Shivendra S. Panwar

Polytechnic Institute of New York University, Brooklyn, New York, United States

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Publications (144)61.79 Total impact

  • Huawen Ye · Zhong-Ping Jiang · Shivendra Panwar · Weihua Gui
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    ABSTRACT: This paper presents saturated delayed controls for nonlinear multiple integrators that are in a feedforward form, guaranteeing that the closed-loop system are globally asymptotically stable at the origin. To compensate input delay of arbitrary length, the suggested algorithm depends on suitable normal forms rather than the homogeneity of multiple integrators, and consequently leads to the parameterizations different from the existing one. To illustrate the algorithm, saturated delayed controls are presented for the inertia wheel pendulum.
    No preview · Conference Paper · May 2012
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    Shunyuan Ye · Yanming Shen · Shivendra Panwar
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    ABSTRACT: Given the rapid increase in traffic, greater demands have been put on research in high-speed switching systems. Such systems have to simultaneously meet several constraints, e.g., high throughput, low delay and low complexity. This makes it challenging to design an efficient scheduling algorithm, and has consequently drawn considerable research interest. However, previous results either cannot provide a 100% throughput guarantee without a speedup, or require a complex centralized scheduler. In this paper, we design a distributed 100% throughput algorithm for crosspoint buffered switches, called DISQUO, with very limited message passing. We prove that DISQUO can achieve 100% throughput for any admissible Bernoulli traffic, with a low time complexity of O(1) per port and a few bits message exchanging in every time slot. To the best of our knowledge, it is the first distributed algorithm that can provide a 100% throughput for a crosspoint buffered switch.
    Preview · Article · Dec 2011
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    Sha Hua · Pei Liu · Shivendra Panwar
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    ABSTRACT: As cellular networks are turning into a platform for ubiquitous data access, cellular operators are facing a severe data capacity crisis due to the exponential growth of traffic generated by mobile users. In this work, we investigate the benefits of sharing infrastructure and spectrum among two cellular operators. Specifically, we provide a multi-cell analytical model using stochastic geometry to identify the performance gain under different sharing strategies, which gives tractable and accurate results. To validate the performance using a realistic setting, we conduct extensive simulations for a multi-cell OFDMA system using real base station locations. Both analytical and simulation results show that even a simple cooperation strategy between two similar operators, where they share spectrum and base stations, roughly quadruples capacity as compared to the capacity of a single operator. This is equivalent to doubling the capacity per customer, providing a strong incentive for operators to cooperate, if not actually merge.
    Preview · Article · Nov 2011
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    Shunyuan Ye · Marina Thottan · Jesse E. Simsarian · Shivendra S. Panwar
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    ABSTRACT: The rapid increase in Internet traffic is forcing packet routers to grow in capacity to meet the demand. Optical packet routers with less buffering and a greater degree of optical transparency are actively being researched as a way to improve energy efficiency and capacity scaling over traditional electronic routers. Since it is difficult to buffer packets in the optical domain, in this paper we analyze the performance of a hybrid optoelectronic packet router. The router architecture has multiple optical switch planes and a shared electronic buffer to resolve output-port contention. By using multiple ports on the switch planes for each input and output fiber, and by using some switch-plane ports to inter-connect the planes, we can achieve a relatively low packet loss ratio in a router with no buffer. In this case, most traffic can be switched using only the through optical paths of the router without entering the shared buffer. The shared electronic buffer is primarily used to reduce the packet drop ratio under periods of heavy loads and occasionally for optical regeneration of a packet.We run extensive simulations to evaluate the performance of the router with varying number of switch plane ports, number of connections to the electronic buffer, and number of interconnections between the switch planes. We show that the router can provide good throughput, with realistic on-off bursty traffic and asynchronous packet arrivals.
    Full-text · Conference Paper · Jul 2011
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    ABSTRACT: Relay-assisted cooperative wireless communication has been shown to have significant performance gains over the legacy direct transmission scheme. Compared with single relay based cooperation schemes, utilizing multiple relays further improves the reliability and rate of transmissions. Distributed space-time coding (DSTC), as one of the schemes to utilize multiple relays, requires tight coordination between relays and does not perform well in a distributed environment with mobility. In this paper, a cooperative medium access control (MAC) layer protocol, called \emph{STiCMAC}, is designed to allow multiple relays to transmit at the same time in an IEEE 802.11 network. The transmission is based on a novel DSTC scheme called \emph{randomized distributed space-time coding} (\emph{R-DSTC}), which requires minimum coordination. Unlike conventional cooperation schemes that pick nodes with good links, \emph{STiCMAC} picks a \emph{transmission mode} that could most improve the end-to-end data rate. Any station that correctly receives from the source can act as a relay and participate in forwarding. The MAC protocol is implemented in a fully decentralized manner and is able to opportunistically recruit relays on the fly, thus making it \emph{robust} to channel variations and user mobility. Simulation results show that the network capacity and delay performance are greatly improved, especially in a mobile environment.
