What is WiFi? Wi-Fi: what does this concept mean and why do you need a wi-fi network?

At the beginning of the development of the Internet, the network connection was carried out using a network cable, which had to be installed indoors in such a way that it would not interfere. They secured it and hid it as best they could. IN old furniture There are still holes for cables for computers.

When wireless technologies and Wi-Fi networks became popular, the need to run network cables and hide them disappeared. Wireless technology allows you to receive the Internet “over the air” if you have a router (access point). The Internet began to develop in 1991, and closer to 2010 it had already become especially popular.

What is Wi-Fi

This is a modern standard for receiving and transmitting data from one device to another. In this case, the devices must be equipped with radio modules. Such Wi-Fi modules are included in many electronic devices and technology. At first they were included only in a set of tablets, laptops, and smartphones. But now they can be found in cameras, printers, washing machines, and even multicookers.

Operating principle

To access Wi-Fi, you must have an access point. Today, such a point is mainly a router. This is a small plastic box, on the body of which there are several sockets for connecting the Internet via wire. The router itself is connected to the Internet via a network wire called twisted pair. Through the antenna, the access point distributes information from the Internet to the Wi-Fi network, through which various devices with a Wi-Fi receiver receive this data.

A laptop, tablet or smartphone can work instead of a router. They must also have an Internet connection via mobile communications via SIM card. These devices have the same data exchange principle as a router.

The method of connecting the Internet to the access point does not matter. Access points are divided into private and public. The former are used only for use by the owners themselves. The latter provide Internet access for money or free of charge to a large number of users.

Public hot spots are most often found in public places. It is easy to connect to such networks while being on the territory of this point or near it. In some places it requires you to log in, but you are offered a password and login if you use paid services of this establishment.

In many cities, their entire territory is completely covered by a Wi-Fi network. To connect to it, you need to pay for a subscription, which is not expensive. Consumers are provided with both commercial networks and free access. Such networks are built by municipalities and private individuals. Small networks for residential buildings, public institutions become larger over time, use peering agreements to interact freely with each other, work on voluntary assistance and donations from other organizations.

City authorities often sponsor similar projects. For example, in France, some cities provide unlimited Internet access to those who give permission to use the roof of the house to install a Wi-Fi antenna. Many universities in the west allow online access to students and visitors. The number of hotspots (public points) is growing steadily.

Wi-Fi standards

IEEE 802.11– protocols for low data rates, the main standard.

IEEE 802.11a– is incompatible with 802.11b, for high speeds, uses 5 GHz channels. Capable of transmitting data up to 54 Mbit/s.

IEEE 802.11b– standard for fast speeds, channel frequency 2.4 GHz, throughput up to 11 Mbit/s.

IEEE 802.11g– speed equivalent to standard 11a, channel frequency 2.4 GHz, compatible with 11b, bandwidth up to 54 Mbit/s.

IEEE 802.11n– the most advanced commercial standard, channel frequencies 2.4 and 5 GHz, can work in conjunction with 11b, 11g, 11a. The highest operating speed is 300 Mbit/s.

To provide a more detailed understanding of how different standards work wireless communication, consider the information in the table.

Using a Wi-Fi network

The main purpose of wireless communications in everyday life is to access the Internet to visit websites, communicate online, and download files. There is no need for wires. Over time, the spread of access points throughout cities is progressing. In the future, it will be possible to use the Internet using a Wi-Fi network in any city without restrictions.

Such modules are used to create a network within a limited area between several devices. Many companies have already developed mobile applications for mobile gadgets that make it possible to exchange information via Wi-Fi networks, but without connecting to the Internet. This application organizes a data encryption tunnel through which information will be transmitted to the other party.

Information exchange is carried out much faster (several tens of times) than via Bluetooth as we know it. The smartphone can also act as a game joystick in connection with a game console or computer, or perform the functions of a TV remote control operating via Wi-Fi.

How to use a Wi-Fi network

First you need to buy a router. You must insert the power cord into the yellow or white socket and configure it according to the included instructions.

