Indoor White Space Networking in Metropolises

Joint work with Xuhang Ying, Jincheng Zhang, Lichao Yan, and Guanglin Zhang from The Chinese University of Hong Kong, and Ranveer Chandra from Microsoft Research.

It is a promising vision to utilize white spaces, i.e., vacant VHF and UHF TV channels, to satisfy skyrocketing wireless data demand in both outdoor and indoor scenarios. While most prior works have focused on exploring outdoor white spaces, the indoor story is largely open for investigation. Motivated by this observation and that 70% of the spectrum demand comes from indoor environments, we carry out a comprehensive study of exploring indoor white spaces.

As the initial step in exploring indoor white spaces opportunities in metropolises, we first present a large-scale measurement of outdoor and indoor TV spectrum occupancy in 30+ diverse locations in a typical metropolis Hong Kong. Our measurement results confirm abundant white spaces available for exploration in a wide range of areas in metropolises. In particular, more than 50% and 70% of the TV spectrum are white spaces in outdoor and indoor scenarios, respectively. While there are substantially more white spaces in indoor scenarios than in outdoor scenarios, there is no effective solution for identifying indoor white spaces. To fill in this gap, we propose the first system WISER (for White-space Indoor Spectrum EnhanceR), to identify and track indoor white spaces in a building, without requiring user devices to sense the spectrum. We discuss the design space of such systems and jus- tify our design choices using intensive real-world measurements. We design the architecture and algorithms to address the inherent challenges. We build a WISER prototype and carry out real-world experiments to evaluate its performance. Our results show that WISER can identify 30%-50% more indoor white space with negligible false alarms, as compared to alternative baseline approaches.

Our follow-up and on-going works also investigate the architecture and algorithmic solutions for efficient utilization of the identified indoor white spaces.

Note: this is a large project built up from one IE MSc research project, one IE undergrad research project, and one IE graduate research project.


  • X. Ying, J. Zhang, L. Yan, G. Zhang, M. Chen, and R. Chandra, “Exploring Indoor White Spaces in Metropolises”, in Proceedings of ACM MobiCom, Miami, Fl, USA, Sept. 30 - Oct. 4, 2013. [PDF]

  • J. Zhang, W. Zhang, M. Chen, and Z. Wang, “WINET: Indoor White Space Network Design”, in Proceedings of IEEE INFOCOM, Hong Kong, Apr. 26 - May 1, 2015. [PDF]

  • X. Ying, J. Zhang, L. Yan, Y. Chen, G. Zhang, M. Chen, and R. Chandra, “Exploring Indoor White Spaces in Metropolises”, (invited), accepted for publication in ACM Transactions on Intelligent Systems and Technology. [ final version to be available ]


  • Minghua Chen, “Exploring Indoor White Spaces in Metropolises”, ACM MobiCom presentation. [PowerPoint]

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