    Full-text · Article · May 2011 · IEEE Transactions on Wireless Communications
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    Sha Hua · Hang Liu · Mingquan Wu · Shivendra S. Panwar
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    ABSTRACT: Recently, a new paradigm for cognitive radio networks has been advocated, where primary users (PUs) recruit some secondary users (SUs) to cooperatively relay the primary traffic. However, all existing work on such cooperative cognitive radio networks (CCRNs) operate in the temporal domain. The PU needs to give out a dedicated portion of channel access time to the SUs for transmitting the secondary data in exchange for the SUs' cooperation, which limits the performance of both PUs and SUs. On the other hand, Multiple Input Multiple Output (MIMO) enables transmission of multiple independent data streams and suppression of interference via beam-forming in the spatial domain over MIMO antenna elements to provide significant performance gains. Researches have not yet explored how to take advantage of the MIMO technique in CCRNs. In this paper, we propose a novel MIMO-CCRN framework, which enables the SUs to utilize the capability provided by the MIMO to cooperatively relay the traffic for the PUs while concurrently accessing the same channel to transmit their own traffic. We design the MIMO-CCRN architecture by considering both the temporal and spatial domains to improve spectrum efficiency. Further we provide theoretical analysis for the primary and secondary transmission rate under MIMO cooperation and then formulate an optimization model based on a Stackelberg game to maximize the utilities of PUs and SUs. Evaluation results show that both primary and secondary users achieve higher utility by leveraging MIMO spatial cooperation in MIMO-CCRN than with conventional schemes.
    Full-text · Conference Paper · May 2011
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    Sha Hua · Yang Guo · Yong Liu · Hang Liu · Shivendra S. Panwar
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    ABSTRACT: Mobile video broadcasting service, or mobile TV, is expected to become a popular application for 3G wireless network operators. Most existing solutions for video Broadcast Multicast Services (BCMCS) in 3G networks employ a single transmission rate to cover all viewers. The system-wide video quality of the cell is therefore throttled by a few viewers close to the boundary, and is far from reaching the social-optimum allowed by the radio resources available at the base station. In this paper, we propose a novel scalable video broadcast/multicast solution, SV-BCMCS, that efficiently integrates scalable video coding, 3G broadcast, and ad-hoc forwarding to balance the system-wide and worst-case video quality of all viewers at 3G cell. We solve the optimal resource allocation problem in SV-BCMCS and develop practical helper discovery and relay routing algorithms. Moreover, we analytically study the gain of using ad-hoc relay, in terms of users' effective distance to the base station. Through extensive real video sequence driven simulations, we show that SV-BCMCS significantly improves the system-wide perceived video quality. The users' average PSNR increases by as much as 1.70 dB with slight quality degradation for the few users close to the 3G cell boundary.
    Full-text · Article · May 2011 · IEEE Transactions on Multimedia
  • Huawen Ye · Zhong-Ping Jiang · Shivendra S Panwar
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    ABSTRACT: () () () . . () () I () . n . () ( ) ( ) . . . (, , ) : ! . ## () ( ) $ % () . () () (( ) ) . () ( ) % (( ) ) ( ( ) ) . % � () ( ) ( ) ( ) () ( ) ( ) () ( ) ( ) () () ( ) ( ) () . & & () ! () ! & () . , () ( ) , [ ( ) ] ( ). ( ) () [ ] ( ). % , () ( ) ( ) [( ) ] ( ) () ( ) ( ). ( ) ( ) . () ’ () {| ( ) }. {| ( ) } ( ) [( ) ] . ’ {| ( ) } ( & (, ) ( � & . () { , , } ( ) & & () (, , () ( ) [( ( ) { , , }) ] ( ) [( { , , }) ] ( ) (( ) )[ ] ( ) ) (( ) )[ ] ( ) ) ) ) () ) ) () () ! ! ! ) ) ) . () ! . .
