·         Tayel A. F., Rabia S. I., Abd El-Malek A. H. and Abdelrazek A. M. (2021). Throughput Maximization of Hybrid Access in Multi-class Cognitive Radio Networks with Energy Harvesting, IEEE transactions on communications, doi: 10.1109/TCOMM.2021.3059862.

·         Abdelfattah I. S., Rabia S. I., Abdelrazek A. M. (2021). Optimal sensing energy and sensing interval in cognitive radio networks with energy harvesting, International Journal of Communication Systems, Vol. 34, e4742.

·         Zakariya A. Y., Rabia S. I., and Zahra W. K. (2021) Optimal decision making in multi-channel RF-powered cognitive radio networks with ambient backscatter capability, Computer Networks, Vol. 189, 107907.

·         Tayel A. F., Abd El-Malek A. H., Rabia S. I., and Abdelrazek A. M. (2021). Securing hybrid channel access cognitive radio networks with energy harvesting, Physical Communication, Vol. 45, 101260.

·         Tayel A. F., Rabia S. I., Abd El-Malek A. H., and Abdelrazek A. M. (2020). An Optimal Policy for Hybrid Channel Access in Cognitive Radio Networks with Energy Harvesting, IEEE Transactions on Vehicular Technology, Vol. 69, 11253 - 11265.

·         Zakariya A. Y., Tayel A. F., Rabia S. I., and Mansour A. (2020). Modeling and Analysis of Cognitive Radio Networks with Different Channel Access Capabilities of Secondary Users, Simulation Modelling Practice and Theory, Vol. 103, 102096.

·         Attalla S. A., Seddik K. G., El-Sherif A. A. and Rabia S. I. (2019). Hybrid ARQ-CQI Feedback-Based Access Scheme in Cognitive Radio Networks, IEEE Transactions on Cognitive Communications and Networking, Vol. 6, 728-739.

·         Zakariya A. Y., Rabia S. I., and Abouelseoud Y. (2019). An Optimized General Target Channel Sequence for Prioritized Cognitive Radio Networks, Computer Networks, Vol. 155, 98-109.

·         Mansour A., Tayel A. F., Khames A., Azab M., Rabia S. I., Shehata N (2019). Towards Software Defined Antenna for Cognitive Radio Networks Through Appropriate Selection of RF-Switch Using Reconfigurable Antenna Array, AEU - International Journal of Electronics and Communications, Vol. 102, 25-34.

·         Attalla S. A., Seddik K. G., El-Sherif A. A. and Rabia S. I. (2018). Soft-Sensing CQI Feedback-Based Access Scheme in Cognitive Radio Networks, IEEE Transactions on Cognitive Communications and Networking, Vol. 4, 486-499.

·         Fahim T. E., Zakariya A. Y. and Rabia S. I. (2018). A Novel Hybrid Priority Discipline for Multi-Class Secondary Users in Cognitive Radio Networks, Simulation Modelling Practice and Theory, Vol. 84, 69-82.

·         Tayel A. F. and Rabia S. I. (2018).  A New Probabilistic Target Channel Selection Approach for Load Balancing in Cognitive Radio Networks. IEEE Transactions on Cognitive Communications and Networking, Vol. 4, 43-52.

·         Abdul Maksoud I., Rabia S. I. and Algundi A. M.  (2017). A Discrete-Time Multi-Server Queueing Model for Opportunistic Spectrum Access Systems. Performance Evaluation, Vol. 109, 1-7.

·         Tayel A. F., Rabia S. I. and Abouelseoud Y. (2016).  An Optimized Hybrid Approach for Spectrum Handoff in Cognitive Radio Networks with Non-Identical Channels. IEEE transactions on Communications, Vol. 64, 4487-4496.

·         Elrasad A., Rabia S. I, Mahmoud M., Moustafa H. Aly and Shihada Basem (2016).  Dropping Probability Reduction in OBS Networks: A Simple Approach. Optik, Vol. 127, 9947-9960.

·         Zakariya A. Y., Tayel A. F. and Rabia S. I (2015).  Comments on “Optimal Target Channel Sequence Design for Multiple Spectrum Handoffs in Cognitive Radio Networks”. IEEE transactions on Communications, Vol. 63, 3021-3024.

·         Rabia S. I. (2014).  An improved truncation technique to analyze a Geo/PH/1 retrial queue with impatient customers. Computers & Operations Research, Vol. 46, 69-77.

·         Abd El-Rahman A. I., Rabia S. I. and Shalaby H. M. (2014).  Assessment of an Optical Burst Switched Core Node With a Restricted Number of Simultaneous Active Users Using the Burst Error Loss Rate. Journal of Optical Communications and Networking, Vol. 6, No. 4, 408-420.

·         Abd El-Rahman A. I., Rabia S. I. and Shalaby H. M. (2012).  MAC-layer performance enhancement using control packet buffering in optical burst-switched networks. Journal of Lightwave Technology, Vol. 30, No. 11, 1578-1586.

