Motorola AP-51 Series Product Reference Manual page 189

Network Management 5-31
3. Set the parameters in the Configuration field as required for the WLAN.
ESSID Enter the Extended Services Set Identification (ESSID) associated
with the WLAN. The WLAN name is auto-generated using the
ESSID until changed by the user. The maximum number of
characters that can be used for the ESSID is 32.