Ph. D. Computer Science, University of British Columbia

M. Engg, Automation, Indian Institute of Science

B. Engg, Electronics & Communications, Indian Institute of Science

The main research direction is on distributed management and control of complex networked systems. Specific areas of research focus are adaptive fault-tolerance & QoS, autonomic network resource management, declarative networks, QoS auditing in clouds, and cyber-physical network systems. A common thread in these research activities pertains to the design and management of trustable computer network systems. Specific research activities are listed below.

1. Assessment & Certification of large-scale networked systems

When designing dependable network systems, it is necessary to certify that a networked system behaves in the way it is supposed to. A certification process involves verifying how good S behaves relative to its stated objectives, and assigning a score therein for S. For instance, S may obtain a numerical score of 0.9 (on a scale of [0,1]) in the face of currently prevalent environment conditions, but may obtain a score of 0.8 under more hostile conditions. In an example of end-to-end connectivity service over a data network, how stable is the data transfer rate sustained in the presence of packet loss fluctuations may be of interest to a video application. The candidate network system S as a whole is subject to stress tests, whereupon an external management entity reasons about the ability of S to fight through the stressful conditions incident on S. An analogy to the network certification problem is the assignment of course grade for a student: the grade basically tells how good the student is relative to the declared expectations (the exams is a means to assess the student performance under a particular criteria). We develop policy and rule-based network management techniques to assess the para-functional attributes of the behavior of network system S: such as system resilience, stability, and responsiveness. The certification mechanisms are based on machine intelligence tools (such as PO-MDP) and probabilistic reasoning methods. These mechanisms however do not require detailed domain-specific knowledge. We use declarative specification methods to externalize the network algorithm workflows & processes for assessment by an external management module.

Network assessment & certification is beneficial in two ways. First, it offers the means to measure the goodness of a complex network system in domain-specific metric spaces and compare it with other competing systems. For instance, a military commander deploying different network systems in a theater of operation can use the numerical scores to reason about the overall effectiveness of the combined system under various external conditions. Second, the certification enables an autonomic controller to improve upon the workflow processes and algorithms embodied in the system to deal with the environment conditions in a better way. The domain-independent nature of the certification methods developed in this research make them employable in diverse application domains: which lowers the software development costs of complex network systems. We are currently studying the certification methods in the domains of content distribution networks (CDN), replicated web services, and adaptive video transport.

2. QoS auditing in cloud-based distributed services

Given cloud-based realization of a distributed system, QoS auditing enables risk analysis and accounting of SLA violations under various security threats and resource depletions faced by the system. The problem of QoS failures and security infringements arises due to the third-party control of cloud resources and components that are used in realizing the application-oriented services. The less-than-100% trust between the various sub-systems is a major issue that necessitates a probabilistic analysis of the application behavior relative to the SLA negotiated with the service provider. In this light, QoS auditing allows reasoning about how good the SLA is complied by the provider in the face of hostile environment conditions.

SLA refers to the contractual obligations between a cloud service provider and a service consumer. The SLA can document the promised QoS from a service provider and the para-functional requirements of service delivery to the client. In cloud setting, the SLA evaluation involves the following entities:

1. The direct parties involved in a QoS specification and enforcement: the cloud service provider and the client;
2. The third parties involved in QoS assessment and verification: the QoS monitor, audit provider, and certifier.

These parties are provided with a service description which specifies the QoS that will be guaranteed to the client applications under the agreement. Domain-specific information is included to map the specification onto application-level objectives. The latter, which define the service-level indicators, correspond to the promised QoS values from the service provider: such as the response time, availability, and overhead. The SLA also includes a prescription of the penalty in case that the service provider under-performs or is unable to provide service at the promised level. Violation of different guaranteed service objectives may lead to different penalties. An SLA thus provides the needed transparency of operations between cloud-based service providers and consumers.