·         Omar, M. A., Aboul-Hassan A. and Rabia S. I. (2011).  The Composite Milstein Methods for the Numerical Solution of Ito Stochastic Differential Equations. Journal of Computational and Applied Mathematics, Vol. 235, No. 8, 2277-2299.

·         Omar, M. A., Aboul-Hassan A. and Rabia S. I. (2009).  The Composite Milstein Methods for the Numerical Solution of Stratonovich Stochastic Differential Equations. Applied Mathematics and Computation, Vol. 215, No. 2, 727-745.

·         Aboul-Hassan, A. Rabia S. I. and Taboly A. (2009).  Performance Evaluation of a Discrete-Time Geo^[X]/G/1 Retrial Queue with General Retrial Times. Computers and Mathematics with Applications, Vol. 58, No. 3, 548–557.

·         Aboul-Hassan, A.,  Rabia S. I. and Taboly A. (2008). A Discrete-Time Geo/G/1 Retrial Queue with General Retrial Times and Balking Customers. Journal of the Korean Statistical Society, Vol. 37, No. 4, 335–348.

·         Aboul-Hassan A. and  Rabia S. I. (2006). Markovian Early Arrival Discrete Time Jackson Netwroks. Journal of the Korean Statistical Society, Vol. 35, No. 3, 281–303.

·         Zakariya A. Y., Rabia S. I. and Zahra W. K., Dynamic Spectrum Access for RF-Powered Ambient Backscatter Cognitive Radio Networks, Presented in the 11st International Conference on Simulation and Modeling Methodologies, Technologies and Applications, SIMULTECH 2021, July 2021 (Virtual conference).

·         Elbattrawy A. N., Abdel El-Malek A. H., Rabia S. I. and Zahra W. K., Cooperative Spectrum Sharing Scheme for Enhancing Primary User Performance under Denial of Service Attack, Presented in the 11st International Conference on Simulation and Modeling Methodologies, Technologies and Applications, SIMULTECH 2021, July 2021 (Virtual conference).

·         Tayel A. F., Rabia S. I., Abd El-Malek A. H. and Abdelrazek A. M. (2021). Spectrum Access Management of Multi-class Secondary Users in Hybrid Cognitive Radio Networks, IEEE Vehicular Technology Conference (VTC 2021), April 2021 (Virtual conference).

·         Attalla S. A., Seddik K. G., El-Sherif A. A. and Rabia S. I. (2017). Hybrid Feedback-Based Access Scheme for Cognitive Radio Systems. Presented in the IEEE Global Communications Conference (GLOBECOM 2017), Singapore, December 2017.

·         Zakariya A. Y. and Rabia S. I (2016).  Analysis of an Interruption-Based Priority for Multi-Class Secondary Users in Cognitive Radio Networks. Presented in IEEE International Conference on Communications (IEEE-ICC 2016), Kuala Lumpur, May 2016.

·         Tayel A. F. and Rabia S. I. (2015).  Load Balancing Probabilistic Spectrum Handoff for Cognitive Radio Networks. Presented in International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS 2015), Chicago, July 2015.

·         Abdul Maksoud I. and Rabia S. I. (2015).  A Discrete-Time Multi-Server Model for Opportunistic Spectrum Access Systems. Presented in 10th International Conference on Cognitive Radio Oriented Wireless Networks, Doha, April 2015.

·         Abd El-Rahman A. I., Rabia S. I. and Shalaby H. M. (2011).  Contention Resolution using Control Packet Buffering in Optical Burst Switched Networks. Presented in Access Networks and In-house Communications Conference, Toronto, June 2011.

·         Rabia S. I. (2010). Numerical investigation of a Geo/PH/1 retrial queue with non-persistent customers. Presented in the Third Madrid Conference on Queueing Theory, Madrid, July 2010.

·         Rabia S. I. (2006). Waiting Time Distribution in a Discrete-Time Geo/G/1 Retrial Queue. Presented in the Second Madrid Conference on Queueing Theory, Madrid, July 2006.    

·         Aboul-Hassan A. and Rabia S. I. (2002). Approximate Analysis of Discrete Time Queueing Systems with Early Arrival Scheme.     Presented in the First Madrid Conference on Queueing Theory, Madrid, June 2002.      

·         Rabia S. I. and Aboul-Hassan A. (2000). A Unified Approach for the Approximate Analysis of Discrete Time Queueing Systems.        Presented in the Conference on Stochastic Networks, Madison, June 2000.

·         Aboul-Hassan A. and Rabia S. I. (2000). Performance Bounds for Queueing Networks with Erlangian Interarrival      Times and Service Times. Presented in the Conference on Stochastic Networks, Madison, June 2000.

