Cell phones 800mhz analog /.digital ?

Archived from groups: alt.cellular.tech (More info?)

On Sat, 15 Jan 2005 13:07:13 GMT, "NeuRoNS" <mwin8730@bigpond.net.au>
wrote:

>Hi all,
>
>Can somebody confirm for me, if 'Cell phones' in usa (800Mhz band) are
>analog ???

800 Mhz is used for analog and at least three types of digital service
in North America. 800 Mhz is commonly known as the "cellular"
standard in North America. Digital cellular standards presently in
use are CDMA (commonly Sprint PCS and Verizon), TDMA (cingular and
AT&T Wireless) and GSM (cingular and AT&T Wireless.) They refer to
GSM "850" but the reality is it uses the same spectrum as analog and
the other digital "cellular" frequencies. T-Mobile is GSM but only at
PCS 1900 Mhz frequency. There is also iDen systems which is digital
and uses 800 Mhz but is not really "cellular" but SMR.

>What freq's are the digital cell phones in usa?

As above either CDMA, TDMA or GSM with the major carriers noted above.

>I've seen various posts in forums for phones/scanners/hacking/listening etc,
>but i *think* the 800mhz phones in usa are still analog system???

Analog AMPS is still in use and is not as secure as digital and can be
cloned. 800 Mhz is in use for analogue and digital.

>The reason i ask, is because i see scanners radios in usa (and amateur
>radios) claiming to receive 800mhz cell phones, although i think theyre
>still referring to analog phones???
>would i be correct? ;-)

As I've tried to indicate multiple times mobile in the US and Canada
uses 800 Mhz for both digital and analogue.

> then the
>remaining 9 people can be receivers at their scanner.

Impossible or at least very difficult with digital.
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Archived from groups: alt.cellular.tech (More info?)

NeuRoNS wrote:
> Hi all,
>
> Can somebody confirm for me, if 'Cell phones' in usa (800Mhz band) are
> analog ???

There are some (or perhaps quite a few) cell phones in the US that still
use the AMPS standard, and are analog. In addition, a good deal of CDMA
digital phones are also built with the capability to fall back to analog
mode if, for whatever reason, a CDMA signal is not available.

> What freq's are the digital cell phones in usa?

Digital cell phones oeprate in 800MHz and 1900MHz in the US.

> I've seen various posts in forums for phones/scanners/hacking/listening etc,
> but i *think* the 800mhz phones in usa are still analog system???

It's a mixture of GSM, CDMA and AMPS, depenidng on which carrier you're
talking about.

> The reason i ask, is because i see scanners radios in usa (and amateur
> radios) claiming to receive 800mhz cell phones, although i think theyre
> still referring to analog phones???
> would i be correct? ;-)

Yes, analog phones can be eavesdropped on with conventional equipment
(though technicially it has been illegal to sell such equipment in the
US for some time).

> In case you're wondering, i have been asked to design a system whereby
> several ppl could monitor 1 DIGITAL cell phone, as a monitoring of
> data/voice etc, and yet "any" of the phones could be assigned as the
> transmitter while all other people are scanner receivers.

Good luck! In digital, this probably isn't going to happen, mainly
because the whole idea of going to digital was to explicitly prevent
people from doing what you are trying to do. Your motives are probably
legit (or at least I would hope so), but many have done with analog what
you are proposing, with fraudulent intentions. As such, GSM and CDMA
standards were built to be resistant to this.

> This system is sort of an alternative to using vhf/uhf radios for
> broadcast/news gathering communications, and since the company will be
> sending staff state-wide, the mobile phones seemed to be a good answer for
> all purpose coverage....
> (the people are usually outside vhf/uhf or 'repeater' ranges).

Although your sig says you're in Australia, it seems like you are
focusing on US-based cellular systems, so I'm going to assume this is a
US application. That said, why not just get your crew Nextel phones?
They offer group call, two-way communication capability in addition to
cell phone functions. And they do it legally.   www.nextel.com.

> In the above scenario, i guess it sort of defies the laws of telephone
> eavesdropping?

Yes, it does. And technically it's infeasable, as digital cell phones
tend to use a pseudorandom key for identifying itself to the network.
If the correct key is not being used, then the handset isn't authorized
to connect. It would be an amazing stroke of luck to get several phones
to match the same ESN and PN codes simulteously, and for the network to
accept all of those connections as one call.


, since it's run within 1 company, but i realise i may be
> pushing limits to find a scanner (or mod) that would allow me to receive
> DIGITAL cell phones ????

There are presently no commercially available scanners that can
interpret a GSM or CDMA signal.

--
E-mail fudged to thwart spammers.
Transpose the c's and a's in my e-mail address to reply.

Anonymous's transparent attempt to get information about cell phone frequencies was annoying. Just come out and say what you want. Don't try to disguise your voyeuristic ways. It's insulting to our intelligence. I'm sure you have an important project that you're working on. It just happens to be the "listen in on people's conversations" project. Don't feel bad. I'd like listen in on people's conversations, too. But I ADMIT it. So far, I've only heard one side of the conversation and it was usually quite dull. There was one call I heard where the guy told the girl what he was going to do with her when he got home. That was mildly stimulating.

is there any scanners that will pick up digital phone calls i live in australia