Defense Event

Enhancing Coexistence, Quality of Service, and Energy Performance in Dynamic Spectrum Access Networks

Ashwini Kumar

Friday, December 03, 2010
4:30pm - 6:30pm
3725 Beyster Bldg.

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About the Event

Dynamic Spectrum Access (DSA) is an upcoming wireless technology with the potential to alleviate spectrum-usage inefficiency from the current static spectrum allocation model of wireless communication. However, DSA technology is still in its infancy. There are several technical challenges in achieving effective DSA. This research work identifies problems associated with existing DSA schemes along three key dimensions---coexistence, quality of service (QoS), and energy. This thesis proposes novel and practical system-oriented solutions in order to address the identified shortcomings with traditional DSA. “Awareness-cum-adaption” is the central theme across the proposed methods. First, the thesis focuses on the generic DSA coexistence problem. It presents a dual-mode DSA operation scheme featuring joint sensing and transmission scheduling in order to enable safe and efficient time-domain incumbent-unlicensed coexistence on a licensed channel. A prototype called Spectrum-Conscious WiFi (SpeCWiFi), is also developed. Second, it provides important insights into the QoS impact of DSA through the case-study of a consumer DSA-based wireless network. Third, it presents the Context-Aware Spectrum Agility (CASA) optimization strategy, to address the DSA's QoS issues from a device-centric perspective. Fourth, to tackle the QoS problems at the network level, it proposes a network service framework called DSA Synchronization (DSASync). DSASync consists of algorithms based on buffering and traffic-shaping to effectively manage end-to-end connections in DSA networks. Finally, this thesis explores the energy cost of DSA through an empirical analysis, and proposes the Dynamic Energy Management for DSA (DEMD) scheme to reduce its energy footprint.

Additional Information

Sponsor(s): Kang G. Shin

Open to: Public