Description of WIMAX technology
Today wireless technology «WiMAX» is the most advanced of all. Having appeared in the distant 2003, it was aimed to satisfy market broadcast devices.
Worldwide a large number of operators have started to create a wireless communication network. Such networks exist in the United States, Japan, Korea, Russia and many others. If you take into consideration the words of the leading analysts in the field of communications, «WiMAX» soon the total number of Internet users will be more than 100 million people.
Today we can safely say that «WiMAX» there is no alternative technology that makes it the best product. In this article we consider the features of this technology, its advantages and disadvantages.
What is it?
«WiMAX» («International cooperation for microwave access») technology developed in 2003, which is aimed at providing wireless communication for workstations, desktop computers, portable computers and mobile devices. Based on the communication standard «IEEE 802.16».
What tasks does «WiMAX»:
- the provision of broadband, instead of dedicated lines and «DSL/ADSL»;
- providing remote monitoring systems;
- creating points remote access that are not tied to any geographical location;
- providing access points «Wi-Fi» and connect them with each other, as well as other areas of the Internet.
I would also like to briefly tell about the main stages of development of the technology:
- 2001 – the primary event in this time period was the approval of the communication standard 802.16-2001. Also this year, was founded by the «WiMAX Forum». But the main events of 2001 is not the end, another major highlight is the development of the communication standard 802.16 a;
- the following year, which became the basis for «WiMAX» – 2003. In 2003 was approved by the communication standard 802.16 a, which was developed in 2001;
- in 2004 a major event was the adoption of a new format of communication — 802.16-2004;
- in 2005 followed the chain of events in the development of «WiMAX»: the adoption of a new format of communication «802.16/HiperMAN». Later in the same year there was opened laboratory of WiMAX in Spain;
- In 2006 was born the first product based on fixed WiMAX technology.
The scope and feasibility of
Today, developers around the world acute problem of «last mile» (the channel that connects end-user equipment with the access point provider). Fortunately, now there are many varieties of technology «last mile», which each provider can solve the problem of the choice of this technology.
Today, the last mile problem has no clear and universal solutions. Absolutely every existing technology has its own application area, advantages and disadvantages.
The choice of a particular technology and can influence a large number of factors and the main of them are:
- a way of achieving goals, efficient use of resources, target audience,
- the allocation of investment, which subsequently will go to the development of the network;
- the availability and serviceability of the existing network infrastructure, as well as some resources that will be used to support the technical operation of the network.
Each of these factors plays a special role in the choice of technological solutions.
I would also like to note, comparing Wi-Fi and WiMAX is that the latter allows users to have access to the Internet at a fairly high speed. The area coverage of WiMAX is much larger than Wi-Fi.
video: WiMax technology
The technology options
The family of WiMAX technology has a wide range of advantages, which have certain differences from each other. The developers of WiMAX technology tried to find the most appropriate variant, designed for mobile and fixed use.
However, it is worth noting the fact that the combination of requirements in one standard still not solved the problem. Standard requirements have complete similarity between themselves, but each technology has a specific focus on different areas of the market. Therefore, it was the impetus to create two separate versions of the standard.
Each specification WiMAX has its technical characteristics: the radiation power, frequency, access and transfer, reuse of radio frequencies. And it is because of these features of the system is WiMAX, which is based on the standard IEEE 802.16 e, and d practically do not have compatibility.
- 802.16-2004 was approved in 2004. It uses frequency division multiplexing. Everything else has support for so-called fixed access in areas where it is not present direct visibility. In most cases, using a frequency of 3.5 and 5 GHz.
- 802.16-2005 was approved in 2005. The new version is a big step in the evolution of fixed access. The new version received the support of mobile Amonatov, and its distinguishing feature is the support of a number of special features such as «Idle mode», the «Handover».
The distinctive features between the two specifications is that due to the fixed WiMAX (802.16-2004) work exclusively static subscribers, and in the 802.16-2005 (mobile WiMAX) are subscribers who move at speeds of up to 110 kilometers per hour.
I would also like to note that due to mobility all functions of the roaming and so-called «seamless connection» between the major work stations at a time when the subscriber is in motion. There are also exceptional cases where 802.16-2005 may well be used during the maintenance of static subscribers.
I would also like to note that the majority of companies give their preference to WiMAX, providing services to high-speed communication.
And it has its own reasons:
- first 802.16 efficient from an economic point of view when providing its customers with access to the network and expanding services and covering new territories;
- secondly, it is easy to use in contrast to wired channels. WiMAX and Wi-Fi is quite simple to use, deploy and, of course, zoom. Quite a convenient way when you create a large enough network in the shortest time.
WiMAX subscriber equipment
Currently, equipment for the use of WiMAX can be installed in the premises (such devices typically do not exceed its size traditional DSL modems), or on the streets (the device the size of a laptop).
Device for indoor use more convenient to use, but can only work at small distances from the base station.
Because of this equipment, which is installed inside the premises, require the larger investment, so as to ensure the quality of work will require a large number of access points.
The principle of operation and concepts
WiMAX consists of the following elements: stations (base and client), equipment that is installed between the stations and the network. For connecting the base station and the client uses frequencies from 2 to 11 GHz.
Between base stations, as a rule, there is a direct visibility, and it uses a working frequency band from 10 to 66 GHz. Line of sight between work stations and the frequency range can achieve speeds up to 120 Mbps. But you need one of the workstations connected to the network provider using the standard method wired connection.
The IEEE 802.16 has the structure of a GSM network. The range of base stations to a few kilometers and the construction of any additional towers to improve signal, it is not required.
In the standard wimax 802.16 e-2005 includes all versions that came out earlier:
- Fixed WiMAX. Used as an alternative to broadband access. The frequency range is 10-66 GHz. Between the signal receiver and the transmitter you must have line of sight.
- Nomadic WiMAX. Nomadic in English the word «nomadic», and it is from this word comes this version of the technology. They have the ability to freely move the client between sessions.
- Portable WiMAX. This mode includes the ability to automatically connect the client from one workstation to another, excluding the disconnection. Mode has limitations — the movement speed of the client equipment shall be 40 kilometers per hour and not more.
- Mobile WiMAX developed in the standard 802.16 e-2005, allows for greater speed of movement of client equipment to 120 km/h.
MAC / link layer
Networks 802.16 MAC will use the so-called scheduling algorithm. The principle of this algorithm is based on the following: the absolute, any client station can connect to the hotspot and after connecting to it will automatically create a separate slot directly on the access point. Everything else the other users can’t influence this and therefore it eliminates the connection problem.
At the WiMAX Forum was created, the specification of the architecture through which it is possible to determine a lot of the nuances of the work. This includes the distribution of network addresses, the interaction with other networks, authentication.
It should be noted that the network architecture is not strictly bound to any single configuration, thus provides relatively high flexibility and scalability.
Advantages and disadvantages
- long range pokrytii high speed;
- standardization of WiMAX technology, which allows users to purchase joint equipment from different suppliers;
- operation in the absence of prima of sight between the equipment core networks and subscriber equipment;
- high quality transmission of images and voices.
The disadvantages besideme:
- a deficiency of devices of frequencies;
- the unpreparedness of the legislative framework;
- difficulties in the introduction of new technology, which at the moment there is no possibility to ensure a quality connection at low cost.
In this article, we examined WiMAX. It’s safe to say that at the moment, WiMAX is an advanced wireless technology. To date, she has gained quite a wide popularity in the modern world.