关于AP Config中的一些参数的意义：
Radio Type................................... RADIO_TYPE_80211ac-5
Radio Subband................................ RADIO_SUBBAND_ALL
Administrative State ........................ ADMIN_ENABLED
Operation State ............................. UP
Mesh Radio Role ............................. ACCESS
Radio Role .................................. Client Serving (Remote)
CellId ...................................... 0
1) Access Points 28/38 Appeared as dual-band radios , i don't what is the mean of dual band and what is the benefit of using it
AP看起来像双频段无线电，不知道双频段的意思是什么，使用它的好处是什么？
This mean that radio can operate in both 2.4GHz and 5GHz band. But at a given time only in one band. In addition to dedicate 2.4GHz and 5GHz radio, these 2800/3800 include additional radio which can be operate in either band (called FRA -Flexible Radio Assignment) and different role as well (servicing client, monitor mode, etc)
这意味着无线电可以在2.4GHz和5GHz频段运行。 但是在给定时间只在一个band中。 除了专用的2.4GHz和5GHz无线电之外，这些2800/3800还包括可以在任一频段（称为FRA-灵活的无线电分配）和不同角色（服务客户端，监控模式等）中运行的附加无线电。
2) in the attachments Access points in 2.4 GHZ band appeared in radio role column as ( 2.4 GHZ remote) , what is the remote word mean ?
2.4 GHZ频段的AP出现在Radio Role栏中（2.4 GHZ Remote），Remote的意思是什么？
Refer chapter 5 of below white paper for more details about FRA. I believe "Local" mean that radio is in client servicing mode. "remote" mean it is in monitor mode.
http://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-3/b_RRM_White_Paper.pdf
In 8.2.x and above, FlexConnect mode APs could run FRA as well, then if the AP is in Flex and also running FRA Serving clients, Radio Role would be shown as "remote", this is:
- If AP is in flex, radio role would be shown as remote.
- In AP is in local, radio role would be shown as local.