WiMAX standard: technical description, implementation options and application specifics. WiMAX - wireless standard for long-distance broadband communications

- market in the country, an assessment of its current state can be reduced to the phrase “not very good yet, but the situation is getting better.” No one has any doubts that this particular wireless communication standard will be leading during the next technological cycle. Unless, of course, you urgently need to implement some 5.5 G.

However, this was not always the case. In 2008, when in many regions of the country there was not even 3 G, claimed to be the “next generation of wireless communications” WiMax. At that distant time, the standard turned out to be the only one capable of providing mobile access speeds of several megabits and implemented in hardware. It should be noted that at that time the situation with high-speed Internet (and with the Internet in general) was quite sad. At the same time, it was sad not only in the cellular segment, but also in the wired segment. There was no trace of 50 megabit/s for 600 rubles; for that money you could have bought much less. Against this background, proposals from Yota (Skartel LLC) seemed incredible: speeds up to 10 Mbit/s, no traffic threshold, subscription fee of less than a thousand rubles, the ability to use anywhere in the coverage area, no roaming...

After Yota’s excellent start, second-tier operators reached out: Comstar, Freshtel, Soyuz-Telecom, WiTe. Everyone tried to join WiMax and snatch the subscriber base from cell phones. When did the “locomotive” in the person of Yota announce his own phone?"Yota Cosmos" with with unlimited calls within the network and an affordable price, mobile operators have become even worse. It’s not surprising - they make a significant part of their revenue in the capital’s markets, as they are the most capacious and solvent. To lose them meant to stand on a par with Tele 2.

However, Yota's plans was not destined to come true. After some time, it was announced that the project to introduce native voice communication would be stopped. The official reason given was the inability to provide acceptable quality, which contains some guile - voice requires noticeably less bandwidth than data. Be that as it may, the project was curtailed and failed to be revived. Around the same time, the triumphal procession WiMax - the operators lost their pace, and the previously vigorous players lost their wings and descended to the sinful earth.

Why didn't it work out? Yota and almost everyone else?

There are several reasons for the failure of the standard in general (and Scartel in particular).

Firstly, the company spread itself too thin. Instead of focusing exclusively on the Russian market, it decided to go international and began building networks in Nicaragua and Belarus. After a short time I had to leave there. The same applies to the phone Cosmos and “the first network in Russia LTE" - all the work was simply thrown away. Net LTE in Kazan was completely empty, since Scartel did not have the appropriate licenses. One of the results of this policy was underfunding and delay in the construction/modernization of networks in Russia.

Secondly, inflexible pricing policy. At the time of launch, only two tariffs were offered: daily (50, and then 90 rubles) and monthly (900 rubles per month). The speed on the tariffs was maximum, so those who needed inexpensive, not too fast, but stable Internet were not covered by the offer.

Thirdly, the company's networks were heavily overloaded. This was a consequence of the pricing policy, which did not imply any restrictions on traffic or speed. As a result, subscribers rushed to download torrents and watch videos, which destroyed a significant number of base stations. Rumors “about the disgustingly functioning Internet” immediately spread across the Internet.

Fourth and finally, the coverage policy is strange. The network's subscribers were residents of multi-storey buildings in the largest cities. Although, as we mentioned above, wired Internet was not very developed at that time, providers did not stand still. The speeds grew, the price fell, they bought WiFi -routers. As a result, Scartel ceased to be an “operator for everyone” and was forced out of apartments as the main channel. The private sector and cities in the regions (Moscow and Leningrad) were carefully ignored by marketers, guided by the saying “There is no life behind the Ring Roads.” But it is precisely there that access to the network is much more necessary than in the capitals, because in those days everything was very bad even in high-rise buildings. Residents of the regions would be happy to use Yota as a fixed channel, even with a strong speed limit (2 or even 1 Mbit/s), because, as at the end of 2013, not everything was in order with the Internet in the private sector.

Other providers have slightly different reasons for shutting down. For example, Comstar through MGTS was purchased by MTS and closed so as not to create competition for the technology LTE. Other operators simply did not have enough money to achieve at least operational payback. Some did not go further at all, limiting themselves to a couple of cities, because they did not see themselves as a competitor to the Big Three. In general, the reasons were different, but the result was the same - curtailment or freezing of almost all projects.

We decided to review proposals WiMax in the country, at the same time seeing how operators are feeling at the moment.

Yota

We talked a lot about it in the previous paragraph. To what has been said, it should be added that nothing remains not only from the original plans, but also from the company itself: its Megafon. In general, the company fully justified its logo in the form of a man standing upside down.

The official website is still active and offers to connect, but this is unlikely to last long. The pricing policies of Scartel and Megafon are fundamentally different.

Comstar

Another operator that fell under the pressure of competitors from the world of cellular communications. In 2011, MTS joined COMSTAR-United TeleSystems, and at the end of the summer of 2012 the network WiMax was finally closed. All clients were redirected online LTE:

Unlike the Yota website, where there was no mention of the technology, on the Comstar website everything was preserved in its original form (without connection and purchase functions, of course) and you can see “how it was.” For example, here are the tariffs:

The operator introduced tariffs with traffic restrictions, but with reasonable prices for overruns. Apparently, Iota’s experience prompted this decision.

