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Ahmed Helmy
Associate Professor of Computer Networks
Computer and Information Science and Engineering (CISE) Department
Founder and Director: Mobile and Sensor Networks Laboratory (the NOMADS group)
University of Florida, Gainesville
email: helmy at ufl.edu


Dr. Ahmed Helmy is conducting research on design and analysis of mobile ad hoc networks and wireless sensor networks, in addition to protocol testing techniques. He currently has three active NSF projects (MARS, ACQUIRE and STRESS). In 2002, Dr. Helmy received the National Science Foundation (NSF) CAREER Award for his research on 'Resource Discovery, Query Resolution, Rendezvous and Mobility Modeling in Large-Scale Wireless Ad Hoc and Sensor Networks' (also called MARS). His current research interests lie in the areas of modeling and analysis of mobile wireless networks, robust protocol design for ad hoc and sensor networks (geographic routing and efficient query resolution), network security and systematic design and stress testing of networking protocols.

Since 2002, Dr. Helmy has led the MARS projects (funded by NSF, Intel and Pratt&Whitney) on efficient architectures and protocols for large-scale ad hoc and sensor networks. He developed the IMPORTANT mobility simulation tool with his group under the MARS project. He is also co-leading the NSF funded project ACQUIRE for 'Data-centric Active Querying in Sensor Networks'. Furthermore, he is leading the NSF/NASA funded project for highly dependable protocols ( STRESS). From 1998-2002 STRESS was funded by DARPA to develop scenario generation algorithms for multicast protocols. He has also led the M&M project (funded by Nortel and Intel) to develop a multicast-based mobility protocol for efficient IP mobility support. He has worked on the VINT (NS-2) and PIM projects at USC and USC/ISI. In addition, he received the Zumberge award (2000) to pursue work on power-aware wireless routing protocols. He founded and directed the wireless networking laboratory at USC's Electrical Engineering from 1999 until 2006 (from his HP grant), and co-founded and co-directed the sensor networking laboratory at USC from 2005-2006. He also founded and is currently directing the mobile networking laboratory at the CISE department at the University of Florida.

Most recently, Dr. Helmy is studying wireless user behavior through trace-based analyses. He has initiated an effort to form a community-wide mobility library of Wireless LAN measurements (MobiLib) with millions of traces available.

Updates: News.
Teaching: (I am teaching CNT5106C Computer Networks in Fall'08 at UFL).

Projects & Publications
[News ]
CV (pdf) (updated Feb 08) Teaching
(Courses, Statistics)
Committees
(Conferences, Journals, ... )

Projects and Selected Publications [click here for a more detailed website (somewhat out-of-date)]
Projects: MARS, ACQUIRE, M&M, STRESS, AQM-marking, VINT/NS, PIM

MARS PROJECT: Resource Discovery, Query Resolution, Rendezvous and Mobility Modeling in Large-Scale Wireless Ad Hoc and Sensor Networks (MARMALADeS projects): [A related project on active querying in sensor networks, 'ACQUIRE', has started with funding from NSF NETS]

