Ionut Cardei


My research is in two main areas: wireless networking and in system/software engineering. Recently, I focused on the following topics:

Wireless Networking for Emergency Response Teams

First responders operate sometimes in environments that are cluttered, remote, and where mobile devices used to communicate with colleagues and with people from other agencies may be inoperable. This can happen from radio interference, shadowing, limited radio range, or power failure. We investigate network protocols that rely on ubiquitous smartphones equipped with WiFi that can self-configure to form a delay tolerant network capable to offer end-to-end communication in a sporadically connected topology even where spectrum availability is hindered by primary users. We apply cross-layer design and cognitive networking principles to improve delivery performance metrics.

Underwater Laser Networking

Research in this area is motivated by the needs of collaborative applications for seabed scanning and underwater environmental monitoring for high-speed wireless data communication. Acoustic modems are limited by the small bandwidth and slow signal propagation speed to about 100 kbps over hundreds of meter range. Recent advances in optical technology, such as low cost violet lasers and sensitive avalanche photomultiplier tubes, bring the possibility of building underwater laser links capable of hundreds of Mbps over tens to hundreds of meters closer to reality. High-speed underwater laser data links face multiple challenges when deployed in mobile topologies, among others: molecular absorption dominated attenuation and scattering and absorption from dissolved or organic matter in turbid waters causing beam spreading and pulse delay spreading. Ambient light, tough sea/weather conditions, and device electronic noise raise additional problems. These issues are open problems that need to be solved. In collaboration with Dr. Fraser Dalgleish from HBOI we investigate channel modeling, signal modulation and adaptation techniques, noise models, and upper layer protocols for reliable underwater optical networking under the aforementioned conditions.

Mechanisms for Resilient System Design

Cyber-physical systems operating in difficult environments require a robust design that reduces failure probability and maintenance costs. We collaborate with the Southeast National Marine Renewable Energy Center to develop methodologies and tools for designing resilient systems that span mechanical subsystems, wireless networks, computing resources, and software. Our methodology involves hierarchical state decomposition and risk analysis with Bayesian networks to identify design weaknesses and perform trade-offs.

Business Object Patterns for Enterprise Applications

Enterprise applications are the backbone supporting the modern corporation and are typically implemented on web and mobile software platforms. A business object encapsulates the data, relationships, and operations representative of an entity in a business problem domain, like for instance an invoice or a purchase order. A business object in a multi-tier enterprise application has a more sophisticated design than a class in the traditional object-oriented sense. Business object design must support a sophisticated lifecycle, concurrent access from different platforms, version management, state management, and so on. We formulate architecture elements for business objects as design patterns that are reusable solutions for design problems in the enterprise application domain.

Current Students

  • Russ Rubis, PhD candidate
  • Lynn Grande, PhD candidate
  • James Junco, PhD candidate
  • David Rashkin, PhD candidate

Graduated Students

  • Cong Liu, PhD, 2009 (co-adviser), "Design and Implementation of Efficient Routing Protocols in Delay Tolerant Networks"
  • Quan Yuan, PhD, 2009, "Probabilistic Prediction-Based Routing in Disruption-Tolerant Networks"
  • Mihai Fonoage, PhD, 2010 "Framework for Requirements-Driven System Design Automation"
  • Timur Tavtilov, MSc, 2011, "Prognosis and Health Monitoring Communications Quality of Service"
  • Anthony Marcus, PhD, 2013, "Resilient System Design and Efficient Link Management for the Wireless Communication of an Ocean Current Turbine Testbed"
  • Saeid Azandaryani, MSc, 2013, "Indoor Localization Using Wi-Fi Fingerprinting"