@conference {
	title = {Studying Real-time Traffic in Multi-hop Networks Using the EMANE Emulator: Capabilities and Limitations},
	author = {Jain, Kaustubh., Roy-Chowdhury, Ayan., Somasundaram, Kiran K., Wang, Baobing., Baras, John S.},
	year = {2011},
	month = {03/2011},
	abstract = {In this paper, we provide an open-source software emulator setup for MANETs and study its fidelity in providing reliable performance estimates for real-time traffic. We emulate the IEEE 802.11 MAC/PHY (DCF) using the EMANE software emulator deployed on a cluster and run experiments for different multi-hop wireless scenarios. As an instance, we study the performance of real-time streaming media over a mesh network supported by OLSR. We also use the setup to analyze the impact of the wireless network on the self-similarity of the traffic.},
	address = {Barcelona, Spain},
	booktitle = {SIMUTools 2011- 4th International Conference on Simulation Tools and Techniques},
	pages = {pp. 93-95}
}
@conference {
	title = {Path Optimization and Trusted Routing in MANET: An Interplay Between Ordered Semirings},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2010},
	month = {12/2010},
	abstract = {In this paper, we formulate the problem of trusted routing as a transaction of services over a complex networked environment. We present definitions from service-oriented environments that unambiguously capture the difference between trust and reputation relations. We show that the trustworthiness measures associated with these relations have a linear order embedded in them. Identifying this order structure permits us to treat the trusted routing problem as a bi-objective path optimization problem. We consider bottleneck trust and present polynomial time solutions to obtain the optimal routing paths in various bi-objective settings. In developing these algorithms, we identify an interesting decomposition principle for (min,+) and (min,max) semirings, which yields a distributed solution.},
	address = {Chennai, India},
	booktitle = {The Second International Conference on Networks \&amp; Communications (NetCoM - 2010)},
	pages = {pp. 1-11}
}
@conference {
	title = {Distributed Topology Control for Stable Path Routing in Multi-hop Wireless Networks},
	author = {Somasundaram, Kiran K., Baras, John S., Jain, Kaustubh., Tabatabaee, Vahid.},
	year = {2010},
	month = {12/2010},
	abstract = {In this paper, we introduce the stable path topology control problem for routing in mobile multi-hop networks. We formulate the topology control problem of selective linkstate broadcast as a graph pruning problem with restricted local neighborhood information. We develop a multi-agent optimization framework where the decision policies of each agent are restricted to local policies on incident edges and independent of the policies of the other agents. We show that under a condition called the positivity condition, these independent local policies preserve the stable routing paths globally. We then provide an efficient algorithm to compute an optimal local policy that yields a minimal pruned graph, which we call the Stable Path Topology Control (SPTC) algorithm. Using simulations, we demonstrate that this algorithm, when used with the popular ETX metric, outperforms topology control mechanisms commonly used for Mobile Ad Hoc Networks.},
	address = {Atlanta, Georgia},
	booktitle = {49th IEEE Conference on Decision and Control (CDC 2010)},
	pages = {pp.  2342-2347}
}
@conference {
	title = {Local Pruning for Information Dissemination for the Idempotent Semiring Algebraic Path Problem},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2010},
	month = {07/2010},
	abstract = {The advent of pervasive mobile devices has created the need for new algorithm design mechanisms for mobile computing platforms. The limited capabilities of these mobile devices have created several interesting problems that do not exist in traditional networks. These limitations have made communication an expensive commodity for distributed algorithms. In this paper, we consider the communicationintensive information broadcast problem for distributed computation. In distributed computing, several different computations can be viewed from a common viewpoint as instances of the Semiring Algebraic Path Problem (SAPP) on graphs. We first show that many algorithms broadcast information to enable recomputation of the SAPP on a dynamic graph. We then develop a general theory of local pruning for the SAPP problem for idempotent semirings. We motivate the pruning problem as a multi-agent optimization problem, where the agents try to limit the amount of information they broadcast while ensuring that the broadcast is sufficient to recompute the SAPP. The main contribution of this paper is establishing that this local pruning scheme chooses sufficient information to compute the original SAPP. For the dynamic SAPP, the information broadcast required to recompute the SAPP is reduced by the pruning. We also show that our solution corresponds to a local Gauss elimination solution over an extended semiring.},
