Technical information

Wireless LAN Mode
2-46 AT+i Commands Reference Manual May 31, 2008
If the connection is active, W24 waits for an IP activity command from the host. When such a
command is sent, W24 performs a software reset and starts scanning for APs. W24 responds with
ERROR (074) to indicate that the current connection has been lost.
Multiple SSIDs
The Multiple SSIDs feature allows you to define an ordered list of SSIDs of Access Points (APs)
or ad-hoc networks with which W24 attempts to connect upon power-up. Each SSID listed can
have one of the following security types:
• WEP-64
• WEP-128
• WPA-TKIP
• WPA2-AES
• No security
The following parameters allow you to define multiple SSIDs:
• WSIn - Defines an ordered list of allowable SSIDs.
• WPPn - Sets the Wireless LAN PSK passphrase for WPA and WPA2 encryption for each
individual SSID on the list.
• WKYn - Sets the Wireless LAN WEP key for each individual SSID on the list.
• WSTn - Sets the Wireless LAN security type for each individual SSID on the list.
W24 Power Save Mode
W24 has a Power Save mode for achieving energy savings. You enable Power Save mode by
setting the PSE parameter to any value n between 1 and 255 seconds. When n seconds have
elapsed without any activity on the host or modem serial ports, W24 shuts down most of its
circuits. Renewed activity on the serial ports, or incoming data from the WLAN, restores W24 to
full operational mode.
If, in addition, the WLPS parameter is set to any value m between 1 and 5, W24 can force the
Marvell WiFi chipset into either Power Save or Deep Sleep mode:
• If W24 is currently associated with an AP, or is configured to operate in ad-hoc mode, W24
will force the Marvell chipset into Power Save mode. In Power Save mode, the Marvell
chipset will go to sleep for m beacon periods when no communication has taken place
(command, Tx, or Rx activity) for one full beacon period.
• If W24 is not associated with an AP, W24 will force the Marvell chipset into Deep Sleep
mode. W24 will perform a periodic scan every p seconds, as set by the WPSI parameter, for
APs in its vicinity. If it fails to locate and associate with an AP, it will wait for n seconds, as
set by the PSE parameter, before forcing the Marvell chipset back to Deep Sleep.