MARS Selected Publications: (For more complete list of publications please check the updated CV) M&M Project: Multicast-based Architecture for IP Mobility
  1. A. Helmy, M. Jaseemuddin, G. Bhaskara, "Multicast-based Mobility: A Novel Architecture for Efficient Micro-Mobility", IEEE Journal on Selected Areas in Communications (JSAC), Special Issue on All-IP Wireless Networks, Vol. 22, No. 4, pp. 677-690, May 2004.
  2. A. Helmy, "A Multicast-based Protocol for IP Mobility Support", ACM SIGCOMM Int'l Workshop on Networked Group Communication (NGC), November 2000 [ ppt] [Here is a library of topologies used for the simulations of M&M (NGC), in a format compatible with the network simulator (NS-2)].
  3. F. Bai, G. Bhaskara, A. Helmy, "Building the Blocks of Protocol Design and Analysis - Challenges and Lessons Learned from Case Studies on Mobile Ad hoc Routing and Micro-Mobility Protocols", ACM Computer Communications Review (CCR), Special issue on Science of Networking Design, Volume 34, Number 3, pp. 57 - 69, July 2004. [Acceptance rate: 15% of 40 submissions]
  4. G. Bhaskara, A. Helmy, "TCP over Micro Mobility Protocols: A Systematic Ripple Effect Analysis", IEEE Vehicular Technology Conf (VTC), Sept '04
  5. A. Helmy, "State Analysis and Aggregation Study for Multicast-based Micro Mobility", IEEE ICC, Vol. 5, pp. 3301-3306, May 2002. [Slides (.ppt)].
STRESS PROJECT: Systematic Testing and Evaluation of Networking Protocols (Completed 4-yrs of DARPA funding) [A follow up project: 4-yr NSf/NASA-funded 'Obtaining Highly Dependable Communication Protocols' has started in Sept '02]
  1. S. Ebrahimi, A. Helmy, S. Gupta, "TCP vs. TCP: a Systematic Study of Adverse Impact of Short-lived TCP Flows on Long-lived TCP Flows", IEEE INFOCOM, March 2005. [Earlier version as ACM SIGCOMM poster, August 2004. (Poster (pdf))]
  2. K. Seada, A. Helmy, S. Gupta, "A Framework for Systematic Evaluation of Multicast Congestion Control Protocols", IEEE Journal on Selected Areas in Communications (JSAC), Special issue on Protocol Design and Testing, Vol. 22, No. 10, Dec 2004. [Earlier version at IEEE GLOBECOM, Nov '02]
  3. A. Helmy, S. Gupta, D. Estrin, 'The STRESS Method for Boundary-point Performance Analysis of End-to-end Multicast Timer-Suppression Mechanisms', IEEE/ACM Transactions on Networking (ToN), Vol. 12, No. 1, pp. 44-58, February 2004. [Earlier version in FORTE/PSTV Oct 2000.]
  4. F. Bai, G. Bhaskara, A. Helmy, "Building the Blocks of Protocol Design and Analysis - Challenges and Lessons Learned from Case Studies on Mobile Ad hoc Routing and Micro-Mobility Protocols", ACM Computer Communications Review (CCR), Special issue on Science of Networking Design, Volume 34, Number 3, pp. 57 - 69, July 2004. [Acceptance rate: 15% of 40 submissions].
  5. A. Helmy, D. Estrin, S. Gupta, "Systematic Testing of Multicast Routing Protocols: Analysis of Forward and Backward Search Techniques", The 9th International Conference on Computer Communications and Networks (IEEE ICCCN 2000), pp. 590-597, October 2000. Abstract.
  6. S. Begum, M. Sharma, A. Helmy, S. Gupta, "Systematic Testing of Protocol Robustness: Case Studies on Mobile IP and MARS", Proceedings of the 25th annual IEEE conference on Local Computer Networks (LCN), pp. 369-380, Florida, November 2000. Abstract
  7. A. Helmy, D. Estrin, S. Gupta, "Fault-oriented Test Generation for Multicast Routing Protocol Design", Proceedings of Formal Description Techniques & Protocol Specification, Testing, and Verification (FORTE/PSTV), IFIP, Kluwer Academic Publication, Paris, France, p. 93-109, November 1998.
AQM-based Marking & Fairness
  1. A. Das, D. Dutta, A. Helmy, A. Goel, J. Heidemann, "Low State Fairness: Lower Bounds and Practical Enforcement", IEEE INFOCOM, March 2005.
  2. A. Das, D. Dutta, A. Helmy, "Fair Stateless Aggregate Marking using Active Queue Management Techniques", IEEE International Conference on Management of Multimedia Networks and Services (MMNS), pp. 211-223, October 2002. (Best Paper Award).
VINT/NS PROJECT: The Virtual Internet Network Simulation and the Network Simulator NS-2) (Completed)
  1. L. Breslau, D. Estrin, K. Fall, S. Floyd, J. Heidemann, A. Helmy, P. Huang, S. McCanne, K. Varadhan, Y. Xu, H. Yu, "Advances in Network Simulation", IEEE Computer, vol. 33, No. 5, p. 59-67, May 2000. Abstract
  2. A. Helmy, D. Estrin, "Simulation-based `STRESS' Testing Case Study: A Multicast Routing Protocol", IEEE Sixth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS), Montreal, Canada, July 1998. Abstract
PIM PROJECT: Multicast Routing Protocols (Completed)
  1. D. Estrin, M. Handley, A. Helmy, P. Huang, D. Thaler, " A Dynamic Bootstrap Mechanism for Rendezvous-based Multicast Routing", Proceedings of IEEE INFOCOM '99, New York, Vol. 3, pp. 1090-1098, March 1999. Abstract [Extended]
  2. D. Estrin, D. Farinacci, A. Helmy, D. Thaler, S. Deering, V. Jacobson, M. Handley, C. Liu, P. Sharma, L. Wei, "Protocol Independent Multicast - Sparse Mode (PIM-SM): Protocol Specification, Version 2", RFC 2362/2117 of the Internet Engineering Task Force (IETF), Inter-Domain Multicast Routing (IDMR), June 1998. [RFC2362]
  3. D. Estrin, D. Farinacci, A. Helmy, D. Thaler, S. Deering, V. Jacobson, M. Handley, C. Liu, P. Sharma, L. Wei, "Protocol Independent Multicast (PIM): Motivation and Architecture", Proposed RFC of the IETF/IDMR, October 1996. [.ps]
  4. D. Estrin, D. Farinacci, A. Helmy, V. Jacobson, L. Wei, "Protocol Independent Multicast - Dense Mode (PIM-DM): Protocol Specification", Proposed RFC of the IETF/IDMR, September 1996.

Services: Serving the following conferences/journals: (TPC member unless stated otherwise)
Selected recent News:

Teaching and Courses
- Average course evaluations through '04 ~4.66/5.
- Teaching evaluations and statistics [Fall 99 - Fall 04].
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