What is the diffrance between GSM 900 and EGSM 900

"Dick Silk" <[email protected]> wrote in message
news:[email protected]...
> "Steve" <[email protected]> wrote in message
> news:[email protected]...
> > My understanding is that EGSM is used in newer phones as the BTS emits
> > signal on the old analogue frequencies which are generally better
quality
> > then normal GSM 900.
>
> oh, that's just *great*... now my analogue cell phone spectrum is gonna
get
> clogged and I'll be right back to "all circuits are busy" again. (I
never
> understood why people would give up the clarity of analogue to get that
> digital crap!)

Depends on the digital service - here in the UK we have been all-GSM for
several years, there is no analogue any more, and the call quality is as
good as any I've ever experienced in the US..!

One excellent reason to use digital over analogue is call security - it's
all too easy to eavesdrop on an analogue phone and before we ditched it
there were many documented cases of criminals hijacking the ESN of an
analogue phone and cloning it, running up huge bills for the genuine user.
I myself had this happen to me on one occasion, to the tune of £300.
Fortunately it was a company phone and they took it up with the airtime
provider, so it didn't cost me personally.

Digital systems are much harder to hack, in fact I don't know of any cases
where this has successfully been done. That's not to say that it isn't
possible to hack into the system somewhere and listen to the calls, but it
takes the budget of the security services and it isn't done by listening
to the radio signals..!

I look forward to the day when the US is all-GSM, then I might get
coverage in the wilds of Yosemite, which is totally non-existent at the
moment..!

Ivor

---

› See More: What is the diffrance between GSM 900 and EGSM 900

"Dick Silk" <[email protected]> wrote in message
news:[email protected]...
> "Steve" <[email protected]> wrote in message
> news:[email protected]...
> > My understanding is that EGSM is used in newer phones as the BTS emits
> > signal on the old analogue frequencies which are generally better
quality
> > then normal GSM 900.
>
> oh, that's just *great*... now my analogue cell phone spectrum is gonna
get
> clogged and I'll be right back to "all circuits are busy" again. (I
never
> understood why people would give up the clarity of analogue to get that
> digital crap!)

Depends on the digital service - here in the UK we have been all-GSM for
several years, there is no analogue any more, and the call quality is as
good as any I've ever experienced in the US..!

One excellent reason to use digital over analogue is call security - it's
all too easy to eavesdrop on an analogue phone and before we ditched it
there were many documented cases of criminals hijacking the ESN of an
analogue phone and cloning it, running up huge bills for the genuine user.
I myself had this happen to me on one occasion, to the tune of £300.
Fortunately it was a company phone and they took it up with the airtime
provider, so it didn't cost me personally.

Digital systems are much harder to hack, in fact I don't know of any cases
where this has successfully been done. That's not to say that it isn't
possible to hack into the system somewhere and listen to the calls, but it
takes the budget of the security services and it isn't done by listening
to the radio signals..!

I look forward to the day when the US is all-GSM, then I might get
coverage in the wilds of Yosemite, which is totally non-existent at the
moment..!

Ivor

"Ivor Jones" <[email protected]> wrote in message
news:[email protected]...
>
>
> One excellent reason to use digital over analogue is call security - it's
> all too easy to eavesdrop on an analogue phone and before we ditched it
> there were many documented cases of criminals hijacking the ESN of an
> analogue phone and cloning it, running up huge bills for the genuine user.
> I myself had this happen to me on one occasion, to the tune of £300.
> Fortunately it was a company phone and they took it up with the airtime
> provider, so it didn't cost me personally.
>
> Digital systems are much harder to hack, in fact I don't know of any cases
> where this has successfully been done. That's not to say that it isn't
> possible to hack into the system somewhere and listen to the calls, but it
> takes the budget of the security services and it isn't done by listening
> to the radio signals..!
>
> I look forward to the day when the US is all-GSM, then I might get
> coverage in the wilds of Yosemite, which is totally non-existent at the
> moment..!
>

I remember cloning--what a mess that was! We have lots of immigrants in
USA, and they all wanted to call back to the old country for free. Gangs of
thieves would set up equipment in vans to intercept the ESNs of cell phones,
then they would program those numbers into dummy phones and the cellular
carrier had no way of knowing that the call was being made from a phone
other than the one that was signed up on the account.

Wireless phones are always "checking in" with the tower--especially after a
lapse of signal. The thieves would set up vans near the entrances and exits
of tunnels, because as the cars came out, their cell phones would all
dutifully report their ESN to the tower, to tell it that it was available if
a call were to come in. The thieves in the vans harvested thousands of ESNs
in just a couple of hours.

