Broadcast in Cognitive Radio Ad Hoc Networks

Sponsor: National Science Foundation (NSF)

Duration: September 2012 - August 2015

Investigator: Dr. Jiang (Linda) Xie (PI)

Students: Yi Song, Ji Li

Overview:

Cognitive radio has recently emerged as a promising technology to overcome the imbalance between the increase in the spectrum access demand and the inefficiency in the spectrum usage by allowing dynamic spectrum access (DSA). However, a fundamentally unexplored issue in cognitive radio network (CRN) design is how to exchange network-wide control information among CR nodes under varying spectrum availability. Network-wide control information is often sent out as broadcasts, messages that are sent to all other nodes in a network.

The research objective of this project is to design, analyze, and evaluate new broadcast protocols for multi-hop cognitive radio ad hoc networks without a common control channel (CCC). The proposed broadcast design is aimed at maximizing the broadcast success rate and minimizing the average broadcast delay simultaneously. This research is the first that systematically addresses the unique challenges encountered during broadcast processes in CRNs under practical scenarios.

Research Activities and Key Outcomes:

The specific research goal to be accomplished in this project is a suite of fully distributed broadcast protocols and algorithms with optimized performance in dynamic and spectrum-aware environments. The project has the following main research components:

• For single-hop broadcast scenarios: (1) model the spatial correlations in spectrum availability and (2) design efficient channel hopping sequences based on exploiting the spatial correlations of spectrum opportunities;

• For multi-hop broadcast scenarios: (1) design distributed scheduling algorithms based on exploiting the channel diversity of different users for minimizing the multi-hop broadcast delay and (2) design practical collision avoidance algorithms for elliminating collisions and maximizing the broadcast success rate.

• When spectrum availability varies during a broadcast process: design spectrum-aware adaptive algorithms to increase the robustness of broadcast to the changes in spectrum.

Publications:

• Yi Song and Jiang Xie, "BRACER: A Distributed Broadcast Protocol in Multi-hop Cognitive Radio Ad Hoc Networks with Collision Avoidance," IEEE Transactions on Mobile Computing, vol. 14, no. 3, pp. 509-524, March 2015.

• Yi Song, Jiang Xie, and Xudong Wang, "A Novel Unified Analytical Model for Broadcast Protocols in Multi-hop Cognitive Radio Ad Hoc Networks," IEEE Transactions on Mobile Computing, vol. 13, no. 8, pp. 1653-1667, August 2014.

• Yi Song and Jiang Xie, "QB²IC: A QoS-based Broadcast Protocol under Blind Information for Multi-hop Cognitive Radio Ad Hoc Networks," IEEE Transactions on Vehicular Technology, vol. 63, no. 3, pp. 1453-1466, March 2014.

• Yi Song and Jiang Xie, "Enhancing Channel Rendezvous in Cognitive Radio Networks with Directional Antennas," Proc. IEEE International Conference on Communications (ICC 2015), June 2015.

• Ji Li and Jiang Xie, "A New Communication Framework for Wide-band Cognitive Radio Networks," Proc. IEEE International Conference on Sensing, Communication and Networking (SECON), June 2014.

• Yi Song and Jiang Xie, "A Distributed Broadcast Protocol in Multi-hop Cognitive Radio Ad Hoc Networks without a Common Control Channel," Proc. IEEE INFOCOM 2012, pp. 2273-2281, March 2012.

• Yi Song and Jiang Xie, "A QoS-based Broadcast Protocol for Multi-hop Cognitive Radio Ad Hoc Networks under Blind Information," Proc. IEEE Global Communications Conference (GLOBECOM 2011), pp. 1-5, December 2011.

Broader Impact:

This project will have a significant impact on wireless networking research in the area of CRNs. With the active involvement of industrial companies and standard working groups on cognitive radio products and DSA regulatory policies, network-wide control information dissemination is considered as a critical component to ensure the success of CRN deployment, but unfortunately, it is inadequately addressed in current research and development. The research effort will provide complementary solutions, yet a fundamental building block, to existing CRN research on other network operations including spectrum access, routing, and power control.

Education Activities:

• Curriculum Development: graduate-level courses Fundamentals of Wireless Systems and Protocols and Modeling and Performance Analysis of Communication Networks

• Graduate Student Mentoring: Yi Song, "Distributed Intelligent Spectrum Management in Cognitive Radio Ad Hoc Networks," PhD Dissertation, June 2013.