Institute for Systems Research Technical Reports
Permanent URI for this collectionhttp://hdl.handle.net/1903/4376
This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.
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Item Study of OLSR for Real-time Media Streaming over 802.11 Wireless Network in Software Emulation Environment(2010-07) Jain, Kaustubh; Somasundaram, Kiran; Wang, Brian; Baras, John; Roy-Chowdhury, AyanIn 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.Item Local Pruning for Information Dissemination in Dynamic Networks for Solving the Idempotent Semiring Algebraic Path Problem(2010-05-15) Somasundaram, Kiran; Baras, JohnWe present a method, inspired from routing in dynamic data networks, to solve the Semiring Algebraic Path Problem (SAPP) for dynamic graphs. The method can be used in dynamic networks such as Mobile Ad Hoc Networks, where the network link states are highly dynamic. The algorithm makes use of broadcasting as primary mechanism to recompute the SAPP solution. The solution suffers from broadcast storm problems, and we propose a selective broadcasting mechanism that reduces the broadcast storm. We call this method local pruning and prove its correctness.Item Distributed Topology Control for Stable Path Routing in Multi-hop Wireless Networks(2010-03) Somasundaram, Kiran; Baras, John; Jain, Kaustubh; Tabatabaee, VahidIn 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 link-state broadcast as a graph pruning problem with restricted local neighborhood information. We develop a multi-agent optimiza- tion 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.Item Boom-i - A Toolkit for Networked Systems(2010-03) Somasundaram, Kiran; Baras, JohnItem Distributed Topology Control for Stable Path Routing in Mobile Ad Hoc Networks(2009-11-25) Somasundaram, Kiran; Jain, Kaustubh; Tabatabaee, Vahid; Baras, JohnItem Path Optimization Techniques for Trusted Routing in Mobile Ad-Hoc Networks: An Interplay Between Ordered Semirings(2008) Somasundaram, Kiran; Baras, John; Baras, JohnIn 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 solutionItem Distributed Pruning Methods for Stable Topology Information Dissemination in Ad Hoc Networks(2009-01-10) Somasundaram, Kiran; Baras, JohnWe propose a component based modelling and design strategy for the Neighborhood Discovery Component (NDC) and the Selector of Topology Information to Disseminate Component (STIDC) of proactive ad hoc routing protocols. The NDC design strategy focuses on limiting the detection time and removing time of network good and bad links respectively. The STIDC strategy makes sure that only stable links with long life time are selected as the topology information that will be broadcasted in network. We provide analytic performance analysis methods for both components and show that using the proposed methodologies we can significantly reduce the overhead of information dissas OLSR.Item Semiring Pruning for Information Dissemination in Mobile Ad Hoc Networks(2009-06-16) Somasundaram, Kiran; Baras, John; Baras, JohnLink 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.Item Covering Analysis of Flooding Algorithms on a 1-D Continuum Model(2009-05-17) Somasundaram, Kiran; Baras, JohnThis work presents a covering analysis of pruning algorithms on one dimensional random graphsItem Evolutionary Stability in Multi-Objective Games(2008) Somasundaram, Kiran; Baras, John