28-08-2017, 02:58 PM
4G is the fourth generation of mobile telecommunications technology, succeeding 3G. A 4G system must provide ITU-defined capabilities in IMT Advanced. Potential and current applications include modified mobile web access, IP telephony, gaming services, high definition mobile TV, video conferencing and 3D television.
The long-running launch standard (LTE) (a 4G candidate system) has been commercially deployed in Oslo, Norway, and Stockholm, Sweden since 2009. However, it has been debated whether early release versions should be considered 4G, Como is discussed in the technical understanding section below.
In March 2008, the International Telecommunication Union-Radiocommunication Sector (ITU-R) specified a set of requirements for the 4G standards, called the International Mobile Telecommunications Advanced Specification (IMT-Advanced), setting the maximum speed requirements for The 4G service at 100 megabits per (Mbit / s) for high mobility communications (such as trains and cars) and 1 gigabit per second (Gbit / s) for low mobility communication (such as pedestrians and stationary users).
Since the early versions of Mobile WiMAX and LTE support much less than 1 Gbit / s of peak bit rate, they are not fully compatible with IMT-Advanced, but are often branded 4G by service providers. According to the operators, one generation of the network refers to the deployment of a new non-retroactive technology. On 6 December 2010, ITU-R recognized that these two technologies, as well as other technologies that do not meet the IMT-Advanced requirements, could be considered "4G", provided they represent IMT-Advanced precursors in accordance with Versions and " A substantial level of improvement in performance and capabilities over the initial three-generation systems now deployed. "
Mobile WiMAX Release 2 (also known as WirelessMAN-Advanced or IEEE 802.16m) and LTE Advanced (LTE-A) are versions compatible with previous IMT-Advanced compatible versions of the two previous systems, standardized during spring 2011 Promising speeds in The order of 1 Gbit / s. Services were expected in 2013.
Unlike previous generations, a 4G system does not support traditional circuit switched telephone service, but all Internet Protocol (IP) based communication such as IP telephony. As shown below, the spread spectrum radio technology used in 3G systems is abandoned in all 4G candidate systems and is replaced by OFDMA multi-carrier transmission systems and other frequency domain equalization schemes, allowing the transfer of very high bits despite Wide propagation of multiple radio paths (echoes). The peak bit rate is further enhanced by intelligent antenna arrays for multiple-input multiple-output (MIMO) communications.
The long-running launch standard (LTE) (a 4G candidate system) has been commercially deployed in Oslo, Norway, and Stockholm, Sweden since 2009. However, it has been debated whether early release versions should be considered 4G, Como is discussed in the technical understanding section below.
In March 2008, the International Telecommunication Union-Radiocommunication Sector (ITU-R) specified a set of requirements for the 4G standards, called the International Mobile Telecommunications Advanced Specification (IMT-Advanced), setting the maximum speed requirements for The 4G service at 100 megabits per (Mbit / s) for high mobility communications (such as trains and cars) and 1 gigabit per second (Gbit / s) for low mobility communication (such as pedestrians and stationary users).
Since the early versions of Mobile WiMAX and LTE support much less than 1 Gbit / s of peak bit rate, they are not fully compatible with IMT-Advanced, but are often branded 4G by service providers. According to the operators, one generation of the network refers to the deployment of a new non-retroactive technology. On 6 December 2010, ITU-R recognized that these two technologies, as well as other technologies that do not meet the IMT-Advanced requirements, could be considered "4G", provided they represent IMT-Advanced precursors in accordance with Versions and " A substantial level of improvement in performance and capabilities over the initial three-generation systems now deployed. "
Mobile WiMAX Release 2 (also known as WirelessMAN-Advanced or IEEE 802.16m) and LTE Advanced (LTE-A) are versions compatible with previous IMT-Advanced compatible versions of the two previous systems, standardized during spring 2011 Promising speeds in The order of 1 Gbit / s. Services were expected in 2013.
Unlike previous generations, a 4G system does not support traditional circuit switched telephone service, but all Internet Protocol (IP) based communication such as IP telephony. As shown below, the spread spectrum radio technology used in 3G systems is abandoned in all 4G candidate systems and is replaced by OFDMA multi-carrier transmission systems and other frequency domain equalization schemes, allowing the transfer of very high bits despite Wide propagation of multiple radio paths (echoes). The peak bit rate is further enhanced by intelligent antenna arrays for multiple-input multiple-output (MIMO) communications.