802.11b/g/n radios scan in the 2.4-GHz spectrum and 802.11a/n radios scan in the 5.15
GHz spectrum.
Following are the types of scanning performed:
- Proactive scan—A periodic scan during active state to learn about the cache of
nearby APs. This mechanism scans multiple SSIDs that might have different
authentication and encryption mechanism.
- Off-channel scan—A scan when the client device tunes its radio to another
channel to look for available APs or scans for APs on a channel to which it is
not connected.
- Spiral scan—A scan performed by the device every 4,8, and12 seconds to find an
AP.
- Multiple profile scan—A scan that enables you to configure multiple profiles,
such as SSIDs, encryption, and so on in the badges and enable auto-connect to
different profiles.
Following are the states in which scanning is performed:
- Disconnected State—During the disconnected state, contiguous scanning is
performed. The scan is performed on all the channels configured on the selected
bands.
- Standby—During the standby state, scanning is performed when an event is
triggered by the driver.
- In Call—During the in-call state, the following scans are performed:
- A periodic proactive scan for cached details when an event is triggered
by the driver.
- An interleaved scan as and when required.
- Channel-by-channel scan for an active scan on non-DFS channels.
- Passive scan on DFS channels based on the configuration.
