We had isssues with several Symbol/Motorola handheld devices (MC3090, MC3190, MC9190) running on Windows CE 5 not connecting to 5GHz channels greater CH48. We tried with WLC Versions 7.4.100, 7.4.121 and 7.6.100. They connected to lightweight APs on 5 GHz channels 36, 40, 44, 48, but not to channels > CH48.
After some tests and tries, we found out enabling DFS (802.11h): "Channel Announcement" and "Channel Quiet Mode" did the trick. After enabling these options all Symbol/Motorola handhelds connected to all channels without problems.
our mobile wireless end devices (f.k.a. Symbol technologies -> Motorola -> Motorola Solutions -> Zebra Technologies) when using 5 GHz RF band do check entries (spectrum management flag, channel announcement, ...) in the AP beacons, that do state, whether or not the AP (depending on country, channel, ...) did do the radar check and so is announcing correctly, that it is working correctly in terms of regulation on that channel. If the channel would be above 48 and the 802.11 beacon information (here the Cisco channel announcement) is missing, the end device would perhaps work against regulation in case this channel is used by a radar system as well.