LTE network time from nrf9160

RE: LTE network time from nrf9160

Ohad Gal — Tue, 26 Apr 2022 13:50:48 GMT

Hello,

we are using the "AT%CCLK?" at it works very nice.

but now for the challange... since the modem is synchronized with the LTE network and sends on the designated time slot, the modem knows the time in accuracy better than 1msec.

will it be possible to get a synchronization pulse once a complete second ellapses? similar to how the GPS works with PPS

that is:

1. send AT%CCLK2?

2. wait for a pulse on a hardware pin GPIO (or an internal signal)

3. get the string with [sec] resolution as we get from the "AT%CCLK?" command

Does NORDIC support something like this?

This will eliminate the need for GPS if the GPS is used only for accurate time reception

Many thanks

Ohad.

RE: LTE network time from nrf9160

tesc — Mon, 24 Aug 2020 11:49:56 GMT

Hi,

I see that there are some unanswered questions in this thread.

The up-to-date answer to the original question is that AT+CCLK was added (modem firmware v1.0.x), and the time provided by the read command is based on network time if available. Not all network provide the time information, and the accuracy of the time also depend on the network. When time is not provided from the network, you must get the time by other means.

There is also the proprietary AT%CCLK command, which is similar, introduced in v1.1.x.

For details, please consult the nRF91 AT Commands documentation.

Regarding other methods to source time, please search other DevZone threads and create a new question for that specifically if you do not find an existing thread on the subject.

Regards,
Terje

RE: LTE network time from nrf9160

rkguy — Fri, 17 May 2019 03:10:36 GMT

tesc The user guide doesn't say anything about the clock being syncrhonized with the network. I was also told by support that you need to set the clock before you can start querying it. In other words, it is not auomatically set from the network. What is the best way to set the clock in an automated way the first time (assuming that support is correct)?

edit; here is the link to the user guide infocenter.nordicsemi.com/.../nrf91_at_commands_v0.9.1.pdf

RE: LTE network time from nrf9160

rkguy — Wed, 15 May 2019 05:03:22 GMT

I would also like to know if this is in the recent firmware update tesc. If not, is there a simple ntp example to look at for us to get the time?

RE: LTE network time from nrf9160

miked531 — Sun, 28 Apr 2019 22:36:20 GMT

Is there a timeframe for the firmware release? I'd kind of like to use the feature

RE: LTE network time from nrf9160

men — Wed, 10 Apr 2019 11:33:56 GMT

Hi,

That is nice to hear. Is this also the case for NB-IOT version?

RE: LTE network time from nrf9160

tesc — Wed, 10 Apr 2019 11:21:53 GMT

Hi,

Good news!

We will support the AT+CCLK command in the upcoming modem firmware release. It lets you both set and read the current time, which gets updated and kept in sync with network time based on time information pushed from the network. That means you do not need to use %XTIME and to manually keep track of the time in-between notifications.

Regards,
Terje

RE: LTE network time from nrf9160

men — Tue, 09 Apr 2019 07:58:39 GMT

Hi Terje,

Okay, the network time doesn't seem reliable. I will try to get the time using another method, eg. SNTP.

RE: LTE network time from nrf9160

tesc — Mon, 08 Apr 2019 14:03:46 GMT

Hi,

We do have the %XTIME AT command, which enables time data notifications including UTC time. When enabled you will get a notification every time the network sends out time information. It is up to the network to decide when such information is pushed, and you can not request it from your device.

You may or may not be better served using NTP, depending on what accuracy you need, and depending on whether you need to request the time data from your device and get an immediate result. (NTP gives worse accuracy over LTE than over a cabled Internet connection.)

Edit: We will soon support the AT+CCLK command, which lets you read the time and date at any time. Time is updated and kept in sync with network time within the modem firmware. You can also set the time with the set command, for the situation where the network does not push any time information to the device.

Regards,
Terje