Deutsche Telekom and T-Mobile

On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to add
this to the great equation of life, the universe, and everything:

>In article <pcq100dtei59ogtmg3quqn3rkrdo5qsrlv@Pern.rk>,
>Al Klein <ehxong@bcgbayvar.arg> wrote:
>>On Thu, 08 Jan 2004 10:11:08 -0500, Isaiah Beard
>><sacredpoet@sacredpoet.com> posted to alt.cellular.verizon:
>>
>>>2. Wasn't CDMA a military invention meant to be *resistant* to jamming?
>>
>>Pretty much. Jamming is just noise to a CDMA receiver, and it's
>>designed to operate in the presence of noise (the other CDMA phones on
>>the channel are also noise).
>
>The idea is that a CDMA signal is scattered all over a "carrier" (1.25MHz
>for cellular/PCS phones), so the jammer has to spread his signal over
>the entire carrier with sufficient power to jam the communication.

Okay, so how hard is that to do? (Honest question.) It seems to me they
wouldn't need all that much power to block a cellular-strength signal
within the confines of a small building.

--
David Streeter, "an internet god" -- Dave Barry
http://home.att.net/~dwstreeter
Expect a train on ANY track at ANY time.
"I should never have bitten the head off that bat." - Ozzy Osbourne

 

You are right. Direct sequence spread spectrum (which is what CDMA is)
is vulnerable to HIGH levels of broadband noise in the frequency block
in use. Noise at the power level other users generate can be tolerated
very nearby, but serious power (100 watts) can disrupt cellphone level
signals for hundreds of feet.

In most tactical situations, the enemy can't get close enough with
enough power to disrupt communications. DS spread spectrum is capable
of retrieving signals that are actually a bit below the noise level.


Gray


David S wrote:
>
> On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to add
> this to the great equation of life, the universe, and everything:
>
> >In article <pcq100dtei59ogtmg3quqn3rkrdo5qsrlv@Pern.rk>,
> >Al Klein <ehxong@bcgbayvar.arg> wrote:
> >>On Thu, 08 Jan 2004 10:11:08 -0500, Isaiah Beard
> >><sacredpoet@sacredpoet.com> posted to alt.cellular.verizon:
> >>
> >>>2. Wasn't CDMA a military invention meant to be *resistant* to jamming?
> >>
> >>Pretty much. Jamming is just noise to a CDMA receiver, and it's
> >>designed to operate in the presence of noise (the other CDMA phones on
> >>the channel are also noise).
> >
> >The idea is that a CDMA signal is scattered all over a "carrier" (1.25MHz
> >for cellular/PCS phones), so the jammer has to spread his signal over
> >the entire carrier with sufficient power to jam the communication.
>
> Okay, so how hard is that to do? (Honest question.) It seems to me they
> wouldn't need all that much power to block a cellular-strength signal
> within the confines of a small building.
>
> --
> David Streeter, "an internet god" -- Dave Barry
> http://home.att.net/~dwstreeter
> Expect a train on ANY track at ANY time.
> "I should never have bitten the head off that bat." - Ozzy Osbourne

--
Telecommunications Engineering
Gray Frierson Haertig & Assoc.
820 North River Street, Suite 100
Portland, Oregon 97227
503-282-2989
503-282-3181 FAX
gfh@haertig.com

 

On Tue, 13 Jan 2004 05:57:01 GMT, David S <dwstreeter@att.net> posted
in alt.cellular.verizon:

>On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to add
>this to the great equation of life, the universe, and everything:

>>The idea is that a CDMA signal is scattered all over a "carrier" (1.25MHz
>>for cellular/PCS phones), so the jammer has to spread his signal over
>>the entire carrier with sufficient power to jam the communication.

>Okay, so how hard is that to do? (Honest question.)

Very.

>It seems to me they
>wouldn't need all that much power to block a cellular-strength signal
>within the confines of a small building.

Getting a signal that wide is the problem. A CDMA signal doesn't
exist at all frequencies in the bandwidth at once - a jammer has to.
Once you have a signal that wide, amplifying it isn't the problem.
You could jam an entire city almost as easily as you could jam one
building. (And remember that it would take at least a few
transmitters to jam an entire building - signals at those frequencies
don't penetrate steel walls well.)

