27-09-2010, 12:57 PM
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4G technology
abstract
4G There is no formal definition for what 4G is; however, there are certain objectives that are projected for 4G. These objectives include: that 4G will be a fully IP-based integrated system. 4G will be capable of providing between 100 Mbit/s and 1 Gbit/s speeds both indoors and outdoors, with premium quality and high security.
Many companies have taken self-serving definitions and distortions about 4G to suggest they have 4G already in existence today, such as several early trials and launches of WiMAX. Other companies have made prototype systems calling those 4G. While it ispossible that some currently demonstrated technologies may become part of 4G, until the 4G standard or standards have been defined, it is impossible for any company currently to provide with any certainty wireless solutions that could be called 4G cellular networks that would conform to the eventual international standards for 4G. These confusing statements around “existing” 4G have served to confuse investors and analysts about the wireless industry.
According to the 4G working groups, the infrastructure and the terminals of 4G will have almost all the standards from 2G to 4G implemented. Although legacy systems are in place to adopt existing users, the infrastructure for 4G will be only packet-based (all-IP). Some proposals suggest having an open platform where the new innovations and evolutions can fit. The technologies which are being considered as pre-4G are the following: Flash-OFDM, WiMax, WiBro, iBurst, and 3GPP Long Term Evolution. One of the first technology really fulfilling the 4G requirements as set by the ITU-R will be LTE Advanced as currently standardized by 3GPP. LTE Advanced will be an evolution of the 3GPP Long Term Evolution. Higher data rates are for instance achieved by the aggregation of multiple LTE carriers that are currently limited to 20MHz bandwidth
