11:19 p.m.
Hi all,
I just did some emergency calls in our lab with the Ericsson MBM modem
(3507g). The modem firmware has the voice calls enabled, even while
there is no audio input/output from the modem (as far as I know).
Main results are:
- emergency calls are not possible in offline mode (CFUN=4), ATD112;
returns NO DIALTONE
- emergency calls can be made without SIM card (but they require AT+CFUN=1)
- most MBM modem functionality (AT+COPS, AT+CLCC does not work without SIM card)
- emergency calls cannot be handled with usual AT+CHLD commands (e.g.,
AT+CHLD=11 does not hang up emergency calls)
(ofono cannot hangup emergency call and it does not notice when it ends)
- emergency call gets number "112" and type 128 (unknown type of
number and numbering plan)
Please find attached log. I first made call to 99999 (an ordinary
service number within our lab network) then 118 (non-existing service
number) then 112 (emergency call).
The emergency call was terminated by callee around 02:58:52 (as you
can see, modem indicates it with +CIEV=8,0).
--
Pekka.Pessi mail at nokia.com
11:33 p.m.
Hi Pekka,
I just did some emergency calls in our lab with the Ericsson MBM
modem
(3507g). The modem firmware has the voice calls enabled, even while
there is no audio input/output from the modem (as far as I know).
Main results are:
- emergency calls are not possible in offline mode (CFUN=4), ATD112;
returns NO DIALTONE
- emergency calls can be made without SIM card (but they require AT+CFUN=1)
- most MBM modem functionality (AT+COPS, AT+CLCC does not work without SIM card)
- emergency calls cannot be handled with usual AT+CHLD commands (e.g.,
AT+CHLD=11 does not hang up emergency calls)
(ofono cannot hangup emergency call and it does not notice when it ends)
- emergency call gets number "112" and type 128 (unknown type of
number and numbering plan)
thanks for testing this. However I am not sure how representative these
tests are since we are basically dealing with data-only modem. I know
that the MBM in theory can support some sort of voice calls, but for the
currently on the market MBM devices, that support might not be tested at
all or being proper certified.
So I think we need to get some feedback from the Ericsson guys and how
this is suppose to work (or maybe not work).
Regards
Marcel
1:26 a.m.
Hi Marcel,
2010/7/7 Marcel Holtmann <marcel(a)holtmann.org>:
Hi Pekka,
> I just did some emergency calls in our lab with the Ericsson MBM modem
> (3507g). The modem firmware has the voice calls enabled, even while
> there is no audio input/output from the modem (as far as I know).
>
> Main results are:
> - emergency calls are not possible in offline mode (CFUN=4), ATD112;
> returns NO DIALTONE
> - emergency calls can be made without SIM card (but they require AT+CFUN=1)
> - most MBM modem functionality (AT+COPS, AT+CLCC does not work without SIM card)
> - emergency calls cannot be handled with usual AT+CHLD commands (e.g.,
> AT+CHLD=11 does not hang up emergency calls)
> (ofono cannot hangup emergency call and it does not notice when it ends)
> - emergency call gets number "112" and type 128 (unknown type of
> number and numbering plan)
thanks for testing this. However I am not sure how representative these
tests are since we are basically dealing with data-only modem. I know
that the MBM in theory can support some sort of voice calls, but for the
currently on the market MBM devices, that support might not be tested at
all or being proper certified.
The MBM in question is a crippled OEM piece, modems really intended
for voice use would probably behave better.
However, 27.007 implies (see, for instance, commentary on +CPIN) that
things the atmodem voicecall driver takes as granted (+CLCC, +CHLD) do
not necessary work when there is no SIM or SIM is missing PIN code.
+CIND polling is only thing promised by spec (however, it did not work
on my MBM).
Another thing is the radio handling: making an emergency calls
requires that radio is explicitly turned on (with AT+CFUN=1). If there
is no SIM or SIM is missing PIN and radio is on, modem registers with
its IMEI code (it gets so called limited service). Keeping radio on in
limited service state just wastes battery (unless you want to make an
emergency call).
--
Pekka.Pessi mail at nokia.com
1:52 a.m.
Hi Pekka,
However, 27.007 implies (see, for instance, commentary on +CPIN)
that
things the atmodem voicecall driver takes as granted (+CLCC, +CHLD) do
not necessary work when there is no SIM or SIM is missing PIN code.
+CIND polling is only thing promised by spec (however, it did not work
on my MBM).
I'm not following, why would we ever need +CHLD if the SIM is missing?
Would we ever be able to establish multiple emergency calls to actually
call this?
+CHLD not working when PIN is ready and an emergency 3-way call
situation is another matter though...
Another thing is the radio handling: making an emergency calls
requires that radio is explicitly turned on (with AT+CFUN=1). If there
is no SIM or SIM is missing PIN and radio is on, modem registers with
its IMEI code (it gets so called limited service). Keeping radio on in
limited service state just wastes battery (unless you want to make an
emergency call).
What do you propose here?
Regards,
-Denis
1:47 a.m.
Hi Pekka,
On 07/07/2010 08:19 AM, Pekka Pessi wrote:
Hi all,
I just did some emergency calls in our lab with the Ericsson MBM modem
(3507g). The modem firmware has the voice calls enabled, even while
there is no audio input/output from the modem (as far as I know).
Main results are:
- emergency calls are not possible in offline mode (CFUN=4), ATD112;
returns NO DIALTONE
That was expected, do we have a solution in mind on how to do emergency
dialing in Offline mode? Is it a UI problem?