 

On Tue, 13 Jan 2004 07:35:28 GMT, Gray Frierson Haertig
<gfh@haertig.com> posted in alt.cellular.verizon:

>You are right. Direct sequence spread spectrum (which is what CDMA is)
>is vulnerable to HIGH levels of broadband noise in the frequency block
>in use. Noise at the power level other users generate can be tolerated
>very nearby, but serious power (100 watts) can disrupt cellphone level
>signals for hundreds of feet.

>In most tactical situations, the enemy can't get close enough with
>enough power to disrupt communications. DS spread spectrum is capable
>of retrieving signals that are actually a bit below the noise level.

An 800 MHz equivalent of the old Russian buzz-saw might do the job,
but those transmitters were hardly portable.

Maybe a rotary spark gap resonant at 850 MHz?

 

On Sun, 11 Jan 2004 01:14:47 -0500, Al Klein <rukbat@pern.org> chose to add
this to the great equation of life, the universe, and everything:

>On Thu, 08 Jan 2004 10:11:08 -0500, Isaiah Beard
><sacredpoet@sacredpoet.com> posted to alt.cellular.verizon:
>
>>2. Wasn't CDMA a military invention meant to be *resistant* to jamming?
>
>Pretty much. Jamming is just noise to a CDMA receiver, and it's
>designed to operate in the presence of noise (the other CDMA phones on
>the channel are also noise).

Okay, I've thought about this while actually awake now.

I don't think you need to jam the whole carrier. The jammer just needs to
detect the frequency of the control channel from the tower to the phone and
overpower *that*, again just within the confines of a building.

--
David Streeter, "an internet god" -- Dave Barry
http://home.att.net/~dwstreeter
Expect a train on ANY track at ANY time.
"This makes me so angry it gets my dandruff up." - Sam Goldwyn

 

On Wed, 14 Jan 2004 05:17:24 GMT, Al Klein <rukbat@pern.org> chose to add
this to the great equation of life, the universe, and everything:

>On Tue, 13 Jan 2004 05:57:01 GMT, David S <dwstreeter@att.net> posted
>in alt.cellular.verizon:
>
>>On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to add
>>this to the great equation of life, the universe, and everything:
>
>>>The idea is that a CDMA signal is scattered all over a "carrier" (1.25MHz
>>>for cellular/PCS phones), so the jammer has to spread his signal over
>>>the entire carrier with sufficient power to jam the communication.
>
>>Okay, so how hard is that to do? (Honest question.)
>
>Very.
>
>>It seems to me they
>>wouldn't need all that much power to block a cellular-strength signal
>>within the confines of a small building.
>
>Getting a signal that wide is the problem. A CDMA signal doesn't
>exist at all frequencies in the bandwidth at once - a jammer has to.
>Once you have a signal that wide, amplifying it isn't the problem.
>You could jam an entire city almost as easily as you could jam one
>building. (And remember that it would take at least a few
>transmitters to jam an entire building - signals at those frequencies
>don't penetrate steel walls well.)

But we're talking about a McDonald's, which is pretty much all one room.

--
David Streeter, "an internet god" -- Dave Barry
http://home.att.net/~dwstreeter
Expect a train on ANY track at ANY time.
"Lately, when I tell people I work for a newspaper, I've detected the
subtle signs of disapproval -- the dirty looks; the snide remarks; the
severed animal heads in my bed." - Dave Barry

 

I don't claim to be a wonk on how CDMA cell systems are implemented, but
I believe that the control channel is just another direct sequence
spread spectrum channel, so it is spread across the same block of
spectrum that all the voice channels are spread across. In a direct
sequence spread spectrum system there are no discrete frequencies.

In a frequency hopping spread spectrum system (Heddy Lamar's kind) there
are discrete frequencies but they are constantly changing according to a code.


Gray




David S wrote:
>
> On Sun, 11 Jan 2004 01:14:47 -0500, Al Klein <rukbat@pern.org> chose to add
> this to the great equation of life, the universe, and everything:
>
> >On Thu, 08 Jan 2004 10:11:08 -0500, Isaiah Beard
> ><sacredpoet@sacredpoet.com> posted to alt.cellular.verizon:
> >
> >>2. Wasn't CDMA a military invention meant to be *resistant* to jamming?
> >
> >Pretty much. Jamming is just noise to a CDMA receiver, and it's
> >designed to operate in the presence of noise (the other CDMA phones on
> >the channel are also noise).
>
> Okay, I've thought about this while actually awake now.
>
> I don't think you need to jam the whole carrier. The jammer just needs to
> detect the frequency of the control channel from the tower to the phone and
> overpower *that*, again just within the confines of a building.
>
> --
> David Streeter, "an internet god" -- Dave Barry
> http://home.att.net/~dwstreeter
> Expect a train on ANY track at ANY time.
> "This makes me so angry it gets my dandruff up." - Sam Goldwyn

--
Telecommunications Engineering
Gray Frierson Haertig & Assoc.
820 North River Street, Suite 100
Portland, Oregon 97227
503-282-2989
503-282-3181 FAX
gfh@haertig.com

 

Creating a jamming signal is no more difficult than generating the CDMA
signal. The problem is getting the interfering signal power high enough
AT THE RECEIVER to jam the signal.

