WLAN formation describes basic elements that are the foundation of all Wi-Fi networks. Distribution system, access point, wireless medium, BSS are all the elements of every wireless network. Learn here about them.
Basic Elements of WiFi Networks
Every WiFi network consists of these four basic elements. The WLAN formation is formed from the following parts.
- Access point
- Distribution system
- Wireless medium
Access point – AP
The wireless access point (AP) is the heart of the all Wi-Fi networks – key device in WLAN formation. It is wireless gateway and bridge between wireless networks and wired networks. AP enables that all connected WiFi devices can exchange information with the wired network. Usually the most home wireless networks have a wireless router. Wireless router consists of many devices. Often it is the modem at the same time, so you have a DSL connection to the internet, router with 4 Ethernet ports and access point. Read more about the wireless routers in the post broadband wireless router.
Distribution System – DS
802.11 standards, which defines how all WLAN networks work, defines the distribution system as a combination of bridging engine and backbone network. The distribution system has two functions:
- Connecting access point to the backbone – usually internet.
- Connects two different access points over a wired network.
The wireless medium is the radio frequency (RF) signals that serve for exchanging frames among stations and wired backbone. There are five types of wireless medium or five generations of the WiFi, defined by the 802.11 standard.
Every type is based on different technology and has different specifications. In the post What Does WLAN Stand For and What are the 802.11 Networks, you can see their basic differences.
Stations – Wireless Clients
The stations or wireless clients are all the devices that support WiFi connection. Together with access point they are the most important elements of the WLAN formation. Stations, just like wireless medium of the access points, work according to five types of 802.11 networks. Today there are more and more different kinds of devices which can connect to the wireless access points. Read more about different kinds of wireless stations in Wireless Internet Card – Connecting Your PC to the Wireless Network. BSS – Basic Service Set BSS – basic service set is the basic building block of the WLAN formation. There are two basic types of the basic service sets.
Independent BSS – Ad-hoc
Independent BSS network or ad hoc wireless network is formed only from the stations without the access point. Wireless client in independent BSS communicates directly without the access point.
The infrastructure BSS network consists of the stations and access point. Stations or wireless clients don’t communicate directly. All wireless communication is going via the access point. If the clients can communicate without access point, you could ask why we really need access point then. There are reasons why access point is almost always used.
- Access points connect the wireless network to the wired network. Without access point stations wouldn’t be able to connect to the internet.
- Longer range and better coverage. Range of Infrastructure BSS is defined by the distance between the station and access point. In ad-hoc network range is defined by the distance between stations.
- Stations save power. With the access point, stations save power. When the stations enter into a power-saving mode, access point buffers the frames for them.
WiFi technology is changing the world rapidly. If you are interested, read more about WiFi technology.
Extended Service Set – ESS
ESS – Extended Service Set is kind of WLAN formation which connects together different BSSs to the one wired network, via distribution system. More about the extended service set you can read in Extended Service Set (ESS) and Wireless Distribution System (WDS). More about the WLAN formation and 802.11 architecture you can read in IEEE 802.11 Architecture.