Questions about SAS-CBSD communication logs

[haw057]

Hi. I'm wondering about some details in the SAS-CBSD communication logs. For example,I have a few questions:

1. What does a "temp" grant mean? How is it different from a normal grant?

2. How is the "GRANT ID" column associated with the other columns? E.g., does a "Grant Suspended" in the "State" column mean the corresponding grant displayed in the "GRANT ID" column is suspended, or the CBSD can't transmit on any of its grants?

3. What determines the time spacing between the logs? Is one addition log generated whenever there's an update to the status of the CBSD?

4. What is the cause of the long blank gap from 2022-10-20 23:54:14 to 2022-10-26 3:39:57?

Thank you in advance! Any reference material for these is also greatly appreciated.

[James_S · Accepted solution]

Hello haw057,

Documentation for the SAS-CBSD API can be found here.

These logs look like they are coming directly from the device in question. The logs contain information about the state of the CBSD that the SAS would not know. I will do my best to answer these questions, but I strongly recommend asking them to the CBSD vendor as well.

1. What does a 'temp' grant mean? How is it different from a normal grant?
1. Given the context (a 501 DPA activation related grant suspension), I imagine that the CBSD requested a temporary grant to use while its original grant was suspended. Google SAS itself makes no distinctions between a temporary or normal grants.  I would recommend reaching out to the device vendor for distinctions between the two, as it is likely a term unique to the device.
2. How is the "GRANT ID" column associated with the other columns? E.g., does a "Grant Suspended" in the "State" column mean the corresponding grant displayed in the "GRANT ID" column is suspended, or the CBSD can't transmit on any of its grants?
1. Each grant a CBSD requests successfully from the SAS has its own grant ID. I would assume that if only a single grant ID is listed in the row, then all of the events listed in that row are only affecting that grant. I would recommend reaching out to the device vendor for confirmation though.
3. What determines the time spacing between the logs? Is one addition log generated whenever there's an update to the status of the CBSD?
1. I would guess that the time spacing between logs is due to the device logs only showing certain events.  The logs from the SAS Portal, for instance, filters out most of the heartbeat requests and responses because they happen so frequently. The SAS Portal logs omit all heartbeat requests except: the first heartbeat request per grant, the first heartbeat request that encounters a certain error (such as a suspension), and the first heartbeat request after that error was lifted. 
4. What is the cause of the long blank gap from 2022-10-20 23:54:14 to 2022-10-26 3:39:57? 
1. Your CBSD might have experienced no errors during that window of time and omitted logs of all the heartbeat requests and responses for readability. Alternatively, you CBSD might not have sent any requests or responses at all. If you have another example of a gap in logs from the last 14 days, please provide me with a CBSD ID or serial number and I would be happy to look into it for you.