AT^SMONP returns empty response at times | Telit Cinterion IoT Developer Community
August 28, 2017 - 4:09pm, 2799 views
We're using the AT^SMONP command for cell triangulation. What we regularly see (not only during startup of the BGS5 but also at runtime) is that we get a response
at^smonp
2G:
----,--,----,---,---,-,-,--,--,----,----
The documentation states that
During a CS connection or in Airplane mode the response is empty and displayed as follows:
"----,--,----,---,---,-,-,--,--,----,----"
It is unclear to us when the BGS5 gives that response (what is the definition of a CS connection) or what to wait for when that response is received (what precondition must exist to make the AT^SMONP succesfull).
Could some-one enlighten us?
Hello,
CS is circuit switched connection. Please check if this is consistent with your tests.
How often does it happen? Is it possible to get the values in the next command call if it happens?
The explanation could be that the module (some network measuring component) is not able to provide the measurements at that particular moment for some reason.
Could you verify the firmware version with ATI1 command?
Regards,
Bartłomiej
This happens regularly, 2 out of 10 calls have this behavior. I've tried to repeat that command 2 more ***** when it happens but also these calls return the same result.
ati1
Cinterion
BGS5
REVISION 01.100
A-REVISION 00.000.18
I'm not a GSM guru, so how do I check if my circuit switched connection is ok?
Hello,
Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel (circuit) through the network before the nodes may communicate.
The circuit guarantees the full bandwidth of the channel and remains connected for the duration of the communication session. That would be a voice call or CSD call (where the data is transmitted over a vocie channel).
Circuit switching contrasts with packet switching which divides the data to be transmitted into packets transmitted through the network independently (GPRS, HSPA...).
My intention was to ask if this empty reply happens only during CS calls and airplane mode as described in the document.
It is described so there must be some technical reason for this limitation. If it also happened in idle mode for example I believe that it should be possible to get the proper answer in another attempt.
There is a newr firmware version A-REVISION 00.000.21 if you'd like to try but as this behavior is described in documentation there may be no difference.
Regards,
Bartłomiej
Ok, that explanation sounds familiar, it's similar to what I've found.
Yes, they happen outside CS calls and outside airplane mode, so in idle mode. When in idle mode, doing the call 3 ***** sequentially doesn't help.
I expected the remark about FW21 but we already have devices in the field that will never be updated to that version, so I need to make it work on the current FW18. I was hoping for you to tell me why that command can fail by looking into the code, thereby giving me hints on how to prevent this situation from occurring.
Hello,
So this happens outside the conditions described in the AT spec.
Maybe it would be worth trying with AREV 21 just to know if it can change anything.
On the other hand I've tested with my module and the same firmware and it was working all the time. I've only seen empty reply just after network registration.
Have you also seen this in other locations or with other operators? Was it tested on the idle module or with working application that is actively using the module?
I don't expect that there are strict rules for when it's available and when not. Mayby the measurements are not available at the particular moment because of the system load and/or network conditions. The best that the appliation can do is to query again in some time.
Regards,
Bartłomiej