	address = {Budapest, Hungary},
	booktitle = {The 19th International Symposium on Mathematical Theory of Networks and Systems (MTNS 2010)},
	pages = {pp. 1-8}
}
@conference {
	title = {Compositional Framework for System Security with Multi-metric Optimization"},
	author = {Baras, John S., Jiang, Tao., Somasundaram, Kiran K., Ivanov, Vladimir I.},
	year = {2010},
	month = {03/2010},
	abstract = {The objective of the proposed research is to develop a compositional framework and methods for~performance vs security tradeoffs via multi-criteria optimization of system security, and therefore it aligns~with problem statement 2: {\textquotedblleft}Security Framework.{\textquotedblright} We propose to study a top-down approach ~for~optimizing (1) the security metric(s) of a composite system viewed as a bivariate function of its~subsystems{\textquoteright} security and performance metrics under given constraints and (2) the composition of~subsystems that provides higher system security than that of the composition of the same subsystems~driven solely by performance maximization. In this way, we reconcile the trade-off between security and~performance by introducing a holistic, multi-objective solution that satisfies both the performance and the~security requirements for the system, by overcoming the problem of compartmentalized security solutions~and thus achieving the {\textquotedblleft}best value{\textquotedblright} of the system. Our framework delineates methods for achieving~provably secure composition of secure subsystems and system components {\textendash} a critical problem area~where almost all current results demonstrate infeasibility of achieving compositional security.},
	address = {Washington DC},
	booktitle = {SERC Security Workshop}
}
@conference {
	title = {Semiring Pruning for Information Dissemination in Mobile Ad Hoc Networks},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {12/2009},
	abstract = {Link state routing mechanisms have shown good convergence behaviour with mobile hosts. Pruning methods such as those used in Optimized Link State Routing (OLSR) have showed good throughput behaviour when compared to traditional link-state approaches which suffered from broadcast storm problems. In this paper, we show that the pruning function is a fundamental component of link-state routing protocols for mobile networks. We also show that this component architecture aids in interpreting both distance vector and link-state approaches under a common framework. We develop a class of pruning methods for many of the most commonly used routing objectives and show that these pruning methods are a special case of the semiring distribution property.},
	address = {Chennai, India},
	booktitle = {Proceedings of the The First International Conference on Networks and Communications(NetCoM-2009)},
	pages = {pp. 319-325}
}
@conference {
	title = {Achieving Symmetric Pareto Nash Equilibria using Biased Replicator Dynamics},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {12/2009},
	abstract = {Achieving the Nash equilibria for single objective games is known to be a computationally difficult problem. However, there is a special class of equilibria called evolutionary robust equilibria which can be obtained through a special type of evolutionary dynamics called the replicator dynamics. These dynamics has special properties over the simplex, which has been studied in optimization theory to solve several combinatorial problems. In this work, we consider the essentially hard combinatorial optimization problem of computing the equilibria in games with multiple objectives. We extend the notion of replicator dynamics to handle such games. We establish proofs of dynamic stability of this modified replicator dynamics and present their relation to the Pareto Nash equilibria in multiobjective games.},
	address = {Shanghai, China},
	booktitle = {48th IEEE Conference on Decision and Control},
	pages = {pp.7000 - 7005}
}
@conference {
	title = {Performance Improvements in Distributed Estimation and Fusion Induced by a Trusted Core},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {07/2009},
