Network time
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Hello,
is the feature ‘network time’ (3GPP 27.007 Ch. 8.15) for NB-IOT/Cat-M1 supported in the Deutsche Telekom mobile network?
The NRF9160 SIP returns an error, while requesting the time. Also after a long time of being connected.
AT+CCLK? ERRORBest regards, Sven
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@Sven-Brandau said in Network time:
Hello,
is the feature ‘network time’ (3GPP 27.007 Ch. 8.15) for NB-IOT/Cat-M1 supported in the Deutsche Telekom mobile network?
The NRF9160 SIP returns an error, while requesting the time. Also after a long time of being connected.Hi Sven, sorry that it took us so long.
But now we have a clear statement from our experts that the network time feature is NOT supported in our network in Germany. -
@Sven-Brandau ,
Please note that “network time” has meanwhile been enabled in our NB-IoT network in Germany, so that AT command “AT+CCLK?” should no longer return an error.
Kind regards,
Ronan -
Hi all,
Please note that network time is now also provided over our LTE-M network in Germany, and can be retrieved with the usual AT commands (e.g. AT+CCLK?, AT+QLTS=2, …)
Best regards,
Ronan
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@Ronan-Lacroix - we are using the +CCLK (3GPP 27.007) and it works fine in the Netherlands.
Is the network time mandatory to be present in a NB-IoT network? When the feature is optional in the network itself we cannot rely on it when roaming.
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@Jeroen-van-Bussel
Please do not quote me on this (I’m not a 3GPP specification expert), but according to 3GPP 24.008, the MM (for Mobility Management) information procedure and information message (which optionally contain the time information) unfortunately are optional in the network (see extracts below from the specification in its release 15).Kind regards, Ronan
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@Ronan-Lacroix - thanks, it is obvious that it is defined as Optional :-)
Regarding the DST. In the +CCLK command the timezone is returned. I assume (but I am not sure) that the timezone includes the DST (Daylight Saving Time) changes?
In 3GPP 27.007 the format returned by the +CCLK is defined as:
<time>: string type value; format is “yy/MM/dd,hh: mm:ss+zz”, where characters indicate year (two last digits), month, day, hour, minutes, seconds and time zone (indicates the difference, expressed in quarters of an hour, between the local time and GMT; range -96…+96). E.g. 6th of May 1994, 22:10:00 GMT+2 hours equals to “94/05/06,22:10:00+08”
So my question is whether your network automatically updates the timezone according to DST or not.
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@Jeroen-van-Bussel
Time is provided in GMT, which is not influenced/changed by the DST status.
KR, Ronan -
@Ronan-Lacroix - yep the time is but the zz is the timezone. SO below an example of the time I just retrieved from your NB-IoT network (at 17:16 PM local time).
+CCLK: “2022/06/07,15:16:21+08”
The timezone is +8 quarters of 15 minutes. So UTC +2 hours. Now I assume that the timezone is changed for winter and summertime (DST).
So I assume that in winter the following will be returned (when local time is 17:16PM)
+CCLK: “2022/06/07,16:16:21+04”
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@Lauwie007
I have not tested it myself, but I guess your live test has just proven it, hasn’t it?
Keep in mind that this time is provided by the local network in which you are actually roaming, so if you’re roaming in say, the Vodafone UK network, this time and associated timezone will be provided by Vodafone UK (if supported as just discussed).
Kind regards, Ronan
