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  The Mobile Wireless Networks Design and Testing Laboratory was founded in July 2000 by Prof. Ahmed Helmy. It is located in EEB-351 of the Electrical Engineering Building. The laboratory is used for both instruction and research purposes. Currently, the lab is being used and maintained by the Ph.D. students of our research group. The laboratory is currently sponsored by HP equipment award, and USC Zumberge research individual award to Prof. Helmy
Current main research directions include:

NEWS

  • May/June 2005: Effort has been initiated to establish a community-wide library of wireless networks traces (MobiLib) to help in realistic modeling of user behavior, mobility modeling and traffic modeling in wireless and mobile networks. More soon !
  • May/June 2005: R. Govindan, A. Helmy and B. Krishnamachari to establish the new wireless and sensor networking laboratory in the new RTH bldg.
  • May/June 2005: Karim Seada, Fan Bai and Narayanan Sadagopan pass their PhD defense exams. Congrats !
  • March '05: Paper (and 2 posters) accepted to ACM MOBIHOC 2005 (acceptance rate: 14%)
  • March '05: Two papers (and 3 posters) presented at IEEE INFOCOM 2005 (acceptance rate 17%). Paper accepted to IEEE/ACM DCOSS '05.
  • Nov '04: Paper presented at ACM SenSys 2004 (acceptance rate 14.5%)
  • Sept '04: New NSF funded project, ACQUIRE on querying in sensor networks, has started.
  • New April 2004: US News & World Report: USC Engineering ranked '6'th Nation-wide, and '3'rd among private universities (with only MIT (No. 1) and Stanford (No. 2) ranking higher).
    Click here for more.
  • May 2004: 5 papers accepted at the IEEE Vehicular Technology (VTC) Conference.
  • Jan 2004: acceptance of 10 publications: 3 papers at IEEE ICC, 2 papers at IEEE WCNC, 2 papers at IEEE/ACM IPCCC EWCN, 1 paper at IEEE/ACM IPDPS WMAN, 1 paper at IEEE/ACM IPSN, 1 book chapter.
  • October 2003: "Five" ( 5 ) posters accepted at the IEEE ICNP Conference 2003 (out of 22 refereed posters accepted in total by ICNP) with: S. Begum, J. Faruque, S. Wang, A. Das & D. Dutta, S. Tanachaiwiwat & P. Dave & R. Bhindwale. [List of accepted posters at ICNP]
  • September 2003: "Five" ( 5 ) posters accepted at the ACM MOBICOM Conference 2003 (out of 17 refereed posters accepted in total by Mobicom) with: K. Seada (2), J. Faruque, S. Wang, D. Son & J. Park. [List of accepted Mobicom Posters]
  • USC Today (4/5/02): 'Seven' Junior USC Engineering Faculty Win NSF Early Career Awards.
  • USC Chronicle (4/8/02): NSF Early Career Awards Go to Seven Junior Engineering Faculty.
  • USC School of Engineering (USC News) (4/6/02): A Bright Future: 7 Early CAREER Awards.
  • April 2003: US News & World Report: USC Engineering ranked '8'th Nation-wide for the 2nd year in a row. [School of Engineering News].
  • US News: USC School of Engineering ranks "8th" in the top 10 Engineering Schools for 2002/03. (up from 11th in 2001, 12th in 2000, 16th '99, ~20th '98).
    USC Computer Networks (EE, CS and ISI) ranked 3rd.
    For more information click here.
  • TRN News Journal: Shortcuts lighten wireless load, August 2002. (TRN).
    Also, in ACM TechNews, Volume 4, Issue 391, August 26, 2002.
  • October 2002: CS News [ MMNS 2002 (Best Paper Award)] USC Engineering School Recent Best Paper Honors, NSF Honors.


Recent Papers

  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.