On receiving devices with a Wi-Fi module, turn it on, search for the required network and connect. The more devices connected to one router, the lower the data transfer speed will be, since the speed is equally divided among all devices.

The Wi-Fi module looks like a regular flash drive; the connection is made via a USB interface. It has a low cost. On your mobile device, you can enable an access point that will act as a router. When a smartphone distributes the Internet via an access point, it is not recommended to overload the processor on it, that is, it is not advisable to watch videos or download files, since the speed is divided between the connected and the distribution device on a residual basis.

Wi-Fi technology makes it possible to access the Internet without a cable. The source of such wireless network can be any device that has a Wi-Fi radio module. The propagation radius depends on the antenna. WITH using Wi-Fi create groups of devices, and you can also simply transfer files.

AdvantagesWi— Fi

• No wiring required. Due to this, savings are achieved on cable laying, wiring, and time is also saved.
• Unlimited expansion of the network, with an increase in the number of consumers and network points.
• There is no need to damage the surfaces of walls and ceilings for laying cables.
• Globally compatible. This is a group of standards that works on devices manufactured in different countries.

FlawsWi— Fi

• In neighboring countries, the use of a Wi-Fi network without permission is allowed to create a network in premises, warehouses, and production. To connect two neighboring houses with a common radio channel, an application to the supervisory authority is required.
• Legal aspect. Different countries have different attitudes towards the use of Wi-Fi range transmitters. Some states require all networks to be registered if they operate on premises. Others limit transmitter power and certain frequencies.
• Communication stability. Routers installed at home, of common standards, distribute a signal over a distance of 50 meters inside buildings, and 90 meters outside the room. Many electronic devices, weather factors reduce the signal level. The distance depends on the frequency of operation and other parameters.
• Interference. In cities, there is a significant density of router installation points, so problems often arise connecting to a point if there is another point nearby that operates at the same frequency with encryption.
• Manufacturing parameters. It often happens that manufacturers do not adhere to certain device manufacturing standards, so access points may have unstable operation, and the speed differs from the declared one.
• Electricity consumption. A sufficiently large energy consumption, which reduces the charge of batteries and accumulators, increases the heating of the equipment.
• Safety. Data encryption using the WEP standard is unreliable and easy to crack. The WPA protocol, which is more reliable, is not supported by access points on older equipment. The WPA2 protocol is considered the most reliable today.
• Limitation of functions. During the transmission of small packets of information, a lot of official information is attached to them. This makes the connection quality worse. Therefore, it is not recommended to use Wi-Fi networks to organize IP telephony using the RTP protocol, since there is no guarantee of communication quality.

Features of Wi-Fi and Wi MAX

Wi-Fi network technology was primarily created for organizations to move away from wired communications. However, this wireless technology is now gaining popularity in the private sector. The types of wireless connections Wi-Fi and Wi MAX are related in the tasks they perform, but they solve different problems.

Wi MAX devices have special digital communication certificates. Complete protection of data streams is achieved. Based on Wi MAX, private confidential networks are formed, which make it possible to create secure corridors. Wi MAX transmits the necessary information, despite the weather, buildings and other obstacles.

This type of communication is also used for high quality video communication. We can highlight its main advantages, consisting of reliability, mobility, and high speed.

Wi-Fi is modern technology wireless connection of computers, laptops and smartphones into one network and connecting them to the Internet. You can read more about Wi-Fi and how to set it up on your computer in the article.

How Wi-Fi works

Wireless connection of computers to the Internet occurs through the use of radio waves and, according to the principle of operation, does not differ from the operation of radio stations, cell phones and television receivers. The only significant difference with Wi-Fi is the use of higher frequencies than in radio communications and television broadcasts (2.4 GHz or 5 GHz). Operating at such frequencies makes it possible to transmit large amounts of information.

To implement wireless access To connect to the Internet, you need a router (router) with a built-in module for receiving and transmitting radio signals and a similar module built into a computer or laptop. The router connects to the Internet via network cable through any provider. The cable carries the digital signal from the Internet to the router, where it is converted into radio waves. The router sends a radio signal to the computer's receiving module, which again converts it to digital. Similarly, a digital signal from a laptop is encoded by a transmission module into a radio signal, transmitted “over the air” to the router, converted there into digital and sent to the worldwide network.

