DeviceTimeReq/Ans support within LW 1.1

[Luca Bertoldo]

When the LW 1.1 will be available on xDot/mDot side, how can I figure out to get the time/date at application level?

I immagine to operate with a Network server compliant with LW 1.1.
In this case, can I suppose to have new AT commands to get date&time from the module?

What about the accuracy that can I expect?

Thanks,
Luca

[Jason Reiss]

LW 1.1 is expected to be ready Q2 next year.

We will add an AT command to query the device RTC clock time.
The AT firmware will update the RTC when a device time MAC command is received.

The command will output current UTC seconds.
This command will be available in our next release with LW 1.0.3 with Class B expected next month.

Accuracy according to LoRaWAN DeviceTimeReq/Ans definition:
* The time provided by the network MUST have a worst case accuracy of +/- 100 mSec.

[Luca Bertoldo]

I’ll get the current date and time in term of UTC seconds using AT command.
How to get 0.1 seconds resolution? I would like to be synchronized till the guaranteed accuracy.

I’m working with Class-C devices.
You wrote that DeviceTimeReq/Ans MAC commands will be released within LW 1.0.3. So, we have not to wait for LW 1.1 release. Isn’t it?

Thanks,
Luca

[Luca Bertoldo]

I’m asking about LW 1.1 because reading in “LoRaWAN™ 1.1 Specification” at page 44 they say:
“This MAC command is only available if the device is activated on a LoRaWAN1.1 compatible Network Server. LoRaWAN1.0 servers do not implement this MAC command.”

Going through you answer, you say also: “The AT firmware will update the RTC when a device time MAC command is received.” I’m not sure about how does it works…

At page 44 of “LoRaWAN™ 1.1 Specification” they describe:
“With the DeviceTimeReq command, an end-device may request from the network the current network date and time. The request has no payload.

With the DeviceTimeAns command, the Network Server provides the network date and time to the end device.”

So it seems to be a Device To Network direction task. Isn’t it? Should be available some other new AT commands to enable/disabile and parametrize this time synchronization service on device side?

Thanks,
Luca

[Jason Reiss]

The DeviceTime MAC command is specified in LoRaWAN 1.0.3, the network must be notified out-of-band that it supports this command.

The DeviceTime is used for Class B device to find the first beacon.

We will add a command that makes the DeviceTimeReq to a network server and provide the DeviceTimeAns payload in the response of the AT Command.

We may not modify the RTC on the module as it is not needed for the AT firmware.

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