Real techie question about GSM freqs.

I like the very early Motorola 'brick' GSM phones, like the 3200, 2500
- this kind of thing:

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9126815358

I have a few. I actually use them - they're great when I'm in the
Highlands - the extra power really does help the range. Unfortunately
I spend most of the year in the USA. GSM came much later to the USA,
and AFAIK these big old beasts were never sold here.

What's the prospects of changing the frequency - actually getting in
with a soldering iron and changing oscillators or whatever - on one of
these to US frequencies? Or is there more to it - not just a frequency
change but software too, different signalling protocols or something?

Or can someone tell me I'm wrong and there *were* 'brick' GSM phones
sold in the USA?

Cheers

Mike
--
http://www.corestore.org
'As I walk along these shores
I am the history within'

Hi Mike,

In general, the GSM cellular phones support three bands GSM 900, 1800,
and 1900.

GSM (Global System for Mobile)-900
DCS (Digital Codeless Standard)-1800
PCS (Personal Communication Services)-1900

GSM Frequency Domain
Primary GSM (890 to 915 uplink and 935 to 960 downlink)
Extended GSM (880 to 890 uplink and 925 to 935 downlink)
DCS-1800 (1710 to 1785 uplink and 1805 to 1880 downlink)
PCS-1900 (1850 to 1910 uplink and 1930 to 1990 downlink)

In handset the software has mechanism to adopt the serving environment.
Mean it can work on 900, 1800, 1900. This tri-band phone provides
facility to roam all over that world without changing the cellular
phone.

Aloha,
Saurabh

"Saurabh" <saurabh.be.etc@gmail.com> wrote in message
news:1145960291.644271.163050@t31g2000cwb.googlegr oups.com...
> Hi Mike,
>
> In general, the GSM cellular phones support three bands GSM 900, 1800,
> and 1900.
>
> GSM (Global System for Mobile)-900
> DCS (Digital Codeless Standard)-1800
> PCS (Personal Communication Services)-1900
>
> GSM Frequency Domain
> Primary GSM (890 to 915 uplink and 935 to 960 downlink)
> Extended GSM (880 to 890 uplink and 925 to 935 downlink)
> DCS-1800 (1710 to 1785 uplink and 1805 to 1880 downlink)
> PCS-1900 (1850 to 1910 uplink and 1930 to 1990 downlink)
>
> In handset the software has mechanism to adopt the serving environment.
> Mean it can work on 900, 1800, 1900. This tri-band phone provides
> facility to roam all over that world without changing the cellular
> phone.
>
> Aloha,
> Saurabh

would presume you mean quad-band technology?

Hi Taylor,
I think you misguide to see the EGSM and PGSM both. But it both are GSM
900 only. Just for knowledge check the following bands too.

1.
GSM 450 Band:
For GSM 450, the system is required to operate in the following band:
450.4 MHz to 457.6 MHz: mobile transmit, base receive;
460.4 MHz to 467.6 MHz base transmit, mobile receive.

2.
GSM 480 Band:
For GSM 480, the system is required to operate in the following band:
478.8 MHz to 486 MHz: mobile transmit, base receive;
488.8 MHz to 496 MHz base transmit, mobile receive.

3.
GSM 850 Band:
For GSM 850, the system is required to operate in the following band:
824 MHz to 849 MHz: mobile transmit, base receive;
869 MHz to 894 MHz: base transmit, mobile receive.

4.
Standard or primary GSM 900 Band, P-GSM:
For Standard GSM 900 band, the system is required to operate in the
following frequency band:
890 MHz to 915 MHz: mobile transmit, base receive;
935 MHz to 960 MHz: base transmit, mobile receive.

5.
Extended GSM 900 Band, E-GSM (includes Standard GSM 900 band):
For Extended GSM 900 band, the system is required to operate in the
following frequency band:
880 MHz to 915 MHz: mobile transmit, base receive;
925 MHz to 960 MHz: base transmit, mobile receive.

6.
Railways GSM 900 Band, R-GSM (includes Standard and Extended
GSM 900 Band):
For Railways GSM 900 band, the system is required to operate in the
following frequency band:
876 MHz to 915 MHz: mobile transmit, base receive;
921 MHz to 960 MHz: base transmit, mobile receive.

7.
DCS 1 800 Band:
For DCS 1 800, the system is required to operate in the following
band:
1710 MHz to 1 785 MHz: mobile transmit, base receive;
1805 MHz to 1 880 MHz: base transmit, mobile receive.

8.
PCS 1 900 Band:
For PCS 1 900, the system is required to operate in the following
band:
1850 MHz to 1 910 MHz: mobile transmit, base receive;
1930 MHz to 1 990 MHz base transmit, mobile receive.

Feel free to ask.