How does a Wi-Fi router work?

Routers are capable of transmitting a signal from the Internet to more than one device. This allows one network cable to access the Internet immediately from a desktop computer, laptop, tablet, etc. The coverage area of ​​modern routers is 50-100 meters (if there are no obstacles). This allows a person to move freely around the apartment with mobile device without losing connection with the World Wide Web.

The router's memory contains a routing table that stores paths to all connected devices. The Internet access channel width provided by the provider is also distributed among all mobile and stationary devices. It should be noted that a Wi-Fi connection through a router is convenient for communicating on social networks or via Skype, viewing email, internet surfing. For online viewing of large videos or downloading files, a network connection is more suitable.

How Wi-Fi works on a laptop

Most modern laptops are equipped with a built-in module for receiving and transmitting radio signals that supports a Wi-Fi connection to the Internet. Such devices usually have a sticker with the Wi-Fi logo. Network equipment for wireless connections is produced by many companies, using different technical solutions. However, the presence of the Wi-Fi logo tells consumers that manufacturers use a single communication standard, and devices from different companies will be mutually compatible, that is, they will be able to work with each other on the same network.

Most of the urban population uses Internet access and many say we have Wi-Fi at home, we access websites through it and we don’t need an Internet connection. From this we can conclude that such people, unfortunately, do not understand what they are talking about.

In this article I will talk in detail about what wi-fi is and eliminate the “gap” in the knowledge of such people.

What is Wi-Fi?

I am glad to welcome you, dear reader, in this article we will deal with the modern concept of “Internet connection via wi-fi”. A huge number of users use such a connection, but they do not always understand what it is, much less how Wi-Fi works.

Wi-fi is the ability to transmit data wirelessly and that’s all... Never confuse the Internet and Wi-Fi - these are completely different processes and different equipment. You can easily distinguish them if you carefully read the article to the end.

The concept of the Internet can represent a connection, the ability to exit, access to any sites. And if you pass this Internet connection through special equipment, you can get a so-called wi-fi network that will transmit the same Internet, but without wires and with the ability to connect several devices to it at once, for example, it will simultaneously “deliver” your Internet access to mobile and laptop.

That is, Wi-Fi is a network that distributes Internet access wirelessly, via radio channels. For those interested, it works based on IEEE 802.11 standards, but the network itself does not provide Internet access. Let's figure out how to make it work?

Let's move on to something interesting and very important: by understanding how Wi-Fi networks work, you will be able to correctly formulate your thoughts about Internet connections. So, in order for you to have a Wi-Fi network at home, you must first connect the Internet to your home.

Afterwards, the Internet cable must be connected to special equipment - a router.

A router is a device that receives signals from the Internet and converts them into the so-called wi-fi network and transmits them to specific devices(phone, computer, TV).

How to connect Wi-fi at home?

As I said earlier, the first thing you need to do is install the Internet in your house, apartment, office, the process is not complicated, you need to find out which providers work with your home, call them or visit the office, where they will accept an application for laying an Internet cable in your apartment.

As a rule, you will be given several dates to choose from, choose the one that is most convenient for you, when you can be at home, a technician will arrive at the appointed time and install an Internet cable to the place you need.

By the way, they do not charge money for laying the cable; the company you have chosen does it at its own expense; you only pay for the selected Internet connection tariff, usually from 300 to 1000 rubles per month.

The monthly fee (tariff) will depend on the connection speed you choose.
For comfortable access, choose a speed of 30 Mb/s, approximately 400-500 rubles/month.

After the cable has been installed, you can already connect it to your computer and use the Internet, but our goal is to create a Wi-Fi network, so let’s move on. You need to purchase a router (some companies provide their own routers), it is to this that you will then connect the Internet cable, after which the router will create an active wi-fi network, and you can connect to it without any wires, even from a laptop, even from a phone, and here it is comfortable Internet access from anywhere in the apartment or house.

