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Ultra-Low Duty Cycle MAC with Scheduled Channel Polling
Wei Ye, Fabio Silva, and John Heidemann Presenter: Stu Glaser
Why?
Save Energy by turning the radio off
Low-Power Listening (LPL)
(Existing method 1)
Sleep Poll (no one sending) Sleep Poll (someone sending to me) Receive data Poll (no one sending) Sleep Broadcast preamble Send data
Receiver Sender Only check for activity
Listen
Scheduled Transmissions
(Existing method 2) (no one sending)
Receive data
(no one sending)
Wake up Sleep Send ready (contention) Wake up Wake up Wake up Wake up Wake up Wake up Wake up receive ready Send data
But
In Low-Power Listening (LPL)... ...sender requires more energy
Receive Send
Long Preamble
Receiver Sender
But
In scheduled transmission (S-MAC)... ...receiver requires more energy
Receive Send
Wakeup and listen
Receiver Sender
Send ready (contention period)
Wakeup and listen Wakeup and listen