Soyuz-Telecom

The first active operator in our review, although it can only be called active with a big stretch. The most recent news is dated 2011, there is no coverage map, and user reviews are extremely negative. Subscribers complain about regularly missing services, inadequate technical support, lack of any information and long equipment repair times:

However, problems arise not only from subscribers, but also from official dealers, who also do not know what to do:

At the moment, the discussion of the provider is almoststopped(all active users switched one way or another). There were rumors about the sale of equipment and the transfer of clients to new operators, but there is no official information on this matter.

The operator himself was brought to justice more than once or twice by the supervisory authority for failure to comply with licensing conditions and for working without the necessary documents. For example, in March 2012 an unscheduledexaminationOffice of Roskomnadzor for the Altai Republic, as a result of which several protocols of administrative violation were issued. The company had problems with commissioning SORM, operating without registration of distribution zones and permits for radio frequencies. In November 2012, residents of the city of Chusovo, Perm Territory, complained about the lack of service. Complaintrecognizedlegal, fined the operator 30 thousand rubles and sent the initiated administrative case to the Moscow Arbitration Court. In addition to the cases described, there were several more violations for which the operator was issued fines and warnings.

What is the provider's problem? In our opinion, it consisted of an attempt to cover everything at once. The company received a huge number (47 pieces) of licenses that needed to be implemented:

At the same time, they had to be implemented almost throughout the entire country. Soyuz-Telecom proudly stated that “The company has 47 licenses to carry out activities in the field of providing 5 communication services in 80 regions of Russia, including “Communication services for data transmission for the purpose of transmitting voice information”, “Communication services for data transmission with the exception of data transmission services for the purpose of transmitting voice information” , “Telematic communication services”, “Communication services for the provision of communication channels” and “Local telephone communication services with the exception of local telephone communication services using payphones and public access means”. Of course, without millions of dollars of investment, these plans could not come true. Most likely, the company's strategy was to quickly gain a minimum number of clients that would pay for its current activities. The calculation did not come true, the cash flow turned out to be less than required and the operator began to sink. All in all, another example of how to bite off as much as you can chew.

There was only one tariff, but with the opportunity to pay for several months and get a discount:

WiTe

Another operator with Napoleonic plans that were not destined to come true. In 2009, it was promised to launch networks in 25 cities in six federal districts within two years. However, the plans were not destined to come true, and as a result, the network started operating in only two cities: Kemerovo and Topki. Most likely, the company simply did not have enough money - the $25 million that was planned to be allocated to cover the regions was too small an amount. Despite the losing “all at once” strategy, the company avoided the fate of Soyuz-Telecom. Having managed not to get involved in the race to increase its presence, the provider concentrated in one place and managed to survive until today.

Although work is announced in two cities, the coverage map is shown only for one:

But the company’s tariffs are fine. The operator did not pursue unnecessary unification and minimalism, but presented a whole line:

The line includes tariffs with and without traffic restrictions. In addition, daily rates are available: WHITE DAY for 50 rubles and WHITE EXPRESS for 75 rubles. Everyone is given 2 days to test the network. If the result is not satisfactory, the failed subscriber can return the funds paid in advance by returning the equipment.

For the city of Topki, tariffs are much lower:

A special feature of the tariffs are the terms of use. The fact is that tariffs are tied to the type of equipment, and the name of the equipment is misleading. For example, the “White Fix” tariff is available for equipment called “Modem”, although it is meant as USB modem and router. But the equipment called “Router” means an external antenna and a high-performance router. The point is most likely that “routers” have a much more sensitive antenna. Since with a large antenna the signal becomes more stable and the access speed increases, the tariffs had to be adjusted towards reducing the traffic threshold or increasing the subscription fee. Otherwise, landline subscribers will create a large load on the base station.

Devices are offered in one model per type: modem, router (mobile and stationary), fixed station and external antenna:

Device	price, rub.
USB modem Seowon SWU-3220A
WiFi router Seowon SWU-8200
Router Seowon SWC-3200
Greenpacket OX 350
External antenna for routers

A set of devices for working in the WiTe network

Reviews about the provider vary. More often, of course, they scold, but this in itself is not an indicator - people scold much more willingly than they praise. People complain about low speeds, unstable connections, and unavailable technical support. Some of the complaints are truly justified - speeds of less than 1 Mbit/s can be considered a problem, but there are also complaints like “I can’t watch movies online.” Unfortunately, not all people understand that watching movies online wirelessly without any restrictions is currently only possible with great luck.

FRESHTEL

The only provider that provides services in several cities and is at least somehow developing, and not on the verge of bankruptcy. The network covers several dozen cities in 12 regions of the country, with most of them located in the Central Federal District. Apparently, the company closely monitored the development (more precisely, how they were bending) of competitors and learned from their mistakes. Therefore, Freshtel is not only developing nearby regions, but is also not trying to compete with wired access providers in high-rise buildings, concentrating on the private sector. For example, this is what the coverage area looks like in the city of Shakhty:

If you enlarge the map, you will see that services will mainly be provided to residents of the private sector. There are also apartment buildings in the zone, but they are low-rise, so wireless Internet services will also be in demand there. The operator is developing not only small cities, but also regional centers. For example, there is also a network in Samara. Alas, not in all areas:

The full list of presence includes 37 cities:

Some cities were launched quite a long time ago, while others were launched quite recently. The last cities, Samara and Togliatti, were connected in the fall of the outgoing year.

