Welcome to the fourth generation! This is exactly how the newly developed generation is translated from English (fourth generation (abbreviated as 4G) mobile communications.
If the subscriber cellular communications is in the coverage area of a 4G network, its communication quality is noticeably improved, and the Internet access speed exceeds 100 megabits per second. That is, download a 4.7 gigabyte movie (this is DVD Disc) can be done in just 6 minutes.
4G communication system - packet data transmission is the same as 3G, GPRS and EDGE. The IPv4 protocol is currently used to transfer information, but since the addresses of this protocol are running out, in the near future it will be used updated version This protocol is IPv6.
Most developed countries still use 3G and 3.5G, including Russia. Many countries that do not use 3G are trying to switch directly from GPRS or EDGE to 4G.
The 4G network first appeared in Oslo and Stockholm on December 14, 2009 using the LTE communication standard. As for Russia, the first city covered by LTE communications was Kazan.
For voice transmission, this standard provides VoIP technology, for example, via Skype. Using VoIP, you can get better signal reception from your interlocutor, and depending on tariff plan, you can save on calls.
For the 4G network, centimeter waves are used, namely the frequency of 3600 MHz.
But everything is not so good: 4G, like other communication systems, has its drawbacks. Firstly, with a stable signal level, the waves of this connection can have a negative effect on humans and animals. Secondly, devices using 4G require a lot of electrical resources.
Most likely, we will be using the 3.5G network for several years. It supports a fairly high speed and good quality of communication, especially in all modern devices To use the Internet, equipment is already built in to receive and transmit signals over 3G and 3.5G networks.
In Moscow, St. Petersburg and some other cities, 4G service is widespread, provided by the 4G network operator - the company. This network is designed to provide mobile Internet services. To connect to this network, it is enough to have a special Yota modem.
What’s noteworthy is that some laptop manufacturers have begun to build into their computers Yota modems. Thus, having purchased such a PC, the user can connect to the Yota network operating in the 4G standard without purchasing a special modem for this.
My experience with the Yota network shows that when choosing a suitable tariff, the speed of data exchange between a computer and the Internet is practically indistinguishable from the speed of data exchange when connecting to a fixed wired high-speed Internet network.
And, for example, if you connect to the Internet via a 3G and 3.5G network (via a mobile phone, communicator or special modem), the maximum transmission speed does not exceed 460 kbit/sec. This, of course, is a completely acceptable speed, but when working in 3G or 3.5G you still feel like you are using a mobile connection. The 4G option creates the feeling of working on a fixed wired network with a speed of 100 Mbit/s.
The disadvantages of using Yota include:
- limited distribution of this service (only within some large cities and not even throughout the entire territory of these cities),
- complex and constantly changing tariffs for services provided by Yota(for example, the company’s recent refusal to provide Internet connection services lasting a day and a week),
- the need to purchase a special modem.
The main advantages of 4G are the use of 4th generation technologies, which provide:
- high Internet speed comparable to wired networks,
- and no wires.
In conclusion, it should be noted that the 4G standard has already appeared in Russia, has taken shape in concrete and tangible services, and is gradually developing further, creating conditions for choice and for the convenience of users.
Moreover, additional competition in this matter will never hurt. For example, in this moment Yota offers free annual service, however, at a low limited data transfer speed, which does not allow you to experience all the benefits of 4G technologies.
Although the standards of the third generation of mobile communications provide users with a wide range of services and provide high speed information exchange up to 14 Mbit/s, the volume of information in communication networks continues to grow and therefore the 3GPP organization began work on the creation of a fourth generation standard back in 2004 4G - LTE (Long Term Evolution). The main requirements for the new standard included: increasing the data transfer rate to 100 Mbit/s, increasing system security, reducing energy consumption, reducing system delays, compatibility with mobile networks previous generations. Already in 2009, the first LTE network was launched in Sweden. Theoretically, 4G networks are capable of transmitting data at speeds of up to 326.4 Mbit/s for reception and up to 172.8 Mbit/s for transmission. At this speed, it takes a movie to download good quality it will take no more than one minute.
