Select Publications

Select Publications (On Network Analytics, and Mobile and Sensor Networks):

B. Alipour, L. Tonetto, R. Ketabi, A. Ding, J. Ott, A. Helmy, “Where Are You Going Next? A Practical Multi-dimensional Look at Mobility Prediction”, In proceedings of the ACM MSWiM (22nd International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems), pp. 5-12, November 2019.
R. Ketabi, M. Al-Qathrady, B. Alipour, A. Helmy, “Vehicular Traffic Density Forecasting through the Eyes of Traffic Cameras; a Spatio-Temporal Machine Learning Study”, In proceedings of the ACM MSWiM - DIVANet 9th ACM Symposium on Design and Analysis of Intelligent Vehicular Networks and Applications, pp. 81-88, November 2019.
B. Alipour, M. Al-Qathrady, A. Helmy, “Learning the Relation Between Mobile Encounters and Web Traffic Patterns: A Data-driven Study”, In proceedings of the ACM MSWiM (21st International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems), pp. 289-293, October 2018. [Acceptance rate: ~27%].
B. Alipour, L. Tonetto, R. Ketabi, A. Ding, J. Ott, A. Helmy, "Flutes vs. Cellos: Analyzing Mobility-Traffic Correlations in Large WLAN Traces", IEEE INFOCOM, April 2018. [Best Presentation in session] [Acceptance rate: 19%].
R. Ketabi, B. Alipour, A. Helmy, "En Route: Towards Vehicular Mobility Scenario Generation at Scale", In proceedings of the IEEE INFOCOM – SmartCity workshop, May 2017. (Average review score ‘5/5’). [Related poster is winner of The Best Poster Award, IEEE INFOCOM '17].
G. Thakur, P. Hui, A. Helmy, "Evidence of Long Range Dependence and Self-similarity in Urban Traffic Systems", In proceedings of the ACM SIGSPATIAL (International Conference on Advances in Geographic Information Systems), November 2015. [Acceptance rate: 18%]
G. Thakur, A. Helmy, "COBRA: A Framework for the Analysis of Realistic Mobility Models", In proceedings of IEEE INFOCOM - Global Internet (GI) Symposium, pp. 3351-3356, April 2013. [Winner of The Best Paper Award of the Internet Technical Committee (ITC) for 2013 (announced June 2015). Selected from ~140 published papers in seven IEEE ComSoc conferences, and ~450 submitted papers.]
D. Fay, G. Thakur, P. Hui, A. Helmy, "Knowledge Discovery and Causality in Urban City Traffic: A study using Planet Scale Vehicular Imagery Data", In proceedings of ACM SIGSPATIAL IWCTS (Int'l workshop on Computational Transportation Science), November 2013. (Best Paper Award).
G. Thakur, P. Hui, A. Helmy, "The Structure and Traffic Flow Anatomy of the Planet-Scale Urban Vehicular Mobility", Networking Science Journal - Springer, ISSN 2076-0310, pp. 13-23, December 2013.
W. Hsu, D. Dutta, A. Helmy, TRACE: "Structural Analysis of User Association Patterns in University Campus Wireless LANs", IEEE Transactions on Mobile Computing (TMC), Vol. 11, No. 11, pp. 1734-1748, November 2012.
( Earlier version at ACM MobiCom, pp. 338-341, Sept. 2007. [In the top 11% of 233 submissions.]) [Extended version as technical report].
W. Hsu, D. Dutta, A. Helmy, "CSI: A Paradigm for Behavior-oriented Profile-cast Services in Mobile Networks, Ad Hoc Networks Journal - Elsevier, Vol. 10, Issue 8, pp. 1586-1602, November 2012.
(Earlier short version in ACM Mobile Computer and Communications Review (MC2R), Vol. 12, Issue 1, pp. 52-54, January 2008. [Top 5 in ACM Mobicom 07 SRC, out of ~60 submissions]. Conference version appeared in IEEE WCNC (Wireless Communications and Networking Conference), pp. 3033-3038, March 2008).
