Wi fi protocols

This is why 802.11b/g/n, today, is considered the basic Wi-Fi standard. Most routers and devices simply add support for additional standards rather than replacing or completely eliminating 2.4 GHz. There's also a practical reason for this, which we'll talk about in the next section.

All the differences in Wi-Fi standards: from 802.11b/g/n to Wi-Fi 6E

In just two decades, Wi-Fi has gone from an expensive luxury to a technology most of us can't imagine ourselves without. We all use it in our daily lives as a central wireless technology that connects various home gadgets to the Internet. While Wi-Fi technology may seem unchanged, it has actually undergone many internal changes over the years.

Surprisingly, not all subsequent versions of Wi-Fi have been about improving speed and range. Instead, many are designed with specific usage scenarios in mind. Some standards have even sacrificed speed or range in favor of another.

These days, devices typically support multiple Wi-Fi standards and allow you to choose the one that best suits your needs.

What is Wi-Fi?

Before we can talk about the different Wi-Fi standards in use today, it's important to understand how the technology works.

You may not have thought about it, but Wi-Fi is not that far removed from traditional wireless communication technologies such as television and radio broadcasting. Both rely on electromagnetic waves, for example, rather than mechanical waves such as sound, which require a medium to travel.

The key difference between Wi-Fi and other wireless communication standards, however, is their transmission frequency. FM and AM radios broadcast at low frequencies, usually around 100 MHz (megahertz). Wi-Fi, on the other hand, operates exclusively in the gigahertz (GHz) band. The higher frequencies allow you to transmit more data at a time, which is handy for transferring Internet data and video streams to various devices in your home. But it also has certain drawbacks, which we'll discuss later.

Like any other widely used technology, Wi-Fi is defined by a set of specifications. In particular, the IEEE 802.11 standard. Notably, the 802 family also standardizes other networking protocols, such as Ethernet and Bluetooth.

Wi-Fi protocols and their specifications

The following table shows the maximum data transfer rates for a particular standard:

Let's talk about the most well-known and common types of Wi-Fi.

802.11а

This protocol started the further development of wireless data transmission. The principles of operation were based on the basic version of Wi-Fi, the basic coding of the standard was taken. The difference from the original version was the ability to use the 5 GHz frequency, which allowed to increase the flow rate up to 54 Mbit/s. This protocol was incompatible with the 2.4 GHz frequency used before, and it caused additional inconvenience because you had to tune the reception facilities to both frequencies.

802.11b

This protocol was developed back to the 2.4 GHz frequency because it had more advantages because of the bandwidth. The developers managed to achieve data rates in the range of 5.5 – 11 Mbps. Over time, mobile devices began to operate at these levels as well. It was widely used almost until 2010, because this capacity was quite enough for computer facilities and gadgets. Today's devices can still pick up different kinds of Wi Fi, including this one, though the speed will be low.

802.11g

This is a more advanced 802.11b standard, operating at the same frequency but at higher speeds (up to 54 Mbps).

802.11n

The upgrade to this version occurred by 2009. The technical capabilities of the devices had reached a level that allowed heavier content to be processed, and the upgrade came in handy. Waves are able to pass through concrete barriers. Allows multiple devices in the house to work simultaneously stably and without failures.

Can support both frequencies at the same time, MIMO has been implemented, which provides transmission speeds of up to 150 Mbps. Wi-Fi data transfer speeds are actually laid down to 600 Mbit/s, but due to interference it is much lower. In addition, to make receivers cheaper, many manufacturers eliminate MIMO altogether. Works fine on Windows platforms. The most common protocol.

What mode to choose on the router?

See the following video on how to change the Wi-Fi mode in your router's settings:

All routers support Wi-Fi b/g/n protocols. Dual-band router supports ac standard. All modern devices (tablets, laptops, smartphones, etc.) work in these modes in the 2.4 and 5 GHz bands.

Older gadgets most likely do not support the n and ac protocols. And if your router is only set to n mode, such devices simply won't connect to the Wi-Fi network. Therefore, the best option is to choose a mixed mode 802.11 b/g/n. Then both old and new devices will work. This is the mode most often found on routers from the factory.

However, if you do not have old laptops and smartphones, it is recommended to set the n standard for the 2.4 GHz band. This will increase the speed of the Internet.

How does it work?