The structure of the LTE network differs significantly from the networks and. The subsystem has undergone changes base stations and switching subsystem, as well as data exchange technology between the user terminal and the base station, protocols for transmitting information between network elements. Thus, now absolutely all information (voice, packet data) is transmitted in the form of packets.
In the standard network switching subsystem LTE The following nodes can be distinguished:
- Service gateway Serving Gateway (SGW) replaces the MSC, MGW and SGSN of the UMTS network and performs the functions of processing and routing packet data from the base station subsystem. The serving gateway connects directly to the 2G and 3G networks of the same operator. This greatly simplifies the transfer of connections to previous generation networks when the coverage area deteriorates or the network is congested.
- Gateway for connecting to networks of other operators Public Data Network Gateway (PGW) routes information (voice, packet data) from the network (to the network) of a given operator.
- Mobility Management Node Mobility Management Entity (MME) designed to manage the mobility of LTE network clients.
- Subscriber data server Home Subscriber Server (HSS) is a combination of VLR, HLR, AUC registers in one device.
- Billing Node Policy and Charging Rules Function (PCRF) is intended for generating invoices to clients for communication services provided.
There is only one traditional element left in the base station subsystem - the base station eNodeB, which, in addition to the functions of the base station itself, also performs the functions of an LTE base station controller. This solution simplifies network expansion, since there is no need to add new controllers or expand the capacity of existing ones.
LTE networks use MIMO data transmission technologies and the OFDM coding system. Technology MIMO (Multiple Input Multiple Output) provides for data transmission via N-antennas and reception via M-antennas, with the receiving and transmitting antennas located at such a distance from each other as to obtain minimal correlation. Orthogonal frequency division multiplexing OFDM (Orthogonal Frequency-Division Multiplexing) is a digital modulation scheme that uses a large number of adjacent orthogonal subcarrier frequencies.
Currently, the highest priority for 4G networks are frequencies in the 2.3 GHz range. For example, the Chinese mobile operator China Mobile operates on this frequency. Another frequency range, 2.5 GHz, is widely used in Europe, Japan, India and the USA. There is also a frequency of 2.1 GHz, but a very narrow range is available here - only 15 MHz, and many European mobile operators and even less - up to 5 MHz. In the future, most likely, the 3.5 GHz frequency range will become promising, due to the fact that in many countries wireless broadband Internet access networks already exist in this range and the transition to the LTE network will allow operators to use the frequency without purchasing new expensive licenses. If necessary, other frequencies can be allocated for fourth generation networks. Different 4G network structures can use frequency bands in the range of 1.4 - 20 MHz. For comparison, the UMTS standard uses fixed 5 MHz bands. LTE networks use temporary TDD (Time Division Duplex) and frequency FDD (Frequency Division Duplex) signal separation.
Typically, an LTE network base station can serve an area with a radius of up to 5 km, although if necessary, due to the high location of the base station antennas, this size can be increased to 30 or even 100 km. The big advantage of the LTE standard is big choice terminals. Except cell phones laptops can be used, tablet computers, video cameras and gaming devices with built-in modules for compatibility with fourth generation networks.
LTE standard technology supports handover and roaming with cellular networks of the 2G and 3G generations, which allows these devices to be compatible with these networks. Network structure 4G allows you to immediately redirect a call or Internet session to a 3G or 2G network (UMTS or GSM). In addition, LTE networks easily integrate with WI-FI networks and the Internet.
While using the mobile Internet, you, of course, noticed that when the connection is established in the top panel quick access Different letters and abbreviations appear on the phone: H, H+, LTE, 3G, 4G and others. They indicate the type of connection on which the speed of data transmission and reception depends.
Explanation of symbols and characteristics of connection types
Knowing the meaning of the symbols and the basic parameters of each type of connection, you can understand what speed to expect with the existing signal level. In most cases, the mobile device itself selects the fastest available communication protocol and makes it possible to use the Internet through it.
