SIM card locked to provider?

"John Henderson" <jhenRemoveThis@talk21.com> wrote in message
news:5ucad4F1h4qfmU1@mid.individual.net...
> Jer wrote:
>
>> I'm unaware of any cell-based priority of 911 calls over any
>> other call.
>> Certain IMEI codes can be assigned a higher access priority
>> over other IMEI codes, but this higher access priority would
>> apply whether the special IMEI handset called a hospital or
>> the local crack dealer.
>
> In the more usual configuration, a phone of any access class can
> make an emergency priority call. All that's required is that
> the user dials 112 or a number in the SIM's EF_ECC file.
>
> If there's no SIM fitted, then the handset itself might be able
> to do an equivalent lookup of predefined emergency numbers in
> firmware. So a call to 911 in a handset without a SIM _might_
> be treated as an emergency call within the radio layer, and
> connected with priority. Such a call will connect you to
> emergency services however, rather than your prefered dealer.
>
> While GSM 04.08 does allow for access to the emergency call
> facility to be restricted to access classes 11 through 15, that
> restriction is not normally in place.
>
> John
>
I guess some here don't know John Henderson or Simon Templar, if you have
heard something from somebody and these guys tell the opposite, you can be
sure you had heard incorrect info.

The GSM standard would map 112 as the emergency call number. My phone makes
an emergency call in the US when I dial 112 even if it comes from Europe.
Like explained, later enhancements allow 911 "calls" being interpreted
emergency calls. I guess it was mentioned that no number is delivered when
an emergency call is made, not even 112, the call is explicitly recognised
as an emergency call. An old phone in Europe might not make any emergency
call if you dial 911 but later ones would (you can try calling with your
keypad lock on, the phone would still accept emergency call numbers).

Also priority from IMEI would not work the way priority for emergency calls
works. The point being that the first channel request towards the network
would not have room for IMEI but does carry an indication about an emergency
call. The priority classes were already explained, being different from IMEI
priority (actually I'm not familiar with IMEI based call priority but am
neither claiming there could not be any).

Anonymous schrieb:
> [...] actually I'm not familiar with IMEI based call priority but am
> neither claiming there could not be any

What an IMEI based call priority system be good for? The IMEI is the
international mobile EQUIPMENT identifier, it tells the network
something about the UE beeing used (model and serial number). Now, why
would a network operator want to prioritize calls made with e.g. Samsung
phones over those from Nokia phones?

Andreas

In message <flr76v$fv4$1@online.de> Andreas Wenzel <awspambucket@gmx.de>
wrote:

>Anonymous schrieb:
>> [...] actually I'm not familiar with IMEI based call priority but am
>> neither claiming there could not be any
>
>What an IMEI based call priority system be good for? The IMEI is the
>international mobile EQUIPMENT identifier, it tells the network
>something about the UE beeing used (model and serial number). Now, why
>would a network operator want to prioritize calls made with e.g. Samsung
>phones over those from Nokia phones?

The concept would be that police, firefighters, etc would be issued
special gear which gets priority over you calling your wife to find out
if she wants large or extra-large eggs.

In message <13o1elh22re2s4e@corp.supernews.com> Jer <gdunn@airmail.ten>
wrote:

>I'm unaware of any cell-based priority of 911 calls over any other call.

Luckily, awareness isn't required, the priority happens automatically
behind the scenes.

Andreas Wenzel wrote:
> What an IMEI based call priority system be good for? The IMEI is the
> international mobile EQUIPMENT identifier, it tells the network
> something about the UE beeing used (model and serial number). Now, why
> would a network operator want to prioritize calls made with e.g. Samsung
> phones over those from Nokia phones?

The only reason I could see this possibly be used would be if
Government, Military or Emergency Services required priority access to
the network. In that case it wouldn't matter what SIM was inserted into
the phone either and if the handset was misplaced or stolen it could
easily have it's IMEI black listed.

Even if that were implemented the 112 EMERGENCY would still override the
IMEI priority.


--
The views I present are that of my own and NOT of any organisation I may
belong to.

73 de Simon, VK3XEM.

DevilsPGD wrote:
> In message <flr76v$fv4$1@online.de> Andreas Wenzel <awspambucket@gmx.de>
> wrote:
>
>> Anonymous schrieb:
>>> [...] actually I'm not familiar with IMEI based call priority but am
>>> neither claiming there could not be any
>> What an IMEI based call priority system be good for? The IMEI is the
>> international mobile EQUIPMENT identifier, it tells the network
>> something about the UE beeing used (model and serial number). Now, why
>> would a network operator want to prioritize calls made with e.g. Samsung
>> phones over those from Nokia phones?
>
> The concept would be that police, firefighters, etc would be issued
> special gear which gets priority over you calling your wife to find out
> if she wants large or extra-large eggs.


That's the concept as it was explained to me by someone who has to know
how this works. First responders have their assigned handsets, which
means the IMEI of each is predictable, which means they can get priority
access treatment when call blocking is activated. Of course, I have no
clue about what is happening under the hood, but the end result is
special handsets get special treatment - special enough to bump another
call off the network if/when necessary. As to whether this arrangement
has ever actually been used is a different kettle.