Starting from April 2020, I am working as the PI of the research project entitled “Security-Reliability Tradeoff in Spectrum Sharing Networks with Energy Harvesting” which is supported by the National Telecom Regulatory Authority of Egypt (NTRA). We propose a new spectrum sharing framework to enhance wireless network spectrum utilization under network latency constraints. This framework takes into account the random environment behavior and propose deploying stochastic optimization techniques to select the optimum action to be taken by the network user. Moreover, we enhance the security of the proposed framework by using the recent physical layer security techniques against eavesdropping

Starting from April 2020, I am working as the PI of the research project entitled “Security-Reliability Tradeoff in Spectrum Sharing Networks with Energy Harvesting” which is supported by the National Telecom Regulatory Authority of Egypt (NTRA). We propose a new spectrum sharing framework to enhance wireless network spectrum utilization under network latency constraints. This framework takes into account the random environment behavior and propose deploying stochastic optimization techniques to select the optimum action to be taken by the network user. Moreover, we enhance the security of the proposed framework by using the recent physical layer security techniques against eavesdropping.

·         Zakariya A. Y. and Rabia S. I. (2016). Estimating The Minimum Delay Optimal Cycle Length Based on a Time-Dependent Delay Formula. Alexandria Engineering Journal, Vol. 55, 2509-2514.

·         Aboul-Hassan, A. Rabia S. I. and Al-Mujahed A. (2010).  A Discrete-Time Geo/G/1 Retrial Queue with Starting Failures and Impatient Customers. Transactions on Computational Science, VII, LNCS 5890, 22–50.

·         Aboul-Hassan, A. Rabia S. I. and Al-Mujahed A. (2010).  Performance Analysis of a Geo^[X]/G_H/1 Retrial Queue with an Unreliable Server. International Journal of Applied Mathematics and Statistics, Vol. 17, No. J10, 18–36.

·         Aboul-Hassan A., Rabia S. I. and Kadry A. (2005). Analytical Study of a Discrete Time Retrial Queue with Balking Customers and Early Arrival Scheme. Alexandria Engineering Journal, Vol. 44, No. 6, 911-917.

·         Aboul-Hassan A., Rabia S. I. and Kadry A. (2005). A Recursive Approach for Analyzing a Discrete Time Retrial Queue with Balking Customers and Early Arrival Scheme.      Alexandria Engineering Journal, Vol. 44, No. 6, 919-925.

·         Aboul-Hassan A. and Rabia S. I. (2003). Performance Bounds for Early Arrival Discrete Time Queueing Systems. Alexandria Engineering Journal, Vol. 42, No. 6, 755-766.

·         El-Sherif M. F. and Rabia  S. I. (2018). Performance Enhancement of Real- Time Traffic in Cognitive Radio Networks with Channel Assembling Strategy, Presented in the International Japan-Africa Conference on Electronics, Communications and Computations (JAC-ECC 2018), Alexandria, Egypt, December 2018.

·          

·         Aboul-Hassan, A., Rabia S. I. and Taboly F. A. (2008). On a discrete-time  retrial  queue   with batch  arrivals. Presented in the annual Conference on Statistics, Computer Science   and Operations Research, Cairo, December 2008.

·         Aboul-Hassan, A., Rabia S. I. and Almujahid A. (2008). A discrete-time Geo^[X]/G_H/1 retrial queue with unreliable server. Presented in the annual Conference on Statistics, Computer Science   and Operations Research, Cairo, December 2008.

·         Gabr M., Aboul-Hassan, A., Rabia S. I. and Almujahid A. (2007). A Discrete-Time Geo/G/1 Retrial Queue with Balking Customers and Starting Failures. Presented in The Second International Conference on mathematics: Trends and Developments, Cairo, December 2007.

·         Aboul-Hassan, A., Rabia S. I. and Taboly A. (2007). A Discrete-Time Geo/G/1 Retrial Queue with General Retrial Times and Balking Customers. Presented in The Second International Conference on mathematics: Trends and Developments, Cairo, December 2007.

·         Aboul-Hassan A., Rabia S. I. and Kadry A. (2006).  Generating Function Analysis for Discrete Time Stochastic Dynamical System. Presented in the International Conference on Mathematical Analysis and Its Applications, Assiut, January 2006.

·         Aboul-Hassan A. and Rabia S. I. (2002). Performance Evaluation of ATM Switches using Discrete Time Queueing Systems (II) Blocking Case. Presented in the Conference on Mathematics: Trends and Developments, Cairo, December 2002. 

·         Aboul-Hassan A. and Rabia S. I. (2001). Queueing Networks via Mathematica. Presented in the Workshop on Mathematica in Education and Research, Ismailia, May 2001.

·         Rabia S. I. and Aboul-Hassan A. (2000). Networks with Policies Based on Buffers and Due Dates. Presented in the Conference of Mathematics and the 21st Century,   Cairo, January 2000.

·         Aboul-Hassan A. and Rabia S. I. (2000). Unstable FIFO Queueing Network with General Service Time. Presented in the Conference of Mathematics and the 21st Century,   Cairo, January 2000.

I have been involved in teaching different postgraduate and undergraduate mathematical courses for engineering students. For the postgraduate level, I have taught courses in elementary and advanced stochastic processes, elementary and advanced queueing theory, stochastic modeling, simulation of stochastic systems, linear algebra and statistical inference. For the undergraduate level, I have taught courses in calculus, linear algebra, probability, statistics, numerical methods, complex analysis and vector analysis.