OPNET Technologies
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Washington, DC 20008
Tel: 202-364-4700
Fax: 202-364-8554
E-mail: university@opnet.com
Web: www.opnet.com

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© 2000 OPNET Technologies

University: University of Parma
Professor: Gianluigi Ferrari

Researcher: Marco Martalo', Paolo Medagliani, Stefano Busanelli
Department: Department of Information Engineering

Laboratory: Wireless Ad hoc and Sensor Networks (WASN) Laboratory

Simplified Performance Analysis of RFID Networks
We used OPNET for studying the behavior of radio frequency identification (RFID) systems. In the last years, these systems have found an increasing application in several business areas, such as service, purchasing and distribution logistics, manufacturing, ticketing and animal identification. Therefore, it is very important to develop efficient tools to evaluate the performance of the systems under design. In the literature, the study of RFID networks is somewhat immature, especially in terms of the evaluation of performance metrics such as throughput and delay. In [1] we propose a simple analysis of RFID network performance metrics, such as average delay and throughput. More precisely, the key idea is that of considering a deterministic approach, neglecting the stochastic aspect of the binary tree-based reading operation. This simplifies tremendously the derivation of the analysis, still preserving its validity in an average sense. In order to validate our analytical results, we propose a reliable and scalable RFID network simulator. Our simulator is developed with OPNET 11.0 and implements the binary tree collision arbitration protocol.

Simulations of clustered Zigbee networks
The Opnet Modeler 11.0 has been used in order to evaluate the performance of Zigbee networks. Since this Opnet version does not provide for embedded models of Zigbee devices, we have used the Zigbee model developed by the National Institute of Standards and Technologies (NIST). However, not even this model provides for the relay functionalities of the Zigbee standard, therefore we have developed a relay model for a Zigbee network. Sequently, we have analyzed network performance of Zigbee networks in terms of throughput, delay, and aggregate throughput. The same Zigbee model has also been used for creating clustered networks where the remote sensors (namely the Reduced Function Devices, RFDs) send data to the intermediate nodes (Fusion Centers, FCs), which forward the received packets to the final Access Point (AP). In this case, the FCs can either simply relay the packets or locally combine information received from the RFDs and forward only their local decisions to the AP. We have considered both uniform (all the clusters have the same dimension) and non-uniform (the clusters have different dimensions) clustering. In this case, we have evaluated throughput, delay, and probability of decision error at the final AP as functions of the number of the transmitting RFDs, the clustering configuration and the observation Signal-to-Noise Ratio (SNR) at the RFDs.

More details and papers can be found on the laboratory website