S. Wang, A. Helmy, "BEWARE: Background Traffic-Aware Rate Adaptation for IEEE 802.11", Extended (plenary session) paper at The 9th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM), June 2008 [Acceptance rate of Extended papers at the plenary session: 7% of 181 submissions. Acceptance rate overall: 17%] (Journal version in IEEE/ACM Transactions on Networking, Vol. 19, Issue 4, August 2011.).
(Earlier short version in ACM MC2R, Vol. 13, Iss. 3, pp. 46-49, Jul 09. [4th place finalist in ACM MobiCom 08 SRC, out of ~60 submissions]).
S. Moghaddam, A. Helmy, S. Ranka, M. Somaya, "Data-driven Co-clustering Model of Internet Usage in Large Mobile Societies", 13th ACM Int'l Conf on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWIM), Oct 2010 [Typical acceptance rate: ~20%].
U. Kumar, A. Helmy, "Extract: Mining Social Features from WLAN Traces: A Gender-Based Case Study", ACM MSWIM, Oct 2010.
(Workshop version presented at IEEE/ACM IPSN Int'l Workshop on Mobile Device and Urban Sensing (MODUS), April 2008. Earlier short version in ACM MC2R, Vol. 12, Issue 1, pp. 40-42, January 2008. [Winner of 3rd place prize in ACM Mobicom 2007 Student Research Competition (SRC), out of ~60 submissions]).
W. Hsu, T. Spyropoulos, K. Psounis, A. Helmy, TVC: "Modeling Spatial and Temporal Dependencies of User Mobility in Wireless Mobile Networks", IEEE/ACM Transactions on Networking, pp. 1564-1577, Vol. 17, No. 5, October 2009.
(Conference version appeared in IEEE INFOCOM, pp.758-766, May 2007 [Acceptance rate: ~17%]).
IMPACT study:
- W. Hsu, A. Helmy, "On Nodal Encounter Patterns in Wireless LAN Traces", IEEE Transactions on Mobile Computing (TMC), pp. 1563-1577, November 2010. (Earlier version in IEEE WiNMee, April 2006. Nominated for best paper award at USC EE Dept, 2006).
- W. Hsu, A. Helmy, "On Modeling User Associations in Wireless LAN Traces on University Campuses", IEEE Int'l Workshop on Wireless Network Measurement (WiNMee), April 2006.
K. Seada, A. Helmy, R2D2: "Geographic Rendezvous-based Architectures for Emergency Data Dissemination", Journal on Wireless Communications and Mobile Computing, Wiley, Vol. 10, Issue 9, pp. 1221-1237, September 2010. (Early version). (Conference version appeared in IEEE/ACM IPDPS Int'l Workshop on Algorithms for Wireless, Mobile, Ad Hoc and Sensor Networks (WMAN), pp.218-225, Apr 2004. Paper among the best reviewed.).
S. Tanachaiwiwat, A. Helmy, "Encounter-based Worms: Analysis and Defense", Ad Hoc Networks Journal - Elsevier. Volume 7, Issue 7, Pages 1414-1430, September 2009.
(Conference version appeared in ACM MobiCom Workshop on Challenged Networks (CHANTS), pp. 67-74, September 2007).
Y. Kim, A. Helmy, "CATCH: A Protocol Framework for Cross-layer Attacker Traceback in Mobile Multi-Hop Networks", Ad Hoc Networks Journal - Elsevier, pp. 193-213, Vol. 8, Issue 2, March 2010.
(Conference version in Proceedings of the ACM SASN (fourth ACM workshop on Security of ad hoc and sensor networks), pp. 123-134, October 2006.)
M. Zuniga, K. Seada, B. Krishnamachari, A. Helmy, "Efficient Geographic Routing over Lossy Links in Wireless Sensor Networks", ACM Transactions on Sensor Networks (TOSN), pp. 12:1-33, Article 12 (33 pages), Vol. 4, No. 3, May 2008. (Conference version appeared in ACM SenSys (Conference on Embedded Networked Sensor Systems), pp. 108-121, November 2004. [Acceptance: 14%] [Nominated for best paper award at USC EE Dept, 2005]). (Related work on geographic routing with power control appeared in IEEE SECON, Sep 2005 [Acceptance: 27%]).
