The 2009 International Conference on High Performance Computing and Simulation (HPCS 2009)
June 21 - 24, 2009, Leipzig, Germany


Mobility Modeling for Future Mobile Network Design and Simulation

Ahmed Helmy
University of Florida
Gainesville, Florida, USA

Future networks will consist of numerous wireless devices, many of which will be mobile. With the proliferation of handheld devices that are tightly coupled with our everyday life, human mobility is likely to play a key role in designing and evaluating efficient networks and services of the future. A new generation of infrastructure-less networks is being introduced, including ad hoc, sensor and delay tolerant networks that will rely heavily of mobile nodes for connectivity and communication establishment. Also, with the introduction of vehicular networks, it will be imperative to model and understand vehicular mobility patterns. Hence, there is a compelling need to study, analyze and understand mobility models in order to have valid evaluation tools for future mobile protocols, networks and services. This tutorial discusses issues of mobility modeling, focusing on 'realistic' aspects traditionally ignored in random models (such as random walks, or random way point). The tutorial has two main parts. The first part starts from the classification of major mobility models, establishes a framework (called IMPORTANT) to systematically analyze such models and walks through several key studies that motivate the need for new models. By evaluating the effects of mobility on several classes of future mobile networks and protocols (e.g., ad hoc and encounter routing protocols) the tutorial provides insight into the shortcomings of conventional (random) models and introduces another rich set of models (e.g., Group, Freeway, Manhattan). Focus is given to two main questions: Why and how does mobility affect routing performance? The second part of the tutorial utilizes extensive measurements of existing wireless networks (mainly WLANs and Bluetooth) to establish a more realistic set of mobility models based on time-varying communities (TVC). Insight established from the analysis is utilized to design a new efficient communication paradigm called 'profile-cast' for mobile social networks. Various tools for mobility modeling and simulation are also referenced and discussed.


We cover the following topics:


  1. 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. (Conference version appeared in IEEE INFOCOM, pp. 825-835, April 2003.)
  2. 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. (Conference version appeared in ACM MobiHoc, pp. 245-256, June 2003.
  3. W. Hsu, A. Helmy, IMPACT I: "On Nodal Encounter Patterns in Wireless LAN Traces", IEEE Int'l Workshop on Wireless Network Measurement (WiNMee), April 2006.
  4. W. Hsu, A. Helmy, IMPACT II: "On Modeling User Associations in Wireless LAN Traces on University Campuses", IEEE Int'l Workshop on Wireless Network Measurement (WiNMee), April 2006.
  5. 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. Accepted. To appear Spring 2009. (Conference version appeared in IEEE INFOCOM, pp.758-766, May 2007).
  6. W. Hsu, D. Dutta, A. Helmy, "Profile-Cast: Behavior-Aware Mobile Networking", ACM Mobile Computer and Communications Review (MC2R), Vol. 12, Issue 1, pp. 52-54, January 2008. (Conference version appeared in IEEE WCNC (Wireless Communications and Networking Conference), pp. 3033-3038, March 2008).
  7. W. Hsu, D. Dutta, A. Helmy, "Mining Behavioral Groups in Large Wireless LANs", ACM MobiCom, pp. 338-341 (short paper), Sept. 2007.
  8. F. Bai, A. Helmy, MAID: "Impact of Mobility on Mobility-Assisted Last Encounter Based Routing Protocols", IEEE SECON (4th Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks), pp. 461-470, June 2007.
  9. 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", IEEE Int'l Conf on Communications (ICC), Vol. 6, pp. 3618-3622, June 2004.

Basic understanding of computer networks (wireless and mobile networks preferable), and basic understanding of network simulation.  Target audience includes students and researchers in the area of computer networks.

The tutorial material will be presented in a 2 to 3-hour session.

Computer projector for slides presentation.

Dr. Ahmed Helmy received his Ph.D. in Computer Science (1999) with Prof. Deborah Estrin, M.S. in Electrical Engineering (EE) (1995) from the University of Southern California (USC), M.S. Eng. Math. (1994) and B.S. in EE (1992) with highest honors from Cairo Univ, Egypt. He is an Associate Professor and the founder/director of the wireless networking lab at the Computer and Information Science and Engineering (CISE) Dept, University of Florida, Gainesville.

From 1999 to 2006, he was an Assistant Professor of EE at USC. He was also the founder/director of the wireless networking laboratory at USC. He was a key researcher in the network simulator (NS-2) [in collaboration with UC-Berkeley and LBNL] and the protocol independent multicast (PIM-SM) projects at USC/ISI in collaboration with Cisco, Berkeley LBNL, Xerox PARC. His research interests lie in the areas of network protocol design and analysis for mobile ad hoc and sensor networks, mobility modeling, multicast protocols, IP micro-mobility, and network simulation. His projects have been funded by NSF, DARPA, NASA, Intel, Nortel, P&W, Cisco, SGI. He is a leader of the NSF funded projects: Mars, Stress, Acquire and Aware.

In 2002, he received the NSF CAREER Award. In 2000 he received the USC Zumberge Research Award, and in 2002 he received the best paper award from the IEEE/IFIP Int'l Conference on Management of Multimedia and Mobile Networks and Services (MMNS). In 2003 he was the EE nominee for the USC Engineering Jr. Faculty Research Award, and a nominee for the Sloan Fellowship. In 2004 and 2005 he got the best faculty merit ranking at the EE dept, USC. He was a winner in the ACM Mobicom SRC research competition 2007, and finalist in 2008.

He is an Area editor of the Adhoc Networks Journal - Elsevier since 2004, and Editor of ACM Sigmobile MC2R Journal since 2009. He is the co-chair for the IFIP/IEEE MMNS 2006, IEEE Infocom Global Internet (GI) workshop 2008, local chair for IEEE ICNP 2008, poster and area chair for ICNP 2009, vice-chair for IEEE ICPADS 2006, and IEEE HiPC 2007. He is the ACM Sigmobile workshop coordination chair (including ACM MobiCom, Mobihoc, Mobisys, SenSys) since 2006. He served on the program committees for numerous IEEE and ACM conferences in areas of computer and wireless networks. He currently also holds courtesy appointments at the Electrical Engineering Departments at UFL and USC. [homepage:]