Tip 1: When you discuss the conditions for connecting an Internet cable, ask which router is best for you to buy, because the choice in stores these days is quite large. Correct advice purchasing the right router will save your money and time.

Tip 2: When connecting, the router will need to be configured (once), if you don’t have the slightest idea how to do this, then I recommend asking a specialist who will come to lay the Internet cable. Let him set everything up for you right away (they may require a separate fee for setup, about 500 rubles)

Tip 3: Take care of a secure connection in advance and install an antivirus on all computers from which you will access the Internet.

An alternative option, if for some reason your house or apartment is not serviced by one of the provider companies, this is usually faced by residents of towns, villages, country parks, well, there is no way to install a cable there yet.

You need to find out which telecom operator (MTS, Beeline, Megafon) receives normally in this territory. After that, visit the office of one of these companies and buy a modem that will provide access to the Internet, and for modems they sell separate routers that can convert the signal from the modem to a wi-fi network.

By the way, modems with a built-in Wi-Fi module are now actively being developed; perhaps you can find one for yourself - this will simplify the connection conditions several times.

Wi-Fi is a technology for wireless transmission of network information packets. This means complete elimination of wires, which is very convenient in many situations. For example, the Russian media boasted: from now on, ground broadcasts of telemetry (on-board parameters) of Soyuz-5 rockets will be carried out via Wi-Fi (IEEE 802.11 group of standards). The system simulates a router-workstation connection. The project is going through the design documentation development stage. The management of the cosmodrome is tired of the cables covering the runway. New system will significantly increase reliability and ease of use.

Wireless communication will allow you to connect and put together otherwise literally incompatible devices. Recently, Q-Stick engineers offered TV owners an original solution: turn the device into a full-featured desktop computer. Not surprisingly, the smart device is already equipped with a processor, graphics accelerators, and an operating system. Not much left RAM add, and the built-in access point will help establish communication between home gadgets.

Usage

The core of the system is the broadcast router (access point, base station). To become a member of the network, a computer or telephone must be equipped with wireless modules. The specified combination of equipment is usually called a station. The packet is transmitted by the center via broadcast. Carrier reception does not guarantee 100% delivery. Much is determined by external conditions and signal level.

Providers and public institutions decorate the walls with characteristic stickers, providing unlimited or paid access. They install routers at home, setting the conditions for using the resource themselves.

Router

The evolutionary router was the base station of the star topology, used by prehistoric Hawaiian developers (60-70s of the 20th century). The principle of broadcasting is still used by network equipment. And not only on-air. Surprisingly, today it is logical to begin the presentation of the principle of operation of a router with cable options. The radio channel is more like a public event, where the announcer, who has captured the microphone, conveys information to the audience. Adjacent rows hear each other, and this became the technical background for the introduction of the ad-hoc concept (communication without a router). However, the announcer’s voice is still louder.

A router is traditionally called a piece of equipment that redirects network data packets. Requires at least two computer networks. The home domain is separated from the external domain by the values ​​of assigned IP addresses. Sometimes (in the office of a large company) the block acts as a receiver for the services of several providers, departments, etc. From the outside, all PCs appear to the observer as having the same IP. Macs are different though.

A wireless router is characterized by the ability to send information over the air using a radio channel and electromagnetic waves.

The movement of a network packet is often represented as a chain of information transmission between node routers. The electronics reads the address of the packet, transmitting information in the right direction. Downstream wireless flow is often broadcast. Information is transmitted simultaneously to all participants. A professional router uses an address table, a protocol, substituting addresses, but home administrators often avoid complex configuration.

Well-known routers simply organize a gateway between the home segment and what is located outside (provider, Internet, and so on).

Interfaces and features

In response to the needs of the audience, manufacturers certainly provide the router with a wireless channel. Incoming traffic bypasses a physical Ethernet channel or optical fiber. Hybrid options are not excluded, but this applies more to large enterprises.

Internal tables will allow you to create galaxies of subnets, but a home user rarely appreciates the full range of possibilities. The output interfaces of the thicket are Ethernet cables and a wireless Wi-Fi channel. Enterprise versions like the Cisco CRS-1 are truly unique. Many models are still equipped with the ability to broadcast the IEEE 802.11 protocol.