  2. K. Nahm, A. Helmy, C.-C. Kuo, "TCP over Multihop 802.11 Networks: Issues and Performance Enhancement", ACM MobiHoc, May 2005 (acceptance rate 14%)
  3. S. Tanachaiwiwat, A. Helmy, "Correlation analysis for alleviating effects of inserted data in wireless sensor networks" , IEEE/ACM The Second Annual International Conference on Mobile and Ubiquitous Systems: Networking and Services (MobiQuitous 2005), July 17-21, 2005, San Diego California.pdf
  4. Y. Kim, A. Helmy, " SWAT: Small World-based Attacker Traceback in Ad-hoc Networks", IEEE/ACM Mobiquitous July 2005, San Diego [pdf]
  5. 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
  6. 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, Special Issue on Mobile Sensor Networks, To appear 3rd Quarter, 2004.
  7. 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. December 2004.
  8. J. Faruque, A. Helmy, "RUGGED: RoUting on finGerprint Gradients in sEnsor Networks", IEEE International Conference on Pervasive Services (ICPS), July 2004.
  9. R. Chitradurga, A. Helmy, "Analysis of Wired Short Cuts in Wireless Sensor Networks", ACS/IEEE International Conference on Pervasive Services (ICPS’2004), July 2004.
  10. A. Das, D. Dutta, A. Helmy, "A Low-state Packet Marking Framework for Approximate Fair Bandwidth Allocation", IEEE Communications Letters, To appear 2nd Quarter 2004.
  11. F. Bai, N. Sadagopan, B. Krishnamachari, A. Helmy, "Modeling Path Duration Distributions in MANETs and their Impact on Routing Performance", IEEE Journal on Selected Areas in Communications (JSAC), Special Issue on Quality of Service in Variable Topology Networks, To Appear 3rd-4th Quarter 2004. [Acceptance rate: 24% of 82 submissions]
  12. K. Seada, A. Helmy, R. Govindan, "On the Effect of Location Inaccuracy on Geographic Face Routing in Wireless Networks", ACM Mobile Computer and Communications Review (MC2R), Volume 7, Issue 4, pp. 61-63, October 2003. [Among the best poster papers from ACM MOBICOM selected for MC2R. Selection rate: 20% of 39 submissions.]
  13. J. Faruque, A. Helmy, "Gradient-Based Routing in Sensor Networks", ACM Mobile Computer and Communications Review (MC2R), Volume 7, Issue 4, pp. 50-52, October 2003. [Among the best poster papers from ACM MOBICOM selected for MC2R. Selection rate: 20% of 39 submissions.]
  14. K. Seada, A. Helmy, "Rendezvous Regions: A Scalable Architecture for Service Provisioning in Large-Scale Mobile Ad Hoc Networks", ACM SIGCOMM Computer Communication Review (CCR). To appear.
  15. W. Hsu and A. Helmy, "Encounter-based Message Broadcasting in Ad Hoc Networks with Intermittent Connectivity," MOBIHOC poster, May 2005 (doc)
  16. W. Hsu, K. Merchant, H. Shu, C. Hsu, and A. Helmy, "Weighted Waypoint Mobility Model and its Impact on Ad Hoc Networks - Mobicom 2004 Poster Abstract," Mobile Computing and Communication Review, Jan 2005 (pdf)
  17. W. Hsu,K. Merchant, H. Shu, C. Hsu, and A. Helmy, "Preference-based Mobility Modeling and the Case for Congestion Relief in WLANs using Ad hoc Networks," VTC, Sep. 2004, Los Angeles(pdf)
  18. K. Merchant, W. Hsu,H. Shu, C. Hsu, and A. Helmy, "Weighted Waypoint Mobility Model and Its Impacts on Ad Hoc Networks," Mobicom poster, Sep. 2004, Pheladelphia (ppt)
  19. F. Bai, A. Helmy, "The IMPORTANT Framework for Analyzing and Modeling the Impact of Mobility in Wireless Adhoc Networks", Book Chapter in the upcoming book on "Wireless Ad hoc and Sensor Networks" to be published by Kluwer Academic Publishers.