As a case study of QoS auditing methods, we work on the measurement of available bandwidth estimation on an end-to-end path set up from a client device (e.g., smart-phone) to a cloud data center over a series of routers. This estimate is then reasoned about in light of the SLA negotiated with the cloud provider at the time of path set up. In the future, we plan to employ OPenFlow switches and PlanetLab nodes as part of our experimental platform.

3. Software Cybernetics for networked embedded systems

Future network systems are expected to have various levels of adaptation capabilities: at parametric level, service-level, and application-level. These capabilities are often realized in multiple system layers, with the control logic needed for a specific capability residing in the application agents interfacing with the underlying network system services. For instance, the formation of a first-responder vehicular network for underwater rescue/repair mission may be based on the processing, communication, and sensing capabilities of various nodes as managed by the software agents running in these nodes. We employ a software cybernetics approach, where an intelligent physical system module (IPW) embodies the core adaptation functionality to respond to the changing environment conditions and user inputs. The IPW exhibits an intelligent behavior over a limited operating region of the system --- as in the earlier example of first-responder team. The IPW is augmented by a management-oriented computational module (ICW) housing supervisory feedback loops to deal with the changing external environment conditions (e.g., adding more nodes to the rescue team when the terrain conditions become severe). Our autonomic management of various hierarchical control loops comes under the ambit of Cyber-Physical Systems (CPS). The ICW patches the IPW with suitable control parameters and rules/procedures when the system operating conditions change. Our focus in this research is on the software engineering-aspects of designing networked embedded systems, and the construction of IPW-ICW modules in specific application domains.

Our modular decomposition of a networked embedded system into IPW and ICW has many advantages: lowering the overall software complexity, simplifying system verification, and supporting easier evolution of system features. Other application domains of our research are in automotive control systems and vehicular networks. Existing complex network applications: such as bandwidth-adaptive video transport and latency-adaptive CDN server deployment, can also be structured in terms of our IPW-ICW approach. The attendant advantages arise from software and systems engineering angles: such online model reconfigurations and parameter/algorithm switching (i.e., system morphing).

Facilities description

Distributed Network Management Test-bed
(NAC.7/115, Dept. of Computer Science, CUNY - City College)

Kaliappa Ravindran and his students pursue research in service-level management of distributed networks, system-level support for information assurance, distributed collaboration techniques, cyber-physical & embedded systems, and formal validation of assured distributed software systems. His research lab maintains a distributed network management test-bed that enables the multi-pronged research in the above areas. The test-bed is built using many network equipments:

• 4#s of CISCO core network routers
• 2#s of AT&T access network switches
• 10#s of low-cost Zodiac SDN switches, 10#s of raspberry-PIs, network accessories
• 1# of Spirent traffic analyzer
• 10#s of Pocket PCs & smartphones with IEEE 802.11 (Sharp-Zaurus, HP-iPAQ, Dell-Axim)
• 15#s of Lenavo, IBM, Dell, HP laptops
• 3#s of SUN-Blade computers
• 2#s of Xeon stations for hosting PlanetLab site
• 6#s of SUN-Ultrasparc computers
• 8#s of low-end and high-end Windows and Linux PCs
• 802.11 wireless network cards on laptops and PCs
• 4#s of T1/T4 line cards, 1# of Fore ATM switch
• Network Management Software: HPOpenView
• Simulation software: OPNET, NS-2, SIMULINK/StateFlow, etc
• Languages: JAVA, C++, MATLAB

The various computers are configured as a multi-hop network (maximum diameter is 6 hops), with a hybrid of low and high speed links. The test-bed allows simulating network attacks and resource outages in the study of traffic engineering techniques, distributed implementation of fault-tolerance algorithms, and robustness control under fuzzy network measurements. Traffic analyzer is used to inject controlled amounts of cross-traffic in network paths and simulate denial-of-service attacks on network links. HPOpenView software allows studying "managed QoS assurance" from networked systems (such as clouds). HPOpenView agents implement domain-specific QoS monitoring at faster time-scales (e.g., latency monitoring in a CDN), with recovery from application-level QoS failures occurring at slower time-scales.

