4G vs LTE
4G, known as 4th generation of mobile communications, and LTE (Long Term Evolution) are 3GPP specifications for mobile broadband networks. Different eras of mobile communication are categorized into generations such as 1G, 2G, 3G, and 4G, where each generation has a number of technologies such as LTE. ITU (International Telecommunication Union) considers LTE-Advanced as the true 4G standard, while it also accepts LTE as a 4G standard.
ITU considers IMT-Advanced (International Mobile Telecommunication) technologies as true 4G standards. As per the official definition, IMT-Advanced should be able to deliver peak download speeds of 1Gbps in stationary environments, while 100Mbps in high mobile environments. Initially, ITU completed the assessment of 6 candidate’s wireless mobile broadband standards for official 4G standard. Finally, 2 technologies, LTE Advanced and WirelessMAN-Advanced are accorded the official designation of IMT-Advanced. Even though, LTE Advanced is considered as true 4G standard, ITU also allowed to use HSPA+,WiMax and LTE as 4th generation technologies. As per the IMT-Advanced specification peak spectral efficiency should be 15bps/Hz for downlink and 6.75bps/Hz for uplink. This spectral efficiency and other IMT-Advanced requirements are achieved by 3GPP Release 10 (LTE-Advanced).
LTE was initiated with the 3GPP Release 8 (Freeze in March 2008), and further evolved in 9 and 10 releases. High spectral efficiency is one of the key features of LTE which was achieved using Orthogonal Frequency Division Multiple Access (OFDMA) with 64-QAM (Quadrature Amplitude Modulation) technique. Use of MIMO (Multiple Input Multiple Output) antenna techniques is another key point which improved the spectral efficiency of LTE to 15bps/Hz. LTE should be able to support up to 300Mbps downlink and 75Mbps in uplink as per the 3GPP specification. Architecture of LTE is much simpler and flat when compared with the previous 3GPP releases. eNode-B directly connects with System Architecture Evolution Gateway (SAE-GW) for data transfer, while it connects with Mobile Management Entity (MME) for signaling as per the LTE architecture. This simple eUTRAN architecture allows better utilization of resources, which ultimately ends up with OPEX and CAPEX savings to the service provider.
What is the difference between 4G and LTE?
¤ LTE Advanced, which is also known as true 4G standard, is evolution of LTE standard. Therefore, LTE and LTE Advanced have compatibility, where LTE terminal can work in LTE Advanced network, and LTE Advanced Terminal can work in LTE network.
¤ Capacities of true 4G standards are much higher when compared with LTE. LTE supports up to a maximum of 2.7 bps/Hz/cell, while LTE Advanced (True 4G) has a capacity of 3.7 bps/Hz/cell. Even though, both LTE and LTE-Advanced (true 4G) support the same spectral efficiency in downlink, uplink spectral efficiency is much higher with true 4G.
¤ Both LTE and 4G are focused on data rate improvement. Peak downlink data rate of LTE is 300Mbps, while official 4G definition requires 1Gbps downlink data rate. Therefore, true 4G has much higher data rate when compared with LTE, in both uplink as well as in downlink.
¤ LTE is known as 3GPP release 8, while true 4G is considered as 3GPP release 10, which is evolution of initial LTE technology.
¤ LTE networks are being deployed around the world now, while true 4G networks are still pending for trials. This is simply due to the stability of LTE when compared with LTE-Advanced. Initial LTE standards are published in March 2008, whereas initial stages of LTE-Advanced (True 4G) were standardized in March 2010.
¤ 4G is the next generation of mobile broadband communication, whereas LTE is the basis for true 4G technologies such as LTE-Advanced.