IEEE 802.11 components and mesh BSS

4.3.15.4 IEEE 802.11 components and mesh BSS

Example mesh and infrastructure BSSs are illustrated in Figure 4-8. Only mesh STAs participate in mesh
functionalities such as formation of the mesh BSS, path selection, and forwarding. Accordingly, a mesh
STA is not a member of an IBSS or an infrastructure BSS. Consequently, mesh STAs do not communicate
with nonmesh STAs.
However, instead of existing independently, an MBSS might also access the distribution system (DS). The
MBSS interconnects with other BSSs through the DS. Then, mesh STAs can communicate with nonmesh
STAs. Therefore, a logical architectural component is introduced in order to integrate the MBSS with the
DS—the mesh gate. Data move between an MBSS and the DS via one or more mesh gates. Thus, the mesh
gate is the logical point at which MSDUs from an MBSS enter the IEEE 802.11 DS. Once an MBSS
contains a mesh gate that connects it to the IEEE 802.11 DS, the MBSS can be integrated with other
infrastructure BSSs too, given that their APs connect to the same DS. Several mesh gates are shown in
Figure 4-8 connecting different MBSSs to the DS.
When an MBSS accesses the IEEE 802.11 DS through its mesh gate, the MBSS can be integrated with a
non-IEEE-802.11 LAN. To integrate the IEEE 802.11 DS to which this MBSS connects, the DS needs to
contain a portal. See 4.3.6. Consequently, mesh gate and portal are different entities. The portal integrates
the IEEE 802.11 architecture with a non-IEEE-802.11 LAN (e.g., a traditional wired LAN), whereas the
mesh gate integrates the MBSS with the IEEE 802.11 DS.