I also found some new iDAS sectors at Rupp Arena. DAS typically has 3 sectors, but I only hit one each for the B30 and secordary B4/B66.
Looking at various stadiums and arenas around CellMapper I've found B30 DAS using A3-A8. If I go back to Rupp Arena any time soon I'll lock my phone to B30 and see what I find.
Yeah, 31 corresponds with 23 sector, 4D corresponds with the 3F sector, and 73 corresponds with the 63 sector.
For the B2 second carrier part, I've only seen that while looking through New York. Around here and everywhere I've seen it is a Macro ID. I've noticed with AT&T that 2nd carriers and any of the newer spectrum seems to use different GCI patterns in each market.