Internet of Things Tutorial: WSN and RFID – The Forerunners

WSN and RFID are key to understanding more complex IoT concepts and technologies, but also the structure of non-trivial IoT systems, which are very likely to comprise RFID or WSN components.

Radio Frequency Identification

RFID labels/tags can be attached to physical world items and tranform them to elementary pervasive networked sysems/computers (even though not Turing complete machines), which can transmit information to the internet. An RFID system comprises a unique identifier (such as an Electronic Product Code (EPC)) and a Non-volatile random-access memory  (NVRAM) storing User Data. An RF system allows wireless exchange of ID/EPC & User Data based on a set of tags, interrogators, as well as controlling Middleware. In particular:

  • RFID Tags have a unique EPC and store a piece of USER Data.
  • RFID Interrogators access USER Data on RFID Tags.

An RFID system can be seen as a distributed database or even a network of distributed tagged objects (i.e. an Intenet-of-Things!).

An RFID system is just a reader and a tag communicating over the air at a certain frequency. It comprises readers, antennas and tags.An RFID solution uses a radio frequency (RF) signal to broadcast the data captured and maintained in an RFID chip. An RFID system is composed of three components: a programmable transponder or tag, a reader (with an antenna), and a host. The operation of the RFID system is as follows:

  • The reader sends out an electromagnetic wave at one specific frequency.
  • That wave hits the RFID tag, and the tag then “scatters back” a wave at a different frequency with the chip’s information encoded in those Backscatter waves.

Note that an RFID reader is a radio that picks up analog signals. The reader not only generates the signal that goes out through the antenna into space, but also listens for a response from the tag. It receives analog waves and then turns them into bits of digital information. Each reader is connected to one or more antennas.

RFID technology is comparable to other automatic identification technologies, such as the uniquitous bar-code technology. There are pros and cons when it comes to evaluating the use of one among those two technologies. RFID is superior in reading range, (data holding) capacity and security, but barcode is still much cheaper, which explains its widespread adoption as the primary automatic identification technology. However, RFID has also the advantage of serialization (nowadays provided however by bar codes), which enables unique iterm identification rather than identification of item classes as in the conventional barcode case.

There is a great variety of RFID tags, in terms of functionality, sizes, applications etc. From a functional perspective, RFID tags can be classified in the following categories:

  • Passive Identity Card: Contains only the Electronic Product Code (EPC) in an unalterable form and a CRC for transmission error detection. Also referred to as a “license plate".
  • Passive Functional Tag: Broad category that includes any tag with functions over and above the elementary tag. Examples of such functions or features include User Writable memory, sensors, and encryption.
  • Semi - Passive Tag: Any tag that embeds battery technology to assist in providing power for the tag (i.e., the battery is not the sole source of energy for the tag).
  • Active Tag: Any tag where a battery is the sole source of energy for the tag.

The benefits of RFID technology include:

  • Access Serialized Data i.e. ability to keep accurate account of items and their properties. This enables one to know what, where, and why.
  • Greate automation, as a result of reduced human intervention i.e. not processing one but many items.
  • Enhance Traceability, which can result in higher - throughput supply chains.
  • Security  and prevention of counterfeiting (e.g., in sectors such as apparrel and pharmaceuticals where there is a grey Market).
  • Added Value Services, through the use of specialized RFID tags that can sense physical quantities (e.g., location or temparature). Based on such sensors, Location based services and Cold Chain Management services can be deployed.

On the downside of RFID technologies there are significant privacy concerns, which are very well explained in the scope of Ari Juels paper, titled: "RFID Security and Privacy: A Research Survey".

You can see some real-life RFID applications in practice as part of our RFID-ROI-SME project, and more specifically as part of the YouTube Channel of the project. A short description of the applications can be found in our RFID Journal Article: Toffaletti S., & Soldatos J. (2010, June, 14), RFID-ROI-SME Project Promises Big Help for Small Business, RFID Journal.

Sources for further RFID reading  are provided below:

Ahmed, N. & Ramachandran, U. (2010), RFID middleware systems: a comparative analysis, In: Unique Radio Innovation for the 21st Century: Building Scalable and Global RFID Networks. Springer, Berlin.

Floerkemeier C. & Lampe M. (2005), RFID middleware design – addressing application requirements and RFID constraints, in Proceedings of SOC’2005 (Smart Objects Conference), Grenoble, France, Oct. 2005, pp. 219–224.

Kefalakis N., Leontiadis N., Soldatos J., Gama K. & Donsez D. (2008), Supply chain management and NFC picking demonstrations using the AspireRfid middleware platform,Middleware (Companion) 2008: 66-69.

