WiMax technology: operating principle, equipment, applications

There are a large number of different technologies that allow communication between different entities. Some are more mobile, others have power. 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 are the principles of work? What are her prospects for use?

wimax technology

general information

Initially, let's get acquainted with the full name - Worldwide Interoperability For Microwave Access. That's exactly what WiMax stands for. This is a fairly young technology, the first standard of which was released in 2004. She began to penetrate into the everyday world only now. You should be aware that initially WiMax was positioned as a representative of the fourth generation due to its novelty and transmission speed. But in 2008, it was residually decided to attribute it to 3G. Which, however, does not prevent various characters from positioning it as 4G wireless Internet.

What is she like? WiMax technology is described in the 802.16d specification, which appeared in 2004, which stipulated that subscriber devices did not travel long distances, but at the same time, up to fifty kilometers from the base station were provided. In 2005, the 802.16e specification, better known as Mobile WiMax, was released. This technology can operate in the frequency range of 2-6 GHz. It is most convenient to use 2.3-2.7. But it’s problematic to get permission. Therefore, 3.4-3.6 GHz is often used in equipment, which is considered to be 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 the subscriber devices are located in the line of sight of the working base station.

This technology is used to solve the problem known as the "last mile". It is also used to provide Internet for office and regional networks. By the way, here the last mile is solved very effectively by it. But first things first.

wimax equipment

How is it arranged?

So we figured out what WiMax technology is in general terms. She has the following working principle: there is a subscriber device configured on the operator’s network, which has a base station in the availability range. She sends a request for allocation of radio resources. In case of a successful response, authentication is in progress. The request is redirected to the AAA server, which decides whether to allow or reject it. If authentication was successful, then the modem is assigned an address, an operating mode, and other parameters. That, in general, is all - the device is ready to perform manipulations by the user. This is the simplest scheme.

In addition, WiMax equipment can also be included here, the task of which is to establish links between base stations, service providers and the Internet. By the way, to establish a connection, a wide range from 1.5 to 11 GHz can be used. Under ideal conditions, a data transfer rate of 70 Mbps can be ensured. Although if we talk about base stations, the situation here is slightly different. So, for connection and data exchange they use frequencies in the range of 10-66 GHz. And the data exchange rate between them can reach 120 Mbps. At the same time, it must be ensured 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 rate.

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

wireless Internet

Technical points

How is reliability guaranteed? To do this, use:

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

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

Expediency of use

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

  1. The size of the required investments and their payback period.
  2. The time required to start the network and then start providing services.
  3. The existing network infrastructure, as well as the resources that are needed to support it in a healthy state.
  4. The chosen strategy of the operator, its target audience, services offered and planned in the near future.
  5. Other factors.

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

  1. When you need to provide wireless broadband as an alternative to DSL and leased lines.
  2. Create access points that are not geo-referenced.
  3. It is necessary to provide high-speed telecommunication and data services.
  4. Connect Wi-Fi access points to each other and other segments of the global network.

So, WiMax are used as trunk channels. Thanks to him, you can create high-speed networks throughout the whole city.

last mile

Why is technology attractive to telecommunications companies?

There are several reasons for this:

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

All this allows you to reduce the price of quality services for both business and individual citizens. We should also say about user equipment. If it is used indoors, a device is installed that is the size of a conventional DSL modem. It can 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 that does not require professional skills. But, alas, he has more significant requirements for the maximum distance at which the base and subscriber stations can be.

Architectural features

WiMax defines many different aspects at this level, such as authentication, network address allocation, interaction with other networks, and many other things. It should be noted that in this case, the architecture is not tied to a specific configuration, so it has a high level of flexibility and scale. When working in this case, the planning algorithm is used.

What does it look like in practice? Suppose that we have a large number of user stations that want to transfer data through an access point in real time. In this case, the device simply needs to connect to it, as a certain slot will already be created for it, which other subscribers will not be able to influence. Due to this, stability of data transmission is achieved, which positively affects the overall functioning of the network and its reliability.

base and subscriber stations

WiMax and Wi-Fi Comparison

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 consonance of the name. Perhaps because both the WiMax technology standard and Wi-Fi start with “802.”. The use of a wireless connection to connect to a data exchange channel also contributes to this error. But, despite such superficial similarity, they are still different.

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

Wi-Fi is a shorter-acting system. Usually it covers hundreds or tens of meters, using unlicensed frequency ranges for itself in order to provide access. This technology is used, as a rule, to create a local network, which does not have to be connected to the Internet.

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

Comparison of WiMax and Internet Broadcast

For a country with a large territory, it is important to ensure communication from anywhere. WiMax for this purpose is certainly good if we are talking, for example, about ten kilometers. And if the subscriber is 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, when going beyond certain limits, negatively affects people).

In such cases, the on-air Internet comes to the rescue. This is a technology that uses the same frequencies for transmitting data as television channels. Thanks to this, you can use quite good (up to 3 Mbit / s) Internet at a considerable distance without significant expenses. So, you can have a connection even in cases when the ether tower is at a distance of 80 kilometers. Such a range is possible solely due to the relatively low speed, which is still enough to interact with the world. This radio technology will allow you to use the Internet wherever you can receive radio waves: cottage, car, out-of-town picnic and even a clean field. To connect, it is enough to have a standard decimeter television antenna and the corresponding computer settings.

True, there is a certain drawback. So, 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 rather convenient and unpretentious way of exchanging data. But, alas, you have to pay for it. Compared with the same WiMax, the transmission speed is ten times lower. Although the benefit with a simple visit to the Internet (rather than downloading huge games or lengthy films) the difference is not very noticeable.

broadcast internet

Comparison of WiMax and LTE

But this is the most interesting. If only because these technologies are regarded as direct competitors. Therefore, a comparative analysis of the LTE network and WiMax 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 thing as WiMax. And if you compare them from the technical side, you can see that the differences are minimal.

So, they both use the IP protocol, which allows to minimize capital costs and provide flexible provision of services. It also contributes to the easy integration of various objects and simplifies network management. They also have a similar network structure, where basic elements 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 basic characteristics. In laboratory conditions, almost the same indicators were achieved. But the real situation is not much different. As a rule, the lowest speed. Although LTE has certain problems with free frequencies. In the case of WiMax, the situation is slightly better. But the final choice is made by the provider, while for users the difference between WiMax and LTE in their quality of work is invisible.


As you can see, WiMax is a very advanced technology, which allows it to be successfully used. 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 get access to high-quality communication services and keep up with the process of urbanization. It is enough to work with the usual data that we send: photos, videos, texts. The speed of work is quite enough.

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 the same 5G only if the number of subscribers within a radius of one kilometer approaches the number of one million active devices. And for the countryside and small towns, it’s likely for decades to do nothing better than WiMax. Although it should be recognized, it is very difficult to predict the future, and it is likely that these words will lose their relevance in a few years.

radio technology


So WiMax technology was examined, its principle of operation, construction scheme, and even the most frequently mentioned related developments. Perhaps in the future it will be finalized, and its characteristics will improve significantly, which will give her new chances to win an audience. Until then, it can be considered the optimal solution, the prospects of which are concentrated in small cities and agglomerations that grow around our giants. It is also possible that it will serve as the basis for something more progressive, as the technologies of early generations are used to create ever better methods of data transfer. But while it satisfies our needs, let's use what is already there and at the same time work on something more perfect.

Source: https://habr.com/ru/post/A13459/

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