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Mohamed Kadhem Karray's Homepage

Orange Labs
38-40 rue du Général Leclerc
92794 Issy-Moulineaux cedex 9, France

Email: mohamed.karray (at) orange (dot) com
Tél: 33 1 45295373



Conference Papers

  1. F. Baccelli, B. Blaszczyszyn, M.K. Karray (2005) Blocking rates in large CDMA networks via a spatial Erlang formula, in Proc. of IEEE Infocom, Miami, USA. [ pdf | bib ]
  2. B. Blaszczyszyn, M.K. Karray (2007) Performance evaluation of scalable congestion control schemes for elastic traffic in cellular networks with power control, in Proc. of IEEE Infocom, Anchorage, Alaska, USA. [ pdf | bib  ]
  3. B. Blaszczyszyn, M.K. Karray (2008) Impact of mean user speed on blocking and cuts of streaming traffic in cellular networks, in Proc. of European Wireless Conference, Praha, Czech Republic. [ pdf | bib ]
  4. B. Blaszczyszyn, M.K. Karray (2008) An efficient analytical method for dimensioning of CDMA cellular networks serving streaming calls, in Proc. of ValueTools Conference, Athens, Greece. [ pdf | bib ]
  5. B. Blaszczyszyn, M.K. Karray (2009) Dimensioning of the downlink in OFDMA cellular networks via an Erlang's loss model, in Proc. of European Wireless Conference, Aalborg, Denmark. [ pdf | bib ]
  6. B. Blaszczyszyn, M.K. Karray (2009) Fading effect on the dynamic performance evaluation of OFDMA cellular networks, in Proc. of International Conference on Communications and Networking (ComNet), Hammamet, Tunisia. Best paper award. [ pdf | bib ]
  7. M.K. Karray (2009) Study of a key factor for performance evaluation of wireless cellular networks: The f-factor, in Proc. of IFIP Wireless Days, Paris, France. [ pdf | bib ]
  8. M.K. Karray (2010) Electromagnetic exposure and quality of service in the downlink of wireless cellular networks, in Proc. of International Conference on Wireless and Mobile Communications (ICWMC), Valence, Spain. [ pdf | bib | Slides ]
  9. B. Blaszczyszyn, M.K. Karray, F-X. Klepper (2010) Impact of the geometry, path-loss exponent and random shadowing on the mean interference factor in wireless cellular networks, in Proc. of IFIP Wireless and Mobile Networking Conference (WMNC), Budapest, HungaryBest paper award. [ pdf | bib ]
  10. M.K. Karray (2010) Evaluation of the blocking probability and the throughput in the uplink of wireless cellular networks, in Proc. of International Conference on Communications and Networking (ComNet), Tozeur, Tunisia. [ pdf | bib | Slides ]
  11. M.K. Karray (2010) Spectral and energy efficiencies of OFDMA wireless cellular networks, in Proc. of IFIP Wireless Days, Venice, ItalyBest paper award. [ pdf | bib | Slides ]
  12. M.K. Karray, Y. Khan (2012) Evaluation and comparison of resource allocation strategies for new streaming services in wireless cellular networks, in Proc. of International Conference on Communications and Networking (ComNet), Hammamet, Tunisia. [ pdf | bib ]
  13. B. Blaszczyszyn, M.K. Karray (2012) Linear-regression estimation of the propagation-loss parameters using mobiles' measurements in wireless cellular networks, in Proc. of WiOpt, Germany. [ pdf | bib ]
  14. M.K. Karray , M. Jovanovic (2012) Theoretically feasible QoS in a MIMO cellular network compared to the practical LTE performance, in Proc. of International Conference on Wireless and Mobile Communications (ICWMC), Venice, Italy.  [ pdf | bib | Slides ]
  15. B. Blaszczyszyn, M.K. Karray, H.P. Keeler (2013) Using Poisson processes to model lattice cellular networks, In Proc. of IEEE Infocom, Turin, Italy. [ pdf | bib ]
  16. H. P. Keeler, B. Błaszczyszyn, M.K. Karray (2013) SINR-based k-coverage probability in cellular networks with arbitrary shadowing. In Proc. of IEEE ISIT, Istanbul, Turkey.  [ pdf | bib ]
  17. B. Błaszczyszyn, M. Jovanovic, M.K. Karray (2014) How user throughput depends on the traffic demand in large cellular networks. In Proc. of WiOpt/SpaSWiN, Hammamet, Tunisia. [ pdf | bib | Slides ]
  18. M. Jovanovic, M.K. Karray, B. Błaszczyszyn (2014) QoS and network performance estimation in heterogeneous cellular networks validated by real-field measurements. In Proc. of PM2HW2N, Montreal, Canada. [ pdf | bib | Slides ]
  19. B. Blaszczyszyn, M. Jovanovic, M.K. Karray (2015) Performance laws of large heterogeneous cellular networks. Accepted for WiOpt/SpaSWiN 2015.
  20. B. Blaszczyszyn, M.K. Karray (2015) What frequency bandwidth to run cellular network in a given country? - a downlink dimensioning problem. Accepted for WiOpt/SpaSWiN 2015.

