FIG. 3 is a schematic diagram illustrating an exemplary WiFi stack 300. The WiFi stack 300 can be a typical WiFi product stack compliant to the 802.11 protocol. The WiFi stack 300 includes (from bottom to top) a physical (PHY) layer 306, a media access control (MAC) layer 305, a data stack 303, e.g. for TCP/UDP/IP communication, and an applications layer 301. Optionally a MAC sublayer management entity (MLME) and a supplicant (security) layer 302 may be included. MLME stands for “MAC Sublayer Management Entity”. It provides various management procedures such as association, authentication etc.

As presented in this disclosure, existing 802.11 Access Points can be extended in a minimum invasive way such that WiFi equipment can be made compliant to SAS and can be used as SAS GAA equipment.

In this disclosure a spectrum sharing context is considered, such as the FCC Citizen Broadband Radio System/Spectrum Access System (CBRS/SAS) in 3.5 GHz as shown in FIG. 1 or the Licensed Shared Access (LSA) system in 2.3-2.4 GHz in Europe as shown in FIG. 2. In particular, in the CBRS context, traditional RLAN systems (such as WiFi/MuLTEFire/etc.) can be used as so-called tier-3 devices. Changes over traditional RLAN system include the requirement to vacate the band when the incumbent user is coming in.

The disclosure presents a solution how to efficiently manage the vacating of a shared band by a RLAN system when the incumbent spectrum user retakes the band. RLAN systems traditionally do not offer the possibility to manage a higher-priority incumbent user. Existing RLAN bands indeed do not foresee a hierarchical responsibility chain for spectrum access.