Wi-Fi is a wireless data transmission technology, a wireless local area network (WLAN). The principle of Wi-Fi is based on the transmission of encrypted signals through microwave waves (ultrahigh-frequency waves) over short (tens of meters) distances. A network scheme consists of at least two elements: an access point and a client.

There are client-client schemes – without the use of access points.

The access point broadcasts the identifier (SSID, network name) through special data packets 10 times per second at 100 Kbps. This is theoretically the lowest bandwidth wireless channel.

How does a Wi-Fi network work? When in range and detecting a signal the client device makes a conclusion about the possibility to connect to it (the difference in technology can be a hindrance). The transmitter may not transmit its ID, then the network will be invisible to clients. You can connect to it only by entering the SSID and password, if it is protected.

If there are 2-3 networks with identical SSIDs in the same area, the receiver device connects to the one with the better signal.

The access point in home Wi-Fi networks is mainly a wireless router – a router. It and the clients must work in the same mode (frequency, signal modulation). Let's take the example of Internet distribution in a private house.

The router gets the traffic through the network cable, converts it into radio waves and broadcasts them "through the air" in the form of very high frequency radio signals with certain parameters. A receiver "catches" these waves and decodes them (decodes, extracts information from them, which is encoded by the carrier frequency).

Frequency ranges

Wi-Fi networks operate in two frequency ranges: 2.4 GHz and 5 GHz. The first band (not a static frequency, but 13 frequencies from 2401 MHz to 2461 MHz in 5 MHz increments) differs from the second:

• The signal coverage area – it covers a larger territory;
• speed – it is lower than at 5 GHz;
• lower attenuation coefficient (signal level at 5 GHz decreases approximately 1.5 times, depending on the circumstances, when passing obstacles in the form of walls, furniture);
• greater range of radio wave propagation;
• busier – most devices operate at 2.4 GHz;
• A smaller number of channels (13 vs. 17).

Which mode to choose on a wi-fi router

Routers support Wi-Fi protocols b, g, n. Dual-band devices can function under the as standard. Modern mobile devices, laptops operate in Wi-Fi bgn mode under different bands – from 2.4 to 5 GHz.

Important! Outdated hardware can not support the types of "as" and Wi-Fi n. If the router has one of the specified, the device will not be able to connect to the connection.

A mixture of Wi-Fi standards from b, g, n is considered the optimal solution when choosing the mode. In this case, the newest and oldest devices will function on the line. This mode is preset on most adapters. If there is no obsolete equipment, then experts recommend setting the band to 2.4 GHz – this approach will increase the speed of the Internet.

Characteristics of additional Wi-Fi standards

In addition to the main ones, there are secondary protocols over Wi-Fi, which are used for service functionality. Their name has a common root "802.11," and additional letters clarify the focus of the utility.

• "802.11d" is designed to tweak the device for a variety of state conditions. The Wi-Fi range is different for each country, and it allows you to adjust frequency bands with functionality that has protocols to control access to the transmission environment. It is known as the "Chinese millimeter wave."
• "802.11e" – Related to multimedia, assigns priority to video and audio files. It is used to determine their quality, the main utilities are "VoIP", "Streaming Multimedia".
• "802.11f" – provides authentication of network equipment when reconnecting from one access point to another (at the level of network segments). Activates protocols for exchange of service information, which is necessarily used during the transmission of information between routers. This approach ensures the efficient operation of distributed broadcast lanes.
• "802.11h" – Effectively manages radiation power, allows selection of the carrier frequency of transmission and generates reporting. It introduces new algorithms that can switch to desired bands, increase or decrease transmitter power, which helps make office grids optimal. Provides high quality communications in the face of interference.
• "802.11i" – used to eliminate security flaws. Protects at the channel level, creating secure connections of any size. Operational since 2004.
• "802.11k" – Balances the system load by limiting the number of users simultaneously connecting to a single access point. It increases throughput – due to efficient use of resources.
• "802.11m" – it collected all the fixes and tweaks. A similar release was first announced in 2007, then in 2011.
• "802.11p" – is responsible for ensuring the interaction of devices moving at about 200 km/h and access points are located at a distance of a thousand meters. Included in "WAVE", which defines the structure and secondary package of interfaces and service functionality responsible for secure communication between moving vehicles. The standard was developed for navigation devices, automated toll collection, traffic control, and traffic management.
• "802.11r" – Responsible for determining fast roaming for devices when switching from one broadcast band to the second. It is used for mobile devices, it helps not to go through the connection procedure every time the subscriber leaves the coverage of the access point.
• "802.11s" – under its control, the device functions as a router and adapter. When the nearest access point is loaded, all information is redirected to the nearest node. A packet is transmitted until it reaches its destination. New protocols are used in the functionality, with support for multicast and unicast delivery with a wide broadcast format.
• "802.11t" – The view is intended to describe test methods, measurement methods, final processing of the results obtained, and requirements for the hardware to be tested.
• "802.11u" – is responsible for defining access protocols, bans and priorities of work with external systems. It ensures that wired and wireless networks are fully interoperable.
• "802.11v" – creates solutions to improve modifications, has amendments aimed at stabilizing systems by network management. Due to the modifications made, the configuration of the client's hardware connected to the network is stabilized. Works at the "MAC" and "PHY" level.
• "802.11y" is a secondary standard required for the 3.65 to 3.67 GHz frequency band. It is used on the latest generation of equipment operating at 54 Mbps and distances up to 5 thousand meters (assuming open space). Functionality is considered incomplete.

