LTE, LTE-A and LTE-A Pro Evolution

LTE is a standard for wireless communication and LTE Advanced / LTE Advanced Pro (Cat 6 to Cat 19) is a high-speed version of LTE, sometimes marketed as LTE+, 4G+, 4GX,4.5G or 4G LTE Ultra. LTE support varies from country to country, and the speed may vary depending on user location and how fast they’re traveling.


LTE (Cat 1~5)

  • LTE has been introduced in 2012 in order to provide high data rate mobile broadband connection.
  • It has been introduced to provide 10 times faster data rate compared to 3G.
  • LTE provides 100 Mbps.
  • LTE has been specified in 3GPP Rel.8.
  • LTE supports carrier bandwidth of 20 MHz.

LTE Advanced (Cat 6~16)

  • LTE Advanced is an enhancement to LTE with data rate increase to the factor of 10.
  • It supports carrier aggregation and higher order MIMO techniques.
  • It supports the data rate of 1 Gbps in downlink (From eNB to UE) and 500 Mbps in uplink direction (From UE to eNB).

LTE Advanced Pro (Cat 17~19)

  • It is enhanced version of LTE Advanced to support higher data rate beyond 3 Gbps.
  • It supports increased Bandwidth, increased efficiency and improved latency.
  • It makes use of both licensed (400 MHz to 3.8 GHz) and unlicensed (5GHz) spectrum to support up to 32 carriers of 20MHz each.
  • It is backward compatible with existing LTE and LTE Advanced devices.
  • It makes use of spectrum more efficiently by increasing number of antenna paths as well as multi beam approach. It serves single radio cell with 16 to 64 antenna paths.
  • It grows network capacity to about 200% without any additional spectrum or base stations.
  • Increased battery life about 10 times than LTE.

Real 4G LTE Advanced Technology and the Future

Since November 2008, under the name IMT-Advanced, LTE and WiMAX are the specifications for the fourth generation of mobile. The International Telecommunication Union (International Telecommunication Union, ITU short) set these requirements.


Since October 2009, two technology families apply for the title of 4G wireless data technology of the future, according to the International Telecommunication Union. Firstly, there is the advanced technology LTE Advanced, which evolutes from LTE. Second, the applicant is provided with the bulky abbreviation IEEE 802.16m technology, which has evolved from the WiMAX group.

Colloquially LTE or Mobile WiMAX is already now referred to as 4G technologies. In colloquial usage, technical standards, there are 3G systems.

The ITU standards: A gigabit per second is the goal

Some key requirements on wireless technologies of the fourth generation: Higher transmission rates, greater bandwidth, high spectral efficiency and low latency and better coverage of the peripheral areas in the radio cells are crucial criteria.

As research targets for the transmission rate is at 100 megabits per second per the International Telecommunications Union, and gigabit per second high with low mobility. There are also up to 40 megahertz scalable bandwidth for the transmission channel, but the researchers are encouraged to draw bandwidths up to 100 MHz considered. The spectral efficiency is measured by measuring the transmission rate per bandwidth. The ITU for IMT-Advanced set 15 bits per second per hertz (bits/s/Hz) on the downlink and 6.75 bit / s / Hz in the uplink.

As examples of different high top speeds in different widths, radio channels are given by the ITU on a channel of 40 megahertz (MHz) 600 Mbit/s and on a channel of 100 Megahertz 1500 Mbit/s respectively in the downlink.

The 4G LTE-Advanced candidate

The bandwidth is LTE-Advanced is significantly higher than the 3G. Instead of 20 megahertz, LTE-Advanced can bundle multiple carriers and thus use up to 100 MHz simultaneously. It is also possible that frequency bands in different frequency ranges are combined, since no operator has been on a continuous frequency range of 100 MHz Currently these 100 MHz are only theoretically achievable, in practice more spectra has to be assigned. This can happen only in 2015 at the World Radio Conference (WRC). Until then, the bandwidth will probably be limited to 40MHz.

Another innovation that could keep up with LTE-Advanced collection is called “relay nodes”, i.e. relay stations. This will allow, even outside the range of a base station to receive the signal. In the edge region reinforce the signal relay stations. Connected the relay stations are connected to the base station. Thus, the signal strength inside buildings can be improved.

Increase the spectral efficiency

The concept of multiple antennas (MIMO: Multiple Input / Multiple Output) technology, which is already partially used, will also be expanded. Instead of two antennas at the transmitter and receiver (2×2 single-user MIMO) to be introduced up to eight antennas for the downlink (8×8 single-user MIMO). For upload, still four antennas are used. Simultaneously by using multiple antennas, a plurality of data streams on the same frequency is transmitted. This not only increases the spectral efficiency, but also the transmission quality.