Varieties

Often routers are assembled into branches of a tree structure, where the channel throughput gradually decreases. Home Internet is no exception. Subscriber models are usually referred to by the capacious term SOHO. According to tradition, this includes equipment serving 1-10 workstations. The legislation of individual countries provides further clarification according to which equipment is purchased and manufactured. For example, New Zealanders consider a group of 6-19 employees to be a small office. The numbers below are described by the term “micro”.

The patterns for each level of the tree structure are very different. They produce special models for home users, organizations, and providers. The commercial success of a technology is ensured by reaching the maximum target audience with minimal effort. We have to greatly reduce prices, making the concept accessible to the masses.

SOHO

Below we will show the variety of wireless standards, as a tribute to European traditions. For now, let’s note the features of the hardware implementation of routers that correspond to the historical aspects of the development of offices in the West. A major achievement in computer communications technology at the end of the 20th century was the possibility of territorial separation (division) of large departments. Decentralization often greatly increased productivity, necessitating the production of SOHO routers.

Gradually, small-sized models reached private households. And today the number of router channels significantly exceeds the average statistical needs of the population. Some models even come with their own operating systems(Linux).

Scalability

Typical routers aim to easily scale the network through simple expansion and the use of a central station. The speed of the periphery drops significantly, sharply reducing the usefulness of the technology. Security is a separate issue. Today, the harmful effects of microwave radiation, including 2.4 GHz, used by commercial communications, are considered proven.

Etymology

Commercial use now existing name began no earlier than August 1999. The American one was fiddling with Wi-Fi advertising company Interband with British roots. Among the creations of the creative giant is a 5-level method for assessing the economic value of a brand. The 2016 annual report contains the following first 10 lines:

1. Apple.
2. Google.
3. Coca-Cola.
4. Microsoft.
5. Toyota.
6. Samsung
7. Amazon
8. Mercedes-Benz.
9. General Electric.

In August 1999, the company's managers were hired by Phil Belanger to come up with a name more euphonious than “IEEE 802.11b Direct Sequence.” The result is intended to be a parody of hi-fi (high-fidelity acoustic equipment). The first syllable hinted at the wireless nature of the communication channel. In addition, the company proposed a logo that is now well-known, imitating the Chinese mandala of fighting opposites (yin and yang).

The Alliance's advertising slogan played on the awkward combination of wireless clarity. Wits immediately dubbed the association the Wireless Clarity Alliance Inc. Although IEEE partially confirmed the rumors, the phrase in question was never the official name.

How to spell

The organization's letterers adhere to the same type of spelling of Wi-Fi. Considering the specifics of the mandala logo (see above), one can see in this a confrontation between the concept of quality and the fact of transmitting information wirelessly. Simply put, the incompatibility of these two concepts. In fact, the quality of wireless transmission is steadily improving. The following spellings are considered incorrect:

Story

You're probably wondering why people created a billion wireless technologies. To Wi-Fi you should add:

1. Generations of mobile communications (far from one standard).
2. Bluetooth.

At one time there was serious rivalry, but high specialization prevailed. Each protocol solves a narrow range of problems. The formulation of the question causes the usual surprise of domestic specialists. Russian universities continue to train personnel with relatively broad competencies. Western educational institutions are sharply tailoring their diploma to a specific segment of the labor market. Continuing the analogy, we see the complete similarity of the variety of highly specialized standards with the legendary monopolies of the beginning of the industrial revolution. If the USSR had decided to dictate fashion to the planet, everything could have looked different.

The history began with the concept of the interface computer, formulated (1966) by Donald Davis. In fact, the machine was doing the work of a router, forwarding packets. Before this, strictly two network nodes directly connected by cable could communicate. The use of routers greatly simplified the organization of communications. Initially, the idea was denoted by the short term “gate”; the first implementation is considered to be the IMP board, designed to provide communications for US defense computers.

Hawaiian Islands

The mid-60s were filled with Cold War fears. Canada's air defense lines were cut through; the significant length of the fortifications required the creation of a central coordination computerized system that calculated algorithms for further actions of the allies. Americans quickly realized the benefits of emerging digital technologies. The question of the appearance of the first networks became a matter of time. Soon (1969) super-large computers united the cable industry.

