Bio


Prabhakar's research focuses on the design, analysis, and implementation of data networks: both wireline and wireless. He has been interested in designing network algorithms, problems in ad hoc wireless networks, and designing incentive mechanisms. He has a long-standing interest in stochastic network theory, information theory, algorithms, and probability theory.

Academic Appointments


Professional Education


  • PhD, UCLA (1994)

2013-14 Courses


Journal Articles


  • EyeQ: Practical Network Performance Isolation for the Multi-tenant Cloud REM Jeyakumar, V., Alizadeh, M., Mazieres, D., Prabhakar, B., Kim, C., Greenberg, A. 2013; 1005 (A1): A2
  • INSINC: A Platform for Managing Peak Demand in Public Transit Land Transport Authority, Journeys Pluntke, C., Prabhakar, B. 2013
  • The Regulation of Ant Colony Foraging Activity without Spatial Information PLOS COMPUTATIONAL BIOLOGY Prabhakar, B., Dektar, K. N., Gordon, D. M. 2012; 8 (8)

    Abstract

    Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.

    View details for DOI 10.1371/journal.pcbi.1002670

    View details for Web of Science ID 000308553500045

    View details for PubMedID 22927811

  • Asymptotic independence of queues under randomized load balancing QUEUEING SYSTEMS Bramson, M., Lu, Y., Prabhakar, B. 2012; 71 (3): 247-292
  • Optimal throughput-delay scaling in wireless networks - Part I: The fluid model IEEE TRANSACTIONS ON INFORMATION THEORY El Gamal, A., Mammen, J., Prabhakar, B., Shah, D. 2006; 52 (6): 2568-2592
  • Randomized gossip algorithms IEEE TRANSACTIONS ON INFORMATION THEORY Boyd, S., Ghosh, A., Prabhakar, B., Shah, D. 2006; 52 (6): 2508-2530
  • Optimal throughput-delay trade-off in wireless networks – Part II: Constant-size packets IEEE Transactions on Information Theory Gamal, A., El, Mammen, J., Prabhakar, B., Shah, D. 2006; 11 (52): 5111-5116
  • SHRiNK: A method for enabling scaleable performance prediction and efficient network simulation IEEE-ACM TRANSACTIONS ON NETWORKING Pan, R., Prabhakar, B., Psounis, K., Wischik, D. 2005; 13 (5): 975-988
  • Near-optimal depth-constrained codes IEEE TRANSACTIONS ON INFORMATION THEORY Gupta, P., Prabhakar, B., Boyd, S. 2004; 50 (12): 3294-3298
  • Modeling correlations in web traces and implications for designing replacement policies COMPUTER NETWORKS Psounis, K., Zhu, A., Prabhakar, B., Motwani, R. 2004; 45 (4): 379-398
  • Delay bounds for combined inputoutput switches with low speedup Performance Evaluation Giaccone, P., Leonardi, E., Prabhakar, B., Shah, D. 2004; 1-2 (55): 113-128
  • The existence of fixed points for the ./GI/1 queue ANNALS OF PROBABILITY Mairesse, J., Prabhakar, B. 2003; 31 (4): 2216-2236
  • The attractiveness of the fixed points of a ./GI/1 queue ANNALS OF PROBABILITY Prabhakar, B. 2003; 31 (4): 2237-2269
  • Invariant rate functions for discrete-time queues ANNALS OF APPLIED PROBABILITY Ganesh, A., O'Connell, N., Prabhakar, B. 2003; 13 (2): 446-474
  • Approximate fairness through differential dropping COMPUTER COMMUNICATION REVIEW Pan, R., Breslau, L., Prabhakar, B., Shenker, S. 2003; 33 (2): 23-39
  • Incentive mechanisms for smoothing out a focused demand for network resources COMPUTER COMMUNICATIONS Leyton-Brown, K., Porter, R., Prabhakar, B., Shoham, Y., Venkataraman, S. 2003; 26 (3): 237-250
  • Randomized scheduling algorithms for highaggregate bandwidth switches IEEE Journal on Selected Areas in Communications Giaccone, P., Prabhakar, B., Shah, D. 2003; 4 (21): 546-559
  • Approximate fair allocation of link bandwidth IEEE MICRO Pan, R., Prabhakar, B., Breslau, L., Shenker, S. 2003; 23 (1): 36-43
  • The attractiveness of the fixed points of a ·/GI/1 queue Annals of Probability Prabhakar, B. 2003; 4 (31): 2237-2269
  • The existence of fixed points for the ·/GI/1 queue Annals of Probability Mairesse, J., Prabhakar, B. 2003; 4 (31): 2216-2236
  • Energy-efficient packet transmission over a wireless link IEEE-ACM TRANSACTIONS ON NETWORKING Uysal-Biyikoglu, E., Prabhakar, B., Gamal, A. E. 2002; 10 (4): 487-499
  • Efficient randomized web-cache replacement schemes using samples from past eviction times IEEE-ACM TRANSACTIONS ON NETWORKING Psounis, K., Prabhakar, B. 2002; 10 (4): 441-454
  • An implementable parallel scheduler for input-queued switches IEEE MICRO Giaccone, P., Shah, D., Prabhakar, B. 2002; 22 (1): 19-25
  • Efficient randomized algorithms for input-queued switch scheduling IEEE MICRO Shah, D., Giaccone, P., Prabhakar, B. 2002; 22 (1): 10-18
  • Maintaining statistics counters in router line cards IEEE MICRO Shah, D., Iyer, S., Prabhakar, B., McKeown, N. 2002; 22 (1): 76-81
  • Approximate fairness through differential dropping - (summary) COMPUTER COMMUNICATION REVIEW Pan, R., Breslau, L., Prabhakar, B., Shenker, S. 2002; 32 (1): 72-72
  • An implementable parallel scheduler for input queued switches IEEE Micro Giaccone, P., Shah, D., Prabhakar, B. 2002; 1 (22): 19-25
  • Approximate fair dropping for variable-length packets IEEE MICRO Psounis, K., Pan, P., Prabhakar, B. 2001; 21 (1): 48-56
  • Approximate fair dropping for variable length packets by invitation, IEEE Micro, Psounis, K., Pan, R., Prabhakar, B. 2001; 1 (21): 48-56
  • The synchronization of Poisson processes and queueing networks with service and synchronization nodes ADVANCES IN APPLIED PROBABILITY Prabhakar, B., Bambos, N., Mountford, T. S. 2000; 32 (3): 824-843
  • On the speedup required for combined input- and output-queued switching AUTOMATICA Prabhakar, B., McKeown, N. 1999; 35 (12): 1909-1920
  • Induction of experimental autoimmune Graves' disease in BALB/c mice JOURNAL OF IMMUNOLOGY Kaithamana, S., Fan, J. L., Osuga, Y., Liang, S. G., Prabhakar, B. S. 1999; 163 (9): 5157-5164

