University: University of Cyprus
Professor: Andreas Pitsillides
Laboratory: Networks Research Laboratory
Department: Department of Computer Science

Research

List of Projects that NetRL is involved

	C-MOBILE: FP6 IST: Advanced MBMS for the future mobile world
	MOTIVE: FP6 IST MObile Terminal Information Value addEd Functionality
	M-POWER: FP6 IST Middleware platform for eMPOWERing cognitive disabled and elderly
	CRUISE: NoE IST CReating Ubiquitous Intelligent Sensing Environments
	LINKCARE (e-TEN): Linking Health Professionals in Emerging Care Environments
	GEANT (GN2): The Next Generation of European Research Networking
	GINSENG: Performance Control in Wireless Sensor Networks

Title: A Resilient Transport Control Scheme for Metro Ethernet Services

This paper aims to enhance the transport services of Ethernet MANs by utilizing SLA information to control traffic more intelligently, to detect congestion more accurately, and to handle packet losses more adaptively. Ethernet services convert Ethernet from a best effort technology to a service level agreement (SLA) driven carrier-grade technology, extending the simplicity and flexibility of Ethernet beyond the LAN to the MAN/WAN. Although current bandwidth allocation schemes are able to reassign idle capacity and provide QoS at link layer, the end-to-end throughput in the application layer is not optimized. The performance of TCP over SLA driven Ethernet services is not adequate, because the mechanisms of TCP are designed for best effort networks. Because of the stochastic nature of Ethernet networks, a small but non-zero random loss rate is inevitable, which can be tolerated by Ethernet services, but not by TCP. In this paper, a novel SLA-aware transport control scheme is proposed to utilize reserved bandwidth more efficiently using a shifted additive increase multiplicative decrease (AIMD) algorithm, and to detect congestion more accurately using a new decision rule based on hypothesis test. The new congestion control method can keep false-alarm probability under control and therefore it increases throughput significantly. The performance of the proposed scheme is compared with traditional TCP through theoretical analyses and simulations.

Teaching: OPNET has been used for demonstration of concepts in the graduate and undergraduate subjects EPL657, EPL653, EPL420, EPL224, and undergraduate and postgraduate student projects of communication networks.

• EPL 324: Computer Networks
• EPL 420: High Speed Multimedia and Multiservice Networks
• EPL 606: Computer Networks and Internet
• RPL 657: Wireless Networks

A number of papers are published in very well respected journals and conferences, with OPNET explicitly mentioned as the simulation tool. Full list of publications, please visit the Publications Section.

Partial list of publications where OPNET is explicitly referred to:

Partial list of publications where OPNET is explicitly referred to:

1. Christophoros Christophorou, Andreas Pitsillides “Radio Resource Management in MBMS Enabled 3G Mobile Cellular Networks: A New Handover Control Approach”, European Wireless 2007, April 2007
   
   
2. Christophoros Christophorou, Andreas Pitsillides, Nicola Binucci, “Handover Control in MBMS Enabled 3G Mobile Cellular Networks”, IST Mobile Summit 2007, July 2007, Still Pending
   
   
3. A. Pitsillides, C. Christoforou, MBMS Handover Control: A New Approach for Efficient Handover in MBMS Enabled 3G Cellular Networks, Accepted for publication in Computer Networks Journal (COMNET), (subject to revision).
   
4. M. Neophytou, A. Pitsillides, Hybrid CAC for MBMS-enabled 3G UMTS Networks, 17th International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC) 2006, Helsinki, Finland, 11-14 September, 2006.
Christophoros Christophorou, Andreas Pitsillides, “MBMS Handover Control for Efficient Multicasting in IP-Based 3G Mobile Networks”, ICC 2006, June 2006



Christophoros Christophorou, Andreas Pitsillides, “An Efficient Handover Algorithm for MBMS Enabled 3G Mobile Cellular Networks”, ISCC 2006, June 2006 

A. Pitsillides, P. Ioannou, M. Lestas, L. Rossides, Adaptive nonlinear congestion controller for a differentiated-services framework, IEEE/ACM Transactions of Networking, Vol. 13, Number 1, Feb. 2005, pp. 94-107.

C. Christoforou, A. Pitsillides, Enhanced Handover Control for Efficient Multicasting in MBMS 3G mobile networks, EVEREST Workshop, 16th November, Barcelona, Spain, 2005. (5 pages). Invited.

N. Vlotomas, J. Antoniou, G. Hadjipollas, V. Vassiliou, A. Pitsillides, Power Control for Efficient Multicasting in IP-based 3G and beyond mobile networks, 11th European Wireless 2005, April 10-13, 2005, Nicosia, Cyprus.

5. A. Pitsillides, Petros Ioannou, Marios Lestas, Loukas Rossides, "Adaptive Non-linear Control Theory based Integrated Dynamic Congestion Controller for a Differentiated-Services Framework", Technical Report, Computer Science Dept, University of Cyprus, 2004.
6. A. Pitsillides, P. Ioannou, L. Rossides, "Congestion Control for Differentiated-Services using Non-Linear Control Theory", in Proceedings of the Sixth IEEE Symposium on Computers & Communications, ISCC 2001, Hammamet, Tynisia, 3-5 July 2001, pp. 726-733.
7. Ahmet Sekercioglu, Andreas Pitsillides, Petros Ioannou, "A Simulation Study on the Performance of Integrated Switching Strategy for Traffic Management in ATM Networks", ISCC98, Athens, June 2-4 1998.
8. Ahmet Sekercioglu, Andreas Pitsillides, "Fuzzy Traffic Flow Control in ATM Networks", EUFIT'97, 5th European Congress on Intelligent Techniques and Soft Computing, Aachen, Germany, 8-12 September, 1997.
9. A. Sekercioglu, A. Pitsillides, "Intelligent Control techniques for Efficient Regulation of ABR Queue Length in ATM Switches", ISCC'97, IEEE Symposium on Computers and Communications, Alexandria, Egypt, 1-3 July 1997.
10. A. Pitsillides, A. Sekercioglu, G. Ramamurthy, "Effective Control of Traffic Flow in ATM Networks Using Fuzzy Explicit Rate Marking (FERM)", IEEE Journal on Selected Areas in Communications (JSAC), Volume 15, Issue 2, pp. 209-225, February 1997.
11. Ahmet Sekercioglu, A. Pitsillides, "Rate based flow control using fuzzy backward congestion notification (FBCN): A comparative evaluation", ICT'96, International Conference on Telecommunications, Istanbul, Turkey, 14-17 April 1996, pp.37-40.
12. Ahmet Sekercioglu, A. Pitsillides, "Fuzzy Control of ABR traffic flow in ATM LANs", IEEE Symposium on Computers and Communications, Alexandria, Egypt, 27-29 June 1995, pp.227-232.
13. A. Pitsillides, A. Sekercioglu, G. Ramamurthy, "Fuzzy backward congestion notification (FBCN) congestion control in asynhronous transfer mode (ATM) networks", IEEE GLOBECOM'95, Global Telecommunications Conference, Singapore, November 13-17, 1995, pp. 280-285.
14. Ahmet Sekercioglu, A. Pitsillides, "Fuzzy congestion control in Asynchronous Transfer Mode", ICT'95, International Conference on Telecommunications, Bali, Indonesia, 3-5 April 1995, pp.299-302.
15. A. Pitsillides, Y. Ahmet Sekercioglu, "Fuzzy Backward Congestion Notification "ATNAC94, Australian Telecommunication Networks and Applications Conference, Melbourne, 5-7 Dec. 1994, pp.249-254.