K. Seada, A. Helmy, R. Govindan, "Modeling and Analyzing the Correctness of Geographic Face Routing under Realistic Conditions", Ad Hoc Networks Journal - Elsevier, Special issue on Recent Advances in Wireless Sensor Networks, pp. 855-871, Vol. 5, Issue 6, August 2007. (Conference version appeared in IEEE/ACM IPSN (Int'l Symposium on Information Processing in Sensor Networks), pp. 71-80, April 2004. [Acceptance rate: 33% of 150] [Nominated for best paper award at USC EE Dept, 2004]).
K. Nahm, A. Helmy, C.-C. Kuo, "Cross-layer Interaction of TCP and Ad Hoc Routing Protocols in Multihop 802.11 Networks", IEEE Transactions on Mobile Computing (TMC), pp. 458 - 469, Vol. 7, Issue 4, April 2008. (Conference version appeared in ACM MobiHoc (Int'l Symposium on Mobile Ad Hoc Networking and Computing), pp. 277-287, May 2005. [Acceptance rate: 14% of 281 submissions]).
F. Bai, A. Helmy, MAID: "Impact of Mobility on Mobility-Assisted Last Encounter Based Routing Protocols", IEEE SECON (Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks), pp. 461-470, June 2007. [Acceptance: 20%]. (Journal version in submission).
K. Seada, A. Helmy, "Efficient and Robust Geocasting Protocols for Sensor Networks", Computer Communications Journal-Elsevier, Special Issue on Dependable Wireless Sensor Networks, Vol. 29, Issue 2, pp. 151-161, January 2006 (Conference version appeared IEEE WCNC, pp. 2551 - 2556, March 2004).
A. Helmy, S. Garg, P. Pamu, N. Nahata, "CARD: A Contact-based Architecture for Resource Discovery in Ad Hoc Networks", ACM Mobile Networks and Applications (MONET) Journal, Vol. 10, Issue 1, pp. 99-113, February 2005. [Acceptance rate: 22% of 60 submissions] (Conference version appeared in IEEE/ACM IPDPS Int'l Workshop on Wireless, Mobile and Ad Hoc Networks (WMAN), pp. 219-227, Apr 2003. [Acceptance: 29%] [Paper was among the best reviewed. Selected for forwarding to the ACM MONET Journal]).
N. Sadagopan, B. Krishnamachari, A. Helmy, ACQUIRE: "Active Query Forwarding in Sensor Networks", Ad Hoc Networks Journal - Elsevier, Vol. 3, Issue 1, pp. 91-113, January 2005. [Acceptance rate: 12%] (Conference version" appeared in IEEE ICC Int'l Workshop on Sensor Network Protocols and Applications (SNPA), pp. 149-155, May 2003. [Acceptance: 37%]).
A. Helmy, TRANSFER: "Contact-extended Zone-based Routing for Transactions in Ad Hoc Networks", IEEE Transactions on Vehicular Technology, Vol. 54, No. 1, pp. 307-319, January 2005. (Conference version appeared in IEEE GLOBECOM (Global Telecom. Conf), pp. 398-404, December 2003. [Acceptance: 27%]).
F. Bai, N. Sadagopan, B. Krishnamachari, A. Helmy, PATHS: "Modeling Path Duration Distributions in MANETs and their Impact on Routing Performance", IEEE Journal on Selected Areas in Communications (JSAC), Vol. 22, No. 7, pp. 1357-1373, September 2004. [Acceptance rate: 18% of 82] [Nominated for best paper award at USC EE Dept, 2005]. (Conference version appeared in ACM MobiHoc, pp. 245-256, June 2003. [Acceptance rate: 15% of 189 submissions]).
D. Son, A. Helmy, B. Krishnamachari, "The Effect of Mobility-induced Location Errors on Geographic Routing in Mobile Ad Hoc and Sensor Networks: Analysis and Improvement using Mobility Prediction", IEEE Transactions on Mobile Computing (TMC), Special issue on Mission-Oriented Sensor Networks, Vol. 3, No. 3, pp. 233-245, July 2004 [Acceptance rate: 25%] (Conference version appeared in IEEE WCNC, pp. 189-194 March 2004).
