由於網際網路與通信科技帶動資訊與通信科技產業(Information and Communication Technology, ICT) 的發展以及近幾年物聯網(Internet of Things) 的興起，ICT產業的能源消耗逐年提高，為了降低全球暖化與能源短缺的危機，減少能源的消耗是一件刻不容緩的事。軟體定義網路(Software Defined Network, SDN) 為近幾年推出的一種新型態網路架構，在過去幾年SDN 的應用包含虛擬網路、整合運算功能、頻寬管理、能源感知路由等等。本篇論文將探討在SDN 架構下的能源感知路由方法。本文在研究在SDN 網路中的能量感知路由方法，目的在減少網路中使用的鏈結數量，使得能量消耗可以減少。我們將能量消耗問題化為整數線性規劃（ILP）方程式並提出一個創新的演算法，即靜態能量感知路由（SEAR），以降低能量消耗。此外，因流量需求會不時地出現或消失，我們考慮流量需求的動態屬性，並提出另一個演算法，及動態能量感知路由（DEAR）以降低計算時間。實驗結果顯示本篇提出的演算法較現有的演算法更有效率。

The Internet and communications technology brings the growth of Information and Communication Technology (ICT) industry and the rise of the Internet of Things (IoT). However, the power consumption of ICT industry increases every year. The energy consumption is a critical factor causing the energy crisis and global warming issues, and thus approaches are needed to effective reduce the power usage ICT. Software Defined Network (SDN) is a modern network architecture introduced recently to adaptively manage network resources. Several applications such as virtual network, integrated computing capability, bandwidth management, energy aware routing, etc. are also supported in SDN. In this paper, we investigate energy aware routing methods aimed to efficiently decrease the number of used links for packet delivery in SDN enabled networks so that the energy consumption can be reduced. Specifically, we formulate the energy consumption problem into an integer linear programming (ILP) problem, and propose an innovative algorithm namely SEAR to route flows in an energy efficient manner. Thus, low energy consumption can be properly supported without expensive computational cost. Moreover, from existing energy aware routing schemes which only consider static demands, we also consider the dynamic properties of demands since the flows join or leave the networks from time to time, and propose another algorithm namely DEAR to reduce the processing time. The evaluation results show that the proposed algorithms are more energy efficient than the existing energy aware routing algorithms, and can better support traffic flows in real world than the existing energy aware routing algorithms.

[1] L. Chiaraviglio, M. Mellia, and F. Neri, “Minimizing ISP Network Energy Cost: Formulation and
Solutions,” IEEE/ACM Transactions on Networking, pp. 463–476, Apr. 2012.
[2] M. Etoh, T. Ohya, and Y. Nakayama, “Energy Consumption Issues on Mobile Network Systems,” in
2008 International Symposium on Applications and the Internet, pp. 365–368, Jul. 2008.
[3] R. S. Tucker, J. Baliga, R. Ayre, K. Hinton, and W. V. Sorin, “Energy Consumption in IP Networks,”
in 34th European Conference on Optical Communication, pp. 1–1, Sep. 2008.
[4] J. Chabarek, J. Sommers, P. Barford, C. Estan, D. Tsiang, and S. Wright, “Power Awareness in
Network Design and Routing,” in 2008 IEEE Conference on Computer Communications, Apr. 2008.
[5] P. Mahadevan, P. Sharma, S. Banerjee, and P. Ranganathan, “A Power Benchmarking Framework for
Network Devices,” in 8th International IFIP-TC Networking Conference, pp. 795–808, 2009.
[6] F. Giroire, J. Moulierac, and T. K. Phan, “Optimizing Rule Placement in Software-Defined Networks
for Energy-aware Routing,” in 2014 IEEE Global Communications Conference, pp. 2523–2529, Dec.
2014.
[7] N. McKeown, T. Anderson, H. Balakrishnan, G. Parulkar, L. Peterson, J. Rexford, S. Shenker, and
J. Turner, “OpenFlow: Enabling Innovation in Campus Networks,” ACM SIGCOMM Computer Communication
Review, vol. 38, pp. 69–74, Mar. 2008.
[8] S. Orlowski, M. Pióro, A. Tomaszewski, and R. Wessäly, “SNDlib 1.0–Survivable Network Design
Library,” in 3rd International Network Optimization Conference, Apr. 2007.
[9] U. C. Kozat, G. Liang, and K. Kökten, “On Diagnosis of Forwarding Plane via Static Forwarding Rules
in Software Defined Networks,” in 2014 IEEE Conference on Computer Communications, pp. 1716–
1724, Apr. 2014.
