Green Communications: From Concept to Practice Honggang ZHANG International Chair - CominLabs Université Européenne de Bretagne (UEB) & Supélec/IETR Supélec SCEE Seminar March 21, 2013 – Rennes, France
Part I – the Concept: Energy-efficient Cognitive Green Radio Communications Part II – the Practice: Cognitive Green Communications for Achieving Energy Saving within Cellular Mobile Networks ACKNOWLEDGEMENT: This presentation is supported by the International Chair Program, CominLabs Excellence Center, Université Européenne de Bretagne (UEB) and SUPELEC/IETR. (GREAT: Green Cognitive Radio for Energy-Aware wireless communication Technologies evolution) Also, thanks to Prof. Jacques Palicot (SUPELEC), Dr. Tao Chen (VTT), Dr. Xianfu Chen (VTT), Mr. Rongpeng Li (ZJU), and Mr. Xuan Zhou (ZJU) for their supporting materials.
Climate Change: Trans-Arctic Shipping Routes Navigable 21st-midcentury Source: Laurence C. Smith and Scott R. Stephenson, “New Trans-Arctic Shipping Routes Navigable by Midcentury,” PNAS, January 2013.
Sector Commitments to Targets and Deadlines for CO2 and Greenhouse Gas Emissions and Energy Efficiency/Consumption (European Commission 2009/03/12) Energy Crisis and Challenges (2)
Sector Commitments to Targets and Deadlines for CO2 and Greenhouse Gas Emissions and Energy Efficiency/Consumption (European Commission 2009/03/12) Energy Crisis and Challenges (3)
Consumption Reference Model for Base Station 2400 500 300 150 110 Source: Tao Chen, et al., “Network Energy Saving Technologies for Green Wireless Access Networks”IEEE Wireless Communications Magazine, 2011.
Energy Saving Strategies & Techniques Increasing bandwidth can also save energy, depending on context Source: Tao Chen, et al., “Network Energy Saving Technologies for Green Wireless Access Networks”IEEE Wireless Communications Magazine, 2011.
& Key Functionalities of Cognitive Radio (Cognitive Cycle) Source: Gurkan Gur and Fatih Alagoz, “Green Wireless Communications via Cognitive Dimension: An Overview”, IEEE Network, March 2011.
Intelligence in a General Cognitive Radio Transceiver Cognitive Radio Node PHY Layer MAC Layer Network Layer Application Layer Source: Xianfu Chen, Zhifeng Zhao, and Honggang Zhang, “Stochastic Power Adaptation with Multi-agent Reinforcement Learning for Cognitive Wireless Mesh Networks,” IEEE Transactions on Mobile Computing, Q4 2012. Xianfu Chen, Zhifeng Zhao, Honggang Zhang, and Tao Chen, “Conjectural variations in multi-agent reinforcement learning for energy-efficient cognitive wireless mesh networks,” in Proceedings of IEEE WCNC 2012, Paris, France, Apr. 2012.
of Reinforcement Learning Policy: What to do Reward: What is good Value: What is good because it predicts reward Model: What follows what Policy Reward Value Model of environment
of Energy Saving Mechanism Enabled by Cognitive Process/Cycle Source: Oliver Blume, et al. “Energy Savings in Mobile Networks Based on Adaptation to Traffic Statistics,” Bell Labs Technical Journal 15(2), 77–94 (2010).
upon a Time – What was Cognitive Radio, Really? Joe Mitola’s Cognitive Radio (1999) Simon Haykin’s Cognitive Radio (2005) DySPAN’s Cognitive Radio (2007) Cognitive Radio (G. Gur and F. Alagoz, 2011)
load of three different cell sectors over 3 weeks. The moving average of each cell over one second has been plotted. The cells show high load (Top), varying load (Middle), and low load (Bottom). Source: Daniel Willkomm et al., “Primary User Behavior in Cellular Networks and Implications for Dynamic Spectrum Access”. Representative Patterns of Traffic Loads during 3 Weeks (Cellular Networks)
website: 292 production web servers over 5 days. (Traffic varies by day/weekend, power doesn’t.) Representative Patterns of Traffic Load during 5 Days (Core Networks/Internet)
Stations’ Traffic Loads Measurement Campaigns in Zhejiang (China) Source: Xuan Zhou, Zhifeng Zhao, Rongpeng Li, Yifan Zhou, and Honggang Zhang, “The Predictability of Cellular Networks Traffic,” IEEE ISCIT2012, October 2012. Traffic records from 9 MSCs and SGSNs with about 7000 BSs with coverage of 780 km2 Both GSM and UMTSBSs traffic from January to December in 2012, serving about 3 million subscribers
Examples of Measured Base Stations’ Traffic Loads in Zhejiang (China) Source: Rongpeng Li, Zhifeng Zhao, Yan Wei, Xuan Zhou, and Honggang Zhang, “GM-PAB: a grid-based energy saving scheme with predicted traffic load guidance for cellular networks,” in Proceedings of IEEE ICC 2012, Ottawa, Canada, Jun. 2012.
