Smart Camera NetworksWill be updated soon...
Architecture and design of Cognitive Radio Networks
Cognitive Radio Networks present a promising avenue to solve the capacity shortage problem in current wireless systems. These networks employ Software Defined Radios (SDRs), which provide low-level control to detect and exploit available wireless spectrum. SDRs allow "intelligent" programming and reconfiguration of the low-level radio features, enabling a variety of strategies to improve the network performance.
The project is aimed towards building a realistic, scalable and portable "Cognitive Resource Manager" (CRM) that facilitates optimization of Cognitive Radio Networks. The framework operates in real-time and supports decision-making in an environment where multiple conflicting optimization modules co-exist. The CRM facilitates rapid experimentation with novel control and learning architectures in Cognitive Wireless Networks. Examples problems solved using this architecture include interference-pattern detection using SDRs and cross-layered solution for optimizing video streaming. A majority of this work was a part of the ARAGORN project
NetMon: Network Monitoring in Multi-hop Wireless Networks
In wireless networks, several applications and protocols utilize data from lower layer to enhance the performance of the system. However, precise characterization of wireless links in realistic wireless networks is a challenging problem since the links experience frequent channel variations and complex interference patterns. It requires precise data about how the channel and environment varies, and the type of interactions that happen at lower layers such as PHY and MAC. Such data is generally inaccessible -- or even unavailable -- to the higher layer protocols. In this project, we design, implement and analyze measurement-based protocols that sense and predict important network characteristics. Please refer to the NetMon project for further details.
Traffic Engineering in Wireless Networks (Dissertation topic)
Wireless networks attract significant interest due to the minimal infrastructure demands and their potential in supporting mobile and pervasive computing. The high demand placed by a growing user base on the limited available bandwidth places a premium on effective wireless communication and networking. Two key challenges in wireless networks are the routing and scheduling problems: the problems of delivering packets across multiple wireless hops, considering the complex interference effects in wireless networks.
My dissertation targets developing a formally grounded and practical approach for solving joint routing and scheduling problems, while taking into account the effects of interference. The scheduling and routing problems are substantially more complicated than wired networks: wireless interference is complex and leads to effects such as packet collisions and unfairness. I have developed practical models to capture the effect of interference using optimization theory and stochastic processes.
During my post-doctorate research, I have also realized the theoretical models in practical network testbeds. I believe that the models and the practical approach can be applied to: (1) analyze the performance and capacity of existing protocols; (2) develop protocols for traffic engineering; and (3) develop formally grounded and near-optimal distributed routing protocols.
Directional antenna based wireless networks
Directional Antennas increase the performance and capacity of mobile ad hoc networks when compared to the existing omni-directional antenna technology. The motive of the thesis is to analyze the behavior of the network under directional antenna and to come up with solutions to the problems that have no counterpart in omni-directional antennas. The thesis has three primary contributions:
- Analyzes the directional MAC behavior in chain topologies, identifying interesting interactions with upper layer protocols.
- Identifies a head of line blocking problem in directional antennas and proposes new queuing policy to address it.
- Suggests a mechanism to passively discover directional neighbors and use that information to optimize multi-hop routes in directional antenna systems.
Masters Thesis: "Challenges in Directional Antennas"[pdf]
Techical Program Committee Member:
IEEE ICC (2011), IEEE Globecom 2011, IEEE PerNets (2011 -- 2009), ACM PM2HW2N (2010 -- 2008), IEEE SenseApp (2010 -- 2008), MACOM (2010, 2009), ICT Mobile Summit (2011, 2009), ISSNIP 2010, Green Networking 2010, IEEE WiMob 2009, Mobiquitous 2009, MobiCare 2009, SDR 2009, WoWMoM 2009, WCNC 2009