What is Wi-Fi and How it works

If you are at a shopping center, library, hotel or an airport, chances are you’ are able to access a wireless network. Nowadays almost everyone uses wireless networking, also called WiFi or 802.11 networking, to connect their computers at home. Wi-Fi is one of the most important technological developments of the modern age. It’s the wireless networking standard that helps us enjoy all the conveniences of modern media and connectivity. Wi-Fi capable devices can access the internet without the need for restrictive wires. Wi-Fi can operate long or short distance with secured or open options.

Introduction to Wi-Fi

Wi-Fi is the name of a popular wireless* networking technology that uses radio waves to provide wireless high-speed Internet and network connections. A common misconception is that the term Wi-Fi is short for “wireless fidelity,” however this is not the case. Wi-Fi is simply a trademarked phrase that means IEEE 802.11x.However, The tech community calls it “Wireless Fidelity”.  it’s radio transmission technology that’s built upon radio frequency (RF) technology — a frequency within the electromagnetic spectrum between, to allow high-speed and secure communications between a wide variety of digital devices. It makes it possible for Wi-Fi capable devices to access the internet** without the need for restrictive wires. The major advantage of WiFi is that it is compatible with almost every operating system, game device, and advanced printer.

*Wireless Internet access for cell phones is called Cellular technology (3G,4G)

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What is Internet

**The Internet, sometimes called  “the Net,” is a worldwide system of computer networks – a network of networks in which users at any one computer can, if they have permission, get information from any other computer. In other words “A means of connecting a computer to any other computer anywhere in the world via dedicated routers and servers” Interestingly NOBODY OWNS INTERNET like Wi-Fi

What is Radio Frequency

The electromagnetic spectrum contains all the frequencies of electromagnetic waves including gamma-rays, ultraviolet, visible, light waves, microwaves, and radio waves. Electromagnetic waves are categorized according to their frequency. Electromagnetic Spectrum starts with Gamma-Rays with starting frequency of 10×15 GHz to radio waves <300 GHz.  Radio frequency (RF)  refers to the rate of oscillation of electromagnetic radio waves. Radio waves are in the range of 3 kHz to 300 GHz,  This is the frequency band that is used for communications transmission and broadcasting. These frequency bands are divided into different parts, which are then assigned to different technology industries. This is called Radio Spectrum. Although RF really stands for the rate of oscillation of the waves, it is synonymous to the term “radio,” or simply wireless communication.
Radio frequency is produced by oscillating current for a specified number of times (Frequency ) and then radiating it off via a conductor, referred to as an antenna, into empty space (not outer space)

What is Radio Spectrum

ITU (International Telecommunications Union) is the United Nations specialized agency for information and communication technologies(ICTs). Radio Bands are designated by the ITU Radio Regulations.ITU allocates global radio spectrum and satellite orbits.
802.11 is a standard that was developed by the Institute of Electrical and Electronic Engineers (IEEE). It is the original wireless specification. This first IEEE standard for Wi-Fi was released in 1997 and is known as IEEE 802.11. It had major shortcomings of a maximum speed of 2 Mbps Later on various Extensions of the 802.11 were released.
The radio spectrum frequency bands used by the International Telecommunications Union (ITU) ie the variants of 802.11x and are 802.11a,802.11b,802.11d—–802.11k,802.11n, which are either upgrades over the previous spectrum or independently adds more capabilities. So there are different flavors of 802.11with different functionalities. The important Protocols are
    Table A
         Protocol               Frequency              Max data rate (Mbps)
        802.11b                   2.4GHz                             11
        802.11g                    2.4 GHz                           54
        802.11a                     5GHz                               54
        802.11n                    2.4GHz                            217
        802.11n                     5GHz                              450
        802.11ac                   5GHz                              433
A compatible device to receive Wi-Fi can have multiple protocols such as 802.11a/g/as

What is Mbps & MBps

Megabits per second (Mbps) is a unit of measurement for bandwidth (speed) on a network. Each megabit is equal to 1 million bits. (1,000,000 Bits).Mbps is the speed of data transfer over the network. One Mbps means the transfer of one million bits per second. A bit (short for binary digit) is the smallest unit of data in a computer. A bit has a single binary value, either 0 or 1. Please remember, MBps is different from Mbps.MBps refer to Bytes but Mbps refer to bits. Each Bite contains eight bits.