The operator has two tariffs: with a traffic limit of 20 (10) GB and unlimited. They are the same for almost all cities. The first costs 590 rubles, the second - 790 rubles per month. The speed is up to 10 Mbit/s maximum in theory (in practice everything is much more modest). For a tariff with a traffic limit, after it is exhausted, the speed is limited to 256 kbit/s. Modest, but still much better than handouts from mobile operators in the form of 64 kbit/s:

There are quite a lot of devices: two types of modems, five types of routers, an external unit and four external antennas. The price of modems is higher than that of others: 1890 rubles for the ZTE AX320 USB Dongle and 1990 rubles for the Seowon SWU-3220A USB Dongle. Fortunately, since November 7, 2013, the “Internet in your pocket for 99 rubles” promotion has been running, within which modems can be purchased for only 99 rubles. The promotion will continue until the last modems of this type are sold. Promotions are also valid for other devices, but with a time limit:

Separately, it is worth noting the possibility of paying for services. There are several ways to choose from: through terminals, bank cards, electronic money and even Sberbank of Russia:

Such a large number of payment methods indicates that the company understands that it is necessary to fight for the client, and not force him to personally come to the office to give the company his money.

There are many reviews about the operator and the vast majority of them are negative. A significant part of them is that “they promised 10 Mbit/s, but in reality it was much less.” Here, for some reason, the operator decided not to take into account Iota’s experience and walked through the rake with speeds of “up to 10 Mbit/s.” It is clear that the subscriber will be able to see 10 Mbit/s only under the base station, being its only client. Alas, in pursuit of connections, marketers write in tariffs figures that are extremely far from reality. There are a lot of complaints about cut-down torrents, but here we can understand the provider. Torrents will load any communication channel 100%; a wireless connection will not physically support them. So for the convenience of other users, torrents must be limited. Claims here can be made for failure to inform subscribers, some of whom connect specifically to download movies and games from trackers. There are also completely unfounded claims:

Wondering which wireless providers offer consistent speeds of 1 Mbps?

In general, subscribers are indignant and threaten to switch to mobile operators. Their speed is indeed higher, as is stability, but for some reason everyone forgets that traffic is strictly limited and after the monthly volume is exhausted, the speed drops to 64 Kbps.

We went in the summer about the takeover of Freshtel by TransTelecom, but they were never confirmed.

Was there a chance?

Having considered the largest federal operators WiMax, we can say that the standard in Russia is more dead than alive. Cellular players have switched to LTE small locals prefer different variations Wi-Fi. For WiMax There remains a small niche of corporate clients who cannot connect to wires for various reasons, but who can be connected for Wi-Fi is not possible.

Looking into the past from today's perspective, we ask ourselves: did we have a chance? WiMax? We think so. Small, but quite real. Standard was lucky twice: the first time when the crisis came and cellular operators froze large construction projects. A crisis is not very good for most, but not for those who have money. The cost of equipment, wages, logistics costs - everything is cheaper during a crisis. In addition, contractors have less work to do, which means they can build faster. The standard was lucky for the second time when it turned out that there are 3 full-fledged networks G it is impossible to deploy in some places, and LTE It is not known when it will be launched. At the start of implementation WiMax technologically superior to the third generation networks available at that time several times.

Think about what needed to be doneknowing the purchaselooking at all the successful and unsuccessful steps from the perspective of history is not very correct, but we will try. So, for development WiMax As standard, the following steps were required:

Do not scatter efforts across the entire country, but focus on nearby regions and cities. What's the use of roaming without a surcharge between Moscow and Ufa if the flow of people between them is minimal? But roaming between Moscow and Dolgoprudny would be much more in demand.

Make carpeting in capitals first . Moscow and the corresponding regions are a “cash cow” for operators. A significant part of the country's population, which is solvent, lives here. Belarus is, of course, good, but in terms of financial capabilities it is not comparable to Moscow or St. Petersburg.

Collaborate with local players . One of the obstacles to the development of any wireless technology is the need for infrastructure up to the base station. If you plan to make a fairly dense coating, you cannot do without optical networks from the connection point. Building lines takes time and money. You can buy a channel from local players, but then they will not be interested in developing the network. But an agency scheme or a full-fledged partnership could give a synergistic effect: locals would have the opportunity to connect the private sector, and wireless operators would have the necessary network resources and an interest in success. Most importantly, time would be gained and the networks could be deployed much faster.

Joining forces . You can learn something together much faster than separately. If all providers WiMax divided their zones of influence, but operated under a single brand (this was the model used by cellular companies at the beginning of their journey), things went much faster. Unfortunately, this scenario is even more fantastic than the previous one.

Greater variety of tariffs . We have already touched on this topic. The poor tariff line, which does not allow the subscriber to find exactly “his” tariff, has pushed a number of clients away from the standard. Not everyone needed speeds of “up to 10 Mbit/s” for 900 rubles; some wanted to spend 300 and be able to slowly and without restrictions use mail, read the news and listen to the radio.

The speedy introduction of unlimited voice and the release of inexpensive phones . Even if the networks WiMax offered one single service in the form of unlimited calls and SMS for a small amount, a lot of people would connect to them. The experience of Tele2 shows that cheap voice communications are extremely in demand. Basic services in the form of voice load the station very little (these are not torrents or even web pages), and the price tag of 300 rubles makes such communication accessible to a wide segment of the population.

If these conditions were met, the situation with WiMax would be completely different. Who knows, maybe now we would They discussed not the introduction of LTE, but WiMax-2.

The operating principle of WiMAX networks.

The WiMAX Forum company, founded in 2001, is engaged in the promotion and development of WiMAX technology. This technology is based on the IEEE 802.16 or Wireless MAN standard. WiMax Forum includes companies such as Intel, Samsung, Nokia, LG, Motorola.

