Wireless local area networks (WLANs), which use radio frequencies to transmit data, are becoming more widespread today. More often they are called Wi-Fi networks, although earlier this was the name of only one of the standards (802.11b).
One of the main advantages of WLANs, as the name suggests, is that they are wireless. This allows you to speed up the network creation process and eliminate the use of cables. In addition, unlike cellular communication, Wi-Fi wireless networks use a non-licensed (in most countries) and, accordingly, free frequency range, and, therefore, do not require permission what does wlan mean.
The IEEE 802.11 standard also provides security features. Networks, in particular, are assigned a unique name, subscribers can be filtered by MAC addresses (physical addresses of devices) and encryption. At the same time, there are two encryption standards - Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access (WPA). The first, despite being supported by all certified equipment, has serious vulnerabilities and therefore does not provide adequate protection for wireless communication channels. WPA is considered to be much more reliable. At the same time, it is possible to simultaneously work in the network of WPA and WEP clients, as well as those using other security protocols. Some old equipment can be upgraded to WPA by updating the firmware ("firmware").
An important advantage of WLAN networks is the ability to dynamically change access points. Modern devices with built-in Wi-Fi controllers start searching for a new hotspot when the connection deteriorates and automatically switch to a new access point. This provides the user with the ability to move without interrupting work.
One of the main problems typical for Wi-Fi networks is interference, that is, the intersection of reception areas from different stations. Due to the fact that the signal is transmitted on a free frequency, the quality of communication can be significantly reduced due to interference from amateur radio equipment and household appliances, such as microwave ovens. In addition, the conditions for receiving and transmitting are worsened by walls, reinforced concrete floors, metal partitions, etc.
Despite the emergence of the WPA security standard, many access points use equipment that is exclusively WEP compatible. These potentially vulnerable hotspots could theoretically pose a threat to users whose sensitive information could fall into the hands of attackers.
One cannot but mention the problem of relatively high power consumption. It is especially relevant for owners of laptops and smartphones, since the active use of wireless communication significantly reduces the operating time of portable devices from rechargeable batteries.
Finally, the disadvantages of WLAN include limited range.
Developers from the Karlsruev Institute of Technology (Germany) have created a wireless Wi-Fi connection that transmits data at a speed of over 40 Gb / s over a distance of more than 1.5 km. This speed is sufficient, for example, to transmit a regular disc with a film over the network in less than a second. The equipment uses a frequency of 240 GHz instead of the 2 GHz to 5 GHz frequency range used in conventional Wi-Fi devices. The transition to higher frequencies solved the problems with the transmission range, as well as the size of the antenna. The required size of the antenna does not exceed the size of the chip itself, which is responsible for signal transmission, and it is no more than a few millimeters.
A relatively new feature that has found wide application in both office and home digital technology is called Wi-Fi Direct. The technology allows wireless connection between any devices that support this technology. Wi-Fi Direct is the ability to connect gadgets such as cameras, printers to the receiving device to print the desired file without using wires. Gaming and any certified mobile devices that have a Wi-Fi adapter have the same capabilities.
In the coming years, the development of local wireless networks will go in the direction of mass introduction of the so-called WiMAX technology (short for Worldwide Interoperability for Microwave Access). WiMAX networks (IEEE 802.16a standard) use a frequency range from 2 GHz to 11 GHz and provide data rates up to 70 Mbps over distances of up to 50 km. The new standard is positioned as a means of connecting wireless local area networks (WLAN) to the Internet and as a replacement for DSL as the last mile. The bandwidth of one base station is enough to provide dozens of business users and hundreds of home connections.
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