Amendment 4:2021 to CSA ISO/IEC/IEEE 8802-11:19, Telecommunications and exchange between information technology systems - Requirements for local and metropolitan area networks - Part 11: Wireless LAN medium access control (MAC) and physical layer (PHY) specifications - Amendment 4: Enhancements for transit links within bridged network (Adopted amendment 4:2020 to ISO/IEC/IEEE 8802-11:2018)