WiMAX technology allows you to solve a number of problems:

connect Wi-Fi access points to each other and to your Internet service provider;
provide wireless broadband access as an alternative to DSL and leased line;
provide high-speed data transmission and telecommunications services;
create access points that are not tied to geographic locations.

The search for an optimal solution for fixed and mobile applications did not bring results. Therefore, two separate versions of the IEEE802.16e and IEEE802.16d standard are used, which are characterized by their operating frequency ranges, bandwidth, emission power, transmission and access methods, coding and modulation methods, and principles of radio frequency reuse. Some basic indicators are the same, but these versions of WiMAX systems are practically incompatible.

WiMAX fixed, 802.16-d or -2004, is characterized by a 3.5 GHz or 5 GHz band, and uses OFDM (orthogonal frequency division multiplexing). A user device is a stationary modem that is installed indoors or outdoors. A PCMCIA card is installed for the laptop. WiMAX mobile, 802.16-e or -2005, is characterized by several frequency ranges - 2.3 GHz, 2.5 GHz, 2.7 GHz, 3.4 GHz and 3.8 GHz. This version supports similar functions as for third generation cellular networks EVDO or HSDPA - such as handover, roaming and idle mode. Scalable OFDM or SOFDMA is used here.

Difference between WiMAX and Wi-Fi

It would seem that WiMAX's competitor in the wireless segment is Wi-Fi technology, but upon closer examination, you will notice that WiMAX and Wi-Fi have occupied different niches. If you use a home or office Wi-Fi router, you know that Wi-Fi access points can provide a signal within just a few hundred meters. WiMAX is a long-range system covering kilometers of space. WiMAX technology can expand the range of mobile devices to the radius of a block or even a small city!

WiMAX network

The structure of WiMax networks (IEEE 802.16 standard) is similar to traditional mobile networks. Base stations located within line of sight from each other (and this is subject to installation on high-altitude objects up to 50 km) are connected to each other by a constant radio channel in the microwave range. One or more base stations must be connected to an Internet provider. To connect the base station to the user, user equipment is required. If there are several WiMAX base stations in the “visibility zone,” the WiMax modem software automatically selects the station with the strongest signal.

Why WiMAX?

The main advantage of this technology is speed. Mobile WiMAX technology allows you to surf the Internet at speeds of up to 10 Mbit/s. By concluding an agreement, you will be able to use fast Internet anywhere in the coverage area - at home, at work or in the car. To ensure good speed, line-of-sight connections must be established in the 10 - 66 GHz frequency range between WiMAX base stations. In this case, it is possible to achieve information exchange speeds of up to 70 Mbit/s. And the more base stations are installed, the higher the speed and reliability of the created network will be. In this way, distances of tens of kilometers are connected.

WiMAX is a telecommunications technology designed to provide wireless communication and data transmission over long distances for a large number of different devices (we are talking not only about base stations, but also about various devices: smartphones, laptops, tablets, etc.).

Developed as alternative telephone lines and DSL technology. Currently the maximum theoretical level of transmission speed achieved is 1 Gbit/s.

How Wimax works

It works on the principle of a traditional mobile communication network. That is, they are installed base stations, which form the wireless network coverage. This coverage provides continuous telecommunications in a certain area through a permanent radio channel in the microwave range.

How WiMAX works

User device automatically receives the signal from the nearest base station with a stronger signal in the “access zone”.

Distinguish fixed(for stationary devices) and mobile(for portable, moving in space) WiMAX standard.

Each of them has its own characteristics: primarily the operating frequency, as well as access methods and transfers.

Difference between wimax and wifi

The technologies have a lot in common, if we talk about the essence - transmitting data over a distance without the use of wires, cables, etc. using specific radio frequencies. However WiMax is superior Wi-Fi access speeds. Also is different large coverage, due to which it can be used as a backbone channel, which ultimately may allow organizing on their basis scalable urban networks with high access speeds.

They also differ in their areas of application, so they can work complementary to each other. It all depends on the target audience and the ability of operators to provide the technology. For WiMAX you need more powerful network infrastructure, which accordingly incurs large material costs for its construction and a longer payback period.

As you know, the Wi-Fi standard is 802.11, and the WiMAX standard is 802.16. Accordingly, there is a difference in their technical characteristics.

The significant difference is that radius of action Wi-Fi does not exceed 100 meters without obstacles (in everyday conditions this is 20-30 meters). If speak about WiMAX, then the maximum declared range 50 km(in reality 5-10 km), which is much more. It is advisable to use Wi-Fi to create local private networks. With WiMAX you can create regional networks. Only devices that support this standard and are equipped with the appropriate module can connect to this network.

Wi-Fi is used much more due to cheapness And you just settings.

Both technologies are easy to use and allow you to easily deploy and scale networks in the shortest possible time.

Why choose wimax

The future is WiMAX. Already now the mobile version allows you to work at speeds of up to 10 Mbit/s. You can use high-speed Internet anywhere – at home, in the car or at work. The connection is different reliability And quality. WiMAX provides universal wireless access for a wide range of devices.

In theory, everything is just fine, but in practice there are still problems with the implementation of the technology due to a shortage of frequency devices, an insufficient legislative framework and the high cost of setup. However, these flaws can be eliminated, and in the next decade, users will become more familiar with this technology, just as Wi-Fi technology conquered the wireless Internet in its time.

