Expansive networks: Exploiting spectrum sharing for capacity boost and 6G vision

Adaptive capacity with cost-efficient resource provisioning is a crucial capability for future 6G networks. In this work, we conceptualize "expansive networks" which refers to a networking paradigm where networks should be able to extend their resource base by opportunistic but self-controlled expansive actions. To this end, we elaborate on a key aspect of an expansive network as a concrete example: Spectrum resource at the PHY layer. Evidently, future wireless networks need to provide efficient mechanisms to coexist in the licensed and unlicensed bands and operate in expansive mode. In this work, we first describe spectrum sharing issues and possibilities in 6G networks for expansive networks. We then present security implications of expansive networks, an important concern due to more open and coupled systems in expansive networks. We also discuss two key enablers, namely distributed ledger technology (DLT) and network intelligence via machine learning, which are promising to realize expansive networks for the spectrum sharing aspect.