Network Card User Manual

WLAN-IEEE802.11 Tutorial (Maximilian Riegel), 021018-wlan-tutorial.ppt Page 47 © Siemens, 2002
Power Management Considerations
n Mobile devices are battery powered.
– Power Management is important for mobility.
n Current LAN protocols assume stations are always
ready to receive.
– Idle receive state dominates LAN adapter power
consumption over time.
n How can we power off during idle periods, yet maintain
an active session?
n 802.11 Power Management Protocol:
– allows transceiver to be off as much as possible
– is transparent to existing protocols
– is flexible to support different applications
• possible to trade off throughput for battery life