User Manual

18 Introduction to the Extricom Wireless LAN System
SM Power Save
Definition: The basic 802.11n power save mode is based on the earlier 802.11 power save function.
Power save in 802.11n is enhanced for MIMO operation with SM power save mode. Since MIMO
requires maintaining several powered-up receiver chains, standby power draw for MIMO devices is
likely to be considerably higher than for earlier 802.11 equipment. A new provision in 802.11n
allows a MIMO client to power-down all but one RF chain when in power save mode. When a
client is in the ‘dynamic’ SM power save state, the AP sends a wake-up frame, usually an RTS/CTS
exchange, to give it time to activate the other antennas and RF chains. In static mode, the client
decides when to activate its full RF chains, regardless of traffic status.
Extricom 802.11n: Extricom supports SM power save mode static mode.