	abstract = {We consider distributed state estimation and fusion in autonomic ad-hoc sensor networks when some nodes are untrusted, corrupted or malicious. We provide rigorous graph models to capture both trust and network functionality relations. We propose a novel hierarchical scheme, inspired from socio-cognitive dynamics in economics and sociology, that utilizes a trusted core. We provide a component-based architecture to show the interplay between the trust and estimation schemes. As an explanatory example we consider the problem of distributed Kalman filtering. We show that trust-based schemes, implemented by a trusted core, result in significant improvement in the state estimation procedure. We also find that the interplay between estimation and trust updates quickly isolates malicious nodes and helps the observation limited nodes (corrupted sensor nodes).},
	address = {Seattle, WA},
	booktitle = {12th International Conference on Information Fusion (Fusion 2009)},
	pages = {pp. 1942-1949}
}
@conference {
	title = {Evolutionary Dynamics of Collaborative Environments with Heterogenous Agents},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {06/2009},
	abstract = {The seminal work of Maynard Prince and Price in 1973 laid the foundations in establishing the concepts of evolutionarily stable game strategies. It attempts to select strategies which are robust to evolutionary selection pressures. We observe that most of the literature as evolved is concentrated on single objective games. In this work, we extend the notion of evolutionary stability to games with vector payoff functions. We illustrate by examples that this notion of Multicriteria evolutionary stability models a much larger class of interactions in social, economic and biological problems. Particular applications of interest are in autonomic wireless sensor networks and autonomic networked control systems. We present a multi-population replicator dynamics, which models the evolution of agent actions in a network with varying levels of selfishness. We observe this model clearly demarks the regions of co-operation among these selfish agents. We provide analytical results on the dynamic stability of the replication. This clearly characterizes the aforementioned demarcations.},
	address = {Thessaloniki, Greece},
	booktitle = {17th Mediterranean Conference on Control \&amp; Automation (MED 09)},
	pages = {pp 121-125}
}
@conference {
	title = {Component Based Performance Modeling of Wireless Routing Protocols},
	author = {Baras, John S., Tabatabaee, Vahid., Purkayastha, Punyaslok., Somasundaram, Kiran K.},
	year = {2009},
	month = {06/2009},
	abstract = {We propose a component-based methodology for modelling and design of wireless routing protocols. Componentization is a standard methodology for analysis and synthesis of complex systems, or software. The feasibility of the component based design relies heavily on the compositionality property (i.e. system-level properties can be computed from properties of components). To provide a component based design methodology and to test compositionality for routing protocols, we have to develop a component-based model of the wireless network. We present the main components of the routing protocol that should be modelled and focus on three main components: neighborhood discovery, selector of topology information to disseminate, and the path selection components. For each component, we identify the inputs, outputs, and a generic methodology for modelling. Throughout the paper, we use the Optimized Link State Routing (OLSR) protocol as a case study to demonstrate the effectiveness of our approach. Using the neighborhood discovery component, we present our design methodology and design a modified enhanced version of this component, and compare its performance to the original OLSR design.},
	address = {Dresden, Germany},
	booktitle = {IEEE ICC 2009 Ad Hoc and Sensor Networking Symposium},
	pages = {pp.1-6}
}
@conference {
	title = {Loss Network Models and Multiple Metric Performance Sensitivity Analysis for Mobile Wireless Multi-Hop Networks},
	author = {Baras, John S., Perumal, Senni., Tabatabaee, Vahid., Somasundaram, Kiran K., Purkayastha, Punyaslok.},
	year = {2008},
	month = {11/2008},