When the spectral efficiency of LTE-Advanced will even peak values of up to 30 bits/s/Hz can be achieved in the download as well as 15 bits / s / Hz in the upload. LTE has the merit to 15 bits / s / Hz when receiving and at 3.75 bits / s / Hz when sending data. This shows that, although LTE in terms of spectral efficiency can already meet the requirements of IMT-Advanced, but only in the download. The upload, and in the range, it is far from being a 4G technology.

4G: colloquial and technical language

Although often LTE or Mobile WiMAX called 4G technologies, they are from the standpoint of technical standards only further developments in the field of 3G and provide an intermediate step represents some criteria for IMT-Advanced are indeed fulfilled to some extent, by no means all.

Nevertheless, the marketing departments of international mobile operators call the new LTE technology, which is increasingly used in the United States, even as 4G, to illustrate the difference in the speed of data transmission in comparison to UMTS networks. It is becoming apparent that this usage was soon penetrated. Then LTE or similar technology, such as Mobile WiMAX are commonly referred to as 4G technology, and only in the jargon of technical standards still out as 3G technologies.


LTE Technology

The new mobile technology LTE is superior to the existing mobile technologies GSM and UMTS, the link speed which data is transferred is much far higher the response time of the current system and the connection is faster.


This is achieved through a variety of improvements in various areas of technology that each contribute in itself to significantly better overall picture of the data radio technology. Due to the significant improvement in overall performance, LTE mobile technology is increasingly recognized as the 4th Generation (4G) refers. While in technical descriptions of the generation LTE 3.9 is assigned, but the name of LTE as 4G mobile technology is likely to prevail worldwide.

Improvements in wireless technology

A number of technical innovations allow use of the available radio room better. The OFDMA radio technology allows customizing the transmission capacity to meet the needs of each user – who wants to watch TV on the mobile Internet, gets more space than someone who just wants to make calls only. The downlink OFDMA is used for the same transmission speed with a very small range of the radio room – it takes up less space for an equal amount of data transmitted. Also known as High Speed OFDM Packet Access (HSOPA) technology uses the existing radio room two to four times better than the method called Wideband Code Division Muliple Access (WCDMA), which is used in HSDPA.

With the multi-antenna MIMO technology can be transmitted simultaneously with the current standard of four antennas and received simultaneously – what the reception improves performance significantly. Moreover, a possible interference by neighboring radio waves, which prevents so-called interference significantly stronger.

All in all, the radio room with LTE is better used, because the signals from the multiple antenna technology at transmission and reception are separated in space, and because the size of the radio channels can be adjusted according to the user.

Improvement in network construction

There are also improvements in network construction. The networks as a whole should be fit. In the network architecture, the requisite leaner architecture makes first by the absence of an element – namely the mediator between the base station and core network noticeable. The significantly higher amount of data that can be processed thanks to improved techniques the radio part of the network, of course, lead to the fact that mobile operators must also provide the lines between the base station and core network for more capacity.

Overall, the whole network will be improved so that its response times are less than five thousandths of a second (milliseconds). After all, only at a very low response time (latency) of the network can be demanding services such as Mobile TV, video calls and mobile online games provide no problems.

The competition techniques: Ultra Mobile Broadband and Mobile Wimax

LTE is the view of IT expects to be the first mobile technology, which works worldwide as a general standard. Nevertheless, there were – from a technical viewpoint – two other data transmission technologies that were considered LTE competitors: Mobile WiMAX and Ultra Mobile Broadband are techniques that offer similar data transfer speeds as the mobile technology LTE.

Ultra Mobile Broadband was a technology that is used in the USA the third mobile communications standard Should develop a rapid generation CDMA2000 mobile fourth generation. Above all, the U.S. chip maker Qualcomm invested diligently in the development based on CDMA 2000, while the Swedish Ericsson continued to LTE as a new cell phone technology. Both technologies used very similar approaches. In November 2008, Qualcomm ended its funding of research and waved a UMB to LTE.

Mobile WiMAX can achieve with the use of LTE and multi-antenna MIMO method on a 10-megahertz radio channel transmission speeds of a total of 90 megabits per second. These are divided in 63 megabits per second for downloading data (downlink) and 28 Mbit/s for transmission (uplink). However, radio cells are in Mobile Wimax achieved with a diameter of one to four kilometers far smaller than the LTE radio cell in the 800 megahertz range – where the diameter is 20 kilometers.

For network design brings dramatic benefits for this difference. LTE takes much less Send master and base stations to build a nationwide network.