XIE er al:MANAGING RFID DATA:CHALLENGES.OPPORTUNITIES AND SOLUTIONS 1309 the aforementioned physical properties to devise novel security patterns like localization,tracking and authentication.The user schemes for RFID system is a challenging and promising memory of RFID tags can support more than 512-bit storage, research problem. conventionally it can store over 32 English characters.more (3)Developing application-driven localization and ac- information can be further stored with the index number.This tivity sensing using active/passive RFID systems:Due to provides effective support for intelligent applications based on the widespread applications of context-aware and location- information retrieval and query. based services,the localization in RFID systems is basically application-driven.For future research in localization,besides VIII.CONCLUSION the metrics of accuracy and time-efficiency,more properties As a key technology of automatic identification,RFID has are expected to be satisfied,such as the fault tolerance attracted increasing attention in recent years.In this article,we and cost-efficiency.Here,the fault tolerance requires the have discussed several research challenges and opportunities, localization scheme to effectively deal with outliers and be and provided an overview of existing solutions,including robust to the noisy readings.The cost-efficiency requires the anti-collision algorithms,authentication and privacy protection localization scheme to sufficiently reduce all kinds of cost protocols,localization and activity sensing,as well as per- including the hardware cost,computation cost,energy cost formance tuning in realistic settings.Focusing on RFID data and labor cost.In fact,it is up to the specific application management,we describe and analyze the research work on to decide which properties are essential to be obtained.In three aspects:algorithm,protocol and performance evaluation essence,obtaining a Pareto improvement is a major challenge. We offer this survey to help researchers to understand the That is,increasing the performance of one of the metrics state-of-the-art research progress and to address directions of without degradation on others. future research in the area of RFID. (4)Developing software-defined RFID readers for more- refined performance tuning:It is known that the system REFERENCES performance is impacted by issues from various protocol [1]S.Shepard,RFID radio frequency identification. McGraw-Hill layers,e.g.,the frame size of each query round,the coding Networking Professional,Aug.2004. scheme and bit rate for transmission,and so on.However,it is [2]E.Ilie-Zudora,Z.Kemnya,F.van Blommesteinb,L.Monostoria,and A.van der Meulen."A survey of applications and requirements of unique rather difficult to understand how these issues interactively and identification systems and rfid techniques,"Computers in Industry, integrally affect the performance metrics in realistic settings vol.62,no.3,p.227C252,Apil2011. [3]P.M.Reyes,G.V.Frazier,E.L.Prater,and A.R.Cannon,"Rfid:the Due to various reasons,current off-the-shelf RFID readers state of the union between promise and practice,"Int.J.of Integrated do not support to access or set these underlying parameters Supply Management,vol.3,no.2,Jan.2007. and feedbacks for performance improvement.Besides,a single [4]J.Wu,S.Rangan,and H.Zhang,Green Communications:Theoretical Fundamentals,Algorithms and Applications.CRC Press,Sept.2012. reader can only support a typical protocol standard,without [5]E.Hossain,V.Bhargava,and G.P.Fettweis,Green Radio Communica- being compatible with the other kinds of standards.Therefore, tion Nerworks.Cambridge University Press,Aug.2012. it is neither convenient nor cost-effective for researchers to [6]K.Finkenzeller and D.Mller,RFID Handbook:Fundamentals and investigate the RFID system through the commercial read- Applications in Contactless Smart Cards,Radio Frequency Identification and Near-Field Communication. Wiley,Aug.2010. ers.The software-defined radios (SDR)have provided op- [7]H.Lehpamer,RFID Design Principles.Artech House Publishers,Feb. portunities for more-refined performance tuning in a cost- 2012. effective approach.If the software-defined RFID reader can [8]R.Weinstein,"Rfid:a technical overview and its application to the enterprise,"IT Professional,vol.7,no.3,pp.27 -33.2005. be effectively developed,the users can deliberately set those [9]C.Turcu.Current Trends and Challenges in RFID.InTech.July 2011 critical parameters and obtain the underlying feedbacks for [10]D.Klair,K.-W.Chin,and R.Raad,"A survey and tutorial of rfid anti- performance tuning.Moreover,it is ready to support a new collision protocols,"IEEE Commun.Surveys and Tutorials,vol.12. no.3.Aug.2010. form of RFID communication protocol simply by running new [11]J.Myung.W.Lee,and S.Jaideep,"Adaptive binary splitting for efficient software on existing SDR hardware. rfid tag anti-collision,"IEEE Commun.Lett.,vol.10,no.3.pp.144-146. 