There are a large number of different technologies that allow communication between different entities. Some are more mobile, others are powerful. And there are also average parameters, such as WiMax technology. This is a relatively new development and rather poorly known. What is she like? Where is it used? What characteristics does it have? What principles does it work on? What are its prospects for use?

general information

First let's get to know the full name - Worldwide Interoperability For Microwave Access. This is exactly what WiMax stands for. This is a fairly young technology, the first standard of which was released in 2004. It has only now begun to penetrate into the everyday world. You should know that WiMax technology was initially positioned as a representative of the fourth generation due to its novelty and transmission speed. But in 2008, it was finally decided to classify it as 3G. Which, however, does not prevent various characters from positioning it as wireless

What is she like? WiMax technology is described in the 802.16d specification, which appeared in 2004, which provided that subscriber devices do not move over significant distances, but at the same time ensure operability fifty kilometers from the base station. In 2005, the 802.16e specification, better known as Mobile WiMax, was released. This technology can operate in the frequency range 2-6 GHz. It is most convenient to use 2.3-2.7. But it is difficult to obtain permission for them. Therefore, equipment often uses 3.4-3.6 GHz, which is rightfully considered the golden mean. After all, if you get too close to 6 GHz, then a number of problems arise related to the penetration of waves and bypassing existing obstacles. In such cases, it is necessary to ensure that subscriber devices are located in the line of sight of the working base station.

This technology is used to solve a problem known as the last mile. It is also used to provide Internet to office and district networks. By the way, it solves the last mile very effectively. But first things first.

How is it structured?

So we have figured out what WiMax technology is in general terms. Its operating principle is as follows: there is a subscriber device configured for the operator’s network, which has a base station within its reach. It sends a request to allocate radio resources. If the response is successful, authentication occurs. The request is forwarded to the AAA server, which decides whether to allow or reject it. If authentication was successful, the modem is assigned an address, operating mode and other parameters. That, in general, is all - the device is ready to perform manipulations on the part of the user. This is what the simplest diagram looks like.

Additionally, you can also include WiMax equipment, the task of which is to establish connections between base stations, service providers and the Internet. By the way, a wide range from 1.5 to 11 GHz can be used to establish a connection. Under ideal conditions, a data transfer rate of 70 Mbps can be achieved. Although if we talk about base stations, the situation here is a little different. Thus, frequencies in the range of 10-66 GHz are used to connect and exchange data. And the data exchange speed between them can reach 120 Mbit/s. In this case, it is necessary to ensure that at least one base station is connected to the provider’s network via a classic wired connection. In general, the more there are, the higher the data transfer speed.

The overall reliability of the network is also increasing. In general, the WiMax network is very similar to traditional GSM. Base stations operate over long distances, which can be tens of kilometers. To install them, it is not necessary to build towers; you can get by with installations on the roofs of houses. But at the same time it is necessary to observe the conditions of direct visibility. Otherwise, WiMax equipment will not work with the required efficiency (if it functions at all).

Technical points

How is operational reliability ensured? For this we use:

TDD. This component of the technology allows you to use the same band for transmitting and receiving data, which allows you to optimize the operation of the network.
CP. Allows you to prevent interference between reflected and direct signals.
CC&CTC. Used for character encoding.
AMC. Converts digital signals to analog. The specifics of operation depend on the noise level and data transmission strength. The better quality signals are received, the higher the modulation is selected, and we get the highest data transfer rate.
HARQ. This mechanism is used to track errors and, in case of problems, sends a request to retransmit.
MIMO. Allows you to exchange data with several antennas during reception/transmission.
A.A.S. This is an antenna system that changes depending on the movements of subscriber devices.

Of course, these are not all the technical aspects that wireless Internet based on this technology has. But all of the above is more than enough for familiarization.

Feasibility of use

WiMax is especially relevant in the case of solving the last mile problem. Recently, quite a lot of technologies have emerged that offer their answers to this challenge. And the operator is faced with the task of choosing such a configuration that will allow him to optimally solve the problem of delivering data to subscribers. A universal solution has not yet been invented here. Therefore, each technology has its own area of application, disadvantages and advantages. The final choice is influenced by many factors, including:

The size of the required investment and its payback period.
The time required to launch the network and subsequently begin providing services.
Already existing and also the resources that are needed to support it in working order.
The operator’s chosen strategy, its target audience, services offered and planned in the near future.
Other factors.

In what cases is WiMax technology used? The description of the answer to this question is as follows:

When you need to provide wireless broadband access as an alternative to DSL and leased lines.
Create access points that are not tied to geographic location.
It is necessary to provide high-speed telecommunications and data services.
Connect Wi-Fi access points with each other and other segments of the global network.

So, WiMax are used as backbone channels. Thanks to it, it is possible to create high-speed networks across an entire city.

Why is the technology attractive to telecommunications companies?

There are several reasons for this:

WiMax is more cost-effective in providing services and network access to customers (compared to wired technologies). It allows clients to work even from hard-to-reach areas. And this has a positive effect on the number of subscriber bases and the range of services provided.
It is also necessary to note greater ease of use (than working with traditional wired channels). WiMax can be easily deployed and can be easily scaled if necessary. This property is extremely useful when you need to ensure the operation of a large network in a short period of time. To better understand this property, let's give a small example. In December 2004, a strong tsunami hit Indonesia. And to help the survivors, WiMax was deployed. After all, at that time the communication infrastructure of the entire region was out of order. And it was necessary to quickly restore communication.

