PW-Mac

An Energy-Efficient Predictive-Wakeup

MAC Protocol for Wireless Sensor NetworksLei Tang, Yanjun Sun, Omer Gurewitz, David B. Johnson

Infocom 2008

The problem

Duty CyclesIdle Listening & Overhearing

The Ideal

How many wireless MAC protocols are there?

μ-MAC micro-MAC

A-MAC Another MAC

AI-LMAC Adaptive Information-centric and Lightweight MAC

B-MAC Berkeley MAC

BitMAC BitMAC

BMA Bit-Map-Assisted

BuzzBuzz BuzzBuzz

C-MAC Concurrent MAC

CC-MAC Spatial Correlation-based Collaborative Medium Access Control protocol

CMAC Convergent MAC

CMAC -

Crankshaft Crankshaft

CSMA-MPS CSMA with Mimimum Preamble Sampling

CSMA/ARC Randomized CSMA with Adaptive Rate Control

DMAC Data gathering MAC

DW-MAC Demand-Wakeup MAC

E2-MAC Energy Efficiency-MAC

EMACs EYES MAC

f-MAC framelet-MAC

FLAMA FLow-Aware Medium Access

Funneling-MAC Funneling MAC

G-MAC Gateway MAC

HMAC Hybrid MAC

IAMAC Interference Avoidance Medium Access Control

LMAC Lightweight MAC

LPL Low Power Listening

MC-LMAC Multi-channel LMAC

MFP Micro-Frame Preamble MAC for Multihop Wireless

MiX-MAC MiX-MAC

MMAC Mobility-adaptive MAC

MR-MAC Multi-radio Medium Access Control Protocol

nanoMAC nanoMAC

O-MAC Ohio state university MAC

PACT Power Aware Clustered TDMA

PCM Power Control MAC

PEDAMACS Power Efficient and Delay Aware Medium Access

PicoRadio NN

PMAC Pattern-MAC

PMAC Positioning-enabled MAC

Preamble sampling Aloha with Preamble Sampling

PW-MAC Predictive-Wakeup MAC

Q-MAC Query-MAC

Q-MAC QoS-aware MAC

QMAC QoS-oriented MAC

R-MAC don't know

RATE EST Rate Estimation MAC

RI-MAC Receiver-Initiated MAC

ricer Receiver Initiated Cycled Receivers

RL-MAC Reinforcement Learning MAC

RMAC Randomized adaptive MAC

RMAC Reliable MAC

S-MAC Sensor MAC

S-MAC/AL Sensor MAC with adaptive listening

SA-MAC Spectrum Agile MAC Protocol for Wireless Sensor Networks

SCP-MAC Scheduled Channel Polling

SEESAW SEESAW

Sift Sift

SMACS Self-organizing Medium Access Control for Sensor networks

SS-TDMA Self-Stabilizing MAC

STEM Sparse Topology and Energy Management

T-MAC Timeout MAC

TA-MAC Traffic Adaptive MAC Protocol for Wireless Sensor Network

TICER Transmitter Initiated Cycled Receivers

TRAMA TRaffic-Adaptive Medium Access

TrawMAC Traffic Aware Medium Access

U-MAC Utilization-based MAC

WiDOM Wireless Dominance

WiseMAC Wireless sensor MAC

X-MAC X-MAC

Z-MAC Zebra MAC

(Some) Existing Solutions

• Synchronous duty cycle– Example: S-MAC

– Requires: Multi-hop synchronization– Downside: Low throughput

Asynchronous duty cycle

How do we shorten this?

Predictive Wakeup

PW-MAC

Prediction Based Retransmission

On demand prediction error correction

• Measure prediction error

• If error exceeds bounds– request new prediction state

• Prediction state– Seed– Clock difference

On demand prediction error correction

PW-Mac a summary

• Receivers wake up pseudo randomly

• Sender predicts receiver wakeup

• Prediction based retransmission

• On demand prediction-error correction

“When you aim for perfection, you discover it's a moving target.”

Evaluation Method

• Evaluation on motes

• X-MAC, WISE-MAC, RI-MAC, PW-MAC

• Measured– Data packet delivery ratio– Average duty cycle– Data packet latency

Experimental results

Experimental results

Experimental results

Pros / Cons

• Clear goals to optimize

• Extensive comparison

• Combines several novel ideas

• Does not discuss it's own cons

• No tests using burst traffic

• Best used in which conditions?

Questions?