Mobile device shows the type of network being used
The following factors influence the choice of network connection type:
- the place where you are: indoors or outdoors long distance from large cities, the most modern and fastest protocols (for example, 4G) may not be available, and the device will select the type of connection that will work, albeit slowly;
- tariff used: many tariffs do not provide for the use of the high-speed 4G protocol, allowing connection only to 3G and slower connection types;
- technical characteristics of the device: not all mobile devices support the maximum network access speed, so in order to find out how many megabytes per second your phone can send, you need to read the documentation on the official website of the manufacturer.
3G
Alternative names are 3rd Generation and UMTS. This is the most common Internet connection format these days. The number "3" denotes the third generation of communication protocols. Initially, the speed of this type of connection did not exceed 384 Kbps, but now, under favorable conditions, it can reach 21 Mbps. However, most often you will get speeds of up to 2 Mbps on your phone or tablet.
The advantages of the 3G mode include the fact that it is inferior in speed only to a 4G connection, but is available almost everywhere. But if you move faster than 30 km/h by car or train, the connection speed begins to decrease.
Speed mobile internet in 4G networks many times higher than in any other
H, 3.5G, H+, 3G+
Type H is an improved version of 3G, based on HSDPA - High Speed Downlink Packet Access technology. H+, 3.5G and 3G+ are also add-ons to the 3G mode that use the HSPA+ protocol. They allow you to develop higher data transfer speeds: under ideal conditions, when using the dual-channel version of the HSDPA protocol - up to 21 Mbit/s, and in the basic mono-channel version of the HSPA+ protocol - up to 22 Mbit/s. In reality, however, the speed in both protocols usually does not exceed 3.8 Mbit/s.
3.75G
This option is rarely seen as phones usually don't display it in the status bar even though they actually use it. The connection is carried out using the DC-HSPA+ protocol - an improved version of HSPA. Its maximum speed is two times higher than that of the H option - 42 Mbit/s, since it implements two-channel interaction. The best performance of networks of this type is comparable to the average performance of a 4G connection.
4G, LTE
4G (fourth generation networks) are the fastest available at the moment. But only if they implement the LTE (Long Term Evolution) protocol. Initially, 4G networks used WiMAX technology, and their speed did not exceed 40 Mbit/s. But today almost all telecom operators use the LTE protocol.
There are two types of LTE connections: LTE FDD and LTE TDD. Their main difference is the distribution of the available frequency range. But regardless of which version of the protocol is used, the data transfer speed can theoretically reach values from 100 Mbit/s to 1 Gbit/s, and in reality - more than 40 Mbit/s.
4G networks, however, have a number of disadvantages:
- the cost of Internet access in them is higher than in 3G networks, so switching to a tariff that supports 4G is only worth it if you download large files or watch videos via mobile Internet;
- The coverage area, that is, the area where a 4G connection is available, is much smaller than that of 3G, so be prepared to be left without fast Internet if you go out of town.
The coverage areas of 3G and 4G networks in Russia are shown below. In the upper part there is a 4G coverage area, in the lower part - 3G. It can be seen that the 3G network coverage of the territory is much denser, especially at great distances from large cities.
3G network coverage is much denser
4G+, LTE-A
The 4G+ standard is the next stage in the development of networks based on the 4G protocol and supports LTE-Advanced technology. It allows you to combine used frequencies, resulting in increased connection speed.
The maximum speed depends on the specific implementation of LTE-A capabilities by the telecom operator. In some cases, you can get up to 450 Mbps, which is faster than wired connections.
G (General Packet Radio Service)
A very old standard, which at one time was positioned as an improved version of 2G - it was called 2.5G. It works using the GPRS protocol - an improved version of the GSM protocol.
This is, of course, the slowest type of communication of all those described, since its maximum speed does not exceed 200 Kbps. A page on a regular website without a large number of images and other media elements will take about a minute to load in this mode. But sometimes it is possible to connect to such a network in places where 3G and 4G are not available.
E (or EDGE - Enhanced Data Rates for GSM Evolution)
EDGE is not 3G yet, but is already closer to it. The second name of this option is 2.75G. This puncture appeared after G. It is capable of providing a maximum speed of about 300–400 Kbps.
