firing it at the same place
on that route.
* He would probably only press the "trigger" for a second or two, and
maybe again a minute later if the "victim" calls again.
* Very low power output--would it even be detectable outside the bus?
* He would certainly be able to see the detectors coming.

If he builds one such device and uses it discretely, he'll never get
caught. His biggest mistake would be to brag about it (isn't this how
old-time phone phreaks always got caught?) or to sell jammers.

Of course the ethical issues are a different matter.
 
default <R75/5@defaulter.net> wrote:

There are holes in the present systems. Cell phone users are used to
encountering areas where the phone won't work or momentary glitches.
They may not notice a jammer.

If they do, it is still a pretty daunting task to pin it to one person
unless he keeps transmitting for a prolonged period and stays in one
place.

Then the jammer can't be depended on to be stupid, unadaptable or
ignorant either . . . he could switch to directional antennas, use his
device in a vehicle, take advantage of the terrain, keep to short
bursts from one location, switch off when he sees the people with
directional antennas homing in. It is a cat and mouse scenario - the
cat teaches the mouse; the mouse teaches the cat.
Click to expand...
I think the OP would count on factors like these. He (possibly she)
said he wanted a range of up to 5 yards, for use in a bus, with short
directional bursts. He just wants to disconnect specific loud phone
users, not disrupt phone use on the bus in general.

So:

* The "victims" wouldn't know why their calls were cut off (bear in
mind, they are used to momentary glitches.
* The OP would be using it on a moving vehicle; even if he uses the
same bus route every day, he wouldn't be firing it at the same place
on that route.
* He would probably only press the "trigger" for a second or two, and
maybe again a minute later if the "victim" calls again.
* Very low power output--would it even be detectable outside the bus?
* He would certainly be able to see the detectors coming.

If he builds one such device and uses it discretely, he'll never get
caught. His biggest mistake would be to brag about it (isn't this how
old-time phone phreaks always got caught?) or to sell jammers.

Of course the ethical issues are a different matter.
 
On Tue, 23 Dec 2003 10:45:30 -0800, starwars wrote
(in message <d72c4077f7a02194b9af258565c26b09@tatooine.homelinux.net>):

"Ken Taylor" <ken123@xtra.co.nz> wrote:


"Paul Burridge" <pb@osiris1.notthisbit.co.uk> wrote in message
news:5t1cuv4dn8bv354uodkbktss0gqo9rn1mb@4ax.com...
On 21 Dec 2003 13:11:20 -0000, nobody@See.Comments.Header (Italy
Anonymous Remailer) wrote:

Well, the OP did say he wanted a maximum range of 5 yds inside a bus.
Anyone know what sort of wattage that works out to? I suspect we're
talking about a few mW.

Or less, even. What power level do those car lock r/c key fob thingies
work at? That ought to give some sort of indication.


Why would it? The applications are totally different.

I agree. The car lock remote uses infrared (I think) and transmits a
very specific signal that the car receiver detects.

The jammer would use cellphone frequencies (around 9GHz and similar
bands, I think) and would need to transmit--I think--white noise
across the target band, strong enough to drown out the signal the
phone is already receiving.
Click to expand...
No. The car alarm/autolocking remote controls use RF, not IR. Simply arm or
disarm your car alarm (you *do* have one, don't you?) from inside your home
to prove this.

Those owners who "point" the remote control at the car, haven't a clue how
they work...
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group
 
"Ken Taylor" <ken123@xtra.co.nz> wrote:

"Paul Burridge" <pb@osiris1.notthisbit.co.uk> wrote in message
news:5t1cuv4dn8bv354uodkbktss0gqo9rn1mb@4ax.com...
On 21 Dec 2003 13:11:20 -0000, nobody@See.Comments.Header (Italy
Anonymous Remailer) wrote:

Well, the OP did say he wanted a maximum range of 5 yds inside a bus.
Anyone know what sort of wattage that works out to? I suspect we're
talking about a few mW.

Or less, even. What power level do those car lock r/c key fob thingies
work at? That ought to give some sort of indication.


Why would it? The applications are totally different.
Click to expand...
I agree. The car lock remote uses infrared (I think) and transmits a
very specific signal that the car receiver detects.

The jammer would use cellphone frequencies (around 9GHz and similar
bands, I think) and would need to transmit--I think--white noise
across the target band, strong enough to drown out the signal the
phone is already receiving.
 
