BCSM: Blockchain‐based cooperative spectrum management system for 5G NR‐U and WiFi coexistence in the unlicensed band

Abstract

Abstract The licensed band is crowded and suffers from immense mobile data traffic growth, which exceeded 58 exabytes per month in 5 years. Meanwhile, a significant portion of the unlicensed band is underutilized and not coordinated efficiently. Experiments in some urban areas of the world have shown that only 5% of the unlicensed 5 GHz band is being used. 5G NR‐U technology supports 5G networks in the unlicensed band to alleviate the traffic congestion and boosts 5G networks capacity. Different heterogeneous network access technologies already use the unlicensed band. Consequently, 5G NR‐U networks will operate in the proximity of the other coexisting networks, such as WiFi networks in the 5 GHz and 6 GHz bands. In such environments, assessing the shared spectrum becomes challenging and necessitates adequate protocols to identify idle slots for successful transmissions. Cooperative Spectrum Sensing (CSS) improves the spectrum assessment process, as the decision about the spectrum state is rendered based on the local decisions of multiple sensing nodes. CSS is exploited by integrating it with Blockchain technology to design a decentralized cooperative spectrum management system called: Blockchain‐Based Cooperative Spectrum Management (BCSM). The system is attributed to ameliorating 5G NR‐U awareness about the neighboring WiFi networks traffic in the unlicensed band. An algorithm is designed for performing distributed cooperative spectrum assessment between the 5G NR‐U base stations to profile the WiFi networks traffic in their proximity. To ensure fairness based on the effort expended in assessing the spectrum, a priority‐based algorithm is designed for spectrum access scheduling. A proof‐of‐concept is implemented using private Ethereum Blockchain and NS3 simulator. Finally, the system's accuracy is evaluated empirically along with theoretical security analysis.