Motorola WiNG 5.5 Reference Manual page 444

6 - 18 WiNG 5.5 Access Point System Reference Guide
7. Define Key Settings.
Pre-Shared Key
8. Define Key Rotation
Unicast messages are addressed to a single device on the network. Broadcast messages are addressed to multiple devices.
When using WPA2-CCMP, a wireless client can use 2 keys: one unicast key, for its own traffic to and from an access point,
and one broadcast key, the common key for clients in that subnet.
Motorola Solutions recommends rotating these keys so a potential hacker would not have enough data using a single key
to attack the deployed encryption scheme.
Unicast Rotation Interval
Figure 6-6 WLAN Security - WPA2-CCMP screen
Enter either an alphanumeric string of 8 to 63 ASCII characters or 64 HEX characters as
the primary string both transmitting and receiving authenticators must share. The
alphanumeric string allows character spaces. The access point converts the string to a
numeric value. This passphrase saves the administrator from entering the 256-bit key
each time keys are generated.
values.
Define a unicast key transmission interval from 30 - 86,400 seconds. Some clients have
issues using unicast key rotation, so ensure you know which clients are impacted before
using unicast keys. This value is disabled by default.