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Lower echelon forces face significant barriers in utilizing increasingly available networked resources. Network access at the tactical edge continues to present significant problems of limited bandwidth, disruption, and other constraints. Simultaneously, there is an ever-increasing set of video streams, imagery, intelligence, and live reports available on both tactical edge and upper echelon networks...
Femtocell is an effective technology to improve the system performance. In this paper, we address the problem of sub-channels allocation in OFDMA two-tier femtocell networks. Our objective is to maximize the rate sum of multiple femtocells with consideration of cross-tier interference between macrocell and multiple femtocells. A resource optimization approach based on Ant Colony Optimization Algorithm...
In this paper, lightweight identity-based and certificate-based distributed key management algorithms are proposed for self-organized multi-channel cognitive radio networks. Both key management schemes use threshold secret sharing. In identity-based scheme, after system initialization, each cognitive radio sends its channel key request to distributed private key generators. Then, it can construct...
This paper proposes novel relaying schemes based on recently proposed Modified Alamouti Code and Time Switch Space Time Coding for a homogeneous sensor network architecture. New relaying schemes based on the incorporation of aforementioned techniques in a Sensor Network framework are considered. An exhaustive analysis in terms of the total energy consumption and delay characteristics as performance...
The Network Connectivity Analysis Model (NCAM) is a general purpose radio frequency (RF) event-based simulator that addresses the physical layer of the International Organization for Standards (IOS) Open System Interconnect (OSI) 7-layer model for wireless communication systems. With a modular design hierarchically organized to emulate an actual physical test setup, NCAM provides the U.S. Army with...
This paper presents an efficient scheme for a two-dimensional (2-D) direction of arrival angle estimation (DOA) for multiple incident sources in the presence of coherent signals. A new antenna array configuration and innovative signal processing technique are presented. Compared with the well-known classical subspace schemes such as MUSIC and ESPRIT, the proposed method has several advantages. First,...
This article tackles the problem of supplying the low level commanders with information from information sources located on higher command levels, distributed using web services, the most commonly used technology in modern command and control systems. There has been proposed the Adaptation Framework For Web Services Provision (AFRO) that defines a mechanism for effective web services invocation in...
It is well known that malware (worms, botnets, etc…) thrive on communication systems. The process of detecting and analyzing malware is very latent and not well-suited for real-time application, which is critical especially for propagating malware. For this reason, recent methods identify similarities among malware dynamic trace logs to extract malicious behavior snippets. These snippets can then...
The problem of distributed estimation of a parametric physical field is stated as a maximum likelihood estimation problem. Sensor observations are distorted by additive white Gaussian noise. Prior to data transmission, each sensor quantizes its observation to M levels. The quantized data are then communicated over parallel additive white Gaussian channels to a fusion center for a joint estimation...
The overarching theme of this year's conference is Trusted Communications ... Awareness to Action. Topics to be addressed will include the spectrum of command, control, communications, computers, intelligence, surveillance and reconnaissance (C4ISR) technologies and capabilities that address communications challenges related to national defense, homeland security, disaster response and interoperability...
Real-time forensic reconstruction of a processes memory and interaction history is impractical in modern computing environments because the volume of data processed by a typical server is immense. Having this information would speed the search for zero-day exploits and designate precisely which system components could have been affected by an intrusion. Unfortunately, it may be several months after...
Frequency estimation for single-tone complex sinusoidal signals under additive white Gaussian noise is a classical and fundamental problem in many applications, such as communications, radar, sonar and power systems. In this paper, we propose a new algorithm by interpolating discrete Fourier transform (DFT) samples. Different from other existing interpolation methods for frequency estimation, our...
Field operations teams need situational awareness support in order to efficiently carry out high risk safety critical tasks. A field common operating picture (FCOP) provides location tracking, movement history, telemetry, and messaging in near real time to all operators equally. This paper describes a novel scalable distributed algorithm for maintaining such a display using a scalable ad hoc geocast...
For multiple-input multiple-output (MIMO) systems, the optimum maximum likelihood (ML) detection requires tremendous complexity as the number of antennas or modulation level increases. This paper proposes a new algorithm which attains the ML performance with significantly reduced complexity. The proposed scheme is based on combining Branch and Bound algorithm (which solves an integer quadratic programming...
We are interested in estimating the angle of arrival of an RF signal by using commercial-off-the-shelf (COTS) software-defined radios (SDRs). The proposed COTS-based approach has the advantages of flexibility, low cost and ease of deployment, but-unlike traditional phased antenna arrays in which elements are already phase-aligned — we face the challenge of aligning individual SDRs during field deployment...
Quantum error correction codes are needed to protect quantum systems from interference. An important family of quantum error correction codes are stabilizer codes. Many stabilizer codes in the literature belong to a subclass of stabilizer codes, referred to as CSS codes since they are based on the so-called CSS formalism. CSS codes have received significant attention because the dual-containing condition...
We present the design of a cross-layer protocol to maintain connectivity in an earthquake monitoring and early warning sensor network in the absence of communications infrastructure. Such systems, by design, warn of events that severely damage or destroy communications infrastructure. However, the data they provide is of critical importance to emergency and rescue decision making in the immediate...
We take a physical layer perspective in detecting the falsely injected vector (pollution attack) and removing it from the polluted packet to restore the true coded packet in wireless network coding system. The proposed scheme builds on the maximum likelihood detection principle which is optimal in the sense of minimizing the probability of detection error. It discards only the faulty information and...
Interference Alignment and Cancelation (IAC) aims at significantly improving the wireless channel capacity. Existing algorithms for IAC are computationally intensive, which may lead to long execution times. A practical implementation of IAC is infeasible for fast-varying channels (when the coherence time is small, e.g., less than 0.5 s). This is because a significant amount of time has to be spent...
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