The above test-bed is currently being augmented with Android and Windows Smartphones to provide wireless communication capability and device mobility. With a subscription to the PlanetLab, we extend the test-bed capability to accommodate mobile clouds. This allows us to pursue the research activities on mobile cloud SLA and auditing. The above test-bed can also be employed in the study of system-level dependability measures for certification and management purposes.

Past research support from external agencies and Industries

Air Force Research Lab, Naval Research Lab, General Motors, CISCO, NSF, Missile Defense Agency.

D. Significant publications relevant to Trusted Systems and Resilience

D.1 Subject areas of Autonomous System Verification and Agent-based Control

1. A. Adiththan, K. Ravindran, S. Ramesh. Optimal Management and Configuration Methods for Automobile Cruise Control Systems. In Recent Trends and Advances in Model Based Systems Engineering. Springer Publ., pp. 429-439, Mar.2022.
    
2. A. Adiththan, K. Ravindran and M. Iannelli. Inference of Control Structures in Adaptive Networked Systems. In proc. IEEE/ACM conf. on Communication Systems and Networks (COMSNETS), Bangalore (India), Jan.2021.
    
3.  K. Ravindran and A. Adiththan. Effects of Sensing & Control Errors on Quality of Adaptation in Networked
    
4. A. Adiththan and K. Ravindran. Model-based System Identification for Cloud Services Analytics. In proc. IEEE/IFIP Intl. Symp. on Integrated Network Management (IM), Washington (DC), April 2019.
    
5. K. Ravindran, Y. Wardei, and S. Drager. Assessment of QoS Adaptation Capability of Complex Network Systems. In Proc. of IEEE Conf. on Design of Reliable Communication Networks (DRCN), Paris (France), March 2016.
    
6. K. Ravindran and A. Adiththan. Role of System Modeling for Audit of QoS Provisioning in Cloud Services. In proc. IEEE Intl. Conf. on Cloud Computing and Communications (CLOUDCOM), Singapore, Dec. 2014.
    
7. K. Ravindran. Trial Actions: A Transactional Programming Paradigm for QoS Negotiation in Distributed Network Systems, In proc. Workshop on Agent-based Complex Automated Negotiations (held as part of AAMAS), Paris (France), April 2014.
    
8. K. Ravindran. Model-Based Engineering Techniques for QoS Auditing in Distributed Cloud Services, In proc. IEEE-ICDCS workshop on Assurance in Distributed Systems and Networks: ADSN2014, Madrid (Spain), June 2014.
    
9. K. Ravindran. QoS Management by Competitive Agent-based Negotiation in Distributed Cloud Services. In proc. IEEE conference on Cloud Networking (CLOUDNET), Luxembourg, Oct. 2014.
    
10. K. Ravindran and A. Adiththan. Verification of Non-functional Properties of Cloud-Based Distributed System Services, In proc. workshop on Automation of Software Test, Held in conjunction with the ACM Intl. Conf. on Software Engineering (ICSE’14), Hyderabad (India), June 2014.
     
11. K. Ravindran. Autonomic Control of Network Sensing Quality With Situational Assessment, In proc. workshop on Autonomic and Opportunistic Communications, held with IEEE Intl. Symp. on WoWMoM, Sydney (Australia), June 2014.
     
12. K. Ravindran, Self-Assessment and Reconfiguration Methods for Autonomous Cloud-based Network Systems, In proc. of IEEE/ACM symp. on Distributed Simulation and Real-time Applications (DS-RT), Delft (Netherlands), Oct. 2013.
     
13. K. Ravindran. QoS Auditing for Evaluation of SLA in Cloud-based Distributed Services, In proc. Cloud Security Auditing Workshop --- held as part of IEEE Services Computing Conference (SCC), San Jose (CA), June 2013.
     