Video: comparison of 3G and 4G connection speeds
Most fast internet these days it is available over a 4G+ or 4G connection. The second fastest option is 3G+ and H+, then H and 3G. The slowest options, which work a little faster than the regular 2G protocol, are G and E. At the same time, the coverage area of the Internet using the most modern technology, is relatively small, and you can get a 3G, G or E network in most settlements countries.
GSM cellular networks, by their structure, were not originally intended for mobile Internet. Accordingly, today, in order to meet the needs of the population, cellular operators are forced to invest huge amounts of money in upgrading their networks to 3G (UMTS), and now to 4G (LTE). Of course, cellular companies generously borrow these investments from our pockets, but their work is also not very easy.
Now, when the implementation of third generation networks in Russia has not yet been completed, operators have already begun work on next generation networks - 4G or LTE.
The photo shows the first LTE base station from Yota in Sochi:
The term LTE itself stands for Long Term Evolution and translated into Russian means “long-term evolution”. For a long time, the WiMAX standard claimed the role of 4G communications, but was later relegated to the background as a less popular option for fast wireless Internet.
LTE is the next generation of mobile communications after 3G and operates on the basis of IP technologies. The main difference between LTE and its predecessors is high speed data transmission. Theoretically, it is up to 326.4 Mbit/s for receiving (download) and 172.8 Mbit/s for transmitting (upload) information. At the same time, in international standard the figures are 173 and 58 Mbit/s, respectively. This fourth generation communication standard was developed and approved by the 3GPP International Partnership.
Latest generation coding system - OFDM
Let's figure out what it is main feature LTE standard. Just like in 3G networks, the main link in LTE can be called OFDM-MIMO data encoding and transmission technology.
OFDM stands for Orthogonal Frequency-division Multiplexing and in Russian means orthogonal frequency division of channels with multiplexing. It is a digital modulation scheme that uses closely spaced orthogonal subcarriers in large numbers. All subcarriers are modeled using a standard modulation scheme such as quadrature amplitude modulation at a low symbol rate while maintaining the overall data rate, as in simple single-carrier modulation schemes in the same bandwidth. In reality, OFDM signals are generated through the use of a "Fast Fourier Transform".
This technology describes the direction of the signal from the base station (BS) to your mobile phone. As for the return path of the signal, i.e. already from telephone set to the base station, technical developers had to abandon the OFDM system and use another technology called SC-FDMA. In decoding it reads as Single-carrier FDMA and in translation means multiplexing on one carrier. Its meaning is that when a large number of orthogonal subcarriers are added, a signal with a large crest factor (the ratio of the signal amplitude to its root-mean-square value) is formed. In order for such a signal to be transmitted without interference, a high-quality and rather expensive high-linear transmitter is needed.
It was this device that created some difficulties in obtaining a license in Russia for LTE networks. And, nevertheless, as usually happens in our country, despite the artificially created difficulties, the Ministry of Telecom and Mass Communications of Russia recognized the LTE standard as a promising direction for the development of cellular networks. However, when tendering for distribution, often 2.3 - 2.4 GHz in 40 regions Russian Federation only OFDMA technology was specified as a radio access method, which directly excludes LTE, because in the latter case, in addition to OFDMA, SC-FDMA is also required. This once again shows the complete incompetence of Russian officials in the issues they deal with.
MIMO- Multiple Input Multiple Output is a technology for transmitting data using N-antennas and receiving information using M-antennas. In this case, the receiving and transmitting antennas are spaced apart at such a distance as to obtain a weak degree of correlation between adjacent antennas.
LTE position on the air
At the moment, frequency ranges have already been reserved for 4G networks. Frequencies around 2.3 GHz are considered to be the highest priority. The main example here is China with its cellular operator China Mobile, which has already allocated the required frequency range and is conducting test broadcasts. Given the huge volume of local cellular consumption, the use of this frequency is destined for success and dominance in China.
Another promising frequency range, 2.5 GHz, is used in the USA, Europe, Japan and India. There is also a frequency band around 2.1 GHz, but it is relatively small - only 15 MHz are available in the 2.1 GHz range, and most European mobile operators limit the bands in this range to 5 MHz. In the future, the 3.5 GHz frequency band will likely be the most used. This is due to the fact that wireless broadband Internet access networks are already used at these frequencies in most countries, and thanks to the transition to LTE, operators will be able to reuse their frequencies without the need to purchase new expensive licenses. If necessary, other frequency ranges can be allocated for LTE networks.