    No preview · Article · Jan 2011
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    Shunyuan Ye · Yanming Shen · Shivendra Panwar
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    ABSTRACT: Internet traffic has increased at a very fast pace in recent years. The traffic demand requires that future packet switching systems should be able to switch packets in a very short time, i.e., just a few nanoseconds. Algorithms with lower computation complexity are more desirable for this high-speed switching design. Among the existing algorithms that can achieve 100% throughput for input-queued switches for any admissible Bernoulli traffic, ALGO3 and EMHW have the lowest computation complexity, which is O(logN), where N is the number of ports in the switch. In this paper, we propose a randomized scheduling algorithm, which can also stabilize the system for any admissible traffic that satisfies the strong law of large number. The algorithm has a complexity of O(1). Since the complexity does not increase with the size of a switch, the algorithm is highly scalable and a good choice for future high-speed switch designs. We also show that the algorithm can be implemented in a distributed way by using a low-rate control channel. Simulation results show that the algorithm can provide a good delay performance as compared to algorithms with higher computation complexity.
    Preview · Conference Paper · Nov 2010
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    Oezgue Alay · Zhili Guo · Yao Wang · Elza Erkip · Shivendra Panwar
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    ABSTRACT: In this paper, a cooperative multicast scheme that uses Randomized Distributed Space Time Codes (R-DSTC), along with packet level Forward Error Correction (FEC), is studied. For the source packets, two-hop transmission is considered, where a packet is transmitted first by the access point (AP), and then forwarded using R-DSTC by the nodes that receive the packet. On the other hand, parity packets are generated by the nodes that receive all the source packets correctly and are transmitted using R-DSTC. The optimum transmission rates for source and parity packets, as well as the number of parity packets required, are determined such that the video quality at all nodes is maximized. It is shown that this scheme can support a higher video rate than a previously developed R-DSTC based scheme where both source and parity packets go through a two-hop transmission, as well as non-cooperative direct transmission.
    Full-text · Conference Paper · Oct 2010
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    Oezgue Alay · Thanasis Korakis · Yao Wang · Elza Erkip · Shivendra S. Panwar
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    ABSTRACT: Wireless video multicast enables delivery of popular events to many mobile users in a bandwidth efficient manner. However, providing good and stable video quality to a large number of users with varying channel conditions remains elusive. In this paper, an integration of layered video coding, packet level forward error correction, and two-hop relaying is proposed to enable efficient and robust video multicast in infrastructure-based wireless networks. First, transmission with conventional omni-directional antennas is considered where relays have to transmit in non-overlapping time slots in order to avoid collision. In order to improve system efficiency, we next investigate a system in which relays transmit simultaneously using directional antennas. In both systems, we consider a non-layered configuration, where the relays forward all received video packets and all users receive the same video quality, as well as a layered setup, where the relays forward only the base-layer video. For each system setup, we consider optimization of the relay placement, user partition, transmission rates of each hop, and time scheduling between source and relay transmissions. Our analysis shows that the non-layered system can provide better video quality to all users than the conventional direct transmission system, and the layered system enables some users to enjoy significantly better quality, while guaranteeing other users the same or better quality than direct transmission. The directional relay system can provide substantial improvements over the omni-directional relay system. To support our results, a prototype is implemented using open source drivers and socket programming, and the system performance is validated with real-world experiments.
    Full-text · Article · Sep 2010 · IEEE Transactions on Circuits and Systems for Video Technology
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    Shunyuan Ye · Yanming Shen · Shivendra Panwar
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    ABSTRACT: The promise of a buffered crossbar switch - a crossbar switch with a packet buffer at each crosspoint - is that it can provide good delay performance with much less complex, practical scheduling algorithms. With today's technology, it is now possible to implement it in a single chip. Thus it has attracted great attention recently. Though simple distributed algorithms can achieve 100% throughput under uniform traffic, so far there are no distributed algorithms which can achieve 100% throughput under general admissible arrival patterns. In this paper, we propose a distributed scheduling algorithm which achieves 100% throughput for any admissible Bernoulli arrival traffic. To the best of our knowledge, this is the first distributed algorithm which can achieve this. The algorithm is called DISQUO: DIStributed QUeue input-Output scheduler. Our simulation results also show that DISQUO can provide good delay performance for different traffic patterns.
    Preview · Conference Paper · Jul 2010
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    A. Rath · Sha Hua · S.S. Panwar
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    ABSTRACT: The ever increasing user demand for highly data-intensive applications is motivating cellular operators to provide more data services. However, the operators are suffering from the heavy budgetary burden of upgrading their infrastructure. Most macrocell Base Stations still connect to backhauls with capacities of less than 8 Mbps, much too low to be able to serve all voice and data users in the cell. This so-called macrocell backhaul bandwidth shortage problem is encumbering the growth of cellular data services. In this paper, we propose a novel solution, FemtoHaul , which efficiently exploits the potential of femtocells to bear the macrocell backhaul traffic by using relays, enhancing the data rates of cellular subscribers. We design a system architecture and its related signaling and scheduling strategies. Extensive simulations demonstrate that FemtoHaul can effectively serve more users and support higher data demand with the existing macrocell backhaul capacity.