14. K. Ravindran. Model-based Engineering for Certification of Complex Adaptive Network Systems, In Proc. IEEE-ICDCS workshop on Cyber-Physical Networking Systems (CPNS), Macau (China), June 2012.
     
15. K. Ravindran. Management Intelligence in Service-level Reconfiguration of Distributed Network Applications, LNCS-5907 (Service-oriented Computing: Agents, Semantics, and Engineering), Springer, pp.95-110, 2009.
     
16. K. Ravindran. Dynamic Protocol-level Adaptations for Performance and Availability of Distributed Network Services, In Modeling Autonomic Communications Environments, Multicon Lecture Notes, Multicon-Verlag publ., pp. 191-209, Oct.2007.

D.2 Subject areas of Adaptive fault-tolerance, cyber-defense, and Information assurance

1. K. Ravindran, M. Iannelli, and A. Adiththan: Moving-Target-Defense based Security Mechanisms: A System Management Perspective. In proc. IEEE/ACM workshop on Cyber-Security, pp. 13-18, COMSNETS, Bangalore (India), Jan. 2023.
    
2. V. Venkateswaran, C. T.Huang, and K. Ravindran: Security Management in Content Distribution Networks: a delay-variance reduction approach for content mirror site placement. In proc. IEEE/ACM Conf. On Communication Networks and Systems (COMSNETS), pp. 505-512, Bangalore (India), Jan.2023 --- Invited for publication in Ad-Hoc Networks Journal.
    
3. K. Ravindran, M. Iannelli, A. Adiththan, S. Drager, and M. Anderson. Inference of Control Structures in Adaptive Networked Systems: A Security Perspective. In chapter MBSE for Systems and SoS Integration / MBSE for Network Systems --- Handbook of Model-Based Systems Engineering, Springer Publ., pp. 429-439, (to appear) Dec.2022.
    
4. Kaliappa Ravindran, Chin-Tser Huang. Probabilistic treatment of service assurance in distributed information systems. In proc. IEEE Intl. conf. on Dependable and Secure Computing, Taipei (Taiwan), pp.318-325, Aug.2017.
    
5. Kaliappa Ravindran, Yassine Wardei, A. Kodia, Michael Iannelli, Arun Adiththan, Steven Drager: Assessment of QoS adaptation and cyber-defense mechanisms in networked systems. In proc. IEEE conf. on Dependable and Secure Computing, Taipei (Taiwan), pp.501-508, Aug.2017.
    
6. K. Ravindran, A. Prabhakar, and A. Adiththan. Verifying QoS properties of trusted data sensing, In proc. ACM Intl. Conf. on Distributed Event-Based Systems (DEBS), Mumbai (India), May 2014.
    
7. K. Ravindran, M. Rabby, and A. Adiththan. Model-based control of device replication for trusted data collection, In proc. of workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), held as part of CPSWeek, Berlin (Germany), April 2014.
    
8. M. Rabby, K. Ravindran, and K.A. Kwiat. Hierarchical adaptive QoS control for voting-based data collection in hostile scenarios, In proc. IEEE/IFIP Intl. Conf. on Network and Service Management (CNSM), Las Vegas (NV), Oct. 2012.
    
9. K. Ravindran and M. Rabby. Replica Voting based Mechanisms for Dissemination of Multi-modal Surveillance Data In the Presence of Failures, In proc. IEEE-ICDCS workshop on Assurance in Distributed Systems and Networks: ADSN2012, Macau (China), June 2012.
    
10. K. Ravindran and M. Rabby. Protocol-level Reconfigurations for Infusion of Resilience in Distributed Network Services, In proc. IEEE/IFIP Intl. Workshop on Distributed Autonomous Network Management Systems (NOMS12), Maui (HI), Apr.2012.
     
11. K. Ravindran. Probabilistic Fault-tolerance of Distributed Services: A Paradigm for Dependable Applications, In proc. IEEE symp. on Availability, Reliability and Security (AReS), Vienna (Austria), Aug. 2011 (invited for publication of Extended Version in ElSevier Journal of Computers and Security, Febr.2012).
     
