09-11-2012, 03:31 PM
4G Technology
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4G Definition
4G is not one defined technology or standard, but rather a collection of technologies at creating fully packet-switched networks optimized for data.
4G Networks are projected to provide speed of 100Mbps while moving and 1Gbps while stationary.
0G (Zero Generation Mobile System)
At the end of the 1940’s, the first radio telephone service was introduced, and was designed to users in cars to the public land-line based telephone network.
In the 1960’s, a system launched by Bell Systems, called, Improved Mobile Telephone Service (IMTS), brought quite a few improvements such as direct dialing and more bandwidth. The very first analog systems were based upon IMTS and were created in the late 60s and early 70s.
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
For 1 and 2G standards, bandwidth maximum is 9.6 Kbit/sec, (I.E) approximately 6 times slower than an ISDN
Advantages in Previous Technology - 2G
The digital voice encoding allows digital error checking
increase sound quality
lowers the noise level
Going all-digital allowed for the introduction of digital data transfer
SMS –“short message service”
Disadvantages in Previous Technology - 2G
Cell towers had a limited coverage area
Jagged Decay curve
Abrupt dropped calls
Analog –gradual sound reduction
“Spotty” coverage