All this allows us to reduce the price of quality services both for businesses and for individual citizens. Separately, it is worth mentioning about user equipment. If it is used indoors, a device is installed that is the same size as a regular DSL modem. It can also be used outside the building, in which case it grows slightly in size and already resembles a laptop. Indoor placement is a more profitable option, which does not require professional skills. But, alas, it has more significant requirements for the maximum distance at which the base and subscriber stations can be located.

Architectural features

In WiMax, many different aspects are defined at this level, such as authentication, distribution of network addresses, interaction with other networks and many other points. It should be noted that in this case the architecture is not tied to a specific configuration, due to which it has a high level of flexibility and scale. When working in this case, a planning algorithm is used.

What does this look like in practice? Let's say that we have a large number of user stations that want to transmit data through an access point in real time. In this case, the device just needs to connect to it, and a specific slot will already be created for it, which other subscribers will not be able to influence. Thanks to this, stability of data transmission is achieved, which has a positive effect on the overall functioning of the network and its reliability.

Comparison of WiMax and Wi-Fi

No matter how strange it may sound, for many citizens these technologies are no different. Which, of course, is completely wrong. Perhaps they are often compared because of the similarity of the name. Perhaps because both the WiMax and Wi-Fi technology standards begin with “802.” The use of a wireless connection to connect to a data exchange channel also contributes to this misconception. But, despite such superficial similarity, they are still different.

Thus, WiMax is a long-range system that is used to provide communications over kilometers of space. In this case, both mobile and fixed approaches can be used. What's the difference? When using a mobile approach, data transfer is not tied to a specific location of the subscriber. Fixation provides for a situation where, although a wireless network is being used, the user must be located at a specific point.

Wi-Fi is a shorter-acting system. It typically covers hundreds or tens of meters, using unlicensed frequency bands to provide access. This technology is used, as a rule, to create a local network, which does not necessarily need to be connected to the Internet.

Actually, WiMax can be compared to mobile communications, while Wi-Fi is like a landline wireless phone. There is also a certain difference in the cost of use. The same Wi-Fi is cheaper, which allows it to be used within (relatively) small organizations such as hotels, cafes, train stations and airports. Even if to cover more or less significant territories, it is necessary to ensure the operation of several points.

Comparison of WiMax and terrestrial Internet

For a country with a large territory, it is important to provide communications from anywhere. WiMax is certainly good for this purpose, if we are talking about, for example, ten kilometers. What if the subscriber is located at a distance of 50 or even 80 km? Well, WiMax cannot provide such a range without violating the sanitary rules of the network (remember that its range depends on the power, which, if it goes beyond a certain limit, negatively affects people).

In such cases, the ethereal Internet comes to the rescue. This is a technology that uses the same frequencies as television channels to transmit data. Thanks to this, you can use fairly good (up to 3 Mbit/s) Internet at a considerable distance without significant expenses. Thus, communication can be established even in cases where the ethereal tower is located at a distance of 80 kilometers. Such a range is possible solely due to the relatively low speed, which is still sufficient to interact with the world. This radio communication technology will allow you to use the Internet wherever you can receive radio waves: a cottage, a car, a country picnic, and even an open field. To connect, it is enough to have a standard decimeter television antenna and the appropriate computer settings.

True, there is a certain drawback here. Thus, two different channels are used to transmit and receive data, which affects productivity. But, on the other hand, this technology is quite cheap. Together with a significant range, this allows us to consider it as a fairly convenient and unpretentious way to exchange data. But, alas, you have to pay for it. Compared to the same WiMax, the transmission speed is tens of times lower. Although the benefit is when simply visiting the Internet (and not downloading huge games or long movies), the difference is not very noticeable.

Comparison of WiMax and LTE

But this is the most interesting. If only because these technologies are seen as direct competitors. Therefore, a comparative analysis of the LTE and WiMax networks will better reveal the properties of the latter. LTE was first mentioned in the Rel-8 standard. At the time of its appearance, it used almost the same things as WiMax. And if you compare them from the technical side, you can see that the differences are minimal.

Thus, they both use the IP protocol, which allows minimizing capital costs and ensuring flexible provision of services. It also facilitates easy integration of various objects and simplifies network management. They also have a similar network structure, where basic elements that are similar in functionality are used, such as a client device, a base station, gateways, a central node, a transport network (IP/MPLS protocol), and a control system.

Also, these technologies do not have fundamental differences in their main characteristics. In laboratory conditions, almost identical results were achieved. But the real situation is little different. As a rule, lower operating speed. Although LTE has certain problems with free frequencies. In the case of WiMax, the situation is little better. But the final choice is made by the provider, while for users the difference between WiMax and LTE in the quality of their work is invisible.

Usage

As you can see, WiMax is a very progressive technology, which allows it to be used successfully. It is likely that over time it will be used to provide wireless communications in small cities or for agglomerations of large settlements, such as Moscow or St. Petersburg. The low cost of this technology and at the same time its high efficiency will allow people to have access to high-quality communication services and keep up with the process of urbanization. It is quite enough to work with ordinary data that we send: photos, videos, texts. The operating speed is quite sufficient.

Perhaps in the future WiMax technology will give way to something else. For example, representatives of 5G. But not a fact and not everywhere. It makes sense to use 5G only if the number of subscribers within a radius of one kilometer approaches one million active devices. And for rural areas and small towns, it is likely that there will be nothing better than WiMax for decades to come. Although it must be admitted that it is very difficult to predict the future, and it is likely that these words will lose their relevance in a few years.