The year 1974 connected the Canadian defense lines with a host of information jumpers. In parallel, the United States, remembering the experience of Pearl Harbor, decided to connect Hawaii. The islands began broadcasting (1971) to the mainland using the ALOHA protocol, which laid the foundation for the future IEEE 802.11 standard.

ALOHA

A performance demonstration took place in warm June. Do you see? The new technology could become dominant among cellular operators because it covered the ocean, but the battle of standards created a different picture. Dedicated frequencies appeared only in 1985.

ALOHA protocol used new way access to the medium (channel resources). Wireless communication duplicated wired and satellite channels. ALOHA was quickly tested in these two categories:

• Ethernet
• Marisat

The developers of the University of Hawaii under the command of Norman Abramson started in September 1968. Participants:

1. Thomas Gaarder.
2. Franklin Kuo.
3. Shu Lin.
4. Wesley Peterson.
5. Edward Weldon.

It was planned to adapt relatively cheap commercial equipment for local communication between the islands' computers. June 1971 pleased with the first successes. The packet, bypassing the airwaves, then reached the terminal via RS-232 (COM port 9.6 kBit/s). The first topology strongly resembled stars. The central hub produced the broadcast. The fact of successful reception of the message was confirmed by an affirmative packet. The station repeated the message if necessary. The technology completely resolved the issue of collisions. The use of addressing simplified the resolution of any conflicts. Transmission and reception were carried out simultaneously: any failed attempt (collision) obligated the node to wait before starting a repeat session.

ALOHA pioneered the use of broadcast broadcasting, which is now the basis for creating Ethernet networks. The first government communications (ARPANET) sent packets strictly between two nodes. The absence of the need to capture a token significantly simplified both the implementation of the protocol and the equipment used.

• The channel is called a random access line.

The new technology quickly captured the minds of developers, serving as the basis for the creation of Ethernet, Wi-Fi, satellite communications, ARDIS, CDPD, GSM, Mobitex networks. A significant drawback of the first implementation is the incomplete use of the channel resource, since there is no way to prevent collisions. Mobile operator I liked the concept too. Signaling of 1G networks is partially implemented with ALOHA.

The random access technique is familiar to European GSM developers, who set the local fashion for mobile communications. Auxiliary channels helped transmit SMS (2G) and even served as a reliable means of delivering Internet packets (GPRS).

Ad-hoc mode

Later they released a version of the protocol for interacting clients directly, bypassing the star base station (Access Point). The concept was first proposed (1996) by Chai To and implemented (IEEE 802.11a) by the Lucent WaveLAN module in the IBM ThinkPads line. The original plan was to cover a one-mile radius. The attempt was a success, noted by Mobile Computing magazine (1999).

Formally, ad-hoc became part of the standard only in 2002. Today the technology is ready to seriously compete with Wi-Fi Direct. Networks devoid of routers immediately fell in love with gamers. The corresponding options help “virtual” access points share Internet access.

Attention! Microwave radiation is harmful to the user's health.

IEEE 802.11

Today Wi-Fi uses several bands:

1. 900 MHz.
2. 2.4 GHz.
3. 3.6 GHz.
4. 5 GHz.
5. 60 GHz.

The basic version dates back to 1997, but the length of previous developments covers over 10 years. The first version of IEEE 802.11a, which is still in use today, appeared two years later. Classified military technologies prevented civilians from taking advantage of science-intensive concepts. The beginning of Perestroika of the USSR in 1985 allowed the FCC committee to develop an ISM band frequency plan, allowing the use of dedicated bands by doctors and industry. For a long time the area was limited to specific uses.

In 1991, American giants AT&T and NCR Corporation offered the Netherlands the use of wireless cash registers. The data transmission technology (1-2 Mbit/s) is called WaveLAN. The 1997 IEEE 802.11 version is very similar to the store version:

• Two speeds (1-2 Mbit/s).
• Forward error correction technology.
• Three options for implementing the physical layer: infrared channel (only 1 Mbit/s), pseudo-random frequency tuning of the radio channel, direct sequence spread spectrum method.