	abstract = {We develop and evaluate a new method for estimating and optimizing various performance metrics of mobile wireless multi-hop networks, including MANETs. The method utilizes approximate (throughput) loss model that couples the physical, MAC and routing layers effects. The model provides quantitative statistical relations between the loss parameters that are used to characterize multiuser interference and physical path conditions on the one hand and the traffic rates between origin-destination pairs on the other. The model considers effects of the hidden nodes, node scheduling algorithms, MAC and PHY layer failures and unsuccessful packet transmission attempts at the MAC layer in~arbitrary time-varying network topologies where multiple paths share nodes. The method then applies Automatic Di{\textregistered}erentiation (AD) to these implicit performance models, to compute sensitivities of various performance metrics with respect to net- work parameters. We demonstrate the method by applying it to time-varying mobile network topologies, including reduced connectivity instances, with both random access MAC (contention mode of the 802.11) as well as reservation-based MAC (USAP TDMA based protocol). We analyze throughput, delay and packet loss as metrics and investigate metric optimization and tradeoff analysis. Finally, we provide numerical results for realistic mobile networks with time-varying topologies.},
	address = {Maui, Hawaii},
	booktitle = {Fourth International Wireless Internet Conference (WICON 2008)}
}
@techreport {
	title = {Study of OLSR for Real-time Media Streaming over 802.11 Wireless Network in Software Emulation Environment},
	author = {Jain, Kaustubh., Somasundaram, Kiran K., Brian, K Wang., Baras, John S., Roy-Chowdhury, Ayan.},
	year = {2013},
	month = {12/2013},
	abstract = {In this paper we present a setup to study the real-time traffic carrying performance of Optimized Link State Routing (OLSR) protocol using software emulation. We emulate the IEEE 802.11 MAC/PHY using the EMANE software emulator, on a cluster of machines, for different multi-hop wireless scenarios. As an instance of real-world usage scenario, we study the performance of real-time streaming media over a mesh network supported by OLSR. In particular, we study the effect of mobility and background traffic on carried load and jitter. We propose to extend this emulation setup to test the real-time performance of prototype routing protocols such as Stable Path Topology Control (SPTC) and other real-time applications.}
}
@article {
	title = {Solving Multi-metric Network Problems: An Interplay Between Idempotent Semiring Rules},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2011},
	month = {10/2011},
	abstract = {We motivate computations in a multifunctional networked system as instances of algebraic path problems on labeled graphs. We illustrate, using examples, that composition operators used in many function computations in a networked system follow semiring axioms. We present an abstract framework, using a special idempotent semiring algebraic path problem, to handle multiple metrics for composition. We show that using different vector order relations in this abstract framework, we can obtain different rules of compositions such as Pareto, lexicographic and max-order efficiency. Under this framework, we identify a class of tractable composition rules that can be solved in different multi-criteria settings at affordable computational cost. We demonstrate using an example of trusted routing in which logical security rules of admission control can be combined with delay performance metrics in the multi-criteria optimization framework.},
	pages = {pp. 1494 -1512},
	volume = {Volume 435},
	number = {Issue 7},
	journal = {LAA Special Issue on the occasion of 1st Montreal Workshop on Idempotent and Tropical Mathematics}
}
@techreport {
	title = {Distributed Topology Control for Stable Path Routing in Multi-hop Wireless Networks},
	author = {Somasundaram, Kiran K., Baras, John S., Jain, Kaustubh., Tabatabaee, Vahid.},
	year = {2010},
	month = {07/2010},
	abstract = {In this paper, we introduce the topology control problem for stable path routing in mobile multi-hop networks. We formulate the topology control problem of selective linkstate broadcast as a graph pruning problem with restricted local neighborhood information. We develop a multi-agent optimization framework where the decision policies of each agent are restricted to local policies on incident edges and independent of the policies of the other agents. We show that under a condition called the positivity condition, these independent local policies preserve the stable routing paths globally. We then provide an efficient algorithm to compute an optimal local policy that yields a minimal pruned graph, which we call the Stable Path Topology Control (SPTC) algorithm. Using simulations, we demonstrate that this algorithm, when used with the popular ETX metric, has lesser control overhead and the resulting pruned routing paths carry more upper layer traffic when compared with other topology control mechanisms commonly used for Mobile Ad Hoc Networks.}
}
@techreport {
	title = {Distributed Topology Control for Stable Path Routing in Mobile Ad Hoc Networks},
	author = {Somasundaram, Kiran K., Jain, Kaustubh., Tabatabaee, Vahid., Baras, John S.},
