- Funded by NSF.

• - Efficient Queries and Resource Discovery in Sensor Networks:
  1. Multi-variable Query Resolution (ACQUIRE): N. Sadagopan, B. Krishnamachari, A. Helmy, "Active Query Forwarding in Sensor Networks (ACQUIRE)", AdHoc Networks Journal - Elsevier, Vol.3, No.1, pp.91-113, January 2005 [Earlier version in IEEE ICC SNPA workshop, May '03]
  2. A. Helmy, "Small Worlds in Wireless Networks", IEEE Communications Letters, pp. 490-492, Vol. 7, No. 10, October 2003.
  3. A. Helmy, " Mobility-Assisted Resolution of Queries in Large-Scale Mobile Sensor Networks (MARQ)", Computer Networks Journal - Elsevier (Special Issue on Wireless Sensor Networks), Vol. 43, Issue 4, pp. 437-458, Nov 2003.
  4. A. Helmy, "Efficient Resource Discovery in Wireless AdHoc Networks: Contacts Do Help", Book chapter in "Resource Management in Wireless Networking", Springer, ISBN: 0-387-23807-7, Vol. 16, 2005. [Earlier Journal Version in IEEE Transactions on Vehicular Technology, Jan '05]
• - Gradient-based Routing:
  1. J. Faruque, K. Psounis, A. Helmy, "Analysis of Gradient-based Routing Protocols in Sensor Networks", IEEE/ACM Int'l Conference on Distributed Computing in Sensor Systems (DCOSS), June 2005.
  2. RUGGED: J. Faruque, A. Helmy, "RUGGED: RoUting on finGerprint Gradients in sEnsor Networks", IEEE Int'l Conf. on Pervasive Services (ICPS), Jul 04. Also, among the best posters from ACM MOBICOM 2003 [Poster, Abstract (.ps)]

M&M (Multicast-based Architecture for IP Mobility) (Completed)

- Funded by Nortel & USC.

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.

STRESS (Systematic Testing and Evaluation of Networking Protocols) (Completed)

- Funded by NSF, NASA, and DARPA.

1. S. Begum, A. Helmy, S. Gupta, "Modeling the Interactions Between MAC and Higher Layers: A Systematic Approach to Generate High Level Scenarios from MAC Level Scenarios", ACM Transactions on Modeling and Computer Simulation (TOMACS). Accepted, to appear in Spring 2010.
2. S. Begum, A. Helmy, S. Gupta, "Modeling and Test Generation for Worst-Case Performance Evaluation of MAC Protocols for Wireless Ad Hoc Networks", IEEE Int'l Symposium on Modelling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS), full presentation, Sept. 2009.
3. S. Begum, S. Gupta, A. Helmy, "Performance Analysis of Wireless MAC Protocols using a Search-based Framework", 15th IEEE Int'l Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS), Oct. 2007.
4. 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))]
5. 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]
6. 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.]
7. 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].
8. A. Helmy, D. Estrin, S. Gupta, "Systematic Testing of Multicast Routing Protocols: Analysis of Forward and Backward Search Techniques", The 9^th International Conference on Computer Communications and Networks (IEEE ICCCN 2000), pp. 590-597, October 2000. Abstract.
9. S. Begum, M. Sharma, A. Helmy, S. Gupta, "Systematic Testing of Protocol Robustness: Case Studies on Mobile IP and MARS", Proceedings of the 25^th annual IEEE conference on Local Computer Networks (LCN), pp. 369-380, Florida, November 2000. Abstract
10. 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 (Completed)

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, "A Low-state Packet Marking Framework for Approximate Fair Bandwidth Allocation", IEEE Communications Letters, Vol. 8, No. 9, pp. 588-590, Sept 2004.
3. 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 (The Virtual Internet Network Simulation & 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.
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.

PIM (The Protocol-Indepent Multicast Routing Protocol) (Completed)

- Partially funded by Silicon Graphics Inc., Sun Microsystems, and Cisco, among others.

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.
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.

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