How Wi-Fi works

WiFi works on the same principle as other wireless devices – it uses radio frequencies to send signals between devices. The radio frequencies used in walky-talkies, car radios, cell phones are normally in the range of Kilohertz and Megahertz whereas in Wi-Fi they are  Gigahertz. They are either 2.4 GHz or 5GHz in Wi-Fi. But Microwave uses 2.450Ghz and a faulty one can interfere with WI-Fi.higher frequency allows the signal to carry more data. The 2.4GHz signal is what all 99% of all global WiFi devices are compatible with. This means that computers, smart TV’s, game consoles, tablets and more are all able to connect to the internet via this frequency.
The radio signals are transmitted from antennas and routers***. These signals are picked up by Wi-Fi receivers, such as computers and cell phones that are Wi-Fi compatible. Antena radiate signals equally well in all directions. These antennas are called omnidirectional (radiation in all directions). The router also has a built-in antenna. Radiowaves are emitted from the antenna with a frequency of 2.4Ghz with the speed of light @300,000 km /186,000 miles per second (With this speed, light can circulate around the earth on the equator line, 7 times in one second). This radiowaves are picked by the antenna of the router and again released by the same antenna at the same frequency and normally reachable to 100 feet with the strength of its Mbps. So Antenna releases Radiowaves and these are picked up by antenna of the router. Router releases radiowaves to Wi-Fi compatible devices. Same is in the reverse process.

What is router

A router*** connects devices within a network by forwarding data packets between them. These data can be sent from the internet to devices and from devices to the internet. The router does this by assigning a local IP address to each of the devices on the network. This ensures that the data packets end up in the right place, rather than getting lost within the network. Normally routers are with one antenna. If two identical antennae router is used, It does not increase the speed (Mbps )of Wi-Fi but covers more area. Say if you have a router on the ground floor with two antennae, one kept horizontal will cover the ground floor and another vertical antenna can cover the 1st floor. To capture 802.11b,g and n radiowaves, Modern Routers have antennae ( Plural of the antenna is antennae) so that there is dual frequency access, 2.4GHz, and 5GHz radio waves. The two antennae in the router help improve the propagation of the signal.

Receiving Device capabilities for Wi-Fi

The router may support the faster 5GHz network but the device might not have the right wireless network adapter. When purchasing a device say computer, one should ensure the capabilities of its Wi-Fi card. The 2.4Ghz network is, at this moment, the standard used for most consumer devices to communicate, With this configuration one may have frequency congestion, which leads to lower speeds and a less stable connection.
The 5Ghz frequency band was introduced as a solution to this. Nowadays modern routers are with the 5GHz protocol. The device should have a 5Ghz card to communicate with the router.

If the wireless network specifications in a device are “BGN” or “802.11b/g/n”, then it supports 2.4GHz.only.If only “N” then it may support either 2.4GHz or 5GHZ. You need to check it. For checking whether your device supports only 2.4GHz or both 2.4GHz and 5GHZ, find out” Supported PHY Modes” in Mac and “Radio types Support ” in windows. It should read something like this

Mac           Supported PHY modes      802.11a/b/g/n/ac
Windows    Radio Types Support        802.11b,802.11g,802.11n
Now refer to Table A which will confirm for 5GHZ if it has 802.11a,802.11n,802.11ac

What is LAN,VLAN & WLAN

When a router connects the internet to various devices at home, the router creates a hotspot and create Wireless Local Area Network (WLAN).
WLAN is a typical local network that utilizes radio waves, rather than wires, to transmit data. Today’s computers have WLAN built onboard, which means no additional WiFi card needs to be installed.
VLAN, Virtual Local Area Network, is a virtual LAN that allows a network administrator to set up separate networks by configuring a network device, such as a router, This allows a network administrator to organize and filter data according to corporate policy in a corporate network.
LAN, Local-Area Network, has networking devices or computers in close proximity to each other, capable of communicating, sharing resources and information. Most home and business networks are on a LAN but wired. When on Wi-Fi, it is WLAN.

Non Overlapping Channels 1,6,11

In the 2.4 GHz band, its spread is from 2.401 GHz to 2.473 GHz.This entire spectrum is separated into 11bands of 22 MHZ each. So the range of 72. MHZ is divided into 11 channels, The channel centers are separated by 5 MHz.All 11 channels are squeezed into the 72 MHz available, and these channels overlap each other except for 1,6,11. These are the only non-overlapping channels. Selecting one or more of these channels is an important part of setting up your network correctly. Currently,  wireless routers automatically select the channel on initial setup.

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