- emergency calls can be made without SIM card (but they require
AT+CFUN=1)
That was again expected...
- most MBM modem functionality (AT+COPS, AT+CLCC does not work
without SIM card)
The only one that can be triggered without a SIM card is AT+CLCC.
However, please note that MBM should not be using CLCC, but instead its
own vendor-specific voicecall extensions.
- emergency calls cannot be handled with usual AT+CHLD commands
(e.g.,
AT+CHLD=11 does not hang up emergency calls)
That is a bit nasty, is there an assumption that every other call is
hung up when an emergency number is dialed?
(ofono cannot hangup emergency call and it does not notice when it
ends)
- emergency call gets number "112" and type 128 (unknown type of
number and numbering plan)
Again, most likely because MBM uses its own voicecall extensions.
Driving it with CLCC is wrong...
Please find attached log. I first made call to 99999 (an ordinary
service number within our lab network) then 118 (non-existing service
number) then 112 (emergency call).
The emergency call was terminated by callee around 02:58:52 (as you
can see, modem indicates it with +CIEV=8,0).
These are Bluetooth Handsfree indicators btw, not typically used for
driving a real modem...
Regards,
-Denis
2:40 a.m.
2010/7/7 Denis Kenzior <denkenz(a)gmail.com>:
> Main results are:
> - emergency calls are not possible in offline mode (CFUN=4), ATD112;
> returns NO DIALTONE
That was expected, do we have a solution in mind on how to do emergency
dialing in Offline mode? Is it a UI problem?
I'd do like we do in the N900 equivivalent of voicecall atom:
- request online
- detach packet radio (if applicable)
- hang up existing calls
E.g., we would have something like
ofono_modem_set_emergency_mode(modem, bool) and
ofono_modem_get_emergency_mode().
In emergency mode (while emergency call is on-going) modem would:
- refuse to make other calls
- refuse to power off device
> - emergency calls can be made without SIM card (but they require
AT+CFUN=1)
That was again expected...
> - most MBM modem functionality (AT+COPS, AT+CLCC does not work without SIM card)
The only one that can be triggered without a SIM card is AT+CLCC.
I mean, like, now atmodem voicecall driver is using +CHLD, but in
order to handle emergency calls gracefully it must know if the SIM is
active or not (and change its behavior accordingly.)
The AT+COPS? or AT+CREG? would be useful if you try to make emergency
call with weak reception.
However, please note that MBM should not be using CLCC, but instead
its
own vendor-specific voicecall extensions.
OK, I hope they work better without SIM or PIN. ;)
> - emergency calls cannot be handled with usual AT+CHLD commands
(e.g.,
> AT+CHLD=11 does not hang up emergency calls)
That is a bit nasty, is there an assumption that every other call is
hung up when an emergency number is dialed?
That sounds reasonable.
> (ofono cannot hangup emergency call and it does not notice when
it ends)
> - emergency call gets number "112" and type 128 (unknown type of
> number and numbering plan)
Again, most likely because MBM uses its own voicecall extensions.
Driving it with CLCC is wrong...
I'd guess this is partly because emergency calls do not have phone
numbers, but some kind of bitmask of desired emergency services
(police, hospital, coast guard, etc.), so modem just fills in fake
information in +CLCC.
> Please find attached log. I first made call to 99999 (an
ordinary
> service number within our lab network) then 118 (non-existing service
> number) then 112 (emergency call).
>
> The emergency call was terminated by callee around 02:58:52 (as you
> can see, modem indicates it with +CIEV=8,0).
These are Bluetooth Handsfree indicators btw, not typically used for
driving a real modem...
Yes, they just provide useful indications what is going on.
--
Pekka.Pessi mail at nokia.com
3:21 a.m.
Hi Pekka,
On 07/07/2010 11:40 AM, Pekka Pessi wrote:
2010/7/7 Denis Kenzior <denkenz(a)gmail.com>:
>> Main results are:
>> - emergency calls are not possible in offline mode (CFUN=4), ATD112;
>> returns NO DIALTONE
>
> That was expected, do we have a solution in mind on how to do emergency
> dialing in Offline mode? Is it a UI problem?
I'd do like we do in the N900 equivivalent of voicecall atom:
- request online
- detach packet radio (if applicable)
- hang up existing calls
E.g., we would have something like
ofono_modem_set_emergency_mode(modem, bool) and
ofono_modem_get_emergency_mode().
In emergency mode (while emergency call is on-going) modem would:
- refuse to make other calls
- refuse to power off device
Fair enough.
>> - emergency calls can be made without SIM card (but they
require AT+CFUN=1)
>
> That was again expected...
>
>> - most MBM modem functionality (AT+COPS, AT+CLCC does not work without SIM card)
>
> The only one that can be triggered without a SIM card is AT+CLCC.
I mean, like, now atmodem voicecall driver is using +CHLD, but in
order to handle emergency calls gracefully it must know if the SIM is
active or not (and change its behavior accordingly.)
The core doesn't use CHLD in a single call situation. If we hangup all
calls before initiating an emergency call then this shouldn't be an
issue, right?
The AT+COPS? or AT+CREG? would be useful if you try to make
emergency
call with weak reception.
I think you will find that most modems have a vendor specific
notification for this and don't use COPS or CREG... About the only
thing that might be useful is the signal strength...
Regards,
-Denis
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6 comments
3 participants
participants (3)
-
Denis Kenzior -
Marcel Holtmann -
Pekka Pessi