Wireless in more detail
We can imagine many things under the term wireless connection. From Bluetooth connection between the phone and hands-free set in the car, through home Wi-Fi internet connection, mobile telephone calls and satellite transmissions. However, we deal with data transmission at higher speeds and over longer distances, such as those used by telecommunications service providers in their WAN networks or by corporate users in larger LAN networks. These are typically point-to-point connections, i.e., two radios with two mostly parabolic antennas facing each other and connected by a very narrow radio beam, requiring direct visibility. Their design, frequency bands used, and user interfaces can be very diverse.
Capacities typically required by operators have been increasing dramatically in recent years, moving from hundreds of Megabits per second to units of Gigabits. Currently, 10Gbps connections are already commonly available and we will soon see two to four times this speed. By contrast, the required spanning distances are decreasing; whereas 10 years ago connections spanning tens of kilometres were built, today the typical distance is measured in units of kilometres.