What is LTE | A Complete Study about LTE

Long Term Evolution (LTE) is a term used to define wireless broadband communication for mobile
devices. Network operators often describe it as advanced network technology.

When we surf the web, watch videos or play online games, more and more datas are consumed. Therefore this has risen the need for a faster network. LTE wan implemented to increase the overall speed of data networks using Digital Signal Processing (DSP). It is capable of offering download speed of 100mbps and upload speed of 50mbps. While being in this speed LTE is slower than the actual 4G but much improved compared to the 3G technology. Therefore it is described as 3.95G and the 1st step towards 4G. Even though LTE is built using the GSM/EDGE and WMTS/HSPA technology and based on the 2G GSM and 3G technology, it is completely incompatible with the 2G and 3G networks. 

Being registered by the European Telecommunication Standard Institute and developed by the 3rd Generation Partnership Project (3GPP), the idea of LTE was 1st proposed by the NTT Docomo in 2004. Only in 2007 operators decided to promote it as LTE/SAE trial initiative. Different countries adopted the LTE use in different time period. For an example the European countries adopted it in 2009 and North Americans made it into use in 2010 and 2011. But nearly all the mobile devices today support the LTE use for 4G services.

How does LTE work ?

LTE uses 2 types of radio links for the wireless connection. One is downlink and the other is the uplink. Downlink is recieving signals from the tower to the mobile phone. To achieve this LTE uses Orthogonal Frequency Division Multiple Access (OFDMA). And sending signals from the mobile phone to the tower is known as Uplink. To achieve this LTE uses Discrete Fourier Transform Spread Orthogonal Frequency Division Multiple Access (DFTS-OFDMA). OFDMA replaced the CDMA2000 which has been in use since 1990s. 

Frequencies released from the tower are split into several Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD) which are different from country to country. Therefore only the dual band phones are able to support the LTE use. And comparing to its predecessors, LTE uses large amount of frequencies and bandwidth. When there is more frequencies there should be more bandwidth as well. LTE mobile devices provides these bandwidths ranging from 1.4MHz - 20MHz.

How does LTE affect battery life ?

When LTE got 1st introduced, one negative effect of it is the battery usage. Mobile devices with LTE suffer high amount of battery drainage and can only last up to 1-2 days. The reason for this is the network operators are forcing the mobile phones to use the Dual mode operations. Most of the devices with LTE connects to both LTE and the CDMA2000 which means that the battery is consumed twice more than when it is connected to either of them. The situation could be even worse when you are taking a call or sending a text message. When a call is made or text message is sent from the mobile device with LTE, CDMA2000 consumes the battery in tremendous amount. Because your mobile constantly changes its mode for a period of time. 

The process of changing the network or the tower constantly is known as Handover. Handover assists users in selecting a tower whenever a user goes away from the range. Therefore without handover cellular networks are almost impossible. Handover alone is not the reason for the high power consumption. What makes the handover to eat the battery life is the link between itself and the EV-DO. However for mobile phones using the AT&T technology, the battery life is slightly better. This is because when pairing with LTE, AT&T uses HSPA+ instead of CDMA2000. 

Key Features

When comparing to the previous cellular technologies, LTE has introduced various new features. It is true that the upgrade to LTE has provided the chance for the user to stream videos without buffering, watch HD movies and call in clear voice. To achieve them there are many key features included in the LTE.

Some of them are,

OFDM - Orthogonal Frequency Division Multiple (OFDM) is a form of modulation that enables high rate of data bandwidths. It has been linked with LTE because it is bale to provide high degree of resistance to reflections and obstacles.

MIMO - In the previous telecommunication systems multiple signals from the reflections are captured by the antenna. Because of this the stability and the latency of the connection is lost. To overcome this Multiple Input Multiple Output (MIMO) was introduced. MIMO captures multiple connections to a single cell unit. Therefore the throughput will be increased.

SAE - To improve the overall performance of the network connection, the System architecture must evolve. One big evolution in the field of telecommunication is the system architecture being in '' flatter '' form. Due to this the data is directed more to its destination and latency time has been reduced. 

LTE Vs 4G

People often confuse LTE with the 4G network. Technically LTE does not meet the specification criterias as a 4G network. There are several differences between those two. For an example LTE is not capable of reaching the speed up to 1000mbits per second or upload speed up to 500mbits per second. Sometimes LTE is marketed as 4G LTE to indicate something advance than LTE but slower than the actual 4G.

Future of LTE

The next stage of LTE is the LTE Advanced. LTE Advanced is much closer to the 4G than the standard LTE. Because of the fact that LTE-A is capable of reaching the speed up to 1000mbits per second, it often described as the True 4G, as it promises to deliver the speed of 4G. The component that assists LTE-A to reach this speed is its carrier aggregation. The carriers of LTE-A allows bandwidths to be combined together up to 20MHz each. 

LTE-A is the overall improvement in the radio technology and the architecture. However in order for a device to support LTE-A, it should have a special chip. Currently only Nvidia and the Broadcom manufactures these chips which support LTE-A. Technically this will make the device reach up to 3Gbps download and 1.5Gbps upload speed.