The principle of operation of Wi-Fi

What is the scheme of Wi-Fi network? It includes two elements, represented by a client and an access point. The second option is a connection between two PCs without the use of an adapter.

Through the access point, an identifier is broadcast using special data packets. Information flows up to 10 times per second at 100 kbit/sec. The specified figure is considered the lowest level of channel bandwidth.

The principle of operation of Wi-Fi: after entering the coverage area and when the signal appears, the client hardware analyzes the possibility of connection. If the transmitter does not transmit an identifier, the network remains invisible to the client. If protection is set, the connection is possible only with the help of a password, SSID.

If there are several identical wireless points in the visibility area, the equipment will automatically select the equipment with the best signal. In the home environment, the router acts in its role. For normal operation, the router and the mobile gadget must function in the same frequency and signal modulation.

The router gets the right to enter through the network cable, then the traffic is converted into radio waves and distributed in the form of radio signals with a certain frequency. The gadget decodes the signal and extracts information from it. Each standard has its own algorithm of data transmission.

The operation of the wireless mesh occurs on two frequency bands, 2.4 or 5 GHz. The first option has differences from the second:

• It is able to cover a larger signal coverage area;
• a greater spread of radio waves over a range;
• give a lower speed;
• congestion – most devices operate on 2.4 GHz;
• smaller number of channels – up to 13, in the second case this figure is 17;
• characterized by a reduced attenuation coefficient – at 5 GHz the indicators are reduced by 1.5 times when colliding with furniture, walls and other obstacles.

How to connect Wi-Fi

To connect a personal computer or laptop to a wireless network, you must meet several conditions:

• Make sure that the equipment's network card is capable of functioning in the specified mode;
• Check whether the router supports creating a wireless network and connecting additional gadgets to it.

You can find out the technical specifications of the equipment through the documents that come with your PC or laptop. All devices are necessarily supplied with them. If there is no documentation, you can find it through the official resource of the manufacturer or the selling company.

A common problem encountered by users is the lack of wi-fi support on desktop computers. In this case, the owner has two options for solving the issue:

• send the PC to a service center and install a new network card – the procedure will require an additional investment, it is practically impossible to do it yourself;
• to purchase a special adapter – visually it resembles a usual flash card, connects via USB, does not require complex settings.

Work with wi-fi begins after the entry into force of the official contract with the service provider. A standard connection scheme is used:

1. The router connects to the World Wide Web via a cable attached to the WAN connector. It has a blue color. The process is completed by activating the router.
2. After going to the settings of the router, it is necessary to find the wireless menu. In most cases it is enabled by default.
3. On the Windows taskbar you need to click on the network shortcut and select the available one, which has the right to enter. On the checkbox, activate the "automatic connection" block, which will help avoid the system asking you to enter your name and password.
4. The procedure is completed by entering the network key located on the router body. Sometimes the provider changes it, which is additionally specified in the contract.

Wi-Fi 802.11ac

At the time of writing this article, it is the newest and fastest protocol. If the previous types of Wi-Fi worked mainly in the 2.4 GHz frequency, which has a number of limitations, here are used strictly 5 GHz. This has almost halved the width of coverage. However, router manufacturers solve this problem by installing directional antennas. Each of them sends the signal in its own direction. However, some people will still find it inconvenient for the following reasons:

• Routers turn out to be cumbersome, since there are four or even more antennas in their composition;
• It is desirable to install the router somewhere in the middle between all the rooms to be served;
• Routers that support 802.11ac Wi-Fi use more electricity than older, lower-priced models.

