Description: Represents the encrypt method, security suite and authentication method
which are used by the detected ESS.
The lowest 8 bits mean encrypt method. The higher 8 bits mean security suite.
The third 8 bits stand for authentication method. The higerest 8 bits
are reserved. The meaning is shown as follows:
31              23              15              7             0
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
|  reserved     |  auth method  | security suite|encryptmethod|
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
For encrypt method, the following values are supported:
1: none     - clear text or no cipher method is configure,
2: wep      - WEP key,
4: tkip     - WPA Temporal Key encryption,
8: ccmp     - WPA AES CCMP encryption
For security suite, the following values are supported:
0x01: clear
0x02: wpa2
0x04: wpa
0x08: wep
For authentication method, the following values are supported:
1:  none     - No key management mode configured,
2:  psk      - pre-shared key authentication,
3:  dot1x    - 802.1x authentication.
4:  other    - other authentication