"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC0DD5D400A112F0F0080600@news.individual.net...
On Tue, 23 Dec 2003 10:45:30 -0800, starwars wrote
(in message <d72c4077f7a02194b9af258565c26b09@tatooine.homelinux.net>):

"Ken Taylor" <ken123@xtra.co.nz> wrote:


"Paul Burridge" <pb@osiris1.notthisbit.co.uk> wrote in message
news:5t1cuv4dn8bv354uodkbktss0gqo9rn1mb@4ax.com...
On 21 Dec 2003 13:11:20 -0000, nobody@See.Comments.Header (Italy
Anonymous Remailer) wrote:

Well, the OP did say he wanted a maximum range of 5 yds inside a bus.
Anyone know what sort of wattage that works out to? I suspect we're
talking about a few mW.

Or less, even. What power level do those car lock r/c key fob thingies
work at? That ought to give some sort of indication.


Why would it? The applications are totally different.

I agree. The car lock remote uses infrared (I think) and transmits a
very specific signal that the car receiver detects.

The jammer would use cellphone frequencies (around 9GHz and similar
bands, I think) and would need to transmit--I think--white noise
across the target band, strong enough to drown out the signal the
phone is already receiving.

No. The car alarm/autolocking remote controls use RF, not IR. Simply arm
or
disarm your car alarm (you *do* have one, don't you?) from inside your
home
to prove this.

Those owners who "point" the remote control at the car, haven't a clue how
they work...
--
DaveC
Click to expand...
I agree about the RF in the car locks, and, also, cell phones aren't (yet)
at 9GHz(!). 900/1800/2400MHz generally. However they are pretty robust from
an RFI perspective (dependant on cell system). The key lock would probably
be a lot easier to jam.

Anyway, all this begs the question - who the f**k do these people who want
to jam/ban cell phones on buses and restaurants think they are? If I'm
talking to the person next to me, is that okay? If I'm still talking to
them, but over the phone, is that still okay? (Dumb maybe, but okay?).
What's the difference whether I'm talking to a person in the flesh or via a
piece of plastic and metal. At the cinema or theatre - sure. But who the
hell is making these rulings about what's socially acceptable?

Ken
 
I read in sci.electronics.design that Ken Taylor <ken123@xtra.co.nz>
wrote (in <bsa80k$b752k$1@ID-76636.news.uni-berlin.de>) about 'mobile
(cell) phone jamming', on Wed, 24 Dec 2003:

What's the difference whether I'm talking to a person in the flesh or via a
piece of plastic and metal.
Click to expand...
It's not the phoning that's annoying, it's the loud voice, which is
quite unnecessary but we've got used to it through using ordinary
phones. Ordinary phones have 'sidetone' anyway - you hear your own voice
in the earpiece and that helps to control your own voice level. Mobile
phones DON'T HAVE SIDETONE, which is a bit of a surprise when you first
realise it. WHY they don't have it, I don't know; maybe the small
dimensions mean that a usable level of sidetone results in acoustic
feedback. But a mobile with sidetone might eliminate the annoying VOICE
LEVEL.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!
 
On Tue, 23 Dec 2003 21:30:57 +0000, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Ken Taylor <ken123@xtra.co.nz
wrote (in <bsa80k$b752k$1@ID-76636.news.uni-berlin.de>) about 'mobile
(cell) phone jamming', on Wed, 24 Dec 2003:

What's the difference whether I'm talking to a person in the flesh or via a
piece of plastic and metal.

It's not the phoning that's annoying, it's the loud voice, which is
quite unnecessary but we've got used to it through using ordinary
phones. Ordinary phones have 'sidetone' anyway - you hear your own voice
in the earpiece and that helps to control your own voice level. Mobile
phones DON'T HAVE SIDETONE, which is a bit of a surprise when you first
realise it. WHY they don't have it, I don't know; maybe the small
dimensions mean that a usable level of sidetone results in acoustic
feedback. But a mobile with sidetone might eliminate the annoying VOICE
LEVEL.
Click to expand...
Agreed. That's the nub of it. And there are still a lot of folks
around who seem to think if the person they're calling is a long way
away, they need to shout even louder!

