Radio Frequency Identification (RFID) and Wireless Sensor Networks (WSN) are two emerging technologies with apparent disparate aims but with notable potential for complementing each other. The integration of RFID and WSN functionalities could expand the horizon of automatic product information gathering, giving birth to a new generation of 'smart objects' that would seamlessly stream richer data to be utilized for their own supply chain and lifecycle management. These new capabilities would enable a full range of new product-centric applications and services, aimed at increasing business profits from manufacturers to retailers and asset management service providers.
This thesis aims to demonstrate that RFID and WSN can effectively complement each other by providing an architecture design that integrates both technologies. The work presented here takes on the current defacto RFID standards, the EPCglobal architecture, and proposes a natural extension to its functionality by incorporating active networking and sensing capabilities to the objects that RFID uniquely identifies. The contribution delivered by our work allows users to track product information in a much richer form than any other previous work. This functionality is achieved by providing a common access to all the products taking part on the same contextual situation. The key objectives of this thesis are to provide a $\It{design}$ for an integration architecture of RFID and WSN, to $\It{evaluate}$ the proposed solution, and to prove its feasibility by $\It{implementing}$ the solution with current available technology.
The architecture $\It{design}$ focuses on offering RFID and WSN functionality fusion by achieving dynamic object networking, structured data and information sharing. Active networks of uniquely identified objects with sensing capabilities aid the creation of groups capable of monitoring their own condition. Structuring the data coming from those networks into hierarchical relationships assures a clear understanding of their interactions and monitoring capabilities. Sharing all that information through an information infrastructure enables business partners andother interested parties to access the integrated data. What is more, by following the changes on the object networks and their members' structure, the condition of specific products can be automatically tracked, providing the ground information for lifecycle management services.
The $\It{evaluation}$ of our work puts special emphasis in the protocols that build and maintain the active networks of objects, due to the challenging features of the considered embedded devices. We prove that the networking strategy which is proposed in this thesis, is able to provide not only extended functionality over other similar wireless networking research, but also better performance and that is more efficient for the purposes of our architecture design. This is achieved by performing extensive simulations on variables such as the number of network members, network structure organization, exchanged messages and latency of the network protocols. Additionally, an analytical model of the functionality of the network is also provided, which allows the derivation of equations that maximize the network lifetime.
Finally, the thesis also analyze the different approaches for $\It{implementing}$ the solution, and prove its viability by building a prototype based on off-the-shelf RFID and WSN technology. Analysis is provided on the alternatives to implement the information sharing infrastructure, choosing defacto standards for Internet interconnectivity that ensure a realistic and functional implementation.
