17-05-2012, 11:19 AM
The Early Development and Impact of 4G Technology
[attachment=22214]
Previous Technology –1G “First Generation”
•Analog
–Continuous in amplitude and time
–Variations in the signal –disrupts over long distances
•Simplest type to wireless data
•Average between 4,800 to 9,600 bps (bits per second)
Previous Technology –2G
–Digital data can be compressed and multiplexed much more effectively than analog voice encodings
•Multiplexing -multiple analog message signals or digital data streams are combined into one signal
Previous Technology -3G
•Large capacity and broadband capabilities •Allows the transmission of 384kbps for mobile systems and up to 2Mbps•Increased spectrum efficiency –5Mhz–A greater number of users that can be simultaneously supported by a radio frequency bandwidth–High data rates at lower incremental cost than 2G–Global roaming
Types of Multiplexing
•FDMA -Each phone call is allocated one frequency for the entire duration of the call.
•TDMA -Each phone call is allocated a spot in the frequency for a small amount of time, and "takes turns" being transmitted.
•CDMA -Each phone call is uniquely encoded and transmitted across the entire spectrum, in a manner known as spread spectrum transmission.
[attachment=22214]
Previous Technology –1G “First Generation”
•Analog
–Continuous in amplitude and time
–Variations in the signal –disrupts over long distances
•Simplest type to wireless data
•Average between 4,800 to 9,600 bps (bits per second)
Previous Technology –2G
–Digital data can be compressed and multiplexed much more effectively than analog voice encodings
•Multiplexing -multiple analog message signals or digital data streams are combined into one signal
Previous Technology -3G
•Large capacity and broadband capabilities •Allows the transmission of 384kbps for mobile systems and up to 2Mbps•Increased spectrum efficiency –5Mhz–A greater number of users that can be simultaneously supported by a radio frequency bandwidth–High data rates at lower incremental cost than 2G–Global roaming
Types of Multiplexing
•FDMA -Each phone call is allocated one frequency for the entire duration of the call.
•TDMA -Each phone call is allocated a spot in the frequency for a small amount of time, and "takes turns" being transmitted.
•CDMA -Each phone call is uniquely encoded and transmitted across the entire spectrum, in a manner known as spread spectrum transmission.