	year = {2010},
	month = {03/2010},
	abstract = {In this paper, we introduce the stable path topology control problem for routing in Mobile Ad Hoc Networks (MANETs). We formulate the problem as a constrained multiagent optimization problem with only local neighborhood information. We develop and prove local pruning strategies that solve this problem. We also introduce the notion of distorted pruning, which offers a systematic method to trade path stability off against the hop count metric. Finally, we quantify the performance of our pruning algorithms using several simulation scenarios.}
}
@techreport {
	title = {Path Optimization Techniques for Trusted Routing in Mobile Ad-Hoc Networks: An Interplay Between Ordered Semirings},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2010},
	month = {02/2010},
	abstract = {In this paper, we formulate the problem of trusted routing as a transaction of services over a complex networked environment. We present definitions from service-oriented environments which unambiguously capture the difference between trust and reputation relations. We show that the trustworthiness measures associated with these relations have a linear order embedded in them. Identifying this order structure permits us to treat the trusted routing problem as a bi-objective path optimization problem. Further, we present polynomial time solutions to obtain the optimal routing paths in various biobjective settings. In developing these algorithms, we identify an interesting semiring decomposition principle that yields a distributed solution.}
}
@techreport {
	title = {Pareto Nash Replies for Multi-Objective Games},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {11/2009},
	abstract = {We observe the notions of Pareto Nash strategies and their relations to multiparametric linear programming has made repeated appearances the game theory literature. . What we contribute . We feel that the theory of MOG has significant potential to model several practical scenarios especially in the context of networked communications}
}
@techreport {
	title = {Semiring Pruning for Information Dissemination in Mobile Ad Hoc Networks},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {08/2009},
	abstract = {Link state routing mechanisms have shown good convergence behaviour with mobile hosts. Pruning methods such as those used in Optimized Link State Routing (OLSR) have showed good throughput behaviour when compared to traditional link-state approaches which suffered from broadcast storm problems. In this paper, we show that the pruning function is a fundamental component of link-state routing protocols for mobile networks. We also show that this component architecture aids in interpreting both distance vector and link-state approaches under a common framework. We develop a class of pruning methods for many of the most commonly used routing objectives and show that these pruning methods are a special case of the semiring distribution property.}
}
@techreport {
	title = {Path Optimization Techniques for Trusted Routing in Tactical Mobile Ad-Hoc Networks},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {03/2009},
	abstract = {Over the past decade a lot of research effort has been invested in trying to understand security principles for Mobile Ad-Hoc Networks (MANETs). Among the various problems that the research community has focussed, a particularly interesting problem is that of trusted routing in MANETs. Unlike in traditional networks like the Internet, the information flow in a MANET is not restricted to a certain class of routing nodes. The MANETs are different in this sense, because every node acts as a potential relay node. Thus for the proper functioning of any higher layer protocols in MANETs it is of paramount importance that the mobile ad hoc nodes co-operate in routing and forwarding. In many practical scenarios where MANETs are deployed, it might be advantageous for individual nodes not to participate in this forwarding game. Thus one might expect under an unsupervised or unmonitored scenario, the network essentially breaks into components with similar interest groups. This raises the major issue of connectivity in a MANET which is a primitive requirement for the routing layer. Thus securing the network from self-interest groups is inherently coupled with the security of the routing layer. This particular observation has spawned several interesting works in the recent past.}
}
@article {
	title = {Local Topology Pruning for Algebraic QoS Path Computations for Link-State Routing},
	author = {Somasundaram, Kiran K., Baras, John S.},
	journal = {IEEE ACM Transactions on Networking}
}