12. M. Rabby and K. Ravindran. Situational Context for Replica Voting based Data Collection in Hostile Environments, In proc. IEEE 11th Intl. Conference on Telecommunications for Intelligent Transport Systems (ITST-2011), Context-aware Middleware track, St. Petersburg (Russia), Aug. 2011.
     
13. K. Ravindran. Cyber-Physical Systems Based Modeling of Dependability of Complex Systems, In proc. workshop on Dynamic Aspects in Dependability Models for Fault-Tolerant Systems – with IEEE AReS 2011, Vienna (Austria), Aug.2011.
     
14. K. Ravindran. Managing Robustness of Distributed Applications Under Uncertainties: An Information Assurance Perspective. In proc. ACM Cyber Security and Information Intelligence Workshop, Oakridge National Lab (TN), April 2010.
     
15. K. Ravindran, K. A. Kwiat, and P. Hurley. Adaptive Voting Algorithms for Reliable Dissemination of Data in Fault-Prone Distributed environments, Intl. Journal of Business Intelligence and Data Mining, Inderscience Publ., Dec. 2008.
     
16. K. Ravindran, and G. Ding. An Observer-based Compositional Approach for Testing of Distributed Protocols in Hostile Environments, In Symp. on Quality Engineering of Embedded Systems (QEES 2008), Berlin (Germany), June 2008.

D.3 Subject areas of Software cybernetics, Networked sensors, and Distributed coordination

1. Kaliappa Ravindran, Ancy Cherian, Arun Adiththan: Virtualized End-to-End Management Functions for Aggregated Control of Video Traffic Flows. In proc. 21st ACM conf. on Modeling, Analysis and Simulation of Wireless and Mobile Systems (Q2SWinet symp.), pp.130-139, Montreal (Canada), Oct.2018.
    
2. Arun Adiththan, Kaliappa Ravindran: Orchestration of cooperative cruise control for networked self-adaptive cars. In proc. IEEE/ACM conf. on Communication Systems and Networks (COMSNETS), Bangalore (India), pp.235-242, Jan.2018.
    
3. Kaliappa Ravindran, Arun Adiththan, Michael Iannelli, Khurshid Fayzullaev: Management of adaptation capability of networked systems in dynamic environments. In proc. IEEE/ACM conf. on Communication Systems and Networks (COMSNETS), Bangalore (India), pp.275-282, Jan.2018.
    
4. Arun Adiththan, Kaliappa Ravindran, S. Ramesh: Management of QoS-oriented Adaptation in Automobile Cruise Control Systems. In proc. IEEE Intl. Conf on Autonomic Computing (ICAC), pp. 79-80, Columbus (OH), Sept. 2017.
    
5. Arun Adiththan, Kaliappa Ravindran: QoS-Oriented Adaptation Management in Networked Multi-vehicle Cruise Control Systems. In proc. conf. on Local Computer Networks - Workshops, pp.82-90, Singapore, Oct.2017.
    
6. Arun Adiththan, Kaliappa Ravindran: QoS-oriented Management of Multi-vehicle Coordinated Cruise Control in Uncertain Environments. In proc. 20th ACM conf. on Modeling, Analysis and Simulation of Wireless and Mobile Systems (Divanet symp.), pp.55-62, Miami (FL), Oct.2017.
    
7. A. Adiththan, K. Ravindran, S. Ramesh: Situation-Based Autonomic Management of Automobile Cruise Control Systems. In proc. IEEE Intl. Conf. on Self-Adaptive and Self-Organizing Systems (SASO), Tucson (AZ), Sept. 2017.
    
8. K. Ravindran, A. Adiththan, S. Mukhopadhyay. Stability of Video Rate Control Algorithms Over Bandwidth-limited Network Paths, In proc. IEEE/IFIP Intl. Conf. on Network and Service Management (CNSM), Rio De Janeiro (Brazil), Nov. 2014.
    
