The fourth generation wireless technology also known as 4G technology has created the buzz all over the wireless market for its high-speed data transfer and internet connectivity. The successor of 3G aims in providing high-speed internet speed and overcomes the shortcomings of 3G technology regarding speed and quality. A 4G technology must qualify the specified set of standards called as International Mobile Telecommunication-Advanced (IMT-advanced) provided by ITU-R (the International Telecommunication Union –Radio communication Sector). According to ITU, a 4G service must providing super past speed of 100 megabits per second in place of high mobility communications like trains and cars and 1 gigabit per second in places of low mobility communication such as stationary users and pedestrians.
Commercially two variations 4G system Mobile WiMAX and LTE support were released in 2008 and 2011 deployed by Sprint and MetroPCS respectively. When the first version of these two released, they supported less than 1 Gbit/per sec and were not fully IMT compliant, but were labeled as 4G by the service provider. But later these two technologies along with other technologies beyond 3G, not compliant with the IMT-Advanced specification, can be considered “4G” if they provide advanced and improved performance and capabilities over the third generation technology. In 2011 Mobile WiMAX 2 and LTE advanced were released and are compliant with the IMT-Advanced i.e. backward compatible version of the previous version. However, Many carriers using orthogonal frequency –division multiplexing (OFDM) in place of TDMA (time division multiple access) or CDMA ( code division multiple access) market their network as 4g even their data speed does not specify to the ITU. They all agree that OFDM is an indicator, which a service can be legally marketed as being “4G” as it is a digital transition in which signals are divided into several small bandwidth channels at different frequencies.
4G VS EARLIER GENERATION:
• 4G system supports all internet protocol based communication like IP telephony whereas earlier generation used circuit based switched telephony service as support.
• 3g system uses the spread spectrum radio technology but this has been replaced by OFDM supporting multi-carrier and other frequency –domain Equalization scheme making high-speed transfer.
• To make the speed of “4G” technology faster, a small antenna array has been used for MIMO or multi-input and multi-output communication.
• It provides enhanced services in the wireless market, including efficient spectrum, low-cost, speedy download links over 100 Mbps.
• It gives user impressive network capabilities and application like high- definition video, high-definition gaming, sophisticated graphical user interface, improving image quality providing an edge over 3G.
• Today customer demands more sophisticated mobile devices and wants to experience high-end applications like three-dimensional and holographic gaming,16-megapixel camera, high-definition recording, etc. which requires 4G support. Such application requires more processing power than a 3G handset can offer. Thus these handsets will have to improve image quality and an efficient application processor to support the future 4G application.
We have seen almost by now almost every country has placed “4G” networks in network service provider or the national cellular provider. It is a wonderful technology that has revolutionized the communication from all dimensions whether speed, HD quality images etc. with full implementation it will create wonder and with seamless connectivity across the globe.