The main advantage of the new standard is a tenfold increase in speeds and expanded support for MIMO technology. From now on, up to eight channels can be interconnected! The result is a theoretical data flow of 6.93 Gbps. In practice, the speeds are much lower, but even they are quite enough to watch some 4K-movie online on the device.

For some people, the capabilities of the new standard seem excessive. That is why many manufacturers do not implement its support in budget smartphones. The protocol is not always supported even by quite expensive devices. For example, the Samsung Galaxy A5 (2016), which even after reducing the price tag cannot be classified as a budget segment, lacks its support. To find out what standards of Wi-Fi support your smartphone or tablet is simple enough. To do this, look at its full specifications on the Internet, or run one of the benchmarks.

History

A 1985 ruling by the U.S. Federal Communications Commission released a portion of the ISM bands for unlicensed communications use. These bands are 2.4 GHz bands that are used by equipment such as microwave ovens, and they are susceptible to interference.

The prototype WLAN testbed was developed in 1992 by researchers from the CSIRO (Commonwealth Scientific and Industrial Research Organisation) Radio Physics Division in Australia. [3]

In 1991, in the Netherlands, NCR Corporation, together with AT&T Corporation, invented a precursor to the 802.11 standard for use in cash register systems. It was called WaveLAN. NCR manager Vic Hayes, who had led the 802.11 IEEA for 10 years, along with Bell Labs engineer Bruce Tuch, approached the Institute of Electrical and Electronics Engineers (IEEE). After that, they were both inducted into the NOW Wi-Fi Hall of Fame.

• In 1999, not only Wi-Fi, but the two protocols 802.11b and 802.11a are created. [4]
• In 2000, the first 802.11b devices went on sale.
• In 2002 – WiFi Alliance membership was increased to 100 member companies.
• In 2003 the 802.11g standard was released, combining the advantages of the previous two versions.
• 2005 saw the release of the best security protocol, WPA2.
• Beginning in 2005, wireless technology is already being used on some game consoles and digital cameras.
• A year later the testing of 802.11n would begin;
• 2009 – the release of devices with the 802.11n version, which can transmit data in two bands (2.4 and 5 GHz). [5]
• The active use of wireless communication in devices began.
• In 2014, the 802.11ac standard was launched.
• 2016 – versions of 802.11ah, 802.11ai appear [6] .
• In 2018, 802.11aj, 802.11aq, 802.11ay protocols are released.
• 2020 – creation of 802.11ax version.

Terminology

Illustration of a Wi-Fi network in infrastructure mode. A device sends information wirelessly to a printer, both connected to the LAN.

WDS

WDS (Wireless Distribution System) – is a technology that allows access points to work simultaneously with wireless clients and other user access points in wireless bridge mode. WEP (Wired Equivalent Privacy) is the oldest wireless traffic protection standard based on the RC4 (shared secret key) encryption method. There are variants with key length of 64, 128 or 256 bits. Using WEP to protect networks is not a reliable way of security. The problem is the implementation of the initialization vector selection as a pseudo-random sequence for data encryption. [7]

A router in a WDS network is a base, remote, or relay-relay station. The devices are usually connected by wire. Typically, remote routers are needed to connect clients over a WiFi network and relay stations are needed to communicate between two other stations. Its job is to relay and amplify the signal.

WLAN

WLAN (Wireless Local Area Network) is a wireless local area network, i.e. a computer network that covers a small area. WLAN is the term for home wireless networks based on an access point or wireless router.

WPA

WPA (Wi-Fi Protected Access) – is one of the security protocols, used for protection in wireless networks. A new protocol that was designed to replace the outdated WEP protocol was created. This protocol is based on TKIP , which effectively fights the problem of reusing the encryption keys.

Wireless Bridge

Wireless Bridge is a network device used for wireless communication between local area networks.

IEEE 802.11a Wi-Fi standard

One of the first updates to the Wi-Fi standard, released in 1999. Thanks to doubling the frequency (up to 5 GHz), engineers managed to achieve theoretical speeds of up to 54 Mbit/s. It is not widespread, as it is incompatible with other versions. Devices that support it must have a dual transceiver for 2.4 GHz networks. Smartphones with 802.11a Wi-Fi are not common.

