Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio for Energy

Neutral Wireless Sensor Network

1

Trong Nhan Le 1,2, Michele Magno3, Alain Pegatoquet2, Olivier Berder1, Olivier Sentieys1 and Emanuel Popovici3

1INRIA/University of Rennes 1 (ENSSAT), 2LEAT/University of Nice, 3University College Cork 1{trong-nhan.le, sentieys, oberder}@irisa.fr

2{alain.pegatoquet}@unice.fr 3{m.magno, e.popovici}@ucc.ie

• Medical and Health Monitoring

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 2

Energy Harvesting (EH) WSN Applications

• Structure Health Monitoring

• Wireless Sensor Networks

• Smart building

Harvesting Energy Sources

Multiple-sources

3 Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio

Heat

Micropelt [Mic]

Light

Cymbet [Cym]

PowWow [Pow]

Autonomous Communication Nodes?

Energy Source Power Density

Solar (outdoor) 15mW/cm2

Solar (indoor) 10µW/cm2

Thermal (5oC) 40µW/cm2

Vibration 200µW/cm3

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 4

• The harvested node is adapted to Energy Neutral Operation (ENO) [Kan2007] by the power manager (PM): – Harvested energy = Consumed energy

• Optimize the consumed energy of MAC protocols to increase the Quality of Service (QoS): – Reduce main RF idle listening time by a nano-watt wake-up radio

receiver (WUR)

Common energy sources [Rou2004]

Protocol State Energy

Send/Receive BEACON 51µJ

Data Transmission 80µJ

Data Reception 100µJ

Idle listening 30ms 2307µJ

Consumed energy in PowWow node [Alm2011]

Contents

• Related Works

• WSN Node with WUR Receiver

• WUR based TICER Protocol

• Duty-Cycle Power Manager

• Simulation Results

• Conclusions

5 Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio

Related Works

• Energy optimization of MAC protocols: – Adapt the sleep period to neighbors [Ana2009] or traffic

[Ala2012] – Nano-watt wake-up radio [Jel2012]

• Power Manager (PM) to respect ENO: – PM based on ENO and predictions of harvested energy

[Kan2007]: high complexity, prediction errors, low reactivity

– Open-Loop and Close-Loop PM based on environmental conditions and SoC [Cas2012]: low complexity, high reactivity, designed for solar-powered WSN with batteries

6 Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio

Ultra Low Power Asynchronous MAC Protocol in Energy Neutral WSN

• Duty-Cycle PM [Le2013]: independent harvesting sources PM for super-capacitor based energy storage

• WUR based TICER protocol: – Transmitter Initiated Cycled Receiver [Lin2004]

– The wake-up beacon (WUB) from transmitter is detected by the WUR at the receiver to reduce main RF idle listening at the receiver

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 7

Wake-Up Radio (WUR)

CPU

Main

Radio

ON/OFF

Wake up radio

receiver Interrupt

Wake up Message

Main RADIO Ton

Wake up

radio

receiver

Toff Toff

Wake up Message Always on nano power consumption

WUR MRF

Sleep < µA 1 mA

Normal < µA 20 mA

Typical Consumption of main radio(MRF) and wake up receiver (WUR)

t

t

Sleep/wake up radio technique

WSN Node with WUR Receiver [Jel2012]

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 9

Wake up signal

and data

Wake up receiver

Receiver

ON OFF

Wake up radio board

Wake-up message

from the sensor node

Matching

Envelope

Detector

(passive)

Filters Wake up

circuit

Main RF MCU

Transmitter

(OOK,125kz –

2.4GHz)

WUR based TICER Protocol

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio

10

Wake-up beacon

(WUB) by MRF Data Transmission (DT)

Clear Channel Assessment (CCA)

Sensing ADC (SEN)

Calculation Before Transmission (CBT)

Receiver

Transmitter TACK

Acknowledgment (ACK) TDATA

Sleep mode

Rx mode

Tx mode

WUB is detected by the WUR

• Transmitter Initiated Cycled Receiver (TICER) [Lin2004]: – The transmitter sends a WUB by MRF. – The receiver detects the WUB by the WUR and responses ACK by

MRF – A data packet is sent after receiving an ACK.

Duty-cycle PM for Super-Capacitor based EH WSN [Le2013]

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio

11

Energy

monitor

Wake up

adaptation

Energy

predictor

(EWMA)

LUT

EWUB 51

ECCA 18

......... …..