F. Bai, N. Sadagopan, A. Helmy, "The IMPORTANT Framework for Analyzing the Impact of Mobility on Performance of Routing for Ad Hoc Networks", Ad Hoc Networks Journal - Elsevier, Vol. 1, Issue 4, pp. 383 - 403, November 2003. [Acceptance rate: 12%][Nominated for best paper award at USC EE Dept, 2004]. On the top 25 most requested articles (Ad Hoc Networks Journal) for Jan-Dec'03 & Jan-Mar'04. (Conference version appeared in IEEE INFOCOM, pp. 825-835, April 2003. Paper selected for fast-track to the Ad Hoc Networks Journal. [Infocom acceptance rate: 20% of 1078 submissions])
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, November 2003. [Acceptance rate: 24% of 25 submissions].
A. Helmy, "Small Worlds in Wireless Networks", IEEE Communications Letters, pp. 490-492, Vol. 7, No. 10, October 2003.
A. Helmy, M. Jaseemuddin, Ganesha Bhaskara, M&M: "Multicast-based Mobility: A Novel Architecture for Efficient Micro-Mobility", IEEE Journal on Selected Areas in Communications (JSAC), Vol. 22, No. 4, pp. 677-690, May 2004. [Acceptance rate: 25% of 60 submissions] (Earlier work on M&M appeared in ACM SIGCOMM Int'l Workshop on Networked Group Communication (NGC), pp. 49-58, November 2000. [Acceptance: 24%]).

Other Select Publications (on Networking and Internet Protocols Design and Testing):

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, pp. 926-937, March 2005. [Acceptance rate: 17% of 1419 submissions] [Nominated for best paper award at USC EE, 2005].
A. Das, D. Dutta, A. Helmy, A. Goel, J. Heidemann, "Low State Fairness: Lower Bounds and Practical Enforcement", IEEE INFOCOM, pp. 2436-2446, March 2005 [Acceptance rate: 17%]. (The framework design appeared in IEEE Communications Letters, Vol. 8, No. 9, pp. 588-590, Sept 2004.) (Earlier work on Fair Stateless Aggregate Marking with A. Das and D. Dutta appeared in IEEE/IFIP MMNS (Management of Multimedia Networks and Services, pp. 211-223, October 2002. (Best Paper Award)).
A. Helmy, S. Gupta, "FOTG: Fault Oriented Stress Testing of Multicast Routing", IEEE Communications Letters, Vol. 9, No. 4, pp. 375-377, April 2005. (Conference version appeared in IFIP FORTE/PSTV, Paris, pp. 93-109, November 1998. [Acceptance rate: 30% of 85], and another conference version" comparing forward and backward search appeared IEEE ICCCN (IC3N), pp. 590-597, October 2000.)
K. Seada, A. Helmy, S. Gupta, "A Framework for Systematic Evaluation of Multicast Congestion Control Protocols", IEEE Journal on Selected Areas in Communications (JSAC), Volume 22, Issue 10, pp. 2048- 2061, December 2004. [Nominated for best paper award at USC EE, 2005].
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, Volume 12, Issue 1, pp. 44-58, February 2004. [Acceptance rate '03: 18% of 439] (Conference version appeared in IFIP FORTE/PSTV (Formal Description Techniques & Protocol Specification, Testing, and Verification, pp. 187-202, October 2000. [Acceptance: 34% of 63]).
L. Breslau, D. Estrin, K. Fall, S. Floyd, J. Heidemann, A. Helmy, P. Huang, S. McCanne, K. Varadhan, Y. Xu, H. Yu, NS-2: "Advances in Network Simulation", IEEE Computer, vol.33, No.5, pp. 59-67, May 2000. [Top 65 most cited papers in computer science in 2000 (Citeseer Jul '03)]
PIM-SM protocol:
- D. Estrin, M. Handley, A. Helmy, P. Huang, D. Thaler, "A Dynamic Bootstrap Mechanism for Rendezvous-based Multicast Routing", IEEE INFOCOM, Vol. 3, pp. 1090-1098, March 1999. [Acceptance rate: 30% of 600 submissions].
- 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", RFCs 2362 of the Internet Engineering Task Force (IETF), Inter-Domain Multicast Routing (IDMR), June 1998. [RFC2362. Earlier version as RFC2117 in 1997]
- 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, Inter-Domain Multicast Routing (IDMR), October 1996.