A Basic Service Set (BSS) is formed when two or more stations have recognized each other and established a network. The network can be configured in two basic ways:
- Peer-to-peer (ad hoc mode) – This configuration is identical to its wired counterpart, except without the wires. Two or more STAs can talk to each other without an AP. When two or more stations form an ad hoc network, this is referred to as an Independent Basic Service Set (IBSS).
- Client/Server (infrastructure networking) – This configuration consists of multiple stations connected to an AP, which acts as a bridge to a wired network. A BSS in this configuration is referred to as being in infrastructure mode.
Range between STAs and APs is up to 100 m (depending on data rate), but the overall range of an ESS is limited only by the range of the wired distribution system. Also, ESSs can be further extended with wireless links up to several miles by the use of directional range extender antennas.