  20. F. Bai, A. Helmy, "A Survey of Mobility Modeling and Analysis in Wireles Adhoc Networks", Book Chapter in the upcoming book on "Wireless Ad hoc and Sensor Networks" to be published by Kluwer Academic Publishers.
  21. Karim Seada, Ahmed Helmy, Ramesh Govindan, "On the Effect of Localization Errors on Geographic Face Routing in Sensor Networks", The Third IEEE/ACM International Symposium on Information Processing in Sensor Networks (IPSN), April 2004.
  22. A. Helmy, "Efficient Resource Discovery in Wireless AdHoc Networks: Contacts Do Help", Book Chapter in the upcoming book on "Resource Management in Wireless Networking" by Kluwer Academic Publishers, To Appear May 2004.
  23. F. Bai, N. Sadagopan, A. Helmy, "BRICS: A Building-block approach for analyzing RoutIng protoCols in Ad Hoc Networks - A Case Study of Reactive Routing Protocols", USC-CS-TR-02-775, IEEE International Conference on Communications (ICC), June 2004. (Acceptance rate: less than 30%).
  24. Y. Lu, H. Lin, Y. Gu, A. Helmy, "Towards Mobility-Rich Performance Analysis of Routing Protocols in Ad Hoc Networks: Using Contraction, Expansion and Hybrid Models", IEEE International Conference on Communications (ICC), June 2004. (Acceptance rate: less than 30%).
  25. C. Shete, S. Sawhney, S. Herwadka, V. Mehandru, A. Helmy, "Analysis of the Effects of Mobility and Node Density on the Grid Location Service in Ad Hoc Networks", IEEE International Conference on Communications (ICC), June 2004. (Acceptance rate: less than 30%).
  26. K. Seada, A. Helmy, "Rendezvous Regions: A Scalable Architecture for Service Location and Data-Centric Storage in Large-Scale Wireless Networks", IEEE/ACM IPDPS 4th Int'l Workshop on Algorithms for Wireless, Mobile, Ad Hoc and Sensor Networks (WMAN), Santa Fe, April 2004. (Acceptance rate: ~32% of ~60 submissions).
  27. K. Seada, A. Helmy, "Efficient Geocasting with Perfect Delivery in Wireless Networks", IEEE Wireless Communications and Networking Conference (WCNC), March 2004.
  28. D. Son, A. Helmy, B. Krishnamachari, "The Effect of Mobility-induced Location Errors on Geographic Routing in Ad Hoc Networks: Analysis and Improvement using Mobility Prediction", IEEE Wireless Communications and Networking Conference (WCNC),March 2004.
  29. F. Bai, A. Helmy, "Comparative Analysis of Algorithms for Tree Structure Restoration in Sensor Network", IEEE Workshop on Energy-Efficient Wireless Communications and Networks (EWCN), in conjunction with IEEE International Performance, Computing, and Communications Conference (IPCCC), April 2004.
  30. S. Tanachaiwiwat, P. Dave, R. Bhindwale, A. Helmy, "Location-centric Isolation of Misbehavior and Trust Routing in Energy-constrained Sensor Networks", IEEE Workshop on Energy-Efficient Wireless Communications and Networks (EWCN), in conjunction with IEEE International Performance, Computing, and Communications Conference (IPCCC), April 2004.
  31. A. Helmy, S. Garg, P. Pamu, N. Nahata, "CARD: A Contact-based Architecture for Resource Discovery in Ad Hoc Networks", ACM Baltzer Mobile Networks and Applications (MONET) Journal, Kluwer publications, Special issue on Algorithmic Solutions for Wireless, Mobile, Ad Hoc and Sensor Networks. To appear 1st Quarter 2004.
  32. A. Helmy, "CAPTURE: location-free Contact-Assisted Power-efficienT qUery REsolution for Sensor Networks", ACM Mobile Computer and Communications Review (MC2R), Special issue on Wireless PAN and Sensor Networks, To appear January 2004.