Conclusion

So the WiMax technology, its operating principle, construction scheme, and even the most often mentioned related developments were examined. Perhaps in the future it will be improved, and its characteristics will improve significantly, which will give it new chances to win over the audience. Until then, it can be considered the optimal solution, the prospects of which are concentrated in small cities and agglomerations that are growing around our giants. It is also possible that it will serve as the basis for something more progressive, just as early-generation technologies are used to create ever better methods of data transmission. But as long as it satisfies our needs, let's use what we already have and work on something better at the same time.

WiMAX(English Worldwide Interoperability for Microwave Access) is a telecommunications technology developed to provide universal wireless communications over long distances for a wide range of devices (from workstations and laptop computers to mobile phones). Based on the IEEE 802.16 standard, also called Wireless MAN. The name "WiMAX" was created by the WiMAX Forum, an organization that was founded in June 2001 with the goal of promoting and developing WiMAX technology. The forum describes WiMAX as "a standard-based technology that provides high-speed wireless network access as an alternative to leased lines and DSL."

Area of use
WiMAX is suitable for solving the following problems:

* Connect Wi-Fi access points to each other and to other segments of the Internet.
* Providing wireless broadband access as an alternative to leased lines and DSL.
* Providing high-speed data transmission and telecommunications services.
* Creation of access points that are not tied to geographic location.

WiMAX allows you to access the Internet at high speeds, with much greater coverage than Wi-Fi networks. This allows the technology to be used as “trunk channels”, a continuation of which are traditional DSL and leased lines, as well as local networks. As a result, this approach makes it possible to create scalable high-speed networks across entire cities.

Feasibility of using WiMAX as an access technology
The last mile problem has always been a pressing issue for telecom operators. By now, many last-mile technologies have appeared, and any telecom operator is faced with the task of choosing a technology that optimally solves the problem of delivering any type of traffic to its subscribers. There is no universal solution to this problem; each technology has its own area of application, its own advantages and disadvantages. The choice of a particular technological solution is influenced by a number of factors, including:

* operator strategy, target audience, currently offered and planned services,
* the amount of investment in network development and their payback period,
* existing network infrastructure, resources to maintain it in working order,
* time required to launch the network and begin providing services,
* other factors.

Each of these factors has its own weight, and the choice of a particular technology is made taking into account their entirety. A simple and effective model that allows you to quickly assess the economic parameters of using WiMAX technology.

Fixed and mobile WiMAX option
The set of advantages is inherent to the entire WiMAX family, but its versions differ significantly from each other. The developers of the standard were looking for optimal solutions for both fixed and mobile applications, but it was not possible to combine all the requirements within one standard. Although a number of basic requirements are the same, the technology's focus on different market niches has led to the creation of two separate versions of the standard (or rather, they can be considered two different standards). Each of the WiMAX specifications defines its operating frequency ranges, bandwidth, radiation power, transmission and access methods, signal coding and modulation methods, principles of radio frequency reuse and other indicators. Therefore, WiMAX systems based on versions of the IEEE 802.16 e and d standard are practically incompatible. Brief characteristics of each version are given below.
802.16-2004 (also known as 802.16d and fixed WiMAX). The specification was approved in 2004. Orthogonal frequency division multiplexing (OFDM) is used and fixed access is supported in areas with or without line of sight. User devices are stationary modems for installation outdoors and indoors, as well as PCMCIA cards for laptops. In most countries, the 3.5 and 5 GHz bands are allocated for this technology. According to the WiMAX Forum, there are already about 175 implementations of the fixed version. Many analysts see it as a competing or complementary technology to wired DSL broadband.
802.16-2005 (also known as 802.16e and mobile WiMAX). The specification was approved in 2005. This is a new stage in the development of fixed access technology (802.16d). Optimized to support mobile users, the version supports a number of specific functions, such as handover, idle mode and roaming. Scalable OFDM access (SOFDMA) is used; operation is possible with or without line of sight. The planned frequency ranges for Mobile WiMAX networks are: 2.3; 2.5; 3.4–3.8 GHz. Several pilot projects have been implemented around the world, and recently the operator Sprint announced the start of a national-scale project. 802.16e's competitors are all third generation mobile technologies (eg EV-DO, HSXPA).
The main difference between the two technologies is that fixed WiMAX allows servicing only “static” subscribers, while mobile is focused on working with users moving at speeds of up to 120 km/h. Mobility means the presence of roaming functions and “seamless” switching between base stations when the subscriber moves (as happens in cellular networks). In a particular case, mobile WiMAX can also be used to serve fixed-line users.

Broadband
Many telecommunications companies are betting big on using WiMAX to provide high-speed communications services. And there are several reasons for this.
Firstly, the 802.16 family of technologies will make it possible to cost-effectively (compared to wired technologies) not only to provide network access to new clients, but also to expand the range of services and cover new hard-to-reach territories.
Secondly, wireless technologies are much easier to use than traditional wired channels. WiMAX and Wi-Fi networks are easy to deploy and easily scalable as needed. This factor turns out to be very useful when it is necessary to deploy a large network in the shortest possible time. For example, WiMAX was used to provide Internet access to survivors of the December 2004 tsunami in Indonesia (Aceh). The entire communication infrastructure of the region was disabled and prompt restoration of communication services for the entire region was required.
In total, all these advantages will reduce prices for the provision of high-speed Internet access services for both business structures and individuals.