Sarma S. (2004), Integrating RFID, ACM Queue, vol. 2, no. 7, pp. 50–57.

Vijayaraman, B.S. & Osyk, B.A. (2006), An empirical study of RFID implementation in the warehousing industry, The International Journal of Logistics Management, 17 (1), pp. 6-20.

Yanbo W., Ranasinghe D., Sheng Q. Zeadally S., Yu J., (2011), RFID enabled traceability networks: a survey, Distrib Parallel Databases (2011) 29:397–443, DOI 10.1007/s10619-011-7084-9.

Zarokostas N., Dimitropoulos P. &  Soldatos J. (2007, September), RFID Middleware Design for Enhancing Traceability in the Supply Chain Management, IEEE PIMRC 2007: 1-5.

AspireRFID (2013). The AspireRFID project, Retrieved from (forge), (wiki)

Dimitropoulos P. & Soldatos J. (2010). RFID-enabled Fully Automated Warehouse Management: Adding the Business Context, International Journal of Manufacturing Technology and Management (IJMTM), Special Issue on: "AIT-driven Manufacturing and Management", IJMTM Vol 21, No.3/4, 2010.

EPCGlobal Architecture Review Committee (2013). The EPCglobal Architecture Framework (version 1.5) EPCglobal, retrieved from

EPCglobal (2013a), The Application Level Events (ALE) Specification (version 1.1.1), parts 1 and 2, retrieved from

EPCglobal (2013b) ,EPC Information Services (EPCIS) Specification (version 1.0.1), retrieved from

EPCglobal (2013c),       Low Level Reader Protocol (LLRP) (version 1.1), retrieved from

Floerkemeier C., Roduner C., & Lampe M. (2007). RFID Application Development with the Accada Middleware Platform, IEEE Systems Journal, Vol. 1, Issue 2, pp.82-94, December 2007.

Kefalakis N., Leontiadis N., Soldatos J. & Donsez D. (2009). Middleware Building Blocks for Architecting RFID Systems, Paper presented at the MOBILIGHT 2009 conference, pp. 325-336.

Kefalakis N., Soldatos J., Mertikas E., & Prasad N. (2011a). Generating Business Events in an RFID network. Paper presented at RFID-TA pp.223-229.

Kefalakis, N., et al. (2011b), APDL: A reference XML schema for process-centered definition of RFID solutions, J. Syst. Software, doi:10.1016/j.jss.2011.02.036

Lampe M. & Floerkemeier C. (2007). High-Level System Support for Automatic-Identification Applications, In: Wolfgang Maass, Detlef Schoder, Florian Stahl, Kai Fischbach (Eds.): Proceedings of Workshop on Design of Smart Products, pp. 55-64, Furtwangen, Germany, March 2007.

Leontiadis N, Kefalakis N. & Soldatos J. (2009). Bridging RFID Systems and Enterprise Applications through Virtualized Connectors, International Journal of Automated Identification Technology (IJAIT), Vol. 1, No.2, 2009.

LogicAlloy (2013). LogicAlloy RFID System. Retrieved from:

Mobitec. (2013). Cuhk epcglobal rfid middleware. Retrieved from

Palazzi C., Ceriali A. & Dal Monte M. (2009, August). RFID Emulation in Rifidi Environment, in Proc. of the International Symposium on Ubiquitous Computing (UCS'09), Beijing, China.

Prabhu S., Su X., Ramamurthy H., Chu C. & Gadh R (2006). WinRFID –A Middleware for the enablement of Radio Frequency Identification (RFID) based Applications Invited chapter in Mobile, Wireless and Sensor Networks: Technology, Applications and Future Directions, Rajeev Shorey, Chan Mun Choon, Ooi Wei Tsang, A. Ananda (eds.), John Wiley.

Rhea Wessel (2010). STAFF JEANS to Introduce RFID-Enabled Customer Services, Retrieved September, 2013 from:

Dimakis N., Soldatos J., Polymenakos L., Fleury P., Curín J., & Kleindienst J. (2008), Integrated Development of Context-Aware Applications in Smart Spaces, IEEE Pervasive Computing Vol. 7, No. 4, pp. 71-79.

Anagnostopoulos A., Soldatos J., & Michalakos S.(2009, February), REFiLL: A Lightweight Programmable Middleware Platform for Cost Effective RFID Application Development, Journal of Pervasive and Mobile Computing (Elsevier), Vol. 5, Issue 1, pp. 49-63.