  33. Y. Kim, J. Lee, A. Helmy, "Impact of Location Inconsistencies on Geographic Routing in Wireless Networks", ACM Mobile Computer and Communications Review (MC2R), Special issue on Wireless PAN and Sensor Networks, To appear January 2004.
  34. A. Helmy, " Mobility-Assisted Resolution of Queries in Large-Scale Mobile Sensor Networks (MARQ)", Computer Networks Journal - Elsevier Computer Science, Special issue on Wireless Sensor Networks, Vol. 43, Issue 4, pp. 437-458, November 2003. [Acceptance rate: 24% of 25 submissions]
  35. F. Bai, N. Sadagopan, A. Helmy, "The IMPORTANT Framework for Analyzing the Impact of Mobility on Performance of Routing for Ad Hoc Networks", AdHoc Networks Journal - Elsevier Computer Science, Vol. 1, Issue 4, pp. 383 - 403, November 2003. [ Technical Report (.pdf) version].
  36. N. Sadagopan, F. Bai, B. Krishnamachari, A. Helmy, " PATHS: analysis of PATH duration Statistics and their impact on reactive MANET routing protocols", ACM MobiHoc (The Fourth ACM International Symposium on Mobile Ad Hoc Networking and Computing), pp. 245-256, June 2003. (Acceptance rate: 15%) [Earlier version as a Technical Report.]
  37. F. Bai, N. Sadagopan, A. Helmy, " IMPORTANT: A framework to systematically analyze the Impact of Mobility on Performance of RouTing protocols for Adhoc NeTworks", IEEE INFOCOM (The 22nd Annual Joint Conference of the IEEE Computer and Communications Societies), pp. 825-835, March/April 2003, San Francisco. (Acceptance rate: 20%) [INFOCOM Slides (.ppt) April 2nd, 2003.]
  38. N. Sadagopan, B. Krishnamachari, A. Helmy, "The ACQUIRE Mechanism for Efficient Querying in Sensor Networks", First IEEE International Workshop on Sensor Network Protocols and Applications (SNPA), in conjunction with IEEE ICC 2003, pp. 149-155, May 2003, Anchorage, AK, USA.
  39. A. Helmy, S. Garg, P. Pamu, N. Nahata, "Contact Based Architecture for Resource Discovery (CARD) in Large Scale MANets", Third IEEE/ACM International Workshop on Wireless, Mobile and Ad Hoc Networks (WMAN), part of IEEE/ACM IPDPS 2003, pp. 219-227, April 2003, Nice, France. (Abstract .PDF) [Presentation slides (in power point)]
  40. N. Sadagopan, B. Krishnamachari, A. Helmy, "Active Query Forwarding in Sensor Networks (ACQUIRE)", April 2003. (Accepted to Journal of Ad Hoc Networks, ElSevier Science).
  41. A. Helmy, "Contact-extended Zone-based Routing for Transactions in Ad Hoc Networks", July 2003 (IEEE Transactions on Vehicular Technology, accepted with revision).
  42. A. Helmy, "Small Worlds in Wireless Networks", IEEE Communications Letters, pp. 490-492, Vol. 7, No. 10, October 2003.
  43. A. Helmy, "TRANSFER: Transactions Routing for Ad-hoc NetworkS with eFficient EneRgy", IEEE GLOBECOM, San Francisco, December 2003.
  44. K. Seada, A. Helmy, "Rendezvous Regions: A Scalable Architecture for Service Provisioning in Large-Scale Mobile Ad Hoc Networks", ACM SIGCOMM Conference, Karlsruhe, Germany, August 2003. (Refereed Poster). [Web site]
  45. Y. Kim, J. Lee, A. Helmy, "Impact of Location Inconsistencies on Geographic Routing in Wireless Networks", Sixth ACM International Workshop on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWIM), in conjunction with ACM MOBICOM, pp. 124-127, Sept 2003. (Short paper) (Acceptance rate: 14.5%. Ranked 16th in 103 papers)
  46. A. Das, D. Dutta, A. Helmy, "A Low-state Packet Marking Framework for Approximate Fair Bandwidth Allocation", (Refereed poster & extended abstract), IEEE ICNP (11th IEEE International Conference on Network Protocols), Atlanta, GA, November 2003.
