SAS - Suspended grants IAP Pending

[cwattswisp]

Hi,

I am writing this post to ask about suspended grants and why they occur so frequently on one of our customers SAS network. Most of them will are regranted in the AM, but we get several of these a day. Is there a way to stop this from occuring?

Thanks,
Carson

[James_S · Accepted solution]

Hi there,

The SAS has to protect higher priority users from interference. An IAP pending suspension indicates that the CBSD has requested a grant that is too powerful. Grants that were previously suspended can sometimes get approval to transmit after CPAS has occurred, which happens every morning between 7 AM and 10 AM UTC. Grants that can't be authorized after CPAS are instead terminated. The issue is resolving itself every morning because the grants are either being authorized or being terminated.

This usually occurs in proximity to higher priority users who require constant protection from the SAS. Most of the time, the higher priority user in question is a PAL user. CBSDs can usually avoid this error by requesting a spectrum inquiry before requesting grants. A spectrum inquiry tells the CBSD the maximum power that can be immediately authorized. So long as the CBSD requests a grant matching what is suggested, an IAP Pending suspension is unlikely. If your CBSD does not support sending spectrum inquiries, you can instead check the device in the SAS Portal. Under the Coex tab for the device, you will find a section labelled "Channel Ranking". If you expand each channel, you will see a field labelled "Power today". This value is equivalent to what the SAS sends in a spectrum inquiry.

[James_S · Accepted solution]

Hi there,

The SAS has to protect higher priority users from interference. An IAP pending suspension indicates that the CBSD has requested a grant that is too powerful. Grants that were previously suspended can sometimes get approval to transmit after CPAS has occurred, which happens every morning between 7 AM and 10 AM UTC. Grants that can't be authorized after CPAS are instead terminated. The issue is resolving itself every morning because the grants are either being authorized or being terminated.

This usually occurs in proximity to higher priority users who require constant protection from the SAS. Most of the time, the higher priority user in question is a PAL user. CBSDs can usually avoid this error by requesting a spectrum inquiry before requesting grants. A spectrum inquiry tells the CBSD the maximum power that can be immediately authorized. So long as the CBSD requests a grant matching what is suggested, an IAP Pending suspension is unlikely. If your CBSD does not support sending spectrum inquiries, you can instead check the device in the SAS Portal. Under the Coex tab for the device, you will find a section labelled "Channel Ranking". If you expand each channel, you will see a field labelled "Power today". This value is equivalent to what the SAS sends in a spectrum inquiry.

[cwattswisp]

James,

I appreciate the detailed response. We checked the coex tab and power today then went ahead and reduced power on the CBSD and pulled a new grant. Yet the max EIRP has remained unchanged sitting at 38 dBm/10MHz. Any idea on what's going on here?

Thanks,
Carson

[James_S · Accepted solution]

@cwattswisp 

38 dBm/10 MHz is the registered EIRP capability of the device. This is why that value is on the Config tab of the CBSD as a whole, rather than on an individual grant in the Status tab. It may be that you specified an EIRP capability when registering the device, either in the SAS Portal or in the registration request itself. I would suggest reregistering the CBSD. Leave the "Max EIRP" field in the SAS Portal and the "EIRP Capability" field in the registration request blank. The SAS will then use the FCC ID to set the EIRP capability of the device at registration, which will always be the highest value possible for that device.