The second early update to the interface, released in parallel with version a. The frequency remained the same (2.4 GHz), but speeds were increased to 5.5 or 11 Mbps (depending on the device). Until the end of the first decade of the 2000s, this was the most common standard for wireless networks. Compatibility with an older version, as well as a fairly large range of coverage, ensured its popularity. Despite being superseded by newer versions, 802.11b is supported by nearly every modern smartphone.

Wi-Fi standard IEEE 802.11g

A new generation of the Wi-Fi protocol was introduced in 2003. The developers left the data transfer frequencies unchanged, making the standard fully compatible with its predecessor (the old devices worked at up to 11 Mbit/s). The data transfer speed has increased to 54 Mbit/s, which was sufficient until recently. All modern smartphones work with 802.11g.

In 2009 there was a major upgrade to the Wi-Fi standard. The new version of the interface received a significant increase in speed (up to 600 Mbps), while maintaining compatibility with previous ones. To be able to work with 802.11a equipment, as well as to combat congestion in the 2.4 GHz band, support for 5 GHz frequencies was returned (in parallel with 2.4 GHz).

Network configuration capabilities were enhanced and the number of simultaneously supported connections was increased. The possibility of communication in multithreaded mode MIMO (parallel transmission of several data streams on one frequency) and combining two channels for communication with one device appeared. The first smartphones supporting this protocol were released in 2010.

Other standards

In addition to popular technologies, the Wi-Fi Alliance manufacturer has developed other standards for more specialized applications. Such modifications that perform service functions include:

• 802.11d – makes wireless communication devices from different manufacturers compatible and adapts them to the specifics of data transmission at the country level;
• 802.11e – defines the quality of sent media files;
• 802.11f – manages a variety of access points from different manufacturers, allows you to work equally across networks;

• 802.11h – prevents loss of signal quality when impacted by weather equipment and military radars;
• 802.11i – Improved version of user privacy;
• 802.11k – monitors the load on a particular network and redistributes users to other access points;
• 802.11m – contains all the patches of the 802.11 standards;
• 802.11p – identifies the nature of Wi-Fi devices that are within 1 km of each other and traveling at speeds of up to 200 km/h;
• 802.11r – Automatically finds a wireless network while roaming and connects mobile devices to it;
• 802.11s – Establishes a full-link connection where every smartphone or tablet can be a router or connection point;
• 802.11t – this network tests the whole 802.11 standard, gives you ways to test it and the results, and sets requirements for your hardware;
• 802.11u – this modification is known to everyone by Hotspot 2.0 developments. It allows for wireless and outdoor interoperability;
• 802.11v – this technology creates solutions to improve 802.11 modifications;
• 802.11y – unfinished technology linking 3.65-3.70 GHz frequencies;
• 802.11w – standard is finding ways to strengthen access protection for information transmission.

The newest and most technologically advanced 802.11as standard

Devices with 802.11as modifications give users a completely new quality of the Internet experience. Among the advantages of this standard should be highlighted the following:

1. High speed. The data transfer through the 802.11as network uses the wider channels and increased frequency, which increases the theoretical speed up to 1.3 Gbps. In practice, the throughput is up to 600 Mbps. In addition, an 802.11as-based device transmits more data per clock cycle.

1. Increased number of frequencies. The 802.11as modification is equipped with an assortment of 5 GHz frequencies. The latest technology has a stronger signal. The high bandwidth adapter covers a frequency band up to 380 MHz.
2. The coverage area of the 802.11as network. This standard provides a wider range of network coverage. In addition, Wi-Fi connection works even through concrete and drywall walls. Interference from home appliances and your neighbor's Internet won't affect your connection in any way.
3. Updated technology. 802.11as is equipped with MU-MIMO extension that allows multiple devices to work seamlessly on the network. Beamforming technology detects the client device and forwards multiple streams of information to it at once.

After getting acquainted with all the modifications of Wi-Fi-connection that exist today, you can easily choose the network that suits your needs. As a reminder, most devices contain a standard 802.11b adapter which is also supported by 802.11g technology. If you are looking for an 802.11as wireless network, the number of devices equipped with it today is small. However, this is a very pressing issue and all modern equipment will soon switch to the 802.11as standard. Do not forget to take care about the security of your Internet access by installing a complex code on your Wi-Fi connection and antivirus to protect your computer from viruses.

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