The Art of Language Invention:  Authentic Language Creation for Television and Film

David J. Peterson 

MLLI SSF Lecture
4-5:30 pm, Thursday, 6 October 2022
AOK Library 7th floor, UMBC

 

 

Existing cellular networks have untapped radio frequency resources, also known as white space, available for cognitive radio applications. A secondary network can opportunistically interweave communication within the white space of an existing cellular signal by leveraging cognitive radio. This thesis presents a novel methodology for forming a cognitive interwoven self-reliant secondary network with no additional physical infrastructure, collaboration from the existing primary network, and software or hardware changes in the primary network. The methodology is tested first with 4G and later with 5G cellular technological standards. For the physical layer, this thesis optimizes synchronization as the initial step in aligning to a cellular signal in time, frequency, and sector identity. We improve synchronization through sensitivity, execution time, and applies a threshold to form a "cell detector" instead of the traditional "cell search," which only considers the most detectable signal. 

After synchronization, resource detectors monitor the available spectral resources of the entire cellular infrastructure. Modern cellular networks have grown in complexity and become an ecosystem that includes the host technologies, such as 4G Long Term Evolution (LTE) and 5G New Radio (NR), along with subsystems such as narrowband internet of things (NB-IoT), category M1 (Cat-M1/LTE-M), observed time difference of arrival (OTDOA), and support for 4G/5G coexistence using dynamic spectrum sharing (DSS). Such an increased complexity has driven the need for network monitoring to enable load tracking, congestion control, spectral efficiency analysis, intrusion detection, and cognitive radio communications.

This thesis develops resource monitoring that can passively monitor the entire cellular ecosystem, including reservations configured with high-layer messages that are only accessible to in-network, active, and sometimes user-specific equipment. Resource monitoring provides white-space reservations for cognitive communications. We define interference control to prevent interference with the primary network through physical layer access schemes and power control cluster protocols to access resources safely. With the added complexity of 5G as a host technology, our research leverages geospatial beamforming of known signals as spatially dependent white space. In this case, the known synchronization signal burst must be detected with a "beam detector" instead of a "beam search" to properly use beam resources that are not close to cognitive radio nodes. The thesis applies the self-reliant methodology, which defines opportunistic access and power control protocols that limit interference between cellular networks in both the time and frequency domains with additional support in the geospatial domain for 5G NR. Our research determines that an adapted version of Slotted ALOHA for medium access control (MAC) with a no-back-off contention fits the self-reliant approach of our work and timing constraints found in 4G LTE and 5G NR networks.

Work by Jason Reinhardt, Merideth Secor, Lindsey Miles, Ron Lafond, Derek Koolman II, Lauren Wind, Ray Ludwig, Jeff Munns

The Cybersecurity and Infrastructure Security Agency (CISA) leads the national effort to understand, manage, and reduce risk to our cyber and physical infrastructure. CISA must assess risks that cover a broad range of scenarios over a complex set of interdependent critical infrastructure (CI) systems. While many threat and hazard impact models and data sets exist, there is no overarching analytic structure that organizes and integrates these disparate sources into a unified risk assessment. CISA is building capabilities that will address these challenges to support stakeholders across all levels of government and the private sector. 

First, CISA has developed a National Critical Functions (NCFs) data structure to organize and describe critical infrastructure. This data set provides a set of decompositions structured as directed graphs that break down each identified function into enabling sub-functions that detail the operation and interdependencies across disparate CI systems.  The functional description of NCFs serves as a complementary lens to the sector-based organization of CI and better facilitates systemic and cross-sector risk analysis. 

Cyrus Jian Bonyadi is a PhD student working on developing a set of corollaries for consensus theory in distributed system security. Cyrus is a former member of the UMBC Cyberdawgs cyberdefense team and maintains a relationship with UMBC as a full time researcher at Sandia National Labs. 

Host: Alan T. Sherman, sherman@umbc.edu. Support for this event was provided in part by the National Science Foundation under SFS grant DGE-1753681.  The UMBC Cyber Defense Lab meets biweekly Fridays 12-1pm. All meetings are open to the public.  Upcoming CDL meetings: Oct 7, Geoffrey Herman (Illinois), Validation of the Cybersecurity Curriculum Assessment (CCA); Oct 21, Peter Peterson (UMN Duluth), Misconceptions in cybersecurity; Nov 4, Josiah Dykstra (DoD), Myths in cybersecurity; Nov 18, Russ Fink (APL), ARMR: Autonomous resilience / machine recovery; Dec 2 Peter Peterson (UMN Duluth), Adversarial Thinking; SFS/CySP Research Study: January 2-6, 2023 (tentative).

With lots of fun activities, over $5,000 in prizes, and swag for all participants, you will be in for an exciting weekend.

There will be four tracks focused on different areas: data analysis and visualization, hardware systems, AI/machine learning, and general ideas that don't fit the other three.

For more information, see the hackUMBC site.

In underwater wireless networks (UWNs), conventionally there is no direct communication between an underwater node and a remote command center, because there is no known physical signal that propagates well in both the water and air mediums. Radio signals are the popular choice in the air while acoustics are the prime means for communication underwater. Hence, the typical architecture of an UWN includes surface nodes or gateways which have dual modems, an acoustic modem to communicate with underwater nodes and a radio modem to interact with terrestrial command centers. However, such an architecture is logistically complicated and could expose the network to security threat. Therefore, it is desirable to establish a direct communication from air to underwater without having any intermediate surface node. 

This dissertation opts to fulfill such a need by pursuing two viable solutions, namely, using visual light communications (VLC) and exploiting the optoacoustic (photoacoustic) effect. Through extensive analysis and experiments we show that VLC is an effective means for scenarios where the distance between the airborne and underwater nodes is relatively short. We first analyze the coverage area and intensity inside the water for a light transmitter placed in the air. We then provide guidelines for using single and multiple light sources to establish robust VLC links under rough environmental conditions like high water current and turbidity. Furthermore, we investigate effective modulation techniques that suit VLC. For long distance communication, VLC is not a viable option since light gets absorbed at an exponentially growing rate with the increase of water depth. Photoacoustic (PA) energy transfer mechanism is the promising method for long distance communication. 

Although the use of the photoacoustic mechanism is quite common in medical imaging, little progress has been made on building the communication protocol stack for air-to-underwater communication. In our research work, at first, we have studied the channel characteristics of the PA based air-to-underwater communication. We show that by carefully choosing the relative position of the airborne unit and underwater node, we can generate a narrowband acoustic signal which is very crucial for long distance communication. Moreover, we develop suitable modulation and demodulation schemes for PA communication.

Committee: Drs. Mohamed Younis, Fow-Sen Choa, Gary Carter, Lloyd Emokpae, Akram Fadhl N. Ahmed

Get more information here and apply onlinebyTuesday September 20. Contact ai4all@csee.umbc.edu with any questions.