Kyle Guan

Cost-Efficient Fiber Connection Topology Design for Metropolitan Area WDM Networks

In this paper, we provide some analytical insights into physical architectures that can serve as benchmarks for designing a cost-efficient WDM metropolitan area network (MAN). For uniform all-to-all traffic and regular topologies with nodal symmetry, we identify a class of regular graphs-Generalized Moore Graphs-that have several attractive properties by formulating a first-order cost model and characterizing the tradeoff between fiber and switching resources. Our results show that, in conjunction with minimum hop routing, Moore Graphs achieve the minimum cost and simultaneously use the least number of wavelengths. We also take steps to broaden the scope of our work by addressing irregular network topologies, which represent most existing networks. Our results show that Generalized Moore Graphs can be used to provide useful estimates of the cost of irregular networks and can serve as good reference architectures for the designs of practical networks.

Adaptive Management of Scalable Mobile Ad-Hoc Networks with Non-homogeneous Topology

In this paper, we discuss the management of scalable mobile ad-hoc networks (MANET) in which nodes are equipped with a range of adjustable capabilities (transmission range, data rate, and radio interface, etc.) and operate in quite diverse environment (in terms of channel condition and node density, etc.). To support communication in such a dynamic networking environment requires a MANET protocol that is adaptable to spatial and temporal changes. As such, it is crucial to optimize node/link controllability so that node/link resources can be best utilized and a good performance can be achieved. Moreover, it is also necessary to feature statistical measures when evaluating the performance, such as the variance of these metrics in addition to the average. As an extension of our previous research, we continue to study Adaptive Hybrid Domain Routing (AHDR) protocol in regard to the effectiveness of the flooding architecture. We also evaluate various topology control techniques that ensure guaranteed service to disadvantaged nodes and across critical links (sparse connectivity). These efforts serve as very first steps to comprehensively study the impact of network non-homogeneity and variance in topology management.

Reliable data fusion in wireless sensor networks: A dynamic Bayesian game approach

In this paper, we consider the reliable data fusion problem in a tactical environment in the presence of adversary. First, we characterize malicious behavior of compromised sensors assuming probabilistic models. Performance of the fusion process, in the presence of malicious sensors, is then quantified. The performance analysis shows that malicious sensors incur significant degradation on the fusion process. Our goal is to substantially improve reliability and robustness of data fusion in sensor networks. To this end, we introduce monitoring nodes (MN) that are distributed across a sensor network to detect,identify and isolate malicious sensors. We formulate the interaction between sensors and MN as a dynamic game with incomplete information, which provides a platform for designing reputation based data fusion. The reputation system ensures reliable data fusion by confining the fusion process to trustworthy sensors. We evaluate performance of the reputation system both by analysis and simulation.

Topology formation for tactical networks with directional RF and free-space optical links

This work addresses the graph theoretical under-pinning of forming a topology during the deployment of directional RF or free space optical (FSO) based tactical networks. The objective is to construct a topology that not only has a good reliability, but also supports the maximal delivery of traffic. Given the fact that each node has a limited number of transceivers, the design problem falls into the category of (node) degree-constrained topology optimization problem, for which an exhaustive search or integer programming approach becomes prohibitive for larger networks. As such, we focus on first developing a design guideline based on theoretic analysis and then proposing algorithms. The algorithms consist of two components. The first component involves forming a minimum spanning tree (MST) or traveling salesman path (TSP) to guarantee a networkpsilas connectivity. The second component involves iteratively connecting node pairs based on an updated criterion, which takes into considerations of traffic, hop distance, link bandwidth, and network load. Extensive tests demonstrate that the proposed algorithms produce optimal or close-to-optimal solutions. Compared with existing approaches, the proposed algorithms outperform in traffic delivery; while they have similar performance in network reliability.

Distributed sensing and communications in tactical robotic networks

In this paper, we address the issues of distributed sensing, communications, mobility control, and self-configuration in robotic networks. In particular, we develop a distributed algorithm that exploits the proactive movements of robotic platforms to achieve a perfect balance between providing sensing coverage and maintaining RF connectivity. The main elements of our proposed approach are based on the concept of virtual potential force (VPF). To circumvent the limitations of existing robotic movement and deployment algorithms, our algorithm takes its inputs directly from local measurements corresponding to RF signal strength or signal to noise ratio (SNR) and maps various control objectives onto a set of corresponding virtual forces. The sum of all the virtual forces directs the adaptive movements of robots. Using simulations, we demonstrate the viability and robustness of our proposed approach.

Military scenarios and solutions from a network science perspective

Network science has recently received a considerable amount of attention from the military and research communities. In this paper we analyze two military scenarios from a network science perspective. We discuss the pros and cons of problem solving for these scenarios using the current fragmented approach versus applying a unified view across three domains: social/cognitive, information, and communication. We perform a step by step evaluation of each scenario. At each stage we present and compare existing solutions with those provided by network science based approaches available through future advances in basic and applied network science research. Our goal is to highlight advantages and challenges in network science research by way of example.

Wireless video multicast in tactical environments

There has been a tremendous increase in demand for real-time video applications over military networks. Multicast provides an efficient solution for simultaneous content delivery to a group of users. It is especially valuable for military applications, as it saves network resources by sharing the data streams across receivers. Even with ever increasing channel bandwidth and computation power, efficiently multicasting video over the tactical edge is still challenging due to factors such as higher packet loss ratio, bandwidth variations and the heterogeneity of the users. In this paper, we explore the use of omni-directional relays to improve the performance of wireless video multicast in tactical environments. We focus on assessing the trade-off between total relay energy, coverage area and video quality. The results provide achievable operational regions, which can serve as a reference and a starting point for system design.

Minimizing Control Management Overhead for Scalable Mobile Ad-Hoc Networks

In this paper, we provide a parametric model for analyzing the control overhead usage In mobile ad-hoc networks (MANET). In particular, we focus on evaluating the Impact of the hierarchy of both topology formation and routing on the scalability of overhead usage. Via an analytical approach, we quantitatively characterize the amount of overhead under different domain sizes, as well as other design parameters. The results help us to assess optimal scaling of overhead traffic as a function of network size N and to provide insights into developing scalable routing architectures for MANET.

Resource allocation for networked electronic warfare

In this work, we consider the challenge of designing an effective networked EW operation against a sophisticated adversary that uses different types of wireless triggers to detonate radio controlled improvised explosive devices. We assume that jamming power on a platform is limited, as a result the jammer can only selectively disrupt communications in certain frequency bands. Meanwhile, the adversary can employ different types of wireless triggers to evade jamming and maximize damage. We capture the interaction between the EW system and the adversary within a game theoretic framework to architect an efficient resource allocation scheme for the networked EW.

Optimal platform placement and configuration in networked electronic warfare (EW)

In this work, we investigate dynamic resource allocation in a networked electronic warfare (EW) environment. In particular, we study the problem of placing EW capable nodes, including both electronic attack (EA) and electronic support (ES) nodes, to collaboratively carry out missions. We first provide a general formulation of the platform placement. The objective is to minimize the cost associated with the placement of both EA and ES nodes, while satisfying the requirement of jamming coverage and network connectivity. Since the placement problem is NP-hard, we next propose two heuristics that can provide good solutions with reasonable computational efficiency. Via several representative case studies, we evaluate the performance of the proposed heuristics.