9. K. Ravindran and S. Ramesh. Model-based design of cyber-physical software systems for smart worlds: a software engineering perspective, In proc. workshop on Modern Software Engineering Methods for Industrial Automation, held in conjunction with the ACM Intl. Conf. on Software Engineering (ICSE’14), Hyderabad (India), June 2014.
    
10. K. Ravindran. Cyber-Physical Software Systems for Smart Worlds: A Case Study of Intelligent Transportation System, In proc. Workshop on Networks of Cooperating Objects for Smart Cities (UBICITEC), held as part of CPSWeek, Berlin (Germany), April 2014 --- Also, appeared as book chapter in CEUR-WS.org/Vol-1156, ISSN: 1613-0073.
     
11. K. Ravindran, S. Mukhopadhyay, S. Sidhanta, and A. Sabbir. Managing shared contexts in distributed multi-player game systems, In proc. IEEE/ACM conference on Comm. Systems and Networks (COMSNETS), Bangalore (India), Jan. 2014.
     
12. K. Ravindran and M. Rabby. Software cybernetics to infuse adaptation intelligence in networked systems, In proc. IEEE Intl. Conf. on Network of the Future (NOF), Pohang (Korea), Oct. 2013.
     
13. K. Ravindran and S. Ramesh. Model-based engineering of cyber-physical software systems for smart worlds: A case study of automobile control systems, In proc. IEEE Intl. Conf. on Advances in Computing, Communications and Informatics (ICACCI), Mysore (India), Aug. 2013.
     
14. K. Ravindran, M. Rabby, J.P. Macker, and B. Adamson. Group communication for event dissemination in dynamic distributed networks, In proc. IEEE/ACM conf. on Comm. Sys. and Networks (COMSNETS), Bangalore (India), Jan. 2013.
     
15. K. Ravindran. Multi-source Cooperative Adaptation for QoE-aware Video Multicast Rate-control. In proc. IEEE/IFIP Intl. Conf. on Network and Service Management (CNSM), Zurich (Switzerland), Oct. 2013.
     
16. K. Ravindran and M. Rabby. Cyber-Physical Systems Based Modeling of Adaptation Intelligence in Network Systems, In proc. IEEE Intl. conf on Systems, Man, Cybernetics (Sys. Science and Engg. Track), SMC2011, Anchorage (AK), Oct.2011.
     
17. K. Ravindran. Model-based Software Integration for Flexible Design of Cyber-Physical Systems, in Springer-Verlag Publ. (Intl. Symp. on Comp. and Inform. Sciences, London, UK), Ed. E. Gelenbe, and et al, ISBN: 978-1-4471-2154-1, Sept.2011.
     
18. K. Ravindran. Service-level Management of Distributed Networks: A Meta-model of Application-layer QoS Assurance, Accepted for publication in Springer Journal of Internet Services and Applications, June 2011.
     
19. K. Ravindran. Information-theoretic Treatment of Sensor Measurements in Network Systems, In 12th IEEE/IFIP Network Operations and Management Symposium (NOMS), Osaka (Japan), April 2010.

D.4 Subject areas of Network architectures, cloud computing, and resource management

1. K. Ravindran, A. Adiththan. Virtualized Network Functions for Video Content Delivery in Bandwidth-limited Networks --- ONAP perspective., Invited Position Paper, presented at ONS-EU Summit, Amsterdam (Netherlands), Oct. 2018.
    
2. Ravindran, Arun Adiththan, Michael Iannelli, Mohammad Rabby: External Assessment of QoS Provisioning in Distributed Cloud Services. In proc. IEEE Conf. on Dependable Systems and Networks (DSN Workshops), Toulouse (France), pp.283-290, July 2016.
    
3. Kaliappa Ravindran: Management Software for Protocol-level Adaptations in Dependable Network Services. In proc. of Intl. conf. on Parallel and Distributed Processing Systems (IPDPS - Workshops), Chicago (IL), pp. 1288-1297, June 2016.
    