User equipment
Equipment for using WiMAX networks is supplied by several manufacturers and can be installed both indoors (devices the size of a regular DSL modem) and outdoors (devices the size of a laptop). It should be noted that equipment designed for indoor placement and not requiring professional installation skills is, of course, more convenient, but can operate at significantly shorter distances from the base station than professionally installed external devices. Therefore, equipment installed indoors requires much greater investment in the development of network infrastructure, since it implies the use of a much larger number of access points.
With the invention of mobile WiMAX, increasing emphasis is placed on the development of mobile devices. Including special handsets (similar to a regular mobile smartphone), and computer peripherals (USB radio modules and PC cards).

Principle of operation

Basic Concepts
In general, WiMAX networks consist of the following main parts: base and subscriber stations, as well as equipment connecting the base stations with each other, with the service provider and with the Internet.
To connect the base station to the subscriber station, a high-frequency radio wave range from 1.5 to 11 GHz is used. Under ideal conditions, data exchange rates can reach 70 Mbit/s without requiring line-of-sight between the base station and the receiver.
As mentioned above, WiMAX is used both to solve the “last mile” problem and to provide network access to office and district networks.
Line-of-sight connections are established between base stations using the frequency range from 10 to 66 GHz, data exchange speeds can reach 120 Mbit/s. In this case, at least one base station is connected to the provider's network using classic wired connections. However, the greater the number of BSs connected to the provider’s networks, the higher the data transfer speed and reliability of the network as a whole.
The structure of networks of the IEEE 802.16 family of standards is similar to traditional GSM networks (base stations operate at distances of up to tens of kilometers; it is not necessary to build towers for their installation - installation on the roofs of houses is allowed, subject to the conditions of direct visibility between the stations).

Operating modes

MAC/link layer
In Wi-Fi networks, all user stations that want to transmit information through an access point (AP) compete for the latter’s “attention”. This approach can cause a situation in which communications for more distant stations are constantly interrupted in favor of closer stations. This state of affairs makes it difficult to use services such as Voice over IP (VoIP), which rely heavily on an uninterrupted connection.
As for 802.16 networks, the MAC uses a scheduling algorithm. Any user station just needs to connect to the access point, a dedicated slot will be created for it on the access point, and other users will no longer be able to influence this

Architecture
The WiMAX Forum has developed an architecture that defines many aspects of the operation of WiMAX networks: interactions with other networks, distribution of network addresses, authentication and much more. The above illustration gives us some idea of the architecture of WiMAX networks.

WiMAX Forum WiMAX Architecture

*SS/MS: (the Subscriber Station/Mobile Station)
* ASN: (the Access Service Network)
* BS: (Base station), base station, part of ASN
* ASN-GW: (the ASN Gateway), gateway, part of the ASN
* CSN: (the Connectivity Service Network)
* HA: (Home Agent, part of CSN)
* NAP:(a Network Access Provider)
* NSP: (a Network Service Provider)

It should be noted that the architecture of WiMax networks is not tied to any specific configuration and is highly flexible and scalable.

WiFi
Comparisons between WiMAX and Wi-Fi are not uncommon, perhaps because the terms sound similar, the names of the standards on which these technologies are based are similar (IEEE standards, both begin with “802.”), and both technologies use wireless connections and used to connect to the Internet (data exchange channel). But despite this, these technologies are aimed at solving completely different problems.

Wireless Standards Comparison Chart

Technology	Standard	Usage	Bandwidth	Radius of action	Frequencies
UWB	802.15.3a	WPAN	110–480 Mbit/s	up to 10 meters	7.5 GHz
WiFi	802.11b	WLAN	up to 11 Mbit/s	up to 100 meters	2.4 GHz
WiFi	802.11g	WLAN	up to 54 Mbit/s	up to 100 meters	2.4 GHz
WiFi	802.11n	WLAN	up to 600 Mbit/s	up to 100 meters	2.4 - 2.5 or 5.0 GHz
WiMax	802.16d	WMAN	up to 75 Mbit/s	6–10 km	1.5–11 GHz
WiMax	802.16e	Mobile WMAN	up to 30 Mbit/s	1–5 km	2–6 GHz

* WiMAX is a long-range system, covering miles of space, that typically uses licensed frequency spectrum (although unlicensed frequencies may also be used) to provide a point-to-point Internet connection from a provider to the end user. The different standards in the 802.16 family provide different types of access, from mobile (similar to data transfer from mobile phones) to fixed (an alternative to wired access, in which the user's wireless equipment is tied to location).
* Wi-Fi is a shorter-range system, typically covering hundreds of meters, that uses unlicensed frequency bands to provide network access. Typically, Wi-Fi is used by users to access their own local network, which may not be connected to the Internet. If WiMAX can be compared to mobile communications, then Wi-Fi is more like a landline cordless phone.
* WiMAX and Wi-Fi have completely different Quality of Service (QoS) mechanisms. WiMAX uses a mechanism based on establishing a connection between a base station and a user's device. Each connection is based on a special scheduling algorithm that can guarantee the QoS parameter for each connection. Wi-Fi, in turn, uses a QoS mechanism similar to that used in Ethernet, in which packets are given different priorities. This approach does not guarantee the same QoS for every connection.
Due to its low cost and ease of installation, Wi-Fi is often used to provide customers with fast Internet access by various organizations. For example, in most cafes, hotels, train stations and airports you can find a free Wi-Fi hotspot.