Journal Papers

  1. F. Baccelli, B. Blaszczyszyn, M.K. Karray (2004) Up and downlink admission/congestion control and maximal load in large homogeneous CDMA networks, in Mobiles Networks and Applications (MONET), vol. 9, no. 6. [ pdf | bib ]
  2. M.K. Karray (2010) Analytical evaluation of QoS in the downlink of OFDMA wireless cellular networks serving streaming and elastic traffic, in IEEE Transactions on Wireless Communications, May 2010, vol. 9, no. 5. [ pdf | bib ] 
  3. M.K. Karray (2010) Analytical expressions for blocking and dropping probabilities for mobile streaming users in wireless cellular networks, in Wireless Networks (Springer), November 2010, vol. 16, no. 8. [ pdf | bib ]
  4. M.K. Karray (2010) User's mobility effect on the performance of wireless cellular networks serving elastic traffic, in Wireless Networks (Springer). [ pdf | bib ]
  5. B. Blaszczyszyn, M.K. Karray (2012) Effect of opportunistic scheduling on the quality of service perceived by the users in OFDMA cellular networks, in Annals of telecommunications (Springer), April 2012, vol. 67, no. 3. [ pdf | bib ]
  6. B. Blaszczyszyn, M.K. Karray (2013)  Quality of service in wireless cellular networks subject to log-Normal shadowing, IEEE Transactions on Communications, February 2013, vol. 61, no. 2. [ pdf | bib ]
  7. M. Jovanovic, M.K. Karray (2013)  A queueing theoretic approach to the dimensioning of wireless cellular networks serving variable bit-rate calls, in IEEE Transactions on Vehicular Technology, July 2013, vol. 62, no. 6. [ pdf | bib ]
  8. S. El Ayoubi, S. Jeux, M.K. Karray, Y. Khan (2013)  A novel hybrid simulation methodology for capacity estimation in mobile networks, in Physical Communication, Elsevier. [ pdf | bib ]
  9. B. Błaszczyszyn, M. Jovanovic, M.K. Karray (2014) Quality of real-time streaming in wireless cellular networks: Stochastic modeling and analysis, in IEEE Transactions on Wireless Communications, June 2014, vol. 13, no. 6. [ pdf | bib ]
  10. B. Blaszczyszyn, , M.K. Karray, and H.P. Keeler (2015) Wireless networks appear Poissonian due to strong shadowing. Accepted for IEEE Transactions on Wireless Communications
  11. M.K. Karray, M. Jovanovic, B. Blaszczyszyn (2015) Theoretical expression of link performance in OFDM cellular networks with MIMO compared to simulation and measurements, Accepted for Annals of telecommunications (Springer).

Thesis

Analytic evaluation of wireless cellular networks performance by a spatial Markov process accounting for their geometry, dynamics and control schemes, 10 Septembre 2007, ENST, Paris under the guidance of Eric Moulines and Bartek Blaszczyszyn. [ pdf | bib ]

Patents

  1. F. Baccelli, B. Blaszczyszyn, M.K. Karray (2003) Contrôle de charge dans le sens montant pour les systèmes de communication sans fil avec contrôle de puissance, April 2003, FR03 05355. 
  2. F. Baccelli, B. Blaszczyszyn, M.K. Karray (2003) Dispositif et procédé de contrôle de charge avec contrôle de puissance, April 2003, FR03 05354. 

Invited presentations

  1. B. Blaszczyszyn, M.K. Karray (2010) Fading effect on the dynamic performance evaluation of OFDMA cellular networks, INRIA/TREC and radio flexible chair (Supélec), Paris, France.
  2. M.K Karray (2010) Global performance evaluation of wireless cellular networks : user's QoS, dimensioning and optimisation, Keynote Speaker at ComNet conference, Tozeur, Tunisia. [ bib | Slides
  3. B. Blaszczyszyn, M.K. Karray (2011) Wireless cellular networks with shadowing, GDR ISIS, Paris, France.
  4. M.K Karray (2014) Stochastic modeling and analysis of wireless cellular networks, Keynote Speaker at WiOpt/SpaSWiN conferenceHammamet, Tunisia. [ Slides
  5. B. Błaszczyszyn, M. Jovanovic, M.K. Karray, (2014). Quality of real-time streaming in wireless cellular networks: Stochastic modeling and analysis, Keynote Speaker at WiOpt/WiVid conferenceHammamet, Tunisia. [ Slides
  6. B. Błaszczyszyn, M.K. Karray, (2015). How performance metrics depend on the traffic demand in large cellular networks, Simons Conference on Networks and Stochastic GeometryUniversity of Texas at Austin. [ Slides

Thesis direction

Evaluation and optimization of the quality perceived by mobile users for new services in cellular networks (more details in pdf ).

Short Biography

I received my diploma in engineering from Ecole Polytechnique (Paris, France) and Ecole Nationale Supérieure des Télécommunications (Paris, France) in 1991 and 1993, respectively.
In 1993 I joined France Telecom R&D in Issy-les-Moulineaux, France.
My research activities aim to evaluate the performance of communication networks. My principle tools are probability and stochastic processes, and more specifically  information and queueing theories as well as stochastic geometry. In my recent research I show how to articulate the tools of these theories to build global analytical performance evaluation methods for wireless cellular networks which are validated by measurements in real networks. These methods are used by Orange Operator for dimensionning its networks and for several practical studies of performance evaluation of these networks.

Teaching

Teaching assistant at Math Spé M' (Louis Le Grand) (1990-1992).
Teaching assistant at Ecole Centrale Paris for the courses by Claude Lamoureux : 'Applied Mathematics' (1992-1996).
Teaching assistant at Ecole Normale Supérieure  (ULM, Paris) for the courses by Pierre Brémaud and François Baccelli :
  1. 'Probability and stochastic processes' (2005-2006)
  2. 'Markov processes, Queueing theory' (2006-2007)
  3. 'Mathematical principles of signal processing' (2007-2008)
  4. 'Random algorithms and structures: Random graphs, Monte Carlo simulation' (2008-2009)