and Prediction of Cellular Networks’ Traffic Flows & Loads ,t ,t ,t x x y 3 2 1 BS1 BS3 BS2 Router route 1 route 3 route 2 link 2 link 1 link 3 6 , 3 6 , 2 6 , 1 5 , 3 5 , 2 5 , 1 4 , 1 3 , 3 2 , 3 4 , 1 3 , 2 2 , 2 4 , 1 3 , 1 2 , 1 1 , 3 1 , 2 1 , 1 x x x x x x x x x x x x x x x x x x X Interpolation: fill in the missing data from incomplete and/or indirect measurements of the Traffic Matrices Future Anomaly Missing
and Prediction of Cellular Networks’ Traffic Flows &Loads (2) Source: Rongpeng Li, Zhifeng Zhao, Xuan Zhou, and Honggang Zhang, “Energy savings scheme in radio access networks via compressive sensing-based traffic load prediction,” European Transactions on Emerging Telecommunications Technologies (ETT), Nov. 2012.
BS Switching Operation with Actor-Critic Learning Source” Rongpeng Li, Zhifeng Zhao, Xian Chen, and Honggang Zhang, “Energy Saving through a Learning Framework in Greener Cellular Radio Access Networks,” in Proceedings of IEEE Globecom 2012, Anaheim, USA, Dec. 2012.
Saving by Actor-Critic Learning (BS Switching & Sleep Mode) Performance comparison between Actor-Critic learning framework (LF) based energy saving scheme and the state-of-the-art (SOTA) scheme (JSAC, Sept. 2012) under various static/variant traffic arrival rates. Source” Rongpeng Li, Zhifeng Zhao, Xian Chen, and Honggang Zhang, “Energy Saving through a Learning Framework in Greener Cellular Radio Access Networks,” in Proceedings of IEEE Globecom 2012, Anaheim, USA, Dec. 2012.
Xuan Zhou, Zhifeng Zhao, R. Li, Y. Zhou, J. Palicot, and Honggang Zhang, “TACT: A Transfer Actor-Critic Learning Framework for Energy Saving in Cellular Radio Access Networks,” arXiv:1211.6616, November 2012. Stochastic BS Switching Operation with Transfer Reinforcement Learning
impact of the transfer rate factor θ to the TACT scheme when λ = 5× 10−6 Energy Saving by Transfer Actor-Critic Learning (BS Switching & Sleep Mode) Performance comparison among classical AC scheme, TACT scheme and SOTA scheme under various homogeneous traffic arrival rates when the transfer rate θ = 0.1 Xuan Zhou, Zhifeng Zhao, R. Li, Y. Zhou, J. Palicot, and Honggang Zhang, “TACT: A Transfer Actor-Critic Learning Framework for Energy Saving in Cellular Radio Access Networks,” arXiv:1211.6616, November 2012.
& Conclusion Environmental-friendly Green Communications: – A paradigm change from traditional coverage- & capacity-driven to energy-efficiency driven communications and networks (Smart, sustainable, and self-harmonized greener ICT). Cognitive Green Radio Communications: – Besides spectrum and energy, intelligence is the THIRD kind of resource, but without limitation of scarcity. – Learning and decision making algorithms under green constraint can play a significant role in enabling energy- and spectral- efficient greener future communications. – Effective energy saving can be realized by using various learning approaches in mobile cellular networks. Cognitive Green Communications: From Concept to Reality!