    Abstract

    We immunized BALB/c mice with M12 cells (H-2d) expressing either mouse (mM12 cells) or human thyrotropin receptor (TSHR) (hM12 cells). Immunized mice developed autoantibodies to native TSHR by day 90 and, by day 180, showed considerable stimulatory Ab activity as measured by their ability to enhance cAMP production (ranging from 6. 52 to 20.83 pmol/ml in different treatment groups relative to 1.83 pmol/ml for controls) by TSHR-expressing Chinese hamster ovary cells. These mice developed severe hyperthyroidism with significant elevations in both tetraiodothyronine and triiodothyronine hormones. Tetraiodothyronine levels in different experimental groups ranged from a mean of 8.66-12.4 microg/dl, relative to 4.8 microg/dl in controls. Similarly, mean triiodothyronine values ranged from 156.18 to 195.13 ng/dl, relative to 34.99 ng/dl for controls. Next, we immunized BALB/c mice with a soluble extracellular domain of human TSHR (TBP), or TBP expressed on human embryonic kidney cells (293 cells) (293-TBP cells). These mice showed severe hyperthyroidism in a manner very similar to that described above for mice immunized with the mouse TSHR or human TSHR, and exhibited significant weight loss, with average weight for treatment groups ranging from 20.6 to 21.67 g, while controls weighed 24.2 g. Early after onset of the disease, histopathological examination of thyroids showed enlargement of colloids and thinning of epithelial cells without inflammation. However, later during disease, focal necrosis and lymphocytic infiltration were apparent. Our results showed that conformationally intact ectodomain of TSHR is sufficient for disease induction. Availability of a reproducible model in which 100% of the animals develop disease should facilitate studies aimed at understanding the molecular pathogenesis of Graves' disease.