2006. (5)Exploring novel application modes for RFID systems: [12]L.Pan and H.Wu,"Smart trend-traversal:A low delay and energy tag The original design purpose of RFID systems is to efficiently arbitration protocol for large rfid systems,"in Proc.28th Annu.Joint label and identify the items,the current applications of RFID Conf.of the IEEE Computer and Commun.Societies (INFOCOM),2009. systems still remain in the areas like supply chains:tracking. [13]Y.Maguire and R.Pappu,"An optimal q-algorithm for the iso 18000-6c rfid protocol,"IEEE Trans.Automation Science and Engineering,vol.6. managing and monitoring the goods.In recent years,RFID no.1,Pp.16-24,2009. has been widely used in various kinds of applications with its [14]B.Zhen,M.Kobayashi,and M.Shimuzu,"Framed aloha for multiple rfid objects identification,"IEICE Trans.Commun.,vol.E88-B,no.3, unique advantage,e.g..anti-counterfeiting,anti-theft,the food pp.991-999,2005. and drug safety,etc.In fact,whether the RFID technology [15]F.Schoute,"Dynamic frame length aloha,"IEEE Trans.Commun., can be spread to new applications depends on whether fea- vol31,no.4,Pp.565-568,1983. [16]C.Floerkemeier,"Bayesian transmission strategy for framed aloha based sible application patterns can be fully exploited according to rfid protocols,"in Proc.IEEE Int.Conf.on RFID,2007. RFID's unique features.Exploration into application patterns [17]H.Vogt,"Efficient object identification with passive rfid tags,"in Proc of RFID mainly includes two aspects:1)replacing the current Ist Int.Conf.on Pervasive Computing,2002. application patterns with RFID in a low-cost approach and [18]S.Lee,S.Joo,and C.Lee,"An enhanced dynamic framed slotted aloha algorithm for rfid tag identification,"in Proc.2nd Annu.Int 2)explore novel application patterns for RFID.For example, Conf on Mobile and Ubiquitous Systems:Networking and Services besides identifying the items,the RFID tag itself is a tiny (MobiQuitous).2005. wireless device,its properties like the signal strength and [19]S.Tang.J.Yuan,X.Y.Li,G.Chen,Y.Liu,and J.Zhao."Raspberry:A stable reader activation scheduling protocol in multi-reader rfid systems," coding scheme have provided technical support for application in Proc.17th IEEE Int.Conf.on Network Protocols,2009.XIE et al.: MANAGING RFID DATA: CHALLENGES, OPPORTUNITIES AND SOLUTIONS 1309 the aforementioned physical properties to devise novel security schemes for RFID system is a challenging and promising research problem. (3) Developing application-driven localization and ac￾tivity sensing using active/passive RFID systems: Due to the widespread applications of context-aware and location￾based services, the localization in RFID systems is basically application-driven. For future research in localization, besides the metrics of accuracy and time-efficiency, more properties are expected to be satisfied, such as the fault tolerance and cost-efficiency. Here, the fault tolerance requires the localization scheme to effectively deal with outliers and be robust to the noisy readings. The cost-efficiency requires the localization scheme to sufficiently reduce all kinds of cost including the hardware cost, computation cost, energy cost and labor cost. In fact, it is up to the specific application to decide which properties are essential to be obtained. In essence, obtaining a Pareto improvement is a major challenge. That is, increasing the performance of one of the metrics without degradation on others. (4) Developing software-defined RFID readers for more￾refined performance tuning: It is known that the system performance is impacted by issues from various protocol layers, e.g., the frame size of each query round, the coding scheme and bit rate for transmission, and so on. However, it is rather difficult to understand how these issues interactively and integrally affect the performance metrics in realistic settings. Due to various reasons, current off-the-shelf RFID readers do not support to access or set these underlying parameters and feedbacks for performance improvement. Besides, a single reader can only support a typical protocol standard, without being compatible with the other kinds of standards. Therefore, it is neither convenient nor cost-effective for researchers to investigate the RFID system through the commercial read￾ers. The software-defined radios (SDR) have provided op￾portunities for more-refined performance tuning in a cost￾effective approach. If the software-defined RFID reader can be effectively developed, the users can deliberately set those critical parameters and obtain the underlying feedbacks for performance tuning. Moreover, it is ready to support a new form of RFID communication protocol simply by running new software on existing SDR hardware. (5) Exploring novel application modes for RFID systems: The original design purpose of RFID systems is to efficiently label