Eliminating the bugs took 2 years, and now the capabilities of the 1997 project are completely outdated.

Father of Wi-Fi

Vic Hayes was a member of the standardizing organization for 10 years before the introduction of the IEEE 802.11a protocol. This allows historians to call the mentioned person the father of Wi-Fi. The main feature was the introduction of orthogonal frequency division multiplexing. The 5.8 GHz band was initially proposed. A similar technology is described in section 18 of the 2012 release, covering the speed range of 1.5 - 54 Mbit/s. Although the original concept has changed significantly, manufacturers still use the term IEEE 802.11a to describe the characteristics of 5.8 GHz equipment.

“Thanks to” errors, the actual speed of the first implementation rarely exceeded 20 Mbit/s. A significant advantage was the use of a low-value frequency range, however, the peculiarities of microwave propagation greatly reduced the range of action of new systems. The first version of the protocol is much inferior to b/g. Theoretically, there is almost zero permeability through the walls. In practice, option b exhibits similar shortcomings. Imitating others wireless channels,IEEE 802.11a is susceptible to interference. The disadvantage is compensated by the low signal permeability (which means there is little chance of crossing the neighbor’s router).

The basis for creating a channel is 52 orthogonal subcarriers. Supported data rates: 48, 36, 24, 18, 12, 9, 6 Mbit/s. 12-13 non-overlapping channels have been identified. Implementation is highly dependent on country legislation. Some states allow more than 24 channels within the 5.47-5.725 GHz band. Conflicts with b are completely excluded, since the order of frequencies is different.

Parent patent

Although Vic Chase is idolized by the owners wireless devices, the new invention became possible thanks to the presence of patents in 1992, 1996. Australian astronomer John O'Sullivan and Co. (Graham Daniels, Terence Percival, John Dean) developed a key principle as part of a failed CSIRO program, described by experts as:

• A failed experiment to detect exploding black holes comparable in size to atomic ones.

Therefore, serious researchers still give parental rights to the specified group of space explorers. As of April 2009, CSIRO had received over $1 billion from 14 companies willing to improve the technology. This became the reason for the raider seizure of the title of the creator of the technology. If you want to work via Wi-Fi, you need permission from the monopolist. Capital inflows continue. American companies paid another 220 million to the homeland of the kangaroo (2012) for the right to use the technology.

This is interesting! Local network Test Bed was selected as a participant in the national exhibition of the History of 100 World Objects.

Development

Generation B has surpassed the capabilities of cash registers fivefold. The connection provided a bitrate of 11 Mbit/s. It was this state of affairs that ensured massive commercial success, and 1999 is considered the year of the creation of the world-famous Wi-Fi Alliance organization. The profits were shared by a dozen large companies:

1. 3Com.
2. Nokia.
3. Zebra Technologies.
4. Aironet.
5. Harris Semiconductor.

The venture was helped by numerous sponsors (more famous ones): Apple, Samsung, LG, Microsoft, Qualcomm, Sony. The organization was engaged in certification and testing. In fact, she acted as a trendsetter in the industry. The IEEE members split off in 1999 and began calling themselves WECA. The name Wi-Fi Alliance was born in 2002. Now the headquarters is located in Austin (USA), Texas, the organization has over 550 member companies.

Certification

A company wishing to produce equipment provides prototypes to the Alliance. Wi-Fi Alliance members are full rights holders trademark and logo. Electromagnetic compatibility, package structure, security protocols, quality, and energy management modes are tested. Interoperability with previously certified devices is assessed. A set of standard applications is launched. The three pillars of receiving a positive assessment are:

1. Successful interaction with any class devices.
2. Availability of backward compatibility. Necessary measure ensuring that end users do not need to constantly upgrade hardware.
3. Degree of accounting for innovations. The committee constantly publishes the latest fashion. The ability of the manufacturer to correctly grasp the voice of progress is considered an advantage.

There are mandatory and optional certifications. In addition, the organization is engaged in related technologies: Wi-Fi Direct, Wi-Fi Aware.