    View details for Web of Science ID 000083256000066

    View details for PubMedID 10528222

  • On the speedup required for combined input and output queued switching invited paper, Automatica Prabhakar, B., McKeown, N. 1999; 12 (35): 1909-1920
  • On the synchronization of Poisson processes and queueing networks with service and synchronization nodes Stanford University Computer Science Department Technical Report, STAN-CS-TR-98-1613 Prabhakar, B., Bambos, N., Mountford, T., S. 1998
  • Multicast scheduling for input-queued switches IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS Prabhakar, B., McKeown, N., Ahuja, R. 1997; 15 (5): 855-866
  • Convergence of departures in tandem networks of ·/GI/1 queues Probability in the Engineering and Informational Sciences Prabhakar, B., Mountford, T., S., Bambos, N. 1996; 10: 487-500
  • On the weak convergence of departures from an infinite series of ·/M/1 queues Annals of Applied Probability Mountford, T., S. 1995; 1 (5): 121-127
  • On infinite queueing tandems Systems & Control Letters Bambos, N., Prabhakar, B. 1994; 4 (23): 305-314

Books and Book Chapters


  • The Cesaro limit of departures from certain ·/GI/1 queueing tandems Stochastic Networks: Theory and Applications Mountford, T., S., Prabhakar, B. edited by Kelly, F., P., Zachary, S., Ziedins, I. Royal Statistical Society Lecture Note Series, Clarendon Press, Oxford. 1996: 309-322
  • IMA Volumes in Mathematics and its Applications Prabhakar, B. edited by Kelly, F., Williams, R. Springer Verlag, New York. 1995