Soldatos J, Dimakis N., Stamatis K, & Polymenakos L. (2007, March). A Breadboard Architecture for Pervasive Context-Aware Services in Smart Spaces: Middleware Components and Prototype Applications,  Personal and Ubiquitous Computing Journal (Springer London), ISSN 1617-4909 (Print), Issue Volume 11, Number 3, Pages 193-212.

Stanford V. (2002, July), Pervasive Computing Goes to Work: Interfacing to the Enterprise, IEEE Pervasive Computing, Vol. 1, No. 3, pp.6-12.

Stanford V. (2003), Pervasive computing goes the last hundred feet with RFID systems, Pervasive Computing, IEEE Computer Science, pp. 9-14

Nath B., Reynolds F., & Want, R. (2006, March), RFID Technology and Applications, IEEE Pervasive Computing, Vol. 5, No. 1, Jan.-March 2006, pp. 22- 24.

Legner, C., & Thiesse F. (2006, March), RFID-based maintenance at Frankfurt airport, IEEE Pervasive Computing, Vol. 5, No. 1, pp. 34- 39.

Riekki J., Salminen T., & Alakarppa, I. (2006, March), Requesting Pervasive Services by Touching RFID Tags, IEEE Pervasive Computing, Vol. 5, No. 1, pp. 40- 46.

Thiesse F., Fleisch E., & Dierkes, M. (2006, March), LotTrack: RFID-based process control in the semiconductor industry, IEEE Pervasive Computing, Vol. 5, No. 1, pp. 47- 53.

Opasjumruskit K., Thanthipwan T., Sathusen O., Sirinamarattana P., Gadmanee P., Pootarapan E., Wongkomet N., Thanachayanont, A., & Thamsirianunt, M. (March 2006), Self-powered wireless temperature sensors exploit RFID technology, IEEE Pervasive Computing, Vol. 5, No. 1, pp. 54- 61.

Want R.(2004, April), Enabling Ubiquitous Sensing with RFID, Computer, vol. 37, no. 4, pp. 84-86.

Floerkemeier C., & Lampe M. (2005, October). RFID middleware design – addressing application requirements and RFID constraints. In Proceedings of SOC’2005 (Smart Objects Conference), pages 219– 224, Grenoble, France.

Romer K., Schoch T., Mattern F, & Dubendorfer T. (2004, December).Smart Identification Frameworks for Ubiquitous Computing Applications. Wireless Networks, 10(6):689–700.

Sarma S. (2004). Integrating RFID. ACM Queue, 2(7):50–57.

Garfinkel S., & Rosenberg B. (2005), RFID: Applications, Security, and Privacy. Addison-Wesley.

Brusey J., Floerkemeier C., Harrison M., & Fletcher M. (2003), Reasoning about Uncertainty in Location Identification with RFID, in Workshop on Reasoning with Uncertainty in Robotics at IJCAI-2003, Acapulco, Mexico.

Chawathe S., Krishnamurthyy V., Ramachandrany S., & Sarma S. (2004), Managing RFID Data, in Proceedings of the 30st international conference on very large data bases (VLDB). Toronto, Canada: VLDB Endowment, pp. 1189–1195.

Staake T., Thiesse F., & Fleisch E. (2005, March), Extending the EPC network: the potential of RFID in anti-counterfeiting, in SAC ’05: Proceedings of the 2005 ACM symposium on Applied computing. Santa Fe, NM, USA: ACM Press, pp. 1607–1612.

Soldatos J. (2009, March, 16), AspireRfid Can Lower Deployment Costs, RFID Journal.

Soldatos J. (2009, March, 16), The AspireRfid Project: Is Open Source RFID Middleware still an option?, RFID World.

Martinelli L., Kefalakis N., & Soldatos J. (2011, Octomber), Automatic Document Tracing Using the RFID Technology, In the Proc. of the eChallenges 2011 conference, Florence, Italy.

Tuán A., Quoc H., Serrano M., Hauswirth M., Soldatos J., Papaioannou T., & Aberer K. (2012), Global Sensor Modeling and Constrained Application Methods Enabling Cloud-Based Open Space Smart Services, UIC/ATC 2012: 196-203.

Kefalakis N., Leontiadis N., Soldatos J., Gama K., & Donsez D. (2008 December), Supply Chain Management and NFC Picking Demonstrations using the AspireRFID Middleware Platform, Demonstration in the scope of the ACM Middleware 2008 conference, Leuwen, Belgium.

Bio: John Soldatos is an Internet of Things and Smart Cities expert, as well as an experienced ICT & business consultant. He is the author of the book Building Blocks for IoT Analytics.

Original. Reposted with permission.