LTE Spectrum Sharing Research Testbed: Integrated Hardware, Software, Network and Data

This paper presents Virginia Tech's wireless testbed supporting research on long-term evolution (LTE) signaling and radio frequency (RF) spectrum coexistence. LTE is continuously refined and new features released. As the communications contexts for LTE expand, new research problems arise and include operation in harsh RF signaling environments and coexistence with other radios. Our testbed provides an integrated research tool for investigating these and other research problems; it allows analyzing the severity of the problem, designing and rapidly prototyping solutions, and assessing them with standard-compliant equipment and test procedures. The modular testbed integrates general-purpose software-defined radio hardware, LTE-specific test equipment, RF components, free open-source and commercial LTE software, a configurable RF network and recorded radar waveform samples. It supports RF channel emulated and over-the-air radiated modes. The testbed can be remotely accessed and configured. An RF switching network allows for designing many different experiments that can involve a variety of real and virtual radios with support for multiple-input multiple-output (MIMO) antenna operation. We present the testbed, the research it has enabled and some valuable lessons that we learned and that may help designing, developing, and operating future wireless testbeds.Comment: In Proceeding of the 10th ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization (WiNTECH), Snowbird, Utah, October 201

Deep Predictive Coding Neural Network for RF Anomaly Detection in Wireless Networks

Intrusion detection has become one of the most critical tasks in a wireless network to prevent service outages that can take long to fix. The sheer variety of anomalous events necessitates adopting cognitive anomaly detection methods instead of the traditional signature-based detection techniques. This paper proposes an anomaly detection methodology for wireless systems that is based on monitoring and analyzing radio frequency (RF) spectrum activities. Our detection technique leverages an existing solution for the video prediction problem, and uses it on image sequences generated from monitoring the wireless spectrum. The deep predictive coding network is trained with images corresponding to the normal behavior of the system, and whenever there is an anomaly, its detection is triggered by the deviation between the actual and predicted behavior. For our analysis, we use the images generated from the time-frequency spectrograms and spectral correlation functions of the received RF signal. We test our technique on a dataset which contains anomalies such as jamming, chirping of transmitters, spectrum hijacking, and node failure, and evaluate its performance using standard classifier metrics: detection ratio, and false alarm rate. Simulation results demonstrate that the proposed methodology effectively detects many unforeseen anomalous events in real time. We discuss the applications, which encompass industrial IoT, autonomous vehicle control and mission-critical communications services.Comment: 7 pages, 7 figures, Communications Workshop ICC'1

An efficient counting method for the colored triad census

The triad census is an important approach to understand local structure in network science, providing comprehensive assessments of the observed relational configurations between triples of actors in a network. However, researchers are often interested in combinations of relational and categorical nodal attributes. In this case, it is desirable to account for the label, or color, of the nodes in the triad census. In this paper, we describe an efficient algorithm for constructing the colored triad census, based, in part, on existing methods for the classic triad census. We evaluate the performance of the algorithm using empirical and simulated data for both undirected and directed graphs. The results of the simulation demonstrate that the proposed algorithm reduces computational time many-fold over the naive approach. We also apply the colored triad census to the Zachary karate club network dataset. We simultaneously show the efficiency of the algorithm, and a way to conduct a statistical test on the census by forming a null distribution from 1,000 realizations of a mixing-matrix conditioned graph and comparing the observed colored triad counts to the expected. From this, we demonstrate the method's utility in our discussion of results about homophily, heterophily, and bridging, simultaneously gained via the colored triad census. In sum, the proposed algorithm for the colored triad census brings novel utility to social network analysis in an efficient package

SPIRITUAL MENTORING DURING EMERGING ADULTHOOD: A DYADIC PERSPECTIVE

Mentoring relationships have long been identified as a valuable means for supporting identity development in young adults and assisting these individuals in navigating life transitions. The guidance and stability afforded by mentoring relationships can be particularly beneficial to individuals undergoing transitions in their personal or professional lives, or both, and are thus well-suited to play a meaningful role in the lives of emerging adults. Emerging adults are also in a unique developmental stage in which they experience increased freedom and opportunity for exploration away from parents and guardians. While this freedom often results in increased risky behavior, it also allows for exploration and evaluation of moral systems and religious beliefs- a process that is at times accomplished alongside a mentor. However, existing mentoring research is largely directed towards three types of mentoring relationships (adolescent, academic, and vocational) and the spiritual mentoring of emerging adults is infrequently addressed. It is even more rare to find research on the influence of spiritual mentors and the ways mentors may be impacted by spiritual mentoring. Guided by the broader mentoring literature and Bandura’s Social Cognitive Theory, the current quantitative study aims to better understand spiritual mentoring relationships and their reciprocal influence on mentors and mentees through the actor-partner interdependence model. The study was conducted using data gleaned from 189 spiritual mentoring pairs. Respondents were obtained through convenience and snowball sampling methods that consistent of contacting colleges, campus organizations, and college ministries across the country that help facilitate spiritual mentoring relationships. Overall, numerous factors from both mentee and mentors’ perspectives that were associated with higher levels of mentee relationship quality, instrumental support, psychosocial support, and mentor relationship quality are detailed. Additionally, a preliminary investigation of the impact of mentee perceptions of psychosocial support, instrumental support, and mentor and mentee relationship quality on mentor and mentee outcomes revealed potential improvements in spirituality, intrinsic religiosity, religious commitment, spiritual modeling self-efficacy, and forms of well-being. Consistencies with, and deviations from, findings in the larger mentoring literature are discussed and examined in light of the distinctiveness of spiritual mentoring relationships. This study serves as an initial and unique investigation into the dyadic nature of spiritual mentoring relationships and highlights numerous factors that may enhance relationship quality, instrumental support, and psychosocial support. Although much of the mentoring literature emphasizes mentee perspectives and outcomes, this study corroborates existing evidence that both mentees and mentors stand to benefit in meaningful ways from engaging in spiritual mentoring relationships. The necessity of considering both mentee and mentor perspectives is also underscored by the numerous partner effects uncovered in the current work, and the reciprocal dynamics likely underlying the relationships that were explored. Theoretically relevant, but less-studied factors like mentee and mentor perceptions of the other’s motivation and credibility-enhancing displays were demonstrated to be important considerations in spiritual mentoring relationship research. Additional implications of these findings include improved insight for spiritual mentees and mentors, preliminary evidence of the impact of spiritual mentoring relationships, and potential guidance and direction for facilitators of spiritual mentoring relationships