Regarding the frequency bands used and distribution methods in LTE, everything is quite unclear and contradictory, because the standard itself is quite flexible. In different structures, fourth generation networks can be based on frequency bands in the range from 1.4 to 20 MHz, in contrast to the fixed 5 MHz in 3G (UMTS). It is also possible to use both time division of signals TDD (Time Division Duplex - duplex channel with time division), and frequency division - FDD (Frequency Division Duplex - duplex channel with frequency division). For example, the LTE network being built in China is of the TD-LTE standard.
The service area of an LTE network base station may vary. Usually it is about 5 km, but in some cases it can be increased to 30 or even 100 km, in the case of a high location of the antennas (sectors) of the base station.
Another positive difference of LTE is the large selection of terminals. In addition to cell phones, many other devices will be used on LTE networks, such as laptops, tablets, gaming devices and video cameras that have built-in LTE support. And since LTE technology supports handover and roaming with cellular networks of previous generations, all these devices will be able to work in 2G/3G networks.
Structure of fourth generation networks
The 4G (LTE) network diagram looks like this:
As can be seen from this diagram, LTE networks include 2.75G (EDGE) and 3G (UMTS) network modules. Because of this feature, the construction of fourth-generation networks will be quite specific and will resemble the next stage in the development of today's technologies rather than something fundamentally new.
For example, in accordance with this structure, a call or Internet session within the coverage area of an LTE network can be transferred to a 3G (UMTS) or 2G (GSM) network without interrupting the connection. In addition, LTE networks integrate quite easily with WI-FI networks (labeled WLAN Access NW in the diagram above) and the Internet.
Let's look at the radio access subsystem in more detail. In its structure, the RAN radio access network - Radio Access Network - looks similar to the UTRAN UMTS network, or eUTRAN, but has one addition: the transmitting and receiving antennas of the base stations are interconnected using a specific X2 protocol, which unites them into cellular network- Mesh Network - and allows base stations to exchange data with each other directly, without using the RNC controller - Radio Network Controller.
In addition, the relationship of base stations with the control system mobile devices MME - Mobility Management Entity - and service gateways S-GW - Serving Gateway - is carried out by “many to many”, which allows for high communication speeds with low delays.
LTE technology vs WiMAX
Surely many of you are wondering why LTE is the future? After all, just a year or two ago everyone considered WiMAX technology, well known by broadband wireless Internet providers such as Yota and Comstar, to be the 4G standard.
In fact LTE standards and WiMAX are quite close to each other. They both use OFDM encoding technology and MIMO data transmission system. Both standards use FDD and TDD duplication when bandwidth channel up to 20 MHz. And both of the communication systems use IP as their protocol. Accordingly, both technologies actually use their frequency range equally well and provide comparable Internet access data transfer speeds. But, of course, they also have some differences.
One of these differences is the much simpler infrastructure of the WiMAX network, and, therefore, more reliable technically. This simplicity of the standard is ensured by its purpose exclusively for data transmission. On the other hand, the “complexities” of LTE are needed to ensure its compatibility with standards of previous generations - GSM and 3G. And you and I will certainly need this compatibility.
There are other details in the difference between LTE and WiMAX. For example, dispatching radio frequency resources. In WiMAX it is produced using Frequency Diversity Scheduling technology, according to which the subcarriers provided to the subscriber are distributed over the entire spectrum of the channel. This is necessary to randomize and average the effect of frequency selective fading on a wideband channel.
LTE networks use a different technology to eliminate frequency selective fading. It is called Frequency Selective Scheduling. In this case, for each subscriber station and each frequency block of the carrier, channel quality indicators CQI - Channel Quality Indicator are created.
Another very important point associated with the planning of mass communication networks - frequency reuse coefficient. Its role is to show the efficiency of using the available radio frequency band for each base station separately.
