There are a number of different wireless infrastructures that can provide connectivity at a variety of levels. The wireless personal area network (PAN) is the smallest of these systems and typically involves Bluetooth® or infrared devices. Wireless local area networks (LANs) can provide connectivity throughout a building or other small area by using infrastructure components such as base stations, repeaters and bridges, or ad-hoc connections between computers. Much larger examples of wireless infrastructure include wireless wide area networks (WANs) and metropolitan area networks (MANs) that offer connectivity throughout entire cities.
The smallest example of wireless infrastructure is a wireless PAN. This type of network can involve a variety of short range Bluetooth® or infrared devices that are interconnected. Other examples of PANs use Wi-Fi® to connect local devices to the Internet. There usually isn't any permanent infrastructure involved in creating a PAN, since an individual can carry all the components on his person.
Some of the most commonly used wireless infrastructure is found in home and business networks. These networks usually take the form of wireless LANs and may make extensive use of hardware infrastructure or rely on ad-hoc connections. The simplest wireless LAN consists of a wireless router that typically also acts as a bridge. This type of LAN can allow computers and other devices in a highly localized area to interconnect. Larger infrastructures can include more base stations and repeaters to extend the reach of the network.
In some cases, a wireless LAN will include the infrastructure necessary to connect components that are physically distant from each other. If it is necessary to connect two different locations to the same network, a wireless infrastructures that uses point to point transmissions is sometimes used. This is referred to as a fixed wireless connection and can make use of a radio link, though a laser bridge or microwave transmitter is sometimes used instead. These types of point to point wireless infrastructure are often used if it would be costly or impossible to create a wired connection.
Wireless WANs and MANs typically involve an even larger amount of infrastructure. These wireless networks can extend over a large outdoor area or even cover an entire city. The wireless infrastructure used for these networks is typically cellular in nature, so these services are often provided by telecommunication companies. A wide area or metropolitan network can operate using any long distance technology, though WiMAX™ is commonly used to provide high speed access.