--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill
 
"Paul Burridge" <pb@osiris1.notthisbit.co.uk> wrote in message
news:6fghuvguul35vq36on1nmc1n0mf3tf5jub@4ax.com...
On Tue, 23 Dec 2003 21:30:57 +0000, John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Ken Taylor <ken123@xtra.co.nz
wrote (in <bsa80k$b752k$1@ID-76636.news.uni-berlin.de>) about 'mobile
(cell) phone jamming', on Wed, 24 Dec 2003:

What's the difference whether I'm talking to a person in the flesh or
via a
piece of plastic and metal.

It's not the phoning that's annoying, it's the loud voice, which is
quite unnecessary but we've got used to it through using ordinary
phones. Ordinary phones have 'sidetone' anyway - you hear your own voice
in the earpiece and that helps to control your own voice level. Mobile
phones DON'T HAVE SIDETONE, which is a bit of a surprise when you first
realise it. WHY they don't have it, I don't know; maybe the small
dimensions mean that a usable level of sidetone results in acoustic
feedback. But a mobile with sidetone might eliminate the annoying VOICE
LEVEL.

Agreed. That's the nub of it. And there are still a lot of folks
around who seem to think if the person they're calling is a long way
away, they need to shout even louder!

Aint that the truth! I'll go along with that argument - discretion is such a
Click to expand...
poorly rated virtue.

Ken
 
"Ken Taylor" <ken123@xtra.co.nz> wrote in message
news:bsag78$bafgl$1@ID-76636.news.uni-berlin.de...
"Paul Burridge" <pb@osiris1.notthisbit.co.uk> wrote in message
news:6fghuvguul35vq36on1nmc1n0mf3tf5jub@4ax.com...
On Tue, 23 Dec 2003 21:30:57 +0000, John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Ken Taylor <ken123@xtra.co.nz
wrote (in <bsa80k$b752k$1@ID-76636.news.uni-berlin.de>) about 'mobile
(cell) phone jamming', on Wed, 24 Dec 2003:

What's the difference whether I'm talking to a person in the flesh or
via a
piece of plastic and metal.

It's not the phoning that's annoying, it's the loud voice, which is
quite unnecessary but we've got used to it through using ordinary
phones. Ordinary phones have 'sidetone' anyway - you hear your own
voice
in the earpiece and that helps to control your own voice level. Mobile
phones DON'T HAVE SIDETONE, which is a bit of a surprise when you first
realise it. WHY they don't have it, I don't know; maybe the small
dimensions mean that a usable level of sidetone results in acoustic
feedback. But a mobile with sidetone might eliminate the annoying VOICE
LEVEL.

Agreed. That's the nub of it. And there are still a lot of folks
around who seem to think if the person they're calling is a long way
away, they need to shout even louder!

Aint that the truth! I'll go along with that argument - discretion is such
a
poorly rated virtue.
Click to expand...
And, for some reason, people on a phone forget they are in a crowd.
Nothing like being in a public venue and having someone shouting into
their phone, discusing someone stool sample (true story).
 
DaveC <me@privacy.net> wrote:

Why would it? The applications are totally different.

I agree. The car lock remote uses infrared (I think) and transmits a
very specific signal that the car receiver detects.

The jammer would use cellphone frequencies (around 9GHz and similar
bands, I think) and would need to transmit--I think--white noise
across the target band, strong enough to drown out the signal the
phone is already receiving.

No. The car alarm/autolocking remote controls use RF, not IR. Simply arm or
disarm your car alarm (you *do* have one, don't you?) from inside your home
to prove this.
Click to expand...
It's TV/hi-fi/etc remotes that use infrared.

Those owners who "point" the remote control at the car, haven't a clue how
they work...
Click to expand...
Mine works inside my pocket.
 
"Gordon Brown" <.> wrote:

"Steve Terry" <g4wwk@despammed.com> wrote in message
news:E55Gb.9655$FN.3222@newsfep4-winn.server.ntli.net...

You mix 45MHz with the phones own TX signal, from any phone nearby.
Then retransmitting itself up 45MHz into the phones receiver.

Whatever channel the phone is on, it's always a precise 45MHz diference

Without the phones transmit signal all the jammer puts out is it's 45MHz
osc

What so difficult to understand ??

The difficult bit is adding the time delay so the phones TX time slots
overlap
it's own RX time slots, otherwise the phone simply won't hear itself,
feedback, and stop working.