  47. J. Faruque, A. Helmy, "Routing on Information Gradients in Sensor Networks", (Refereed poster & extended abstract), IEEE ICNP (11th IEEE International Conference on Network Protocols), Atlanta, GA, November 2003.
  48. S. Wang, A. Helmy, "Effects of Small Transfers and Traffic Patterns on Performance and Cache Efficacy of On-Demand Ad Hoc Routing", (Refereed poster & extended abstract), IEEE ICNP (11th IEEE International Conference on Network Protocols), Atlanta, GA, November 2003.
  49. S. Begum, S. Gupta, A. Helmy, "An Error Oriented Test Generation (EOTG) Framework for Wireless Adhoc MAC Protocols", (Refereed poster & extended abstract), IEEE ICNP (11th IEEE International Conference on Network Protocols), Atlanta, GA, November 2003.
  50. S. Tanachaiwiwat, P. Dave, R. Bhindwale, A. Helmy, "Insecure Location Avoidance and Routing on Trust in Location-aware Sensor Networks", (Refereed poster & extended abstract), IEEE ICNP (11th IEEE International Conference on Network Protocols), Atlanta, GA, November 2003.
  51. K. Seada, A. Helmy, "Rendezvous Regions: A Scalable Architecture for Service Location and Data-Centric Storage in Large-Scale Wireless Networks", (Refereed poster & extended abstract), ACM MOBICOM (The Ninth Annual International Conference on Mobile Computing and Networking), San Diego, CA, Sept 2003.
  52. Karim Seada, Ahmed Helmy, Ramesh Govindan, "On the Effect of Location Inaccuracy on Geographic Face Routing in Wireless Networks", (Refereed poster & extended abstract), ACM MOBICOM (The Ninth Annual International Conference on Mobile Computing and Networking), San Diego, CA, Sept 2003.
  53. Shao-Cheng Wang, Ahmed Helmy, "Effects of Small Transfers and Traffic Patterns on Performance and Cache Efficacy of Ad Hoc Routing", (Refereed poster & extended abstract), ACM MOBICOM (The Ninth Annual International Conference on Mobile Computing and Networking), San Diego, CA, Sept 2003.
  54. Jabed Faruque, Ahmed Helmy, "Gradient-Based Routing in Sensor Networks", (Refereed poster & extended abstract), ACM MOBICOM (The Ninth Annual International Conference on Mobile Computing and Networking), San Diego, CA, Sept 2003.
  55. D. Son, J. Park, A. Helmy, "Mobility-Induced Location Errors and its Effect on Geographic Routing in Ad Hoc Networks: Analysis and Improvement using Mobility Prediction", (Refereed poster & extended abstract), ACM MOBICOM (The Ninth Annual International Conference on Mobile Computing and Networking), San Diego, CA, Sept 2003.
  56. Karim Seada, Ahmed Helmy, Ramesh Govindan, "On the Effect of Localization Errors on Geographic Face Routing in Sensor Networks", The First ACM Conference on Embedded Networked Sensor Systems (SenSys), November 2003. (Refereed Poster) [Extended abstract to appear in conf. proceedings]
  57. S. Tanachaiwiwat, P. Dave, R. Bhindwale, A. Helmy, "Secure Locations: Routing on Trust and Isolating Compromised Sensors in Location-aware Sensor Networks", The First ACM Conference on Embedded Networked Sensor Systems (SenSys), November 2003. (Refereed Poster) [Extended abstract to appear in conf. proceedings]
  58. 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, To Appear 1st Quarter 2004.
  59. G. Bhaskara, A. Helmy, S. Gupta, "Micro Mobility Protocol Design and Evaluation: A Parameterized Building Block Approach", IEEE Vehicular Technology Conference (VTC), October 2003.
  60. 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). To appear April 2004. [Earlier Tech report version ACM-LANL-NCSTRL]