Doing this within a building to jam cell phones would not be terribly
difficult. Doing it in a tactical military situation would be.


Gray



Al Klein wrote:
>
> On Tue, 13 Jan 2004 05:57:01 GMT, David S <dwstreeter@att.net> posted
> in alt.cellular.verizon:
>
> >On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to add
> >this to the great equation of life, the universe, and everything:
>
> >>The idea is that a CDMA signal is scattered all over a "carrier" (1.25MHz
> >>for cellular/PCS phones), so the jammer has to spread his signal over
> >>the entire carrier with sufficient power to jam the communication.
>
> >Okay, so how hard is that to do? (Honest question.)
>
> Very.
>
> >It seems to me they
> >wouldn't need all that much power to block a cellular-strength signal
> >within the confines of a small building.
>
> Getting a signal that wide is the problem. A CDMA signal doesn't
> exist at all frequencies in the bandwidth at once - a jammer has to.
> Once you have a signal that wide, amplifying it isn't the problem.
> You could jam an entire city almost as easily as you could jam one
> building. (And remember that it would take at least a few
> transmitters to jam an entire building - signals at those frequencies
> don't penetrate steel walls well.)

--
Telecommunications Engineering
Gray Frierson Haertig & Assoc.
820 North River Street, Suite 100
Portland, Oregon 97227
503-282-2989
503-282-3181 FAX
gfh@haertig.com

 

"Al Klein" <rukbat@pern.org> wrote in message
news:a1k900ls8icacl77fj9us8c6oo157qhdu3@Pern.rk...
> On Tue, 13 Jan 2004 05:57:01 GMT, David S <dwstreeter@att.net> posted
> in alt.cellular.verizon:
>
> >On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to
add
> >this to the great equation of life, the universe, and everything:
>
> >>The idea is that a CDMA signal is scattered all over a "carrier"
(1.25MHz
> >>for cellular/PCS phones), so the jammer has to spread his signal over
> >>the entire carrier with sufficient power to jam the communication.
>
> >Okay, so how hard is that to do? (Honest question.)
>
> Very.
>
> >It seems to me they
> >wouldn't need all that much power to block a cellular-strength signal
> >within the confines of a small building.
>
> Getting a signal that wide is the problem. A CDMA signal doesn't
> exist at all frequencies in the bandwidth at once - a jammer has to.
> Once you have a signal that wide, amplifying it isn't the problem.
> You could jam an entire city almost as easily as you could jam one
> building. (And remember that it would take at least a few
> transmitters to jam an entire building - signals at those frequencies
> don't penetrate steel walls well.)

Cell towers are how much? 3 watts? (I don't know) so if you had a jamer with
about 500 watts, you should be able to jam a sizable area. The FCC will be
very "angry" with you though.

 

On Wed, 14 Jan 2004 06:00:40 GMT, David S <dwstreeter@att.net> posted
in alt.cellular.verizon:

>On Sun, 11 Jan 2004 01:14:47 -0500, Al Klein <rukbat@pern.org> chose to add
>this to the great equation of life, the universe, and everything:
>
>>On Thu, 08 Jan 2004 10:11:08 -0500, Isaiah Beard
>><sacredpoet@sacredpoet.com> posted to alt.cellular.verizon:
>>
>>>2. Wasn't CDMA a military invention meant to be *resistant* to jamming?
>>
>>Pretty much. Jamming is just noise to a CDMA receiver, and it's
>>designed to operate in the presence of noise (the other CDMA phones on
>>the channel are also noise).
>
>Okay, I've thought about this while actually awake now.
>
>I don't think you need to jam the whole carrier. The jammer just needs to
>detect the frequency of the control channel from the tower to the phone and
>overpower *that*, again just within the confines of a building.

In the event that something goes wrong, there's more than 1 control
channel.