    Preview · Conference Paper · Apr 2010
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    Sha Hua · Yang Guo · Yong Liu · Hang Liu · Shivendra S. Panwar
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    ABSTRACT: Mobile video broadcasting service, or mobile TV, is a promising application for 3G wireless network operators. Most existing solutions for video broadcast/multicast services in 3G networks employ a single transmission rate to cover all viewers. The system-wide video quality of the cell is therefore throttled by a few viewers close to the boundary, and is far from reaching the social-optimum allowed by the radio resources available at the base station. In this paper, we propose a novel scalable video broadcast/multicast solution, SV-BCMCS, that efficiently integrates scalable video coding, 3G broadcast and adhoc forwarding to balance the system-wide and worst-case video quality of all viewers in a 3G cell. We study the optimal resource allocation problem in SV-BCMCS and develop practical helper discovery and relay routing algorithms. Through analysis and extensive OPNET simulations, we demonstrate that SV-BCMCS can significantly improve the system-wide video quality at the price of slight quality degradation of a few viewers close to the boundary.
    Full-text · Conference Paper · Jan 2010
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    Shunyuan Ye · Yanming Shen · Shivendra S. Panwar
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    ABSTRACT: Fast growing traffic for both the Internet and within data centers has lead to an increasing demand for high-speed switching systems. In this paper, we propose a fully distributed scheduling algorithm with an O(1) complexity, for a switch with an optical switching fabric. The inputs only use local queue information to make their scheduling decisions, and the switch consumes much less power than an electronic switch. Therefore, we call the switch HELIOS: High Energy-efficiency Locally-scheduled Input-queued Optical Switch. HELIOS can achieve 100% throughput for any admissible Bernoulli i.i.d traffic. To our knowledge, this is the first distributed scheduling algorithm to guarantee 100% throughput for an input-queued optical switch.
    Preview · Conference Paper · Jan 2010
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    Zhengye Liu · Yanming Shen · Keith W. Ross · Shivendra S. Panwar · Yao Wang
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    ABSTRACT: Although there are several successful commercial deployments of live P2P streaming systems, the current designs; lack incentives for users to contribute bandwidth resources; lack adaptation to aggregate bandwidth availability; and exhibit poor video quality when bandwidth availability falls below bandwidth supply. In this paper, we propose, prototype, deploy, and validate LayerP2P, a P2P live streaming system that addresses all three of these problems. LayerP2P combines layered video, mesh P2P distribution, and a tit-for-tat-like algorithm, in a manner such that a peer contributing more upload bandwidth receives more layers and consequently better video quality. We implement LayerP2P (including seeds, clients, trackers, and layered codecs), deploy the prototype in PlanetLab, and perform extensive experiments. We also examine a wide range of scenarios using trace-driven simulations. The results show that LayerP2P has high efficiency, provides differentiated service, adapts to bandwidth deficient scenarios, and provides protection against free-riders.
    Preview · Article · Dec 2009 · IEEE Transactions on Multimedia
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    Ozgu Alay · Pei Liu · Zhili Guo · Luqin Wang · Yao Wang · Elza Erkip · Shivendra Panwar
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    ABSTRACT: With the increased popularity of mobile multimedia services, efficient and robust video multicast strategies are of critical importance. In a conventional multicast system, the source station transmits at the base rate of the underlying network so that all the nodes can receive the data correctly. The performance of such a multicast system is limited by the node with the worst channel conditions, which usually corresponds to the nodes at the edge of the multicast coverage range. To overcome this problem, we propose a two-hop cooperative transmission scheme where in the first hop the source station transmits the packets and the nodes who receive the packets forward the packets simultaneously in the second hop using randomized distributed space time codes (R-DSTC). We further integrate this randomized cooperative transmission with layered video coding to provide users different video quality based on their channel conditions. The performance of the system is evaluated and compared with a conventional multicast system. Our results show that the proposed cooperative system significantly improves the performance compared to conventional multicast.
