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• 2G
  

  2G (or 2-G) is short for second-generation wireless telephone technology. 2G services are frequently referred as Personal Communications Service, or PCS, in the United States. A key digital advantage is that digital cellular calls are much harder to eavesdrop on by use of radio scanners. While the security algorithms used have proved to not be as secure as initially advertised, 2G phones are immensely more private than 1G phones, which have no protection whatsoever against eavesdropping.

• 3G
  

  3G is the third generation of mobile phone standards and technology, after 2G. It is based on the International Telecommunication Union (ITU) family of standards under the International Mobile Telecommunications programme, "IMT-2000". 3G technologies enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephony and broadband wireless data, all in a mobile environment.

• 4G
  

  4G (a.k.a. beyond 3G), an acronym for Fourth-Generation Communications System, is a term used to describe the next step in wireless communications. A 4G system will be able to provide a comprehensive IP solution where voice, data and streamed multimedia can be given to users on an "Anytime, Anywhere" basis, and at higher data rates than previous generations. There is no formal definition for what 4G is; however, there are certain objectives that are projected for 4G.

• 802.11
  

  IEEE 802.11 is a set of standards for wireless local area network (WLAN) computer communication, developed by the IEEE LAN/MAN Standards Committee (IEEE 802) in the 5 GHz and 2.4 GHz public spectrum bands. Although the terms 802.11 and Wi-Fi are often used interchangeably, the Wi-Fi Alliance uses the term "Wi-Fi" to define a slightly different set of overlapping standards. In some cases, market demand has led the Wi-Fi Alliance to begin certifying products before amendments to the 802.11 standard are complete.

• 802.11a
  

  The 802.11a standard uses the same core protocol as the original standard, operates in 5 GHz band with a maximum raw data rate of 54 Mbit/s, which yields realistic net achievable throughput in the mid-20 Mbit/s.

• 802.11b
  

  802.11b has a maximum raw data rate of 11 Mbit/s and uses the same media access method defined in the original standard. 802.11b products appeared on the market in early 2000, since 802.11b is a direct extension of the modulation technique defined in the original standard. The dramatic increase in throughput of 802.11b (compared to the original standard) along with simultaneous substantial price reductions led to the rapid acceptance of 802.11b as the definitive wireless LAN technology.