 

On Wed, 14 Jan 2004 06:05:03 GMT, David S <dwstreeter@att.net> posted
in alt.cellular.verizon:

>On Wed, 14 Jan 2004 05:17:24 GMT, Al Klein <rukbat@pern.org> chose to add
>this to the great equation of life, the universe, and everything:
>
>>On Tue, 13 Jan 2004 05:57:01 GMT, David S <dwstreeter@att.net> posted
>>in alt.cellular.verizon:
>>
>>>On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to add
>>>this to the great equation of life, the universe, and everything:
>>
>>>>The idea is that a CDMA signal is scattered all over a "carrier" (1.25MHz
>>>>for cellular/PCS phones), so the jammer has to spread his signal over
>>>>the entire carrier with sufficient power to jam the communication.
>>
>>>Okay, so how hard is that to do? (Honest question.)
>>
>>Very.
>>
>>>It seems to me they
>>>wouldn't need all that much power to block a cellular-strength signal
>>>within the confines of a small building.
>>
>>Getting a signal that wide is the problem. A CDMA signal doesn't
>>exist at all frequencies in the bandwidth at once - a jammer has to.
>>Once you have a signal that wide, amplifying it isn't the problem.
>>You could jam an entire city almost as easily as you could jam one
>>building. (And remember that it would take at least a few
>>transmitters to jam an entire building - signals at those frequencies
>>don't penetrate steel walls well.)
>
>But we're talking about a McDonald's, which is pretty much all one room.

I guess I missed the beginning of the thread. Are we talking about
jamming McDonald's radio system? If so, that's a single channel
system, not CDMA. (I believe McDonald's is licensed for high band -
150-170 MHz.)

Or are we talking about jamming cell phones in McDonald's restaurants,
which is highly illegal, even if done by McDonald's.

 

On Wed, 14 Jan 2004 07:02:40 GMT, Gray Frierson Haertig
<gfh@haertig.com> posted in alt.cellular.verizon:

>Creating a jamming signal is no more difficult than generating the CDMA
>signal. The problem is getting the interfering signal power high enough
>AT THE RECEIVER to jam the signal.

And with the same spread.

 

> >But we're talking about a McDonald's, which is pretty much all one room.
>
> I guess I missed the beginning of the thread. Are we talking about
> jamming McDonald's radio system? If so, that's a single channel
> system, not CDMA. (I believe McDonald's is licensed for high band -
> 150-170 MHz.)
>
> Or are we talking about jamming cell phones in McDonald's restaurants,
> which is highly illegal, even if done by McDonald's.

I think it was something along the lines of T-Mobile merging with Mc
Donald's and then putting a cell tower in every McDonalds, and then someone
mentioned that CDMA was a military development and resists jamming. ahhh,
isn't it amazing how conversations wonder?

 

The spread is not particularly difficult - after all, your cell phone
can do it.


Gray


Al Klein wrote:
>
> On Wed, 14 Jan 2004 07:02:40 GMT, Gray Frierson Haertig
> <gfh@haertig.com> posted in alt.cellular.verizon:
>
> >Creating a jamming signal is no more difficult than generating the CDMA
> >signal. The problem is getting the interfering signal power high enough
> >AT THE RECEIVER to jam the signal.
>
> And with the same spread.

--
Telecommunications Engineering
Gray Frierson Haertig & Assoc.
820 North River Street, Suite 100
Portland, Oregon 97227
503-282-2989
503-282-3181 FAX
gfh@haertig.com

 

Gray Frierson Haertig wrote:
> The spread is not particularly difficult - after all, your cell phone
> can do it.

Not quite. The cell phone isn't transmitting on all frequencies in the
channel simultaneously, but a jammer would have to. Otherwise it'd just
look like a particularly rude cell phone.

Jesse

 

On Thu, 15 Jan 2004 04:22:49 GMT, "Trey" <treydog90spam@hotmail.com>
wrote:

>I think it was something along the lines of T-Mobile merging with Mc
>Donald's and then putting a cell tower in every McDonalds, and then someone
>mentioned that CDMA was a military development and resists jamming. ahhh,
>isn't it amazing how conversations wonder?