Basic reuse structure frequency range WiMAX consists of 3 frequency channels. When using a three-sector configuration of sites (base stations of a certain frequency range), one of 3 frequency channels is implemented in each sector. In this case, the frequency reuse coefficient is equal to 3. In other words, at each point in space there is only a third of the radio frequency range.
The LTE (4G) cellular network operates with a frequency reuse factor of 1. That is, it turns out that all LTE base stations operate on the same carrier. Intra-system interference in such a system is minimized due to frequency selective scheduling, flexible frequency plan and coordination of interference between individual cells. Subscribers in the center of each cell can be given resources from the entire band free channel, and users at the edges of cells are provided with frequencies only from certain subbands.
The above features of LTE and WiMAX networks have a great impact on one of their main characteristics - the degree of radio coverage. Based on this parameter, the required number of base stations for high-quality coverage of a specific territory is determined. Accordingly, it directly affects the final cost of building LTE networks.
According to calculations, the LTE network is able to provide a better coverage area with the same number of base stations, which is a definite plus for all cellular operators.
Modern technologies, in particular the development of the Internet and wireless communication, have transformed the world beyond recognition. The population enjoys not only free access to all kinds of information, but also unique opportunities for communication and fun leisure activities. At the same time, the level of quality of the Internet connection, as well as the speed of data transfer, is of great importance. And in our time, the development of these technologies has reached unprecedented heights. Despite the widespread introduction of the new generation of communications, few people still know what 4G means.
1. What is 4G
4G in English means fourth generation. This is a promising generation of wireless communications, which has high data transfer speeds, as well as higher quality voice communication. This generation of communications includes such promising technologies that provide data transmission speeds over a wireless network of at least 10 Mbit/s to moving users. So what does 4G mean? This is the fourth generation of mobile communications, which has a lot of undeniable advantages.
Based on research and numerous evaluations of various 4G broadband technologies, which is known as IMT-Advenced. Based on the evaluation results, only two technologies were awarded the official title of IMT-Advenced. These are promising technologies LTE-Advenced, as well as WirelessMAN-Advenced. These two technologies today fall under the 4G standard - the fourth generation of wireless communications.
2. How 4G works
4G communication systems are based on packet data transfer protocols. This technology uses the IPv4 protocol to transmit information, but in the future it is planned to support the IPv6 protocol.
Modern 4G technology is of great importance in providing broadband Internet access in rural areas, since it is more justified to install one 4G station than to install a fiber optic connection. One station is capable of providing high-speed communications over tens of kilometers.
3. Benefits of 4G
Today it is very difficult to evaluate the advantages of high-speed fourth generation communications, since they are very numerous. Using such technologies, enormous amounts of all kinds of information become available to users. The need to wait for complex and time-consuming web pages to open, as well as long waits for sufficient downloads, becomes a thing of the past. large file, such as a movie, etc.
It is the high speed of data transfer over a wireless network, as well as high quality voice communications, that are the main advantages of the fourth generation of 4G mobile communications. This in turn entails increased convenience and significant time savings, which is the main requirement of users. In addition, 4G mobile communications provide users with the opportunity to access the Internet absolutely anywhere (where there is 4G coverage) and at any time.
Thanks to the introduction of fourth generation wireless technology, Internet television will become available to users in high quality(HD). In addition, people will be able to create video calls as well as video conferences. 4G support for mobile devices opens up a lot of new opportunities.
4. WHAT IS 4G LTE: Video
Thanks to such technologies, many people will be able to perform certain actions remotely. For example, doctors will be able to manage robotic operating rooms while on another continent.
These days, there are several technologies that claim to be the fourth generation of mobile communications. These are technologies such as:
- TD-LTE;
- Mobile WiMAX;
- HSPA+.
Despite this diversity, most mobile operators choose LTE technology, and it is this technology that is developing in Russia and Ukraine. IN currently The data transfer speed in 4G networks based on LTE technology is about 30 Mbit/s, but in the future this figure is planned to increase to 300 Mbit/s.
4G communication is the future wireless networks. Many users today have the opportunity to experience all the benefits of this technology for themselves. At the same time, once you try 4G, you will never want to go back to 3G and such a slow connection.
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