Wi-Fi wireless network that provides Internet access. Usually translates as “wireless precision” two words for Wireless Fidelity. The story begins with systems cash register equipment. It is for this and created the network to provide the speed to 1 or 2 MB per second created in 1991. There were a lot of standards for Wi-Fi. First standard IEEE 802.11 b and IEEE 802.11 a. In 2009, to increase the maximum data transmission speed made standard IEEE 802.11 n. its speed exceeded 4 times compared to previous standards, namely 54 MB/s.
The working principle of wi fi is that it has an access point where customers. The minimum velocity in the wi-fi is 0.1 Mbps. All available access points are combined into one network in several ways:
- In Autonomous access points, in addition, they are called smart.
- When one controls all access points (Central).
- The third is not controlled by anyone, but not Autonomous. They are controlled without a controller.
What are the advantages of the network. First, of course, is that in itself a wireless network – without wires. This much reduces the costs, in contrast to that, if carried out everywhere cables. It would cost a tidy sum. The universality of this network has no equal. At any time and in any place you can connect to the network, and in the present day, where every 5 meters there are 10 access points, it is generally can be done without hindrance.
If they were all without a password, generally wonderful. The third benefit – each phone has wi-fi and phone, you can easily get online. A wireless network can connect several electronic devices (if they have the wi-fi module and they are in the area of coating of the network, i.e. the device “see” the access point). Radiation from a wireless network an order of magnitude smaller than the cell, namely 10 times.
From shortcomings it is possible to count that at frequencies of 2.4 gigahertz work and other devices, for example, a microwave. Because of this obstacle that emits secondary network Wi-Fi loses its output speed, and speed of the Internet becomes significantly less.
In addition, due to the various obstacles lying on the line of the source device, a wireless network, and that, as a rule, the furniture, walls and other various obstacles of a material nature, deteriorates the quality of communication, which also leads to speed, much less than it was according to the manufacturer network.
The network coverage. Now is the active coverage networks Wi-Fi in various locations around the world. If ever you were in a cafe, you could see the words “free wifi”. Means that clear: “Free” or “Free wifi”. Or, for example France decided to cover the entire city with these networks. Began such an operation in 2003. It’s called Ozone and OzoneParis. In contrast to the access points, network of Paris bears a national character.