Wireless internet can be divided into three generations of 2G, 3G and 4G in a separate category include satellite internet and Wi-Fi. 2G – uses GSM, DAMPS, GPRS and TDMA. Has no great speed, very inferior in quality to the next generation. 3G – third generation wireless Internet (HSPA, CDMA EV-DO, WCDMA). Transfer rate is usually up to 3.6 MB / sec. By far the most popular. 4G – fourth generation wireless Internet (OFDM and MIMO). To date, actively developed. Transmission speed up to 40 MB / sec.
Wi-Fi – data transfer standard. Uses equipment Wireless LAN. Developed Wi-Fi Alliance standards-based IEEE 802.11. All mobile devices (laptops, smartphones, PDAs), which are equipped with Wi-Fi, are able to connect to the network and access the Internet through an access point. Many cities have free access points. Wi-Fi was created in 1991 in Nivegeyn, Netherlands. Wi-Fi – the most popular type of wireless internet in the West. Wi-Fi-network almost completely “covers” the territory of all the European countries, USA and Canada. The advantage of Wi-Fi-Internet is the fact that in the case of a public access point (cafe, shopping center or an office, etc.) to connect to the network, you can freely and free of charge. In the case of a private network you will pay only for the traffic. In addition, this type of high-speed Internet, allowing you to view online-video without waiting.Unfortunately, in Russia, this type is not so common and is only available in large cities.
standard for the fourth generation 4G wireless data stands for Worldwide Interoperability for Microwave Access – 802.16 (IEEE). WiMAX was adopted in 2003 Pros 4G (WiMAX):
• principle of WiMAX networks is the same as that of the network designed for mobile phones. The difference is that WiMAX provide connectivity within a radius of about 30 km and a speed of up to 75 Mbit / s.
• Another plus WiMAX is a stable job in the absence of sight BS, in this case using a reflected signal.
• economical use of frequency resource ( 1.5 times less than that of other technologies). • encryption algorithm Triple DES (128 bit key) or RSA (1024 bit key), than an attempt to break reduces to almost zero and allows you to control output power. 4G (WiMAX ) allows you to:
• transfer any data (voice, video, etc.)
• up corporate network
• quality video broadcasting
• the problem of the “last mile”
Satellite Internet is often used in places where there are no other connectivity. To connect to the satellite network, you need a small antenna, and sometimes, if the online one-sided, gprs-modem connection.
3G - new transmission technology 3 generations. Services include high-speed mobile Internet access, a radio technology, which provides a channel for data transmission. Why 3G is better prevyduschih generations? The answer is simple: more speed, better quality and environmental bezrpasnost.Brief description of the standard of the third generation 3G connection is based on the generation of a data connection. Networks operate in the UHF band (2 GHz) with an average speed of 2 Mbit / s. 3G video telephony allows you to organize, view on a mobile phone movies and TV shows. 3G has 5 standard IMT-2000 family. largest circulation in the world, two standards: UMTS (or W-CDMA) and CDMA2000 (IMT-MC), which are based on technology CDMA. According to statistics in 2006, the world had 364 million 3G subscribers. 3G provides two basic services: data and voice. 3G networks must support data rates for subscribers: a high speed (up to 120 km / h ) – not less than 144 kbit / s at low speed (up to 3 km / h) – not menshe384 kbit / s fixed objects – at least 2.048 Mbit / s.