Originally Posted By: artie505
Am I misinterpreting AirPort Utility in assuming that n (b/g compatible) is 2.4GHz and n (a compatible) is 5GHz?
I would not say you are misunderstanding, rather your understanding is incomplete.
  • the 802.11n standard specifies operation in either the 2.4 or 5GHz bands
  • the 802.11b/g standard specifies operation only in the 2.4GHz band
  • therefore, If you are operating in 802.11n with b/g compatibility you must run in the 2.4GHz band
  • if you are operating in 802.11n only you can configure your airport express to operate in either the 2.4 or 5GHz band (assuming the AE is originating the wireless network and not just extending or joining it)
  • if you had a dual band base station such as Apple's Airport Extreme Base station or Time Capsule and you are running 802.11n or 802.11n with b/g compatibiity you can have the equivalent of two separate networks operating simultaneously in both bands and sharing data freely between the two networks.
    • in this case both bands are 802.11n but the 5GHz band is 802.11n only while the 2.4GHz band has b/g compatibility
    • just as an aside, this is how my local network is configured with the computers on 5GHz and relatively low speed devices such as printers, eyeTV, iPhones and iPads run on the 2.4GHz band. FWIW empirical evidence indicates this arrangement has noticeably improved the throughput of the entire network


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