[10] L. F. Müller, R. R. Oliveira, M. C. Luizelli, L. P. Gaspary, and M. P. Barcellos, “Survivor: an Enhanced
Controller Placement Strategy for Improving SDN Survivability,” in 2014 IEEE Global Communications
Conference, pp. 1909–1915, Dec. 2014.
[11] Z. Su, T. Wang, Y. Xia, and M. Hamdi, “FlowCover: Low-cost Flow Monitoring Scheme in Software
Defined Networks,” in 2014 IEEE Global Communications Conference, pp. 1956–1961, Dec. 2014.
[12] C. Y. Chu, K. Xi, M. Luo, and H. J. Chao, “Congestion-Aware Single Link Failure Recovery in Hybrid
SDN Networks,” in 2015 IEEE Conference on Computer Communications, pp. 1086–1094, Apr. 2015.
[13] M. Gupta and S. Singh, “Greening of the Internet,” in 2003 Conference on Applications, Technologies,
Architectures, and Protocols for Computer Communications, pp. 19–26, 2003.
[14] Y. Shang, D. Li, and M. Xu, “Energy-aware Routing in Data Center Network,” in ACM SIGCOMM
Workshop on Green Networking, pp. 1–8, ACM, 2010.
[15] B. Heller, S. Seetharaman, P. Mahadevan, Y. Yiakoumis, P. Sharma, S. Banerjee, and N. McKeown,
“ElasticTree: Saving Energy in Data Center Networks,” in 7th USENIX Conference on Networked
Systems Design and Implementation, pp. 17–17, 2010.
[16] T. M. Nam, N. H. Thanh, N. Q. Thu, H. T. Hieu, and S. Covaci, “Energy-Aware Routing based on
Power Profile of Devices in Data Center Networks using SDN,” in 2015 12th International Conference
on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology,
pp. 1–6, Jun. 2015.
[17] Y. Shang, D. Li, and M. Xu, “Greening Data Center Networks with Flow Preemption and Energyaware
Routing,” in 2013 19th IEEE Workshop on Local Metropolitan Area Networks, pp. 1–6, Apr.
2013.
[18] M. Xu, Y. Shang, D. Li, and X. Wang, “Greening Data Center Networks with Throughput-Guaranteed
Power-aware routing,” Computer Networks: The International Journal of Computer and Telecommunications
Networking, vol. 57, pp. 2880–2899, Oct. 2013.
[19] L. Wang, F. Zhang, K. Zheng, A. V. Vasilakos, S. Ren, and Z. Liu, “Energy-Efficient Flow Scheduling
and Routing with Hard Deadlines in Data Center Networks,” in 2014 34th IEEE International Conference
on Distributed Computing Systems, pp. 248–257, Jun. 2014.
[20] D. Li, Y. Shang, and C. Chen, “Software Defined Green Data Center Network with Exclusive Routing,”
in 2014 IEEE Conference on Computer Communications, pp. 1743–1751, Apr. 2014.
[21] X. Wang, Y. Yao, X. Wang, K. Lu, and Q. Cao, “CARPO: Correlation-Aware Power Optimization
in Data Center Networks,” in 2012 IEEE Conference on Computer Communications, pp. 1125–1133,
Mar. 2012.
[22] L. Chiaraviglio, A. Cianfrani, M. Listanti, L. Mignano, and M. Polverini, “Implementing Energyaware
Algorithms in Backbone Networks: a Transient Analysis,” in 2015 IEEE International Conference
on Communications, pp. 142–148, Jun. 2015.
[23] Y. Wei, X. Zhang, L. Xie, and S. Leng, “Energy-Aware Traffic Engineering in Hybrid SDN/ IP
Backbone Networks,” Journal of Communications and Networks, vol. 18, pp. 559–566, Aug. 2016.
[24] A. Cianfrani, V. Eramo, M. Listanti, M. Polverini, and A. V. Vasilakos, “An OSPF-Integrated Routing
Strategy for QoS-Aware Energy Saving in IP Backbone Networks,” IEEE Transactions on Network
and Service Management, vol. 9, pp. 254–267, Sep. 2012.
[25] D. P. Bertsekas and R. G. Gallager, Data networks. Prentice Hall, 1992.
[26] “Quagga Routing Suite.” http://www.nongnu.org/quagga/.
[27] F. Giroire, D. Mazauric, J. Moulierac, and B. Onfroy, “Minimizing Routing Energy Consumption:
from Theoretical to Practical Results,” in 2010 IEEE Green Computing and Communications (Green-
Com), pp. 252–259, Dec. 2010.