--
jer
email reply - I am not a 'ten'

Jer wrote:

> DevilsPGD wrote:
>> In message <flr76v$fv4$1@online.de> Andreas Wenzel
>> <awspambucket@gmx.de> wrote:
>>
>>> Anonymous schrieb:
>>>> [...] actually I'm not familiar with IMEI based call
>>>> [priority but am
>>>> neither claiming there could not be any
>>> What an IMEI based call priority system be good for? The
>>> IMEI is the international mobile EQUIPMENT identifier, it
>>> tells the network something about the UE beeing used (model
>>> and serial number). Now, why would a network operator want
>>> to prioritize calls made with e.g. Samsung phones over those
>>> from Nokia phones?
>>
>> The concept would be that police, firefighters, etc would be
>> issued special gear which gets priority over you calling your
>> wife to find out if she wants large or extra-large eggs.
>
>
> That's the concept as it was explained to me by someone who
> has to know how this works. First responders have their
> assigned handsets, which means the IMEI of each is
> predictable, which means they can get priority access
> treatment when call blocking is activated. Of course,
> I have no clue about what is happening under the hood, but the
> end result is special handsets get special treatment - special
> enough to bump another call off the network if/when necessary.
> As to whether this arrangement has ever actually been used is
> a different kettle.

This sounds just like the "access class" mechanism defined in
GSM 02.11 (and 3GPP 22.011). Except that it's the SIM rather
than the hardware (IMEI) which is used to define the class and
thus control access:

"All MSs are members of one out of ten randomly allocated mobile
populations, defined as Access Classes 0 to 9. The population
number is stored in the SIM. In addition, mobiles may be
members of one or more out of 5 special categories (Access
Classes 11 to 15)". GSM 02.11, section 4.

Class use
11 network use
12 security services
13 public utilities (e.g. water/gas suppliers)
14 emergency services
15 network staff

"The use of this facility allows the network operator to prevent
overload of the access channel under critical conditions."

This is achieved by blocking the network to members of one or
more selected access classes. "It is not intended that access
control be used under normal operating conditions."

John

John Henderson wrote:
> Jer wrote:
>
>> DevilsPGD wrote:
>>> In message <flr76v$fv4$1@online.de> Andreas Wenzel
>>> <awspambucket@gmx.de> wrote:
>>>
>>>> Anonymous schrieb:
>>>>> [...] actually I'm not familiar with IMEI based call
>>>>> [priority but am
>>>>> neither claiming there could not be any
>>>> What an IMEI based call priority system be good for? The
>>>> IMEI is the international mobile EQUIPMENT identifier, it
>>>> tells the network something about the UE beeing used (model
>>>> and serial number). Now, why would a network operator want
>>>> to prioritize calls made with e.g. Samsung phones over those
>>>> from Nokia phones?
>>> The concept would be that police, firefighters, etc would be
>>> issued special gear which gets priority over you calling your
>>> wife to find out if she wants large or extra-large eggs.
>>
>> That's the concept as it was explained to me by someone who
>> has to know how this works. First responders have their
>> assigned handsets, which means the IMEI of each is
>> predictable, which means they can get priority access
>> treatment when call blocking is activated. Of course,
>> I have no clue about what is happening under the hood, but the
>> end result is special handsets get special treatment - special
>> enough to bump another call off the network if/when necessary.
>> As to whether this arrangement has ever actually been used is
>> a different kettle.
>
> This sounds just like the "access class" mechanism defined in
> GSM 02.11 (and 3GPP 22.011). Except that it's the SIM rather
> than the hardware (IMEI) which is used to define the class and
> thus control access:
>
> "All MSs are members of one out of ten randomly allocated mobile
> populations, defined as Access Classes 0 to 9. The population
> number is stored in the SIM. In addition, mobiles may be
> members of one or more out of 5 special categories (Access
> Classes 11 to 15)". GSM 02.11, section 4.
>
> Class use
> 11 network use
> 12 security services
> 13 public utilities (e.g. water/gas suppliers)
> 14 emergency services
> 15 network staff
>
> "The use of this facility allows the network operator to prevent
> overload of the access channel under critical conditions."
>
> This is achieved by blocking the network to members of one or
> more selected access classes. "It is not intended that access
> control be used under normal operating conditions."
>
> John


Okay, some of this seems familiar, I guess I confused the IMEI thing
with the class thing. And it makes more sense to have the key on the
SIM, considering how handsets get treated. Thanks for the clarity.

--
jer
email reply - I am not a 'ten'

Jer wrote:

> Okay, some of this seems familiar, I guess I confused the IMEI
> thing with the class thing. And it makes more sense to have
> the key on the SIM, considering how handsets get treated.
> Thanks for the clarity.

I needed to have another look at the standards because I
couldn't remember how it was implemented either :)

John

On 2008-01-06, John Henderson <jhenRemoveThis@talk21.com> wrote:
> danny burstein wrote:
>
> Modern GSM phones will often have 911, 999 and 000 entered into
> the SIM's EF_ECC file. So these and 112 will provide identical
> functionality. You may be able to dial them and connect even
> with the keypad locked.

Yes, this is possible with most (all?) Nokia phones, and (from memory)
with Ericsson/Sony Ericsson phones also.

hth,
bernie