This chapter provides an overview on European Telecommunications Standards Institute (ETSI) activities related to opportunistic spectrum sharing technology with a specific focus on (TV) white spaces. Key use cases are outlined and a novel approach for a coordinated and an uncoordinated approach for accessing the spectrum resource is given. A spectrum coordinator is indeed introduced in order to handle resource management. Furthermore, database system design and inter‐database communication solutions are discussed as they are introduced by ETSI. Finally, various sensing mechanisms are detailed, which allow to monitor the radio environment and to feed decision‐making components correspondingly.