and identify the items, the current applications of RFID systems still remain in the areas like supply chains: tracking, managing and monitoring the goods. In recent years, RFID has been widely used in various kinds of applications with its unique advantage, e.g., anti-counterfeiting, anti-theft, the food and drug safety, etc. In fact, whether the RFID technology can be spread to new applications depends on whether fea￾sible application patterns can be fully exploited according to RFID’s unique features. Exploration into application patterns of RFID mainly includes two aspects: 1) replacing the current application patterns with RFID in a low-cost approach and 2) explore novel application patterns for RFID. For example, besides identifying the items, the RFID tag itself is a tiny wireless device, its properties like the signal strength and coding scheme have provided technical support for application patterns like localization, tracking and authentication. The user memory of RFID tags can support more than 512-bit storage, conventionally it can store over 32 English characters, more information can be further stored with the index number. This provides effective support for intelligent applications based on information retrieval and query. VIII. CONCLUSION As a key technology of automatic identification, RFID has attracted increasing attention in recent years. In this article, we have discussed several research challenges and opportunities, and provided an overview of existing solutions, including anti-collision algorithms, authentication and privacy protection protocols, localization and activity sensing, as well as per￾formance tuning in realistic settings. Focusing on RFID data management, we describe and analyze the research work on three aspects: algorithm, protocol and performance evaluation. We offer this survey to help researchers to understand the state-of-the-art research progress and to address directions of future research in the area of RFID. REFERENCES [1] S. Shepard, RFID : radio frequency identification. McGraw-Hill Networking Professional, Aug. 2004. [2] E. Ilie-Zudora, Z. Kemnya, F. van Blommesteinb, L. Monostoria, and A. van der Meulen, “A survey of applications and requirements of unique identification systems and rfid techniques,” Computers in Industry, vol. 62, no. 3, p. 227C252, April 2011. [3] P. M. Reyes, G. V. Frazier, E. L. Prater, and A. R. Cannon, “Rfid: the state of the union between promise and practice,” Int. J. of Integrated Supply Management, vol. 3, no. 2, Jan. 2007. [4] J. Wu, S. Rangan, and H. Zhang, Green Communications: Theoretical Fundamentals, Algorithms and Applications. CRC Press, Sept. 2012. [5] E. Hossain, V. Bhargava, and G. P. Fettweis, Green Radio Communica￾tion Networks. Cambridge University Press, Aug. 2012. [6] K. Finkenzeller and D. Mller, RFID Handbook: Fundamentals and Applications in Contactless Smart Cards, Radio Frequency Identification and Near-Field Communication. Wiley, Aug. 2010. [7] H. Lehpamer, RFID Design Principles. Artech House Publishers, Feb. 2012. [8] R. Weinstein, “Rfid: a technical overview and its application to the enterprise,” IT Professional, vol. 7, no. 3, pp. 27 – 33, 2005. [9] C. Turcu, Current Trends and Challenges in RFID. InTech, July 2011. [10] D. Klair, K.-W. Chin, and R. Raad, “A survey and tutorial of rfid anti￾collision protocols,” IEEE Commun. Surveys and Tutorials, vol. 12, no. 3, Aug. 2010. [11] J. Myung, W. Lee, and S. Jaideep, “Adaptive binary splitting for efficient rfid tag anti-collision,” IEEE Commun. Lett., vol. 10, no. 3, pp. 144–146, 2006. [12] L. Pan and H. Wu, “Smart trend-traversal: A low delay and energy tag arbitration protocol for large rfid systems,” in Proc. 28th Annu. Joint Conf. of the IEEE Computer and Commun. Societies (INFOCOM), 2009. [13] Y. Maguire and R. Pappu, “An optimal q-algorithm for the iso 18000-6c rfid protocol,” IEEE Trans. Automation Science and Engineering, vol. 6, no. 1, pp. 16–24, 2009. [14] B. Zhen, M. Kobayashi, and M. Shimuzu, “Framed aloha for multiple rfid objects identification,” IEICE Trans. Commun., vol. E88-B, no. 3, pp. 991–999, 2005. [15] F. Schoute, “Dynamic frame length aloha,” IEEE Trans. Commun., vol. 31, no. 4, pp. 565–568, 1983. [16] C. Floerkemeier, “Bayesian transmission strategy for framed aloha based rfid protocols,” in Proc. IEEE Int. Conf. on RFID, 2007. [17] H. Vogt, “Efficient object identification with passive rfid tags,” in Proc. 1st Int. Conf. on Pervasive Computing, 2002. [18] S. Lee, S. Joo, and C. Lee, “An enhanced dynamic framed slotted aloha algorithm for rfid tag identification,” in Proc. 2nd Annu. Int. Conf. on Mobile and Ubiquitous Systems: Networking and Services (MobiQuitous), 2005. [19] S. Tang, J. Yuan, X. Y. Li, G. Chen, Y. Liu, and J. Zhao, “Raspberry: A stable reader activation scheduling protocol in multi-reader rfid systems,” in Proc. 17th IEEE Int. Conf. on Network Protocols, 2009