CBRS is really annoying right now.
On some channels in some locations newly registered CBSD's start out in
the state "Grant Suspended - IAP Pending". IAP is a process for
calculating interference. It doesn't happen everywhere, but we are
getting used to the idea if we're installing in Town X we know we'll
have it happen. IAP used to take 5 minutes and it was no big deal.
Later it was taking a few hours....at that point I complained to
Commscope and was told they were working on a solution and give it a few
weeks. Now a month later IAP is taking 16+ hours to complete. So a new
install process apparently has to include telling the customer
everything is ready except waiting for official permission to transmit
and we don't know how long that will take, but you might be up sometime
tomorrow. Total nonsense.
Yesterday an SM that had been online for 7 months suddenly went into
"Grant Suspended - IAP Pending". Cambium support theorized an NTP issue
of some sort, and they had a pretty specific story about pool0.ntp.org
having an issue. By the way, the grant is only for 5 minutes so if your
device's clock is off by a few minutes you can get a grant that ended in
the past or starts in the future and either way you're broken. So NTP
is now a mission critical service. I don't know if an NTP mishap really
caused this, but it doesn't sound impossible.
To fix the broken customer, we learned experimentally that if you set
the AP country code to "Other" that we can transmit in 3.5ghz without
waiting for the SAS. CnMaestro continues proxying the CBRS
registrations for up to 3 days so the "Suspended" client eventually goes
back to "Granted" and then you switch the AP back to "US". Not saying
it's ok, but the purely compliant solution is to leave the customer down
for a day, and I don't like that either.
So yeah.....a house of cards. Don't let the table wiggle or the wind blow.
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