Cooperative and Adaptive Spectrum Management System Using Blockchain for 5G NR-U and WiFi Coexistence in the Unlicensed Band

The licensed band is crowded and suffers from the immense mobile data traffic growth, which exceeded 58 exabytes per month in five years. Meanwhile, a significant portion of the unlicensed band is underutilized and not coordinated efficiently. 5G NR-U technology supports 5G networks in the unlicensed band to tackle the aforementioned concern. Different heterogeneous network access technologies already use the unlicensed band. Consequently, 5G NR-U networks will operate in the proximity of other heterogeneous network access technologies such as WiFi in the 5 GHz frequency band. The standard spectrum access control of the 5G NR-U networks is Listen-Before-Talk. Unfortunately, this protocol is susceptible to inaccurate spectrum assessment due to the wireless medium's nature. Therefore, detecting the signal transmitted over the shared spectrum becomes challenging. Cooperative spectrum sensing (CSS) broadens the spectrum assessment process, as the decision about the spectrum state is rendered based on the local decision of multiple sensing nodes. We exploit CSS by integrating it with Blockchain technology to design a decentralized cooperative and adaptive spectrum management system, attributed to ameliorate spectrum sharing between 5G NR-U and WiFi networks in the unlicensed band. We first design and implement a proof-of-concept using Ethereum Blockchain and NS3 simulator. Then we conduct an empirical evaluation of the system's accuracy and energy consumption. Finally, we present a theoretical security analysis.