Wi-fi is a wireless technology which provides network and internet connectivity for various devices. Wi-fi is used for Laptops, Desktops, Smartphones etc. Wi-fi is a evolving technology with new standards.

Why We Need Wi-Fi?

People are mobile creatures. We need to move in order to be healthy. Also we are free and do not want to stay long time in a place. But we also want to connect internet always. These situation and needs are created the Wi-Fi . and other related wireless technologies. Wi-Fi provides us the freedom with connectivity.

We may have a old laptop that have no Wi-Fi hardware. So we can use its USB ports to add Wifi hardware. Perhaps we need second Wi-Fi hardware if there is empty USB slot we can add more to the system. Or wife do not likes cables so we need USB wifi to connect our Desktop to internet.

Why USB?

USB is very popular protocol used to connect various devices into computer. Wi-fi is one of the most used USB hardware. USB gives the ability to connect or remove devices without a restart or any problem. It is supported by all computers event smartphones.

Standards

Now there are different type of Wi-Fi standards those are created in time. They have different popularity, cost and speed.

Following sections provides information about popular Wi-fi standards. Given speeds can change according to area and AP/Modem and Wi-Fi client range. In order to use standards both AP/Modem and Wi-Fi client should use same standard. Here most used wireless standards.

802.11a

This is the first standard and grand father of the Wi-Fi technology. This type of devices do not exist for now. This standard uses 5 and 3.7 GHz and provides speed up 54 Mbit/s .

802.11g

This stantandard is released 2003. This is standard is very popular. This standard uses 2.4 GHz and provides speed up to 54 Mbit/s.

802.11n

This standard is released 2009 an uses 2.4 and 5 GHz. This standard provides speeds up to 150 Mbti/s

802.11ac

This is new generation standard for the Wi-Fi and released 2013. This standard uses 5 GHz only and provides speeds upto 866 Mbit/s. But in real world numbers a bit less.

802.11d

This is standard is released 2012 and uses 60 GHz differently from other Wi-Fi standards. The bandwidth of this standard is very high up to 6912 Mbit/s. This standard uses very large channel for more bandwidth.

List Of Best Wi-Fi Adaptors

Below list of best USB Wi-fi adaptors are listed according to their speed

550Mbps

Edup Wireless AC600Mbps USB Adaptor with dual band support for 16.99$

300Mbps

Edup Wifi Adaptor Wireless N 3000Mbps  for 12.99$

150Mbps

Rosewill SUB Wireless Adaptor N150 and ideal for Raspberry Pi for 7.99$