Citi Field has an FCC application pending for a slew of UHF frequencies. Looks like they'll be plain old analog (no MOTOTRBO, etc.). According to the license, they'll be using two repeaters and nineteen simplex freqs.
http://wireless2.fcc.gov/UlsApp/ApplicationSearch/applMain.jsp?applID=4723035
Dave
http://wireless2.fcc.gov/UlsApp/ApplicationSearch/applMain.jsp?applID=4723035
Dave