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For emerging high-density Wi-Fi networks, there have been plenty of studies that claim the need for more aggressive channel access to enhance spatial reuse. Against those previous ideas, this paper presents a different perspective that existing Wi-Fi devices already have excessive transmission opportunities, even without protecting each other in certain scenarios. We shed light on an anomaly within actual carrier sensing (CS) behaviors, which makes some neighboring devices become blind to each other and transmit simultaneously, due to undetected preambles. Through experimental study and analysis, we reveal both sides of the anomaly heavily affecting the overall network performance. Based on the observations, we design REFRAIN, a standard-compliant PHY/MAC framework, which copes with and further exploits the anomaly for better spatial reuse. Our prototype using NI USRP and commercial Wi-Fi devices shows the feasibility and effectiveness of our approach, while extensive simulation results demonstrate that REFRAIN achieves up to 1.57× higher average throughput by promoting valid transmissions, without modifying the 802.11 CS specification at all. CCS CONCEPTS • Networks → Wireless local area networks.

Data is a strategic asset for digital transformation. National innovation based on data has become a matter of global competition and survival. For pursuing a national innovation, it is important that the governance clearly defines the role and responsibility to lead innovation at the national level. In this regard, a national chief data officer (CDO) system has emerged recently as a new paradigm for national data innovation, mainly in the United States, the United Kingdom, and South Korea. This study employs a comparative approach to explaining the trends and common features of the national CDO system. The focal point of analysis is the legal base of CDO system, organization and governance, the required capability and authority of CDO, and its hiring process. Summing up, the study shows that an organization-wide awareness of the benefits of data innovation, a powerful authority to lead and coordinate regarding agencies, and a competent supporting organization are crucial to the successful operation of a CDO system.

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