An Access Point runs [BSS] to serve clients.  They allow the connection of wireless clients to a wired network.



At its simplest, an Access Point is a box with a connector for a wired network, and an antenna to transmit and receive a wireless network.  Most APs have capabilities beyond this however.  APs are able to accept connections from between roughly ten to one hundred [Client]s simultaneously, depending on the APs specifications, and the prevailing [RFEnvironment]



Commercial access points tend to come in two flavours:

* Small, single card boxes, with support for [DHCP], [NAT], etc all you need to access the wireless network at home, but with a limit of around ten clients

* Larger, double card boxes, designed more for enterprise networks.  These models tend to support [SNMP] management and up to 50 simultaneous clients.



The [Linux] [HostAP] driver allows a wireless [Client Client Card] to emulate an Access Point.  This has certain advantages in some situations as it gives more hardware and software options having an Access Point inside a PC.



There's also the [OpenAP] project (and also AirportLinux) that convert a commercial AccessPoint to run Linux, or you can use a generic PC Unix and (http://www.live.com/wireless/unix-base-station.html configure it) appropriately (although at this stage, it does not actually support [BSS] mode operation).

Also there is a (http://forums.netstumbler.com/showthread.php?s=5df34487e355945f16e13add0243854c&threadid=575&perpage=15&highlight=hermes&pagenumber=1 Windows hack) to enable [BSS] mode for some hardware.



All access points act as an 802.x [Bridge], exchanging frames between the wireless and wired LANs.



Example access points are

* OrinocoSilver based

* AppleAirport

* [OrinocoRG1000]

* Eumitcom WL11000SA-N based

* US Robotics (USR 2450)

* SMC 2652W EZconnect Wireless AP

* Addtron AWS-100

* Dlink [DWL-900AP]

* Dlink [DWL-1000AP]

* SVEC [SVECWLAP FD1811a]

* Minitar [minitar MNWAPB]



[BSS] Mode is also known by the following names:

* [InfrastructureMode Infrastructure Mode]

* [AccessPointMode Access Point Mode]

* [APMode AP Mode]

* [ClientMode Client Mode]

* [ManagedMode Managed Mode]

* [MasterMode Master Mode] - see [HostApMode]

While these names mean different things depending on whether you want your device to act as a [Client] or Access Point, they are all covered by the [BasicServiceSet Basic Service Set].



Some newer Access Points can do more modes than the standard [BasicServiceSet Basic Service Set].  Some can act as wireless clients themselves - ie they can connect as [Client]s to other APs.  They can do [Bridge Bridging] mode to form a wireless [p2p point-to-point] or [p2mp point-to-multipoint] link between two or more segments of a wired network.  Some, specifically the [minitar] can even emulate [IBSS] or [AdHocMode Ad-Hoc Mode].  Since these modes are not covered by the [BSS] these modes sometimes have problems when using APs from different manufacturers.  (http://www.freenet-antennas.com Rob Clark) has done some (http://www.freenet-antennas.com/minitar_mnwapb.htm tests) involving the [minitar] AP and its various modes.