4. Kaliappa Ravindran, Khurshid Fayzullaev, Yassine Wardei: Model-based techniques for QoS assessment of cloud-hosted CDN services. In proc. Intl. Symp. On Quality of Service (IWQoS), Beijing (China), June 2016.
    
5. Kaliappa Ravindran, Michael Iannelli: Data-oriented abstraction of virtual sensors for energy-aware embedded software systems. In proc. of ACM Conf. on Mobile Communications (Mobicom) --- SmartObjects workshop, New York (NY), pp. 53-58, June 2016.
    
6. Kaliappa Ravindran, Michael Iannelli. Replicated Sensing in Wireless-Networked Smart Systems with Cloud-assisted Support. In proc. ACM conf. on Mobile Ad-hoc Networks (Mobihoc - DIPWN), Chennai (India), July 2017.
    
7. K. Ravindran and X. Liu. Bandwidth Sensing Errors in Network Systems: A Case Study of Video Rate adaptation, In proc. IEEE Intl. Conf. on Computer-Aided Modeling & Design of Comm. Links and Networks (CAMAD), Athens (Greece), Dec.’14.
    
8. K. Ravindran and M. Iannelli. SLA evaluation in cloud-based data-centric distributed services. In proc. IEEE Intl. Conf. on Computers, Communications, and Networks (ICCCN), Shanghai (China), Aug. 2014.
    
9. K. Ravindran, A. Adiththan, M. Iannelli. SLA evaluation with on-the-fly measurements of distributed service implementation over clouds, In proc. workshop on Principles of Engineering Service-Oriented and Cloud Systems, held in conjunction with the ACM Intl. Conf. on Software Engineering (ICSE’14), Hyderabad (India), June 2014.
    
10. M. Rabby, K. Ravindran, S. Mukhopadyay, R. Bharadwaj, G. Mangukiya. Control plane Properties for Signaling in Loss-feedback based Video Rate Adaptation over Shared Multicast Paths, In proc. IEEE-ACM Intl. conf. on Communication Sys. and Networks (COMSNETS), Bangalore (India), Jan. 2011.
     
11. M. Rabby, K. Ravindran, and Jun Wu. Distributed adaptation algorithms for rate-controlled video multicast over shared infrastructure networks, In proc. IEEE-ACM Intl. conf. on Comm. Sys. & Networks (COMSNETS), Bangalore (India), 2010.
     
12. X. Liu, K. Ravindran, and D. Loguinov. A Queuing-theoretic Foundation of Available Bandwidth Estimation: Single-Hop Analysis, In IEEE/ACM Transactions on Networking, 15(4), pp.918-931, Aug.2007
     
13. K. Ravindran, J. P. Fortin, and X.Liu. Flow Management for QoS-controlled ‘data connectivity’ Provisioning, In Computer Communications (ElSevier), vol.30, no.6, March 2007.
     
14. X. Liu, K. Ravindran, D. Loguinov. Towards a Generalized Stochastic Model of End-to-End Packet-Pair, In IEEE Journal on Selected Areas of Communication, Special Issue on Sampling the Internet: Techniques and Applications, Dec. 2006.
     
15. X.Liu, K. Ravindran, and D. Loguinov. What signals do packet-pair dispersions carry? In proc. IEEE INFOCOM’05 (conf. on Information and Communications), Miami (FL), March 2005.
     
16. K. Ravindran, A. Sabbir, D. Loguinov, and G. Bloom. Cost-optimal Multicast Trees for Multi-source Data Flows, In proc. IEEE INFOCOM’01 (conf. on Information and Communications), Anchorage (AK), April 2001.

E. Patent issued

A Method and Apparatus for Timing of Information Flow in a Distributed System
7877748 (June 2011, original application date: Nov.2006) Jointly with Dr. K. A. Kwiat, Dr. A. Sabbir.

