Once the association is complete, the access point’s main job is to bridge traffic either wired-to-wireless or wireless-to-wireless. Wireless LANs, just like Non-Broadcast Multi-Access (NBMA) technologies, can be implemented and configured under many different topologies.
In wireless LAN environments access points can perform different roles, including the following:
- Bridges
- Repeaters
- Mesh topologies
Figure 9.8 – WLAN Bridges Topology
Referring to Figure 9.8 above, wireless bridges function in several ways:
- They accept traffic from traditional LANs and forward it to wireless clients. This process of translation between wired and wireless networks is called Multipoint bridging.
- They can work in Point-to-Point mode to connect two buildings (LANs).
- They can work in Point-to-Multipoint mode to connect multiple buildings.
| Note: When using wireless bridge functionality in Point-to-Point mode, the two buildings/areas must have line-of-sight connectivity.
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Figure 9.9 – WLAN Repeater Topology
Referring to Figure 9.9 above, access points can function as repeaters, accepting a weak RF signal, strengthening (amplifying) it, and then resending it. This operation is used to extend the range of wireless networks.
Figure 9.10 – WLAN Mesh Topology
The mesh access point topology shown in Figure 9.10 above is the most sophisticated and most commonly used wireless topology. With this type of topology, the access point can function as a repeater or as a bridge, as needed, based on RFs. This technology allows engineers to use wireless technologies to cover large geographical areas and to ensure the following features:
- Fault tolerance
- Load distribution
- Transparent roaming
| Note: In addition to their use in the enterprise sector, wireless mesh technologies are also used in the public sector to ensure Wi-Fi access in certain urban areas.
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