    Full-text · Conference Paper · May 2009
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    Shunyuan Ye · S. Panwar
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    ABSTRACT: Carrier sensing has been used as an effective way to reduce collisions and exploit spatial reuse in wireless networks. Previous research has attempted to tune the carrier sensing range to maximize the network throughput. However, the impact of carrier sensing threshold on the probability of successful transmission has been ignored. In this paper, we derive an analytical model to calculate the successful transmission probability. We then calculate the throughput of routing protocols using different link metrics. To the best of our knowledge, this perhaps is the first attempt to derive the throughput of routing protocols like expected transmission count (ETX) [1] and expected transmission time (ETT) [2] in wireless networks. We also investigate the impact of some other important factors, such as node density, average contention window size and packet length. Our results show that optimal routing protocols that are using ETT as the path metric can achieve around 30% more throughput than those using ETX and End-to-end delay. Compared to the minimum hop count protocols such as DSR and AODV, the optimal routing protocol can improve the throughput by up to 100%.
    Preview · Conference Paper · May 2009
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    Jian Lin · Thanasis Korakis · Xiao Wang · Shunyuan Ye · Shivendra Panwar
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    ABSTRACT: Cooperative communication fully leverages the broadcast nature of the wireless channel and spatial diversity, thereby achieving tremendous improvements in system capacity and delay. A cross-layer implementation approach has been pursued in this demonstration, in order to confirm the viability and efficacy of cooperation at the MAC layer, in conjunction with the routing layer, in multi-hop ad-hoc networks. In the cooperative MAC protocol, a station would use a neighboring helper station for MAC layer forwarding, if the two-hop relaying yields to a better performance than a direct single-hop transmission. In this cross layer scheme, the DSDV routing protocol defines a multihop path from the source to the destination, while the cooperative MAC scheme, eventually selects two hop forwarding for each routing layer hop, in order to boost the performance of the routing protocol. The Cooperative MAC scheme has been implemented in the MadWiFi driver, while the DSDV routing protocol has been implemented in the Click modular router. In the demo, a video clip is streamed from a server to a remote client, where the received video is played out in real time. The basic route is discovered by the DSDV routing protocol that runs on every station. The underlying MAC implementation would dynamically alternate between IEEE 802.11 g and the cooperative MAC protocol, for each route hop. In the multi-hop, ad-hoc network, the cooperative cross-layer scheme delivers a smooth user experience while the video playout over the legacy IEEE 802.11 g has noticeable freezes and frequent distortions. The demo verifies the extensibility of the cooperative MAC protocol into multi-hop ad-hoc networks, where in conjunction with the routing protocol, can achieve superior performance, compared to the legacy IEEE 802.11 g.
    Preview · Conference Paper · Apr 2009
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    Thanasis Korakis · Michael Knox · Elza Erkip · Shivendra Panwar
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    ABSTRACT: Cooperative networking, by leveraging the broadcast nature of the wireless channel, significantly improves system performance and constitutes a promising technology for next-generation wireless networks. Although there is a large body of literature on cooperative communications, most of the work is limited to theoretical or simulation studies. To impact the next generation of wireless technologies and standards, it is essential to demonstrate that cooperative techniques indeed work in practice. This article describes two programmable cooperative communication testbeds built at Polytechnic Institute of NYU to achieve this goal. The testbeds are based on open-source platforms and enable implementation of cooperative networking protocols in both the physical and the medium access control layer. Extensive experiments carried out using the testbeds suggest not only that cooperative communication techniques can be integrated into current wireless technologies, but also that significant benefits of cooperation can be observed in terms of network throughput, delay, and video quality in real applications.
    Full-text · Article · Mar 2009 · IEEE Communications Magazine

Publication Stats

3k Citations
61.79 Total Impact Points

Institutions

  • 2006-2014
    • Polytechnic Institute of New York University
      • Department of Electrical and Computer Engineering
      Brooklyn, New York, United States
  • 2013
    • NYU Langone Medical Center
      New York, New York, United States
  • 1989-2013
    • City University of New York - Brooklyn College
      • Department of Computer and Information Science
      Brooklyn, New York, United States
  • 2009
    • Worcester Polytechnic Institute
      • Department of Electrical and Computer Engineering
      Worcester, Massachusetts, United States
  • 2008
    • Indian Institute of Technology Kanpur
      • Department of Computer Science & Engineering
      Cawnpore, Uttar Pradesh, India
  • 1992-2008
    • CUNY Graduate Center
      New York, New York, United States
  • 2007
    • Auburn University
      • Department of Electrical & Computer Engineering
      Auburn, AL, United States
  • 2005
    • Walailak University
      Changwat Nakhon Si Thammarat, Nakhon Si Thammarat, Thailand
  • 1999
    • Telcordia Technologies
      Middlesex, New Jersey, United States
  • 1997
    • AT&T Labs
      Austin, Texas, United States