Does that mean that if you re-up with T-McDonald you can get a free
Big Mac with fries?
- - - - - - - - - - - - - - - - - - - - - - - - - -
remove NO from .NOcom to reply

 

On Thu, 15 Jan 2004 04:22:49 GMT, "Trey" <treydog90spam@hotmail.com> chose
to add this to the great equation of life, the universe, and everything:

>> >But we're talking about a McDonald's, which is pretty much all one room.
>>
>> I guess I missed the beginning of the thread. Are we talking about
>> jamming McDonald's radio system? If so, that's a single channel
>> system, not CDMA. (I believe McDonald's is licensed for high band -
>> 150-170 MHz.)
>>
>> Or are we talking about jamming cell phones in McDonald's restaurants,
>> which is highly illegal, even if done by McDonald's.
>
>I think it was something along the lines of T-Mobile merging with Mc

I thought it was ATTWS + McD.

>Donald's and then putting a cell tower in every McDonalds, and then someone
>mentioned that CDMA was a military development and resists jamming. ahhh,
>isn't it amazing how conversations wonder?

And how they wander, too.

--
David Streeter, "an internet god" -- Dave Barry
http://home.att.net/~dwstreeter
Expect a train on ANY track at ANY time.
"A man's got to be a man or he's not a man." - Maj. Frank Burns

 

On Thu, 15 Jan 2004 03:30:38 GMT, Al Klein <rukbat@pern.org> chose to add
this to the great equation of life, the universe, and everything:

>On Wed, 14 Jan 2004 06:05:03 GMT, David S <dwstreeter@att.net> posted
>in alt.cellular.verizon:
>
>>On Wed, 14 Jan 2004 05:17:24 GMT, Al Klein <rukbat@pern.org> chose to add
>>this to the great equation of life, the universe, and everything:
>>
>>>On Tue, 13 Jan 2004 05:57:01 GMT, David S <dwstreeter@att.net> posted
>>>in alt.cellular.verizon:
>>>
>>>>On 12 Jan 2004 02:10:14 GMT, hoch@exemplary.invalid (CharlesH) chose to add
>>>>this to the great equation of life, the universe, and everything:
>>>
>>>>>The idea is that a CDMA signal is scattered all over a "carrier" (1.25MHz
>>>>>for cellular/PCS phones), so the jammer has to spread his signal over
>>>>>the entire carrier with sufficient power to jam the communication.
>>>
>>>>Okay, so how hard is that to do? (Honest question.)
>>>
>>>Very.
>>>
>>>>It seems to me they
>>>>wouldn't need all that much power to block a cellular-strength signal
>>>>within the confines of a small building.
>>>
>>>Getting a signal that wide is the problem. A CDMA signal doesn't
>>>exist at all frequencies in the bandwidth at once - a jammer has to.
>>>Once you have a signal that wide, amplifying it isn't the problem.
>>>You could jam an entire city almost as easily as you could jam one
>>>building. (And remember that it would take at least a few
>>>transmitters to jam an entire building - signals at those frequencies
>>>don't penetrate steel walls well.)
>>
>>But we're talking about a McDonald's, which is pretty much all one room.
>
>I guess I missed the beginning of the thread. Are we talking about
>jamming McDonald's radio system? If so, that's a single channel

No.

>system, not CDMA. (I believe McDonald's is licensed for high band -
>150-170 MHz.)

At one time, they used the same frequency (49.x) as GE Voice One and some
Maxon wireless headsets.

>Or are we talking about jamming cell phones in McDonald's restaurants,
>which is highly illegal, even if done by McDonald's.

Yes. Someone suggested (probably facetiously) that ATTWS was merging with
McD's. I said that would be a good way to expand their network: put a cell
in every McD's, or as an alternative, CDMA jammers.

--
David Streeter, "an internet god" -- Dave Barry
http://home.att.net/~dwstreeter
Expect a train on ANY track at ANY time.
APOLOGY
Thank you for staying with us Narita View Hotel.
We will have renovation for room at 11th floor following periods.
Feb. 13th - Mar. 27th 10:00a.m.-5:00p.m.
You may hear some noise and get some suffering to go, during this periods.
We appreciate your cooperation.

Thank you
General Manager

- flyer distributed to all guests at a Japanese hotel

 

On Sat, 17 Jan 2004 20:13:12 GMT, David S <dwstreeter@att.net> posted
in alt.cellular.verizon:

>Yes. Someone suggested (probably facetiously) that ATTWS was merging with
>McD's. I said that would be a good way to expand their network: put a cell
>in every McD's, or as an alternative, CDMA jammers.

Difficult to jam CDMA running on the same channels as TDMA, though.
It would take jammers tailored to individual locations.