Hassan Halawa

Majors: BSc in Computer Engineering
BSc in Electronics and Communications Engineering
Minor: Mathematics

Hassan Halawa graduated in Fall 2012, attaining the President’s Cup for academic excellence. Halawa has published several undergraduate research works in the proceedings of IEEE international conferences. He is currently a graduate student and researcher under a special Merit Fellowship at the electronics and communications engineering department of AUC. His research areas of interest, under the supervision of professors Hassanein Amer and Ramez Daoud, include networked control systems and their design and adaptation for use in industrial automation applications using standard network communication protocols such as Ethernet (IEEE 802.3). He focuses specifically on wireless networked control systems using wi-fi (IEEE 802.11), component mobility, industrial, scientific and medical (ISM) band interference as well as the design of fault tolerant system architectures.

"Sensor/Actuator Mobility in Noisy Wi-Fi based Networked Control System"
Abstract - The increase in the application of wireless networked control systems (WNCS) in industrial automation motivates the study of the effect of mobility of WNCS nodes in the presence of noise. A WNCS system should satisfy certain end-to-end delay constraints, with all types of propagation, queuing, encapsulation/decapsulation and processing delays. Also, no data packets should be lost. These requirements should be met in the existence of 2.4GHz industrial, scientific and medical (ISM) band interference. In this paper, an enhanced WNCS system is studied based on previous publications using unmodified wi-fi and Ethernet. The system is modified to include sensor/actuator mobility. A comparison between network and medium congesting interference in the presence of mobility is also presented and analyzed. Simulations are conducted on OPNET Network Modeler and all simulation results are subjected to a 95 percent confidence analysis. The system presented is shown to meet all control system requirements.

"Multicasting for Cascaded Fault-Tolerant Wireless Networked Control Systems in Noisy Industrial Environments"
Abstract - This paper studies a wireless networked control system based on IEEE’s 802.11b wi-fi standard protocol consisting of two identical work cells with zero meter inter-cell distance. It is first shown how to improve system performance and increase the amount of noise that the system can tolerate without violating delay requirements or dropping control packets. Different noise models were studied. It was proved that increasing the short retry threshold increases system tolerance to noise. It was then shown through OPNET simulations that the two cell model is fault-tolerant at the controller level when either unicasting or multicasting is used. However, for the system to operate correctly in the presence of noise, multicasting had to be used.

"On the Effect of Interference on Wi-Fi-Based Wireless Networked Control Systems"
Abstract - This study investigates a wi-fi-based wireless networked control system. This system is first modified in order to enhance resistance to interference. Then, it is subjected to different types of interference. The system consists of a work cell containing 30 sensors, 30 actuators and 1 controller. All forms of interference modeled focus on the operating frequency band used by the control nodes. All simulations are conducted on OPNET Network Modeler and system performance is measured in terms of packet end-to-end delay and correct packet transmission/reception. All results are subjected to a 95 percent confidence analysis. The results show that intentional jamming is more damaging than medium congestion, which in turn is more damaging than network congestion.