Wi-Fi is a wireless technology used in home networks and to connect mobile phones, computers, and other such electronic devices over a wireless network. It is the 802.11 IEEE standard. Let us seethe working of Wi-Fi.
The wireless adapter of a computer translates data into radio signals and transmits the signals over an antenna. The transmitting antenna is generally connected to a DSL or a LAN-based Internet source. The wireless router in the network receives signals and decodes them. The router uses an Ethernet connection to transmit the information over the Internet.
Similarly, data received from the Internet passes through the router which converts it into radio signals. The wireless adapter of the computer (or any device using the connection) receives the signals.
Wi-Fi implements wireless local area network (WLAN) communication between computers using the 2.4, 3.6, 5, and 5.9 GHz frequency bands. 802.11 provides 1 or 2 Mbps transmission in the 2.4 GHz band. While 802.11a provides up to 54 Mbps in the 5 GHz band, 802.11b provides 11 Mbps in the 2.4 GHz band. 802.11e adds the Quality of Service support.
802.11g provides up to 54 Mbps in 2.4 GHz band. 802.11n adds multiple-input-multiple-output to the previous standards. 802.11ac operates in the 5 GHz range and can provide up to 433 Mbps. 802.11ac Wave 2 attempts to increase the connection speeds.
In the United States and Canada, Wi-Fi networks use the 802.11b standard that operates in the 2.4 GHz frequency range. It supports 11 channels of frequencies ranging from 2.401 to 2.473 GHz. The Wi-Fi signals have a range of about 120 feet indoors and 300 feet outdoors.
To set up a Wi-Fi network over a large area such as a university campus, multiple access points with slightly overlapping ranges are needed. For an even larger area such as a city, a wireless mesh network is deployed, wherein several routers are set up and the operator of the network acts as a wireless internet service provider.
With an increase in the distance between the user and the signal, the connection speed decreases. But even if the distance is not large, the signals' range and thus their speed may be affected by physical obstructions such as walls. Radio signals that have to pass through thicker walls are degraded or take a longer time to reach the device receiving them.
Interference from devices such as the microwave or cordless phones interfere with Wi-Fi signals, thus impacting their range. The orientation of the antenna affects the signal range. Directional antennas allow for a greater range in the direction they point.
For large areas, problems with the range and speed of signals are tackled with the use of multiple access points. In smaller areas, Wi-Fi repeaters can be used to extend the range of connection.
Changing the channel that the router uses or upgrading router or adapter firmware are the other ways in which Wi-Fi signals can be boosted. As an immediate solution to speed or range problems, the device (laptop or smartphone) that is using the signals should be taken closer to the Wi-Fi router.
How to set up a Wi-Fi connection?
First connect the modem to the router with the help of an Ethernet cable. Use the WAN port on the router for this connection. Then, using another Ethernet cable, connect the router to the computer on which you wish to configure Wi-Fi. Use the LAN port on the router and an Ethernet port on the NIC of the computer.
If the router and modem are combined into the same device, connect its power cable to an electric outlet, and plug one end of the cable or phone cord to its WAN port and the other end in the wall jack. Restart the computer with the router connected to it. Open a browser and connect to the IP address that your router uses.
For Linksys routers, it is 192.168.1.1. For D-Link, it is 192.168.0.1. The router's documentation will give you the IP address. It will also give you the default username and password. Generally, they are admin and password respectively. The web interface will allow you to give the wireless network a name and password.
You will be required to follow the same process for configuring Wi-Fi on other devices such as a tablet or a video game console. Some routers come with an installation CD, running which you are instructed on the steps for configuration. Once configured, you will be able to use the devices for wireless access to the Internet.
How to connect to a Wi-Fi?
To establish a connection with a Wi-Fi network, a wireless adapter is needed. It may be built-in or plugged into the PCI slot or USB slot of the computer. To check if there is an in-built adapter in your computer, go to Start, right-click on Computer, and click on Properties.
Click on Device Manager and then on the arrow next to Network Adapters to check if there is a Wi-Fi adapter listed. Or go to Control Panel, click on Network and Internet Connections, and then on Network Connections.
If there is a network adapter, you will find it labeled as Wireless Network Connection. If a network adapter is present, the computer system detects Wi-Fi hotspots that can be connected to.
What are Wi-Fi hotspots?
They are places or spots, which offer Wi-Fi access to the Internet. To connect to one, click on the Wi-Fi icon on your device. A list of available networks will be displayed. Click on the network name that you wish to connect to. If it's a secure network, you will be asked a password. On entering it, you will gain wireless access to the web.
The biggest advantage of Wi-Fi is that the connection is wireless. The networks are easy to set up. Wi-Fi makes it possible for LANs to be deployed without cabling. This reduces the costs incurred in the network setup and expansion.
Also, Wi-Fi is easy to use, and available even when on the move. However, as it uses radio waves, there are limitations on the range and speed of connection. There are interference issues and implementing security is difficult.
How does Wi-Fi work on planes?
Transmitters on airplanes communicate with a ground station using radio waves. A Wi-Fi access point is located in the airplane. It allows the passengers to use the standard 802.11 wireless protocols for Internet access. The other way in which Internet can be made accessible during flights is with the use of satellite communication.
In this, a satellite antenna on the airplane communicates with a satellite which communicates with a ground station. If cellular networks are used for Internet access, the plane has an antenna that transmits signals to the nearest cellular tower which transmits it to a ground station.
Ground-based services may work at less speeds when flying over a large water body or when many people are using the connection. Satellite communication solves this problem. The use of Wi-Fi technology for Internet access is on the rise. It is popular for both home and business use.