With the expansion of the channel set, DFS-enabled channels are also supported. Radar detection and automatic
channel reassignment in case of radar detection on RAP/MAPs are also supported. When there is a channel
change, it is also propagated to the corresponding parent/child access point (if applicable) so that the channel
change is synchronized between the parent and child so that there is no link downtime. For example, if radar
is detected on the uplink radio of a child access point, the parent is informed so that it can change the channel
of the downlink radio. The parent in turn informs the child about the channel change, so that the child access
point can set the new channel on its uplink radio as well and does not have to scan again to rejoin the parent
on the new channel.
For countries in the Middle East such as Saudi Arabia and Kuwait, a new regulatory domain for outdoor APs,
the -M domain, has been mandated. With this release, outdoor APs will now support this new -M domain.
Earlier, these countries were part of the -E domain, which supported a channel set of 100 to 140. However,
in the -M domain, channels 149 to 161 are also supported with the 100 to 140 band. Also, in the -M domain,
channels 149 to 161 are DFS enabled, unlike other domains such as -A, -C, -N, and so on, where these channels
are non-DFS. Radar detection is also enabled on these channels. Because the countries that are now part of
the -M domain (that is, Saudi Arabia and Kuwait) were earlier part of the -E domain, both the -E domain and
the -M domain APs are supported, when any of these countries is configured on the controller, which ensures
backward compatibility with the existing -E domain APs in these countries. However, you will have to ensure
that only a valid set of channels (the channels common to both the -E and the -M domains) is selected as part
of the 802.11a DCA list, and that the backhaul channel deselection feature is enabled to ensure correct operation
of the -E domain APs, as these APs can support 100 to 140 channels and not the extended list of 149 to 161
channels available in the -M domain.
Discontinuation of the 116 and 132 Channels from the UNII-2 Extended Band
With the 7.0 release, in AP1522 and AP1524SB platforms, in addition to the 5 channels in the upper ISM
band, there are 3 channels in the UNII-2 band and 8 channels in the UNII-2 Extended band. There are 11
channels in the UNII-2 Extended band, but only 8 are applicable in the outdoors due to stringent dynamic
frequency selection (DFS) conditions for Canada because Canada requires a channel availability check every
10 minutes compared to every 60 seconds in the USA. The 120 (5600 MHz), 124 (5620 MHz), and 128 (5640
MHz) channels have had to be dropped.
The Federal Communications Commission (FCC) has issued a guideline to protect Terminal Doppler Weather
Radar (TDWR) systems operating in the 5600- to 5650-MHz band from interference. Also, the UNII-2 Wi-Fi
operating channels are interfering with the TDWR band. Therefore, with the 7.0.116.0 release, the 116 and
132 channels are dropped in addition to the 120, 124, and 128 channels. The guidelines also require that you
avoid operation in the TDWR band and operate at least 30 MHz away from the TDWR operation frequencies
when devices are installed within 35 km (about 21 miles) or the line-of-sight of the TDWR sites.
Your outdoor installation should be registered in the outdoor database. No fee is required to register your
company. The TDWR location sites can be found on the Internet.
Note
The FCC, the National Telecommunications and Information Administration (NTIA), and the Federal
Aviation Administration (FAA) are continuing to investigate and eliminate cases of interference to TDWRs.
For more information about FCC guidelines for outdoor installations, see
http://www.cisco.com/en/US/
prod/collateral/routers/ps272/data_sheet_c78-647116_ps11451_Products_Data_Sheet.html
.
Note
Cisco Mesh Access Points, Design and Deployment Guide, Release 7.3
OL-27593-01
23
Mesh Network Components
Cisco Outdoor Mesh Access Points