Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio for Energy Neutral Wireless Sensor Network Trong Nhan Le 1,2, Michele Magno 3, Alain Pegatoquet 2, Olivier Berder 1, Olivier Sentieys 1 and Emanuel Popovici 3 1 INRIA/University of Rennes 1 (ENSSAT), 2 LEAT/University of Nice, 3 University College Cork 1 {trong-nhan.le, sentieys, oberder}@irisa.fr 2 {alain.pegatoquet}@unice.fr 3 {m.magno, e.popovici}@ucc.ie 1
Energy Harvesting (EH) WSN Applications Wireless Sensor Networks Medical and Health Monitoring Smart building Structure Health Monitoring Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 2
Harvesting Energy Sources Light Multiple-sources Cymbet [Cym] Heat Micropelt [Mic] Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio PowWow [Pow] 3
Autonomous Communication Nodes? Common energy sources [Rou2004] Consumed energy in PowWow node [Alm2011] Energy Source Power Density Protocol State Energy Solar (outdoor) 15mW/cm 2 Solar (indoor) 10µW/cm 2 Send/Receive BEACON 51µJ Data Transmission 80µJ Thermal (5 o C) 40µW/cm 2 Vibration 200µW/cm 3 Data Reception 100µJ Idle listening 30ms 2307µJ 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) Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 4
Contents Related Works WSN Node with WUR Receiver WUR based TICER Protocol Duty-Cycle Power Manager Simulation Results Conclusions Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 5
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 Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 6
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) Wake up Message Sleep/wake up radio technique Main Radio Wake up radio receiver ON/OFF Interrupt CPU Typical Consumption of main radio(mrf) and wake up receiver (WUR) WUR MRF Sleep < µa 1 ma Normal < µa 20 ma Wake up radio receiver Wake up Message Always on nano power consumption t Main RADIO T off T on T off t
WSN Node with WUR Receiver [Jel2012] Receiver Wake-up message from the sensor node Main RF ON OFF MCU Wake up signal and data Wake up receiver Transmitter (OOK,125kz 2.4GHz) Matching Envelope Detector (passive) Filters Wake up circuit Wake up radio board Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 9
WUR based TICER Protocol Acknowledgment (ACK) Sleep mode T DATA Rx mode Receiver WUB is detected by the WUR Wake-up beacon (WUB) by MRF Sensing ADC (SEN) Clear Channel Assessment (CCA) Calculation Before Transmission (CBT) Data Transmission (DT) T ACK Tx mode Transmitter 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. Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 10
Duty-cycle PM for Super-Capacitor based EH WSN [Le2013] VS ( n) Energy monitor LUT E WUB 51 E CCA 18..... e Active (n) P H (n) V ( n) VRef S Budget energy Energy predictor (EWMA) e Bud (n) eˆ ( n 1) Active Pˆ ( n 1) H T ( 1) WU n Wake up adaptation e Active (n) : Consumed energyinslot n P H (n) : Harvested powerinslot n ê Active (n +1) : Predictedconsumed energy ˆP H (n +1) : Predicted harvested power e Bud (n +1) : Budget energy for slot n +1 V Ref : Desired voltage in ENO state Adaptations are based on the voltage of the supercapacitor (V S ) Independent of harvesters Low complexity, low memory resource, high reactivity Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 11
Harvested Device Simulation Setups (Omnet++) End device (ED) Node [1] Node [0] Node [2] Base station (BS) Node [N] Energy Flow Controller MCU RF Sensor Wake-up signal WUR T WU Super Capacitor V S Power Manager Energy flow Signal control Wireless link Single-hop EH WSN topology Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 12
Simulation Setups (Omnet++) Symbol CC2420 CC2500 CC1100 E CBT (µj) 9.7 9.7 9.7 E WUB (µj) 51 47 42 E ACK (µj) 51 47 42 E DT (µj) 100 73 79 E CCA (µj) 18 14 11 E SEN (µj) 27 27 27 P Tx (mw) 66.33 69.96 57.75 Indoor light energy profile P Rx (mw) 76.89 56.10 61.05 P Sleep (µw) 85.8 21.12 22.77 Metrics for evaluation: Consumed energy of popular RF chips PDR(bits/s): Packet received Data-Rate IDL Rx (ms) : Idle listening time at Rx E Tx and E Rx (µj) : Consumed energy at Tx and Rx E C : Consumed energy for one successful packet. Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 13
Simulation Results (Omnet++) Metrics Non WUR CC2420 CC2500 CC1100 WUR Gain (%) Non WUR WUR Gain (%) Non WUR WUR PDR 11.39 64.00 82 17.64 68.12 74 12.71 62.76 79 IDL Rx 28.94 7.13 75 25.88 8.03 69 20.98 7.74 63 E Tx 959.47 818.75 15 767.24 674.67 12 781.56 682.05 13 E Rx 24411.17 771.14 68 1628.48 639.47 61 1462.76 657.97 55 E C 3370.64 1589.89 53 2395.72 1314.14 45 2244.33 1340.02 40 Gain (%) Idle listening at the receiver is significantly reduced QoS is improved 82%, 74% and 79% Total energy saving is up to 53% Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 14
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 thermalpowered 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 Ultra Low Power Asynchronous MAC Protocol using Wake-Up Radio 16
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