Budget

energy ( )SV n

eActive

(n)

PH

(n)

eBud

(n)( 1)WUT n

( )SV n RefV

ˆ ( 1)Activee n

ˆ ( 1)HP n

• Adaptations are based on the voltage of the super-capacitor (VS)

• Independent of harvesters • Low complexity, low memory resource, high reactivity

eActive

(n) : Consumed energyinslotn

PH

(n) : Harvested power inslotn

eActive

(n+1) : Predictedconsumed energy

PH

(n+1) : Predicted harvested power

eBud

(n+1) : Budget energy for slot n+1

VRef

: Desired voltage in ENO state

Simulation Setups (Omnet++)

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 12

Node [2] Node [1]

Node [0]

Node [N]

Har

ves

ted

Dev

ice Energy

Flow

Controller

Super

Capacitor

MCU

RF

Sensor

Power

Manager

WU

R

TWU

VS Energy flow

Signal control

Wireless link

Wake-up

signal

Base station

(BS)

End device

(ED)

Single-hop EH WSN topology

Symbol CC2420 CC2500 CC1100

ECBT(µJ) 9.7 9.7 9.7

EWUB(µJ) 51 47 42

EACK(µJ) 51 47 42

EDT(µJ) 100 73 79

ECCA(µJ) 18 14 11

ESEN(µJ) 27 27 27

PTx(mW) 66.33 69.96 57.75

PRx(mW) 76.89 56.10 61.05

PSleep(µW) 85.8 21.12 22.77

Simulation Setups (Omnet++)

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 13

Indoor light energy profile

Consumed energy of popular RF chips

• PDR(bits/s): Packet received Data-Rate

• IDLRx (ms) : Idle listening time at Rx

• ETx and ERx (µJ) : Consumed energy at Tx and Rx

• EC : Consumed energy for one successful packet.

Metrics for evaluation:

Simulation Results (Omnet++)

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 14

CC2420 CC2500 CC1100

Metrics Non WUR

WUR Gain (%)

Non WUR

WUR Gain (%)

Non WUR

WUR Gain (%)

PDR 11.39 64.00 82 17.64 68.12 74 12.71 62.76 79

IDLRx 28.94 7.13 75 25.88 8.03 69 20.98 7.74 63

ETx 959.47 818.75 15 767.24 674.67 12 781.56 682.05 13

ERx 24411.17 771.14 68 1628.48 639.47 61 1462.76 657.97 55

EC 3370.64 1589.89 53 2395.72 1314.14 45 2244.33 1340.02 40

• Idle listening at the receiver is significantly reduced

• QoS is improved 82%, 74% and 79%

• Total energy saving is up to 53%

Conclusions

• Idle listening for the WUB is removed at the receiver

• Global consumed energy is significantly reduced up to 53%

• The throughput is improved up to 82%

• Future works:

– Validate the protocol in a multi-hop network

– Other MAC protocols : RICER, WiseMAC,…

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 15

References

[Cym] [Online]. Available: http://www.cymbet.com [Mic] [Online]. Available: http://www.micropelt.com [Pow] [Online]. Available: http://powwow.gforge.inria.fr [Rou2004] S. Roundy, D. Steingart, L. Frechette, P. Wright, and J. Rabaey, “Power sources for wireless sensor networks”,

Wireless Sensor Networks, pp. 1-17, 2004 [Alm2011] M. M. Alam, O. Berder, D. Menard, T. Anger and O. Sentieys, “A hybrid model for accurate energy analysis of

wsn nodes”, EURASIP Journal on Embedded Systems, vol. 2011, p. 16, 2011. [Kan2007] A. Kansal, J. Hsu, S. Zahedi and M.B. Srivastava, “Power management in energy harvesting sensor

networks,” ACM Transactions in Embedded Computing Systems (TECS), vol. 6, no. 4, 2007. [Lin2004] E.-Y. Lin et al., “Power-efficient rendez-vous schemes for dense wireless sensor networks,” IEEE International

Conference on Communications, vol. 7, pp. 3769-3776, 2004. [Jel2012] V. Jelicic, M. Magno, D. Brunelli, V. Bilas, and L. Benini, “Analytic comparison of wake-up receivers for wsns and

benefits over the wake-on radio scheme”, Performance Monitoring and Measurement of Heterogeneous Wireless and Wired Networks (PM2HW2N), pp. 99-106, 2012.

[Cas2012] A. Castagnetti, A. Pegatoquet, C. Belleudy, and M. Auguin, “A framework for modeling and simulating energy harvesting wsn nodes with efficient power management policies,” EURASIP Journal on Embedded Systems, 2012.

[Le2013] T. N. Le, A. Pegatoquet, O. Berder, O. Sentieys, and C. Belleudy, ”Duty-cycle power manager for thermal-powered wireless sensor networks”, International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), pp. 1655-1659, 2013.

[Ana2009] G. Anastasi, M. Conti, and M. Di Francesco, “Extending the lifetime of wireless sensor networks through adaptive sleep”, IEEE Transactions on Industrial Informatics, pp. 351-365, 2009.

[Alm2012], M. M. Alam, O. Berder, D. Menard and O.Sentieys, "TAD-MAC: Traffic-Aware Dynamic MAC Protocol for Wireless Body Area Sensor Networks," IEEE Journal on Emerging and Selected Topics in Circuits and Systems, pp.109,119, 2012

16 Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio

Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio

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•s. J. Marinkovic, E. M. Popovici, "Nano-Power Wireless Wake-Up Receiver With Serial Peripheral Interface“ •J. Ansari, D. Pankin, and P. Mahonen, “Radio-triggered wake-ups with addressing capabilities for extremely low power sensor network applications”