The cellular carriers originally started to suggest that people actually
shut their phones off when not using them--making them useless to receive
incoming calls, of course.

For awhile, some cellular carriers (Cellular One in the Philadelphia area,
for one) had their customers pick a secret 4-digit code. Whenever the
customer dialed out, he would hear a beep tone on the phone, which was his
signal to enter the 4-digit code. If the customer failed to enter the code
properly, the call would not be accepted by the tower.

This procedure minimized the usefulness of stolen serial numbers, but it one
more hassle for the consumer. Entering those code numbers was a
pain--especially while driving.

Finally the phone manufacturers began implementing a new technology, called
authentication. My understanding of it is very limited, but essentially
there was an algorithm deposited in the phone memory by the tower. Let's
say, it was the number "2." When the phone tried to dial out, the tower
would send a number to the phone, which the phone would multiply by the
number "2," and respond back with double the number that the tower
transmitted. (I am grossly oversimplifying this--forgive me).

So if the tower sent out "100," it would expect to receive a response of
"200," or it knew that the phone was not the one that it was supposed to be.
The tower could change the algorithms in phones periodically, so thieves
could not find out what the algorithm was.

That was the end of cloning.

As far as I know, this authentication scheme continues to be used today. By
the time that digital handsets came out, all phones were equipped for it.
The process is instant, and is completely transparent to the user.

What I find ironic is the fact that long distance prices have dropped to
where there are often free in the US--and the very thing that carriers were
trying to eliminate has become almost a non-issue.

Go figure . . .

Cheers

"Ivor Jones" <[email protected]> wrote in message
news:[email protected]...
>
>
> One excellent reason to use digital over analogue is call security - it's
> all too easy to eavesdrop on an analogue phone and before we ditched it
> there were many documented cases of criminals hijacking the ESN of an
> analogue phone and cloning it, running up huge bills for the genuine user.
> I myself had this happen to me on one occasion, to the tune of £300.
> Fortunately it was a company phone and they took it up with the airtime
> provider, so it didn't cost me personally.
>
> Digital systems are much harder to hack, in fact I don't know of any cases
> where this has successfully been done. That's not to say that it isn't
> possible to hack into the system somewhere and listen to the calls, but it
> takes the budget of the security services and it isn't done by listening
> to the radio signals..!
>
> I look forward to the day when the US is all-GSM, then I might get
> coverage in the wilds of Yosemite, which is totally non-existent at the
> moment..!
>

I remember cloning--what a mess that was! We have lots of immigrants in
USA, and they all wanted to call back to the old country for free. Gangs of
thieves would set up equipment in vans to intercept the ESNs of cell phones,
then they would program those numbers into dummy phones and the cellular
carrier had no way of knowing that the call was being made from a phone
other than the one that was signed up on the account.

Wireless phones are always "checking in" with the tower--especially after a
lapse of signal. The thieves would set up vans near the entrances and exits
of tunnels, because as the cars came out, their cell phones would all
dutifully report their ESN to the tower, to tell it that it was available if
a call were to come in. The thieves in the vans harvested thousands of ESNs
in just a couple of hours.

The cellular carriers originally started to suggest that people actually
shut their phones off when not using them--making them useless to receive
incoming calls, of course.

For awhile, some cellular carriers (Cellular One in the Philadelphia area,
for one) had their customers pick a secret 4-digit code. Whenever the
customer dialed out, he would hear a beep tone on the phone, which was his
signal to enter the 4-digit code. If the customer failed to enter the code
properly, the call would not be accepted by the tower.

This procedure minimized the usefulness of stolen serial numbers, but it one
more hassle for the consumer. Entering those code numbers was a
pain--especially while driving.

Finally the phone manufacturers began implementing a new technology, called
authentication. My understanding of it is very limited, but essentially
there was an algorithm deposited in the phone memory by the tower. Let's
say, it was the number "2." When the phone tried to dial out, the tower
would send a number to the phone, which the phone would multiply by the
number "2," and respond back with double the number that the tower
transmitted. (I am grossly oversimplifying this--forgive me).

So if the tower sent out "100," it would expect to receive a response of
"200," or it knew that the phone was not the one that it was supposed to be.
The tower could change the algorithms in phones periodically, so thieves
could not find out what the algorithm was.

That was the end of cloning.

As far as I know, this authentication scheme continues to be used today. By
the time that digital handsets came out, all phones were equipped for it.
The process is instant, and is completely transparent to the user.

What I find ironic is the fact that long distance prices have dropped to
where there are often free in the US--and the very thing that carriers were
trying to eliminate has become almost a non-issue.

Go figure . . .

Cheers