Ah, I see, you mean a broadband jammer (otherwise it will not cope with two
phones transmitting on different channels). For some reason I was assuming
that it was some elaborate narrow band jamming device. Why not just transmit
a burst of white noise at 950Mhz with a 45MHz BW?
Click to expand...
That's what I was thinking. This would be a lot simpler than having to
detect a specific signal, modulate it by 45MHz an retransmit it.

Would the white noise across the right frequency band confuse the
phone enough to disconnnect or garble the call?
 
"George Orwell" <nobody@mixmaster.it> wrote in message
news:b57deee82064347349787c2cd5202d22@mixmaster.it...
"Gordon Brown" <.> wrote:

"Steve Terry" <g4wwk@despammed.com> wrote in message
news:E55Gb.9655$FN.3222@newsfep4-winn.server.ntli.net...

You mix 45MHz with the phones own TX signal, from any phone nearby.
Then retransmitting itself up 45MHz into the phones receiver.

Whatever channel the phone is on, it's always a precise 45MHz
diference

Without the phones transmit signal all the jammer puts out is it's
45MHz
osc

What so difficult to understand ??

The difficult bit is adding the time delay so the phones TX time slots
overlap
it's own RX time slots, otherwise the phone simply won't hear itself,
feedback, and stop working.

Ah, I see, you mean a broadband jammer (otherwise it will not cope with
two
phones transmitting on different channels). For some reason I was
assuming
that it was some elaborate narrow band jamming device. Why not just
transmit
a burst of white noise at 950Mhz with a 45MHz BW?

That's what I was thinking. This would be a lot simpler than having to
detect a specific signal, modulate it by 45MHz an retransmit it.

Would the white noise across the right frequency band confuse the
phone enough to disconnnect or garble the call?


Probably not. Particularly a CDMA system, unless you put out so much power
Click to expand...
that you were obvious to the crowd - the car battery, being up against a
wall, being cavity probed by the FBI........

Ken
 
"George Orwell" <nobody@mixmaster.it> wrote in message
news:b57deee82064347349787c2cd5202d22@mixmaster.it...
"Gordon Brown" <.> wrote:
That's what I was thinking. This would be a lot simpler than having to
detect a specific signal, modulate it by 45MHz an retransmit it.

Would the white noise across the right frequency band confuse the
phone enough to disconnnect or garble the call?
Click to expand...
I am no RF engineer, but IIRC, building a broadband transmitter
intentionally is not that simple. Also the noise will have to be above the
signal from the base station transmitter (say 50W transmitter?). I wonder if
it would not be easier to jam the uplink signal as this would only require
the jammer to transmit in the same order of power as the mobile.
 
"George Orwell" <nobody@mixmaster.it> wrote in message
news:b57deee82064347349787c2cd5202d22@mixmaster.it...
"Gordon Brown" <.> wrote:
"Steve Terry" <g4wwk@despammed.com> wrote in message
news:E55Gb.9655$FN.3222@newsfep4-winn.server.ntli.net...
snip
Ah, I see, you mean a broadband jammer (otherwise it will not cope with two
phones transmitting on different channels). For some reason I was assuming
that it was some elaborate narrow band jamming device. Why not just transmit
a burst of white noise at 950Mhz with a 45MHz BW?

That's what I was thinking. This would be a lot simpler than having to
detect a specific signal, modulate it by 45MHz an retransmit it.

A broad UHF input 45MHz mixer osc with broad UHF output is very simple to make

Would the white noise across the right frequency band confuse the
phone enough to disconnnect or garble the call?

A broadband UHF white noise jammer would have to transmit very much more power
Click to expand...
to have an effect

The whole point of the phone operating on a 45MHz split with odd phased
time slots is so the phones RX doesn't hear it's TX.
Upset any part of that cycle with a relatively low signal, and the phone stops
working.

Steve Terry
 
"Steve Terry" <g4wwk@despammed.com> wrote in message
news:TUmGb.10018$526.67485@newsfep4-glfd.server.ntli.net...
The whole point of the phone operating on a 45MHz split with odd phased
time slots is so the phones RX doesn't hear it's TX.
Upset any part of that cycle with a relatively low signal, and the phone
stops
working.
Click to expand...
So what sort of delay would be necessary and to what tolerance?
 
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