F. Honors and Awards (last 20 years)

• Recipient of external research grants, totaling about $873,700 from Space Missile and Development Command, Philips Research, Air Force Research Lab, Naval Research Lab, NSF, and CISCO.
   
• Sabbatical leave at Air Force Research Lab (Sept.2003-May’04, Sept.17-Aug.’18) and at Naval Research Lab (Sept.’10-Mar.’11)
   
• Consultant for ITT Industries, Griffiss Research Institute, and Florida International University 2002-14 (Study of algorithms for Information assurance, group communications, cyber-infrastructure protection)
   
• Visiting Faculty: 2005-08, 2010-19, 2020-22 (Naval Research Lab, General Motors, Air Force Research Lab)
   
• Research paper reviews (for conferences and journals) and grant proposal reviews (from NSF).
   
• Conducted international workshops on Intelligent Networks for Communication and Adaptation (IAMCOM), Bangalore (India), January of 2007-2011 --- under sponsorship from AOARD & ONR-G, and General Motors.
   
• General Chair of Service-oriented Computing Conference (SCC) to be held in New York City in July 2015; TPC Program Chair of SCC 2014 held in Anchorage (Alaska) in June-July 2014.
   
• Vice-chair of Emerging Technical subcommittee set up by IEEE Communications Society for the area of Cloud Communications & Networking in 2013-14 (responsible for identifying and nurturing new technology directions).
   
• Key-note speaker, Intl. Conf. on Service-oriented Computing (ICSOC workshop), Dubai, 2020.
   
• Member of Ph.D. thesis committees of 50+ students at CUNY (Computer Science, Electrical Engineering).

H.1. Collaborators (over last 20 years)

A. Collaborators K. Han, K.A. Kwiat, S. Drager (AFRL), R.Bharadwaj, J. P. Macker, K. Crandall (NRL),
K.K. Ramakrishnan (AT&T Research), Nakjung Choi (Bell-Labs), R.Steinmetz (Tech. Univ. of Darmstadt),
S. De (Indian Inst. of Technology), S. Mukhopadhyay (Louisiana State Univ), S. Das (Missouri Univ. of Sc. Tech.),
S. Ramesh (General Motors), R. Ghosh (AMEX BigData Analytics), Charles Kamhoua (Army Research Lab)

B. Graduate and postdoctoral advisor
Christopher Amoquarm, Dmitri Loguinov, Xiliang Liu, Ali Sabbir, Jun Wu, Mohammad Rabby, Jean-Piere Fortin,
Amanjeev Singh, Amjad Shaik, Gwang-yu Ding, Arun Adiththan, Ancy Cherian, Jinu Jose, Sindhura Dondapatti,
Sreevarsha Reddy, Rebecca Batat, Esteralla Moreira, Greg Javens, Michael Iannelli, Qasim Zafar, Divya Sankar

C. Academic/graduate advising (short-term)
Suman Bhunia, Jiang Wu, Jiao-Tao, Stoycho Stoev, Anuja Prabhakar, Gaurav Mangukia

D. Recent graduate/undergraduate students
Lalchandra Rampersaud, Michael Fera, Andres Nieves, Joseph Shaker, Tian Chen, Ashik Achu, Yassine Wardei,
Edsn Kensington, Luigi Vingo, Gaurav Kuwar, Esteban Garcia (Indiana University of Pennsylvania)

H.2 Ph.D. graduates from my research group at CUNY (over last 20 years)

1. Dmitri Loguinov (currently, Professor, Computer Science dept., Texas A&M University, College Station, TX);
    
2. Christopher Amoquarm (currently, educator, University of Ghana);
    
3. Xiliang Liu (currently, software engineer at Google, Palo Alto, CA);
    
4. Ali Sabbir (currently, Associate Professor, Independent University, Bangladesh);
    
5. Jun Wu (currently, Lecturer, City College of CUNY, New York, NY);
    
6. Arun Adiththan (currently, software engineer at General Motors, Detroit, MI).