Conference Proceedings


  • Deconstructing Datacenter Packet Transport Alizadeh, M., Yang, S., Katti, S., McKeown, N., Prabhakar, B., B., S., Shenker 2013
  • EyeQ: Practical Network Performance Isolation at the Edge Jeyakumar, V., Alizadeh, M., Mazieres, D., Prabhakar, B., Kim, C., Azure, W. 2012
  • Less Is More: Trading a Little Bandwidth for Ultra-Low Latency in the Data Center Alizadeh, M., Kabbani, A., Edsall, T., Prabhakar, B., Vahdat, A., Yasuda, M. 2012
  • Stability Analysis of QCN: The Averaging Principle Alizadeh, M., Kabbani, A., Atikoglu, B., Prabhakar, B. 2011
  • Analysis of DCTCP:Stability, Convergence, and Fairness Alizadeh, M., Javanmard, A., Prabhakar, B. 2011
  • Data Center TCP (DCTCP) Alizadeh, M., Greenberg, A., Maltz, D. A., Padhye, J., Patel, P., Prabhakar, B., Sengupta, S., Sridharan, M. ASSOC COMPUTING MACHINERY. 2010: 63-74
  • AF-QCN: Approximate fairness with quantized congestion notification for multi-tenanted data centers Kabbani, A., Alizadeh, M., Yasuda, M., Pan, R., Prabhakar, B. 2010
  • Data Center TCP (DCTCP) Alizadeh, M., Greenbergh, A., Maltz, D., A., Padhye, J., Patel, P., Prabhakar, B. 2010
  • Incentive mechanisms for decongesting roads Merugu, D., Gomes, N., R., Prabhakar, B. 2009
  • Approximate bandwidth partitioning—from academia to industry Pan, R., Bonomi, F., Prabhakar, B. 2008
  • ElephantTrap: A low cost device for identifying large flows Lu, Y., Wang, M., Prabhakar, B., Bonomi, F. 2007
  • Detailed network measurements using sparse graph counters: The theory Lu, Y., Montanari, A., Prabhakar, B. 2007
  • Analysis of randomized load balancing with general services using the cavity method Bramson, M., Lu, Y., Prabhakar, B. 2007
  • Optimal throughput-delay scaling in wireless networks - Part II: Constant-size packets El Gamal, A., Mammen, J., Prabhakar, B., Shah, D. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 2006: 5111-5116
  • Congestion control in networks with no congestion drops Lu, Y., Pan, R., Prabhakar, B., Bergamasco, D., Alaria, V., Baldini, A. 2006
  • Systems with multiple servers under heavy-tailed workloads Psounis, K., Molinero-Fernandez, P., Prabhakar, B., Papadopoulos, F. ELSEVIER SCIENCE BV. 2005: 456-474
  • Belief propagation based multi-user detection Montanari, A., Prabhakar, B., Tse, D. 2005
  • Systems with multiple servers under heavy-tailed workloads Psounis, K., Fernandez, P., Molinero, Prabhakar, B., Papadopoulos, F. 2005
  • SIFT: A simple algorithm for tracking elephant flows and taking advantage of power laws Psounis, K., Ghosh, A., Prabhakar, B., Wang, G. 2005
  • Mixing times for random walks on geometric random graphs Boyd, S., Ghosh, A., Prabhakar, B., Shah, D. 2005
  • Network hardware algorithms Prabhakar, B. 2005
  • Bloom filters: Design innovations and novel applications Lu, Y., Prabhakar, B., Bonomi, F. 2005
  • Delay bounds for combined input-output switches with low speedup Giaccone, P., Leonardi, E., Prabhakar, B., Shah, D. ELSEVIER SCIENCE BV. 2004: 113-128
  • A new proof of Parisi’s conjecture for the finite random assignment problem Nair, C., Prabhakar, B., Sharma, M. 2004
  • Analysis and opti+A69mization of randomized gossip algorithms Boyd, S., Ghosh, A., Prabhakar, B., Shah, D. 2004
  • Randomized scheduling algorithms for high-aggregate bandwidth switches Giaccone, P., Prabhakar, B., Shah, D. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 2003: 546-559
  • Entropy and the timing capacity of discrete queues Prabhakar, B., Gallager, R. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 2003: 357-370
  • The scaling hypothesis: Simplifying the prediction of network performance using scaled-down simulations Psounis, K., Pan, R., Prabhakar, B., Wischik, D. ASSOC COMPUTING MACHINERY. 2003: 35-40
  • Constrained wireless scheduling: throughput, energy and delay Giaccone, P., Prabhakar, B., Shah, D. 2003
  • On Parisi’s conjecture for the random assignment problem Sharma, M., Prabhakar, B. 2002
  • Flow table-based design to approximate fairness Pan, R., Breslau, L., Prabhakar, B., Shenker, S. 2002
  • A study of the applicability of a scaling hypothesis Pan, R., Psounis, K., Sharma, M. 2002
  • Towards simple, high-performance schedulers for high aggregate bandwidth switches Giaccone, P., Prabhakar, B., Shah, D. 2002
  • An implementable parallel scheduler for inputqueued switches Giaccone, P., Shah, D., Prabhakar, B. 2001
  • Smoothing out focused demand for network resources Leyton-Brown, K., Porter, R., Venkataraman, S., Prabhakar, B. 2001
  • Packet dropping schemes, some examples and analysis Pan, R., Nair, C., Yang, B., Prabhakar, B. 2001
  • An efficient randomized algorithm for inputqueued switch scheduling Shah, D., Giaccone, P., Prabhakar, B. 2001
  • The randomness in randomized load balancing Nair, C., Prabhakar, B., Shah, D. 2001
  • Entropy and the timing capacity of discrete queues Prabhakar, B., Gallager, R. 2001
  • A randomized cache replacement approximating LRU Psounis, K., Prabhakar, B., Engler, D. 2000
  • CHOKe — a stateless active queue management scheme for approximating fair bandwidth allocation Pan, R., Prabhakar, B., Psounis, K. 2000
  • An approximate fair dropping scheme for variable length packets Psounis, K., Pan, R., Prabhakar, B. 2000
  • Near-optimal routing lookups with bounded worst case performance Gupta, P., Prabhakar, B., Boyd, S. 2000
  • The throughput of data switches with and without speedup Dai, J., Prabhakar, B. 2000
  • Matching output queueing with a combined input/output-queued switch Chuang, S. T., Goel, A., McKeown, N., Prabhakar, B. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1999: 1030-1039
  • The entropies of queue arrivals and queue departures Gallager, R., Prabhakar, B. 1999
  • Invariant rate functions for discrete time queues Ganesh, A., J., O’Connell, N., Prabhakar, B. 1999
  • CHOKe — A stateless mechanism for providing quality of service in the Internet Prabhakar, B., Pan, R. 1999
  • Stochastic analysis of stable marriages in combined input output queued switches Goel, A., Prabhakar, B. 1999
  • Entropy and the Shannon capacity of queueing systems Gallager, R., Prabhakar, B. 1999
  • A two-bit scheme for routing lookup Prabhakar, B., Gupta, P., Boyd, S. 1999
  • A large deviations characterization of the fixed point of a ·/G/1 queue Ganesh, A., J., O’Connell, N., Prabhakar, B. 1998
  • Matching output queueing with combined input and output queueing McKeown, N., Prabhakar, B., Zhu, M. 1997
  • Tetris models for multicast switches Prabhakar, B., McKeown, N., Mairesse, J. 1996
  • The entropy and delay of processes in ATM networks Prabhakar, B., Bambos, N. 1995
  • Entropy methods for high speed communications Prabhakar, B., Bambos, N. 1995
  • Designing a multicast switch scheduler Prabhakar, B., McKeown, N. 1995
  • Convergence of departures from an infinite sequence of queues Mountford, T., S., Prabhakar, B. 1994
  • The asymptotics of traffic processes in large queueing networks Prabhakar, B., Mountford, T., S., Bambos, N. 1994
  • Estimation of wind profile from laser beam propagation distortion Balakrishnan, A., V., Prabhakar, B. 1992