Brief introduction to basic knowledge of wireless internet

Source: Internet
Author: User

Basic knowledge of wireless internet is the focus of our paper. Then we have made a detailed introduction to some of its basic standard parameters. If you've been to an airport, a coffee shop, a library or a hotel recently, you've had a chance to use a wireless network. Many people also use wireless networks (also known as WiFi or 802.11 networks) to connect computers at home, and more and more cities use this technology to provide free or low-cost Internet access to residents. In the near future, wireless networks may become very popular, and you can even access the Internet at any time, anywhere, without using wires.

Wireless internet has many advantages. Wireless networks are easy to build and inexpensive. They're also less conspicuous, unless you're deliberately looking for a place to use your laptop, or you won't even notice you're in a hot spot. In this article, we will focus on technologies that can transmit information over the radio. We'll also look at everything we need to build a wireless network at home.

Wireless

A wireless router allows multiple devices to connect to the Internet.

First, we will introduce some basic knowledge of wireless internet. Wireless networks, like mobile phones, televisions and radios, use radio waves. In fact, the process of communicating over a wireless network is very similar to two-way radio communication. The specific process is as follows:

The computer's wireless adapter converts the data to a radio signal and sends it out using an antenna.

The wireless router receives the signal and decodes the signal. It sends this information to the Internet via a wired physical Ethernet connection.

This process can also be performed in reverse, where the router receives information from the Internet, converts it to a radio signal, and sends it to the computer's wireless adapter.

PC Wireless card photo courtesy URL title; USB Wireless Adapter by HowStuffWorks Shopper Map, PC wireless card by HowStuffWorks Shopper

The wireless adapter can be plugged into the computer's PC Card slot or USB port.

Radios used for wireless network communications are very similar to radios used for walkie-talkie, mobile phones and other devices. They can send and receive radio waves, convert 1s and 0s to radio waves, and convert radio waves back to 1s and 0s. But there are some notable differences between wireless network radios and other radios:

They send signals at a frequency of 2.4GHz or 5GHz. This frequency is much higher than the frequency used for mobile phones, walkie-talkies and televisions. The higher the frequency, the more data the signal will carry. They use 802.11 network standards, specific versions:

802.11B is the first version to be put into the market. It is the slowest but cheapest standard, and it is increasingly less used as faster standards become cheaper. 802.11B sends signals within the 2.4GHZ band of the radio spectrum. It can process up to 11MB of data per second and uses the complement keying (CCK) encoding.

802.11G also sends a signal at 2.4GHZ, but it is much faster than 802.11b, and it can handle up to 54MB data per second. 802.11G is faster because it uses orthogonal crossover multiplexing (OFDM), which is a more efficient coding technique.

802.11A sends a signal at 5GHZ and can move up to 54MB of data per second. It also uses OFDM coding. Newer standards such as 802.11n can even be faster than 802.11g. But the 802.11n standard is not the final standard either.

Wireless network Radio can send signals under any three frequency bands. They can also be fast "hopping" between different bands. Frequency hopping helps reduce interference and allows multiple devices to use the same wireless connection at the same time.

The origin of the name you might want to know why people call WiFi the 802.11 network. 802.11 this term derives from the Institute of Electrical and Electronic Engineers (IEEE). The IEEE establishes standards for a range of technical protocols and classifies them using a numbering system.

As long as there are wireless adapters, multiple devices can use a router to connect to the Internet. This connection is convenient and almost intangible, and quite stable. However, users may experience interference or loss of connectivity if the router fails or if too many users attempt to use high-bandwidth applications at the same time.

The above is about the basic knowledge of wireless Internet introduction, hope to help everyone.

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