Basic-Station: get null time in uplink message

[sagar-patel-sls]

• [x] The issue is present in the latest release.
• [x] I have searched the issues of this repository and believe that this is not a duplicate.

What happened?

we have enabled GPS in our basic-station gateway but we are not getting time in the uplink message.

Can we use rxtime for uplink time if GPS is not available?

Could you share your log output?

Your Environment

Component	Version
Gateway Bridge	v3.10.0

[sagar-patel-sls]

@brocaar any update on this issue? should I make PR for this?

[brocaar]

@sagar-patel-sls a PR would be very welcome :) Could you check if the gpstime is correctly set (if this value is parsed at all)?

https://doc.sm.tc/station/tcproto.html#radio-metadata

https://github.com/brocaar/lorawan/tree/master/gps provides functions to convert the GPS time to a time.Time type (for setting the time field). I think both should be exposed in the RxInfo. Failing that, if the fake rx time is enabled, just set the time with time.Now().

[sagar-patel-sls]

Could you check if the gpstime is correctly set (if this value is parsed at all)?

Currently, GPS is not available in our gateway so we need to send time as a fallback.

{"msgtype":"updf","MHdr":64,"DevAddr":xxxxxxxx,"FCtrl":0,"FCnt":10,"FOpts":"","FPort":2,"FRMPayload":"B3354E4C7F7C4356CE207E51AF7C4F","MIC":-433357060,"RefTime":0.000000,"DR":0,"Freq":865062500,"upinfo":{"rctx":0,"xtime":7599824395191180,"gpstime":0,"fts":-1,"rssi":-109,"snr":-2.5,"rxtime":1613033399.383087}}

currently, basic station sending above payload with a GPSvalue of 0. I think we need to take time from rxtime using the below math function so we can convert it to Unix time.

sec, nsec := math.Modf(rmd.UpInfo.RxTime)

[brocaar]

Looks like that field is not documented (see my previous link). In that case it makes sense to map the rxtime to time (if not 0) and gpstime (if not 0) to time_since_gps_epoch instead of doing any gps time > time.Time conversions.