Future

Data transfer speeds are constantly increasing. The 2016 version combines basic capabilities with 5 implementations at once:

The ac variant surpassed the technical capabilities of wired Ethernet for the first time. For this purpose, a carrier frequency of 5 GHz, a channel width of up to 160 MHz, and parallel transmission of packets by multiple nodes (MIMO) are used. The modulation level reached 256 QAM. The total speed of implementation in 2013 (channel width 80 MHz, frequency 5 GHz) reached 1.3 Gbit/s. Devices designed for the 160 MHz band of the “second wave” generation will transmit 4 streams simultaneously.

Ad will introduce the 60 GHz (millimeter wave) carrier. Since the value is significantly higher than the established standard, products are supposed to be marked with a WiGig sticker. However, certification is carried out by the good old Wi-Fi Alliance. A peak throughput of 7 Gbps is expected. The first commercial router was announced (January 2016) by TP-Link.

The af implementation intended to cover the “white spots” of the television band (54-790 MHz). Cognitive radio technologies will transmit information about the level of interference to the base station. The hardware will independently determine its own location, adjusting the broadcast parameters in accordance with local legislation.

The physical layer is formed by orthogonal frequency division multiplexing. The protocol is a logical continuation of IEEE 802.11ac. Relatively low frequencies television range will significantly increase the range. Small channel width (6-8 MHz) allows flexible adjustment technical specifications organized communication channel.

The range is characterized by relatively low speeds, however, the use of simultaneous transmission of 4 frequency channels by four antennas will allow reaching the limit of 426-568 Mbit/s (depending on the channel width).

In addition to the above, the 2016 version eliminates certain outdated functions, others are marked as “superfluous” (will be removed later). The information structure of the document is characterized by a high degree of orderliness.

Let me start with the fact that wired communications today are acquiring a touch of anachronism. After all wired networks- This is the technology of the last century. Today, even computers are sold wirelessly (all-in-one computers), let alone the Internet. But, one way or another, not everyone knows what types of wireless communications exist. Today we will learn what Wi-Fi is and what you can do with it.

No wires!

The first and fundamental distinguishing feature this method communication is the complete absence of cords and wires. What is Wi-Fi? This is a way to connect a device to the Internet via a radio link. With this method, all sorts of problems with damage to cables, plugs and other connecting equipment completely disappear. There are many types of wireless networks. But why has Wi-Fi gained the most popularity? Yes, because this technology, thanks to its range of action and transmission speed, is the most the best option of all possible. Why doesn't anyone install WiMax in their apartment? Because this is too expensive a pleasure, which, in fact, is simply of no use to the average user. For a large corporation, organizing a WiMax wireless network can still be economically justified. But Wi-Fi is suitable for use by almost everyone! Its range of action extends to the entire area of ​​an apartment or house; the connection speed does not make you stare at the screen in a frenzy and wait for the VKontakte page to load.

Types of Wi-Fi

The Wi-Fi wireless network has the following types: IEEE802.11b, IEEE802.11 a, IEEE802.11 g. They all differ in throughput. The most popular and widespread option is the model with the letter b at the end. The maximum throughput of this method of data transfer is impressive - 11 Mbit/sec. And the operating range is quite large - 100 meters, taking into account unfortunate obstacles in the form of walls, metal structures and other things. And in open areas, this range, as a rule, increases by 2-3 times, while the transmission speed can reach up to 40 Mbit/s.

What's good?

What is Wi-Fi? The most convenient way to go online! After all, in order to access the Internet, the user only needs to be within the range of the point Wi-Fi access and press one button that launches the necessary systems on the device. That's all. Then all settings and the connection itself are made automatically. Another advantage of such a wireless network is that it can be installed on all portable devices, be it a smartphone, tablet or laptop. In addition, today Wi-Fi access points are installed in all cultural and public places. Any user with a portable device can access the network for free and enjoy high-speed surfing. I hope now you know what Wi-Fi is! This is a fundamentally new and optimal way to connect to the Internet, guaranteeing high-speed and stable access without any wires.