Evolution wireless data

Like the computers, the evolution of wireless technology has also been defined in gen­erations. The first generation (1G) of wireless technology uses the analog technology. It uses FDMA (Frequency Division Multiple Access) technology for modulation; for exam­ple, AMPS (Advanced Mobile Phone Service) in US. The second generation or 20 tech­nology uses digitized technology. It uses a combination of TDMA (Time Division Multiple Access) and FD/vIA technologies. An example is GSM. In 20 technology, voice is digitized over a circuit. In 10 and 20 networks, data is transacted over circuits. This technology is called Circuit Switched Data or CSD in short. Using modems, a data connection is established between the device and the network. This is similar to what happens in a dial-up network over analog telephones at home. The next phase in the evolution is 2.5G. In 2.50 technology, voice is digitized over a circuit. However, data in 2.5G is packetized. 2.50 uses the same encoding techniques as 20 does. GPRS networks is an example of 2.50. The Third Generation or 30 wireless technology makes a quan­tum leap from a technology point of view. 30 uses Spread Spectrum techniques for media access and encoding. In 30 networks, both data and voice use packets. UNITS and CDMA2000 are examples of 3G networks.

While 10, 20, or 30 were making their marks in the metropolitan area wireless networks (MAN), wireless technology has been getting popular in local area networks (LAN) and per­sonal area networks (PAN) as well. Wireless offers convenience and flexibility. With the suc­cess of wireless telephony and messaging services like paging, wireless communication is beginning to be applied to the realm of personal and business computing in the domain of local area networks. Wireless LAN s are being deployed in homes, campuses, and commer­cial establishments. Wireless LANs are also being deployed in trains and commercial vehi­cles. The domain of wireless data networks today comprises of Wireless PAN (Bluetooth, Infrared), Wifeless LAN (IEEE 802.11 family) and Wireless WAN (Wide Area Networks) (GSM, GPRS, 3G).