Aloha,
Saurabh

[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]

In <j30q42925d99n0gusa5cmikam4u1prb6r4@4ax.com> on Mon, 24 Apr 2006 12:55:52
-0400, Mike Ross <mike@corestore.org> wrote:

>I like the very early Motorola 'brick' GSM phones, like the 3200, 2500
>- this kind of thing:
>
>http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9126815358
>
>I have a few. I actually use them - they're great when I'm in the
>Highlands - the extra power really does help the range. Unfortunately
>I spend most of the year in the USA. GSM came much later to the USA,
>and AFAIK these big old beasts were never sold here.
>
>What's the prospects of changing the frequency - actually getting in
>with a soldering iron and changing oscillators or whatever - on one of
>these to US frequencies? Or is there more to it - not just a frequency
>change but software too, different signalling protocols or something?

It's neither legal nor practical to do that.

>Or can someone tell me I'm wrong and there *were* 'brick' GSM phones
>sold in the USA?

Why not simply use a current phone with a booster amp?

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

On Wed, 26 Apr 2006 23:42:58 GMT, John Navas
<spamfilter0@navasgroup.com> wrote:

>[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]
>
>In <j30q42925d99n0gusa5cmikam4u1prb6r4@4ax.com> on Mon, 24 Apr 2006 12:55:52
>-0400, Mike Ross <mike@corestore.org> wrote:
>
>>I like the very early Motorola 'brick' GSM phones, like the 3200, 2500
>>- this kind of thing:
>>
>>http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9126815358
>>
>>I have a few. I actually use them - they're great when I'm in the
>>Highlands - the extra power really does help the range. Unfortunately
>>I spend most of the year in the USA. GSM came much later to the USA,
>>and AFAIK these big old beasts were never sold here.
>>
>>What's the prospects of changing the frequency - actually getting in
>>with a soldering iron and changing oscillators or whatever - on one of
>>these to US frequencies? Or is there more to it - not just a frequency
>>change but software too, different signalling protocols or something?
>
>It's neither legal nor practical to do that.

I'm quite prepared to believe it's impractical - I didn't know if it
was or wasn't, that's why I asked the question. I had hoped it would
be practical - I have a Pogo which was modified to work on American
frequencies. But why should it be illegal?

>>Or can someone tell me I'm wrong and there *were* 'brick' GSM phones
>>sold in the USA?
>
>Why not simply use a current phone with a booster amp?

Nostalgia.

Mike
--
http://www.corestore.org
'As I walk along these shores
I am the history within'

[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]

In <vh305212q26jl1n5b4h1ult1rlbo456kda@4ax.com> on Wed, 26 Apr 2006 20:22:44
-0400, Mike Ross <mike@corestore.org> wrote:

>On Wed, 26 Apr 2006 23:42:58 GMT, John Navas
><spamfilter0@navasgroup.com> wrote:
>
>>In <j30q42925d99n0gusa5cmikam4u1prb6r4@4ax.com> on Mon, 24 Apr 2006 12:55:52
>>-0400, Mike Ross <mike@corestore.org> wrote:

>>>What's the prospects of changing the frequency - actually getting in
>>>with a soldering iron and changing oscillators or whatever - on one of
>>>these to US frequencies? Or is there more to it - not just a frequency
>>>change but software too, different signalling protocols or something?
>>
>>It's neither legal nor practical to do that.
>
>I'm quite prepared to believe it's impractical - I didn't know if it
>was or wasn't, that's why I asked the question. I had hoped it would
>be practical - I have a Pogo which was modified to work on American
>frequencies. But why should it be illegal?

FCC regulations.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

you might be able to spend thousands on getting design approval from
Motorola for your proposed changes, then submit it for testing and type
approval and so on, so don't give up hope yet

In the US the Federal Communications Commission (FCC) does not allow
modifications to transmitters without testing and approval. While doing
a one off wouldn't require that you go through ALL the hoops, there
would be enough to make it more expensive and inconvenient than the
nostalgia would likely be worth.
>
> I'm quite prepared to believe it's impractical - I didn't know if it
> was or wasn't, that's why I asked the question. I had hoped it would
> be practical - I have a Pogo which was modified to work on American
> frequencies. But why should it be illegal?
>
> Mike

On Thu, 27 Apr 2006 03:36:35 GMT, "BruceR" <br@NOhawaiiSPAM.com>
wrote:

>>
>> I'm quite prepared to believe it's impractical - I didn't know if it
>> was or wasn't, that's why I asked the question. I had hoped it would
>> be practical - I have a Pogo which was modified to work on American
>> frequencies. But why should it be illegal?
>>
>> Mike
>
>In the US the Federal Communications Commission (FCC) does not allow
>modifications to transmitters without testing and approval. While doing
>a one off wouldn't require that you go through ALL the hoops, there
>would be enough to make it more expensive and inconvenient than the
>nostalgia would likely be worth.

Ahhh ok - I'd planned to do the work in the UK anyway so FCC wouldn't
be involved. Certainly when I had the Pogo modified it was done in the
UK, the hardware work was very simple - one chip was changed - and I
took it to the USA and used it, no FCC involvement.

Mike
--
http://www.corestore.org
'As I walk along these shores
I am the history within'

[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]

In <cu9152ta6bl7sttt102usl3k4i6scgq6h5@4ax.com> on Thu, 27 Apr 2006 07:19:10
-0400, Mike Ross <mike@corestore.org> wrote:

>On Thu, 27 Apr 2006 03:36:35 GMT, "BruceR" <br@NOhawaiiSPAM.com>
>wrote:

>Ahhh ok - I'd planned to do the work in the UK anyway so FCC wouldn't
>be involved. Certainly when I had the Pogo modified it was done in the
>UK, the hardware work was very simple - one chip was changed - and I
>took it to the USA and used it, no FCC involvement.

Gee, thanks.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

On Wed, 26 Apr 2006 20:22:44 -0400, Mike Ross <mike@corestore.org>
wrote:

>On Wed, 26 Apr 2006 23:42:58 GMT, John Navas
><spamfilter0@navasgroup.com> wrote:
>
>>[POSTED TO alt.cellular.gsm - REPLY ON USENET PLEASE]
>>
>>In <j30q42925d99n0gusa5cmikam4u1prb6r4@4ax.com> on Mon, 24 Apr 2006 12:55:52
>>-0400, Mike Ross <mike@corestore.org> wrote:
>>
>>>I like the very early Motorola 'brick' GSM phones, like the 3200, 2500
>>>- this kind of thing:
>>>
>>>http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9126815358
>>>
>>>I have a few. I actually use them - they're great when I'm in the
>>>Highlands - the extra power really does help the range. Unfortunately
>>>I spend most of the year in the USA. GSM came much later to the USA,
>>>and AFAIK these big old beasts were never sold here.
>>>
>>>What's the prospects of changing the frequency - actually getting in
>>>with a soldering iron and changing oscillators or whatever - on one of
>>>these to US frequencies? Or is there more to it - not just a frequency
>>>change but software too, different signalling protocols or something?
>>
>>It's neither legal nor practical to do that.
>
>I'm quite prepared to believe it's impractical - I didn't know if it
>was or wasn't, that's why I asked the question. I had hoped it would
>be practical - I have a Pogo which was modified to work on American
>frequencies. But why should it be illegal?
Because current FCC regulations prohibit anyone other than those
specically authorized from modifying mobile phones. It violates the
type acceptance. It also prevents cloning of AMPS phones.
>
>>>Or can someone tell me I'm wrong and there *were* 'brick' GSM phones
>>>sold in the USA?
>>
>>Why not simply use a current phone with a booster amp?
>
>Nostalgia.
>
>Mike

You could likely do the same thing if you can source the parts. While
it's illegal to use ANY transmitter in the US that doesn't have FCC
approval and generates more than 100mw, you would "get away with it" as
long as the device didn't cause any problems. The FCC finds it far more
profitable and entertaining to concern itself with millisecond glimpses
of nipples than milliwatts of radiated cellphone power.


> On Thu, 27 Apr 2006 03:36:35 GMT, "BruceR" <br@NOhawaiiSPAM.com>
> wrote:
>
>>>
>>> I'm quite prepared to believe it's impractical - I didn't know if it
>>> was or wasn't, that's why I asked the question. I had hoped it would
>>> be practical - I have a Pogo which was modified to work on American
>>> frequencies. But why should it be illegal?
>>>
>>> Mike
>>
>> In the US the Federal Communications Commission (FCC) does not allow
>> modifications to transmitters without testing and approval. While
>> doing a one off wouldn't require that you go through ALL the hoops,
>> there would be enough to make it more expensive and inconvenient
>> than the nostalgia would likely be worth.
>
> Ahhh ok - I'd planned to do the work in the UK anyway so FCC wouldn't
> be involved. Certainly when I had the Pogo modified it was done in the
> UK, the hardware work was very simple - one chip was changed - and I
> took it to the USA and used it, no FCC involvement.
>
> Mike

"Mike Ross" <mike@corestore.org> wrote in message
news:vh305212q26jl1n5b4h1ult1rlbo456kda@4ax.com

[snip]

> I'm quite prepared to believe it's impractical - I didn't
> know if it was or wasn't, that's why I asked the
> question. I had hoped it would be practical - I have a
> Pogo which was modified to work on American frequencies.
> But why should it be illegal?

Because messing with radio transmitters unless you are authorised to do so
is illegal. In the UK it comes under the Wireless Telegraphy Act. In the
US the FCC have similar legislation in place, but I don't know offhand
what it's called. It's why you need to take an exam to hold a radio
amateur licence.

Ivor

"Mike Ross" <mike@corestore.org> wrote in message
news:cu9152ta6bl7sttt102usl3k4i6scgq6h5@4ax.com

[snip]

> Ahhh ok - I'd planned to do the work in the UK anyway so
> FCC wouldn't be involved. Certainly when I had the Pogo
> modified it was done in the UK, the hardware work was
> very simple - one chip was changed - and I took it to the
> USA and used it, no FCC involvement.

It's irrelevant where you *modify* a transmitter, it's very relevant where
you *use* it.

Only licensed radio amateurs are allowed to tinker with transmitting
equipment without submitting it for type approval, and even then only when
it operates on licensed amateur bands.

Ivor