Wireless Internet - How Does Wireless Internet Work / Wi-Fi Technology

Let us first explore Wi-Fi and the technology behind it that drives its functionality. Wi-Fi in short for Wireless Fidelity is a set standard in the wireless domain based on IEEE 802.11 specifications. In simple terms, it allows a user to connect to the local area network and also have access to the Internet without any wires connected to the computer.

The technologies with making wireless communication possible can actually be split up into three different terms.

The first is FHSS. Frequency hopping is one of two basic modulation techniques used in spread spectrum signal transmission. It is the repeated switching of frequencies during radio transmission, often to minimize the effectiveness of "electronic warfare"—that is, the unauthorized interception or jamming of telecommunications. It also is known as FH-CDMA (Frequency Hopping Code Division Multiple Access).

The second term can be labeled as DSSS. Direct sequence spread spectrum, also known as DS-CDMA (Direct Sequence Code Division Multiple Access), is one of two approaches to spread spectrum modulation for digital signal transmission over the airwaves. In direct sequence spread spectrum, the stream of information to be transmitted is divided into small pieces, each of which is allocated across to a frequency channel across the spectrum. A data signal at the point of transmission is combined with a higher data-rate bit sequence (also known as a chipping code) that divides the data according to a spreading ratio. The redundant chipping code helps the signal resist interference and also enables the original data to be recovered if data bits are damaged during transmission.

The last term that we need to familiarize ourselves with is OFDM which is actually the most prominent technology in wireless technology. Orthogonal frequency-division multiplexing is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. OFDM is actually not too different from FHSS and DSSS; however the difference lies in the way in which the signals are modulated and demodulated. Priority is given to minimizing the interference, or crosstalk, among the channels and symbols comprising the data stream. Less importance is placed on perfecting individual channels. Now that we have defined the technology, let us take a look at the variety that Wi-Fi has to offer.

We'll start with a few Wi-Fi basics. A wireless network uses radio waves, just like cell phones, televisions and radios do. In fact, communication across a wireless network is a lot like two-way radio communication. Here's what happens:

A computer's wireless adapter translates data into a radio signal and transmits it using an antenna.
A wireless router receives the signal and decodes it. It sends the information to the Internet using a physical, wired Ethernet connection.

The process also works in reverse, with the router receiving information from the Internet, translating it into a radio signal and sending it to the computer's wireless adapter. Wireless adapters can plug into a computer’s PC card slot or USB port.

The radios used for Wi-Fi communication are very similar to the radios used for walkie-talkies, cell phones and other devices. They can transmit and receive radio waves, and they can convert 1s and 0s into radio waves and convert the radio waves back into 1s and 0s. But Wi-Fi radios have a few notable differences from other radios:

They transmit at frequencies of 2.4 GHz or 5GHz. This frequency is considerably higher than the frequencies used for cell phones, walkie-talkies and televisions. The higher frequency allows the signal to carry more data.
They use 802.11 networking standards, which come in several flavors:
- 802.11b was the first version to reach the marketplace. It's the slowest and least expensive standard, and it's becoming less common as faster standards become less expensive. 802.11b transmits in the 2.4 GHz frequency band of the radio spectrum. It can handle up to 11 megabits of data per second, and it uses complimentary code keying (CCK) coding.
- 802.11g also transmits at 2.4 GHz, but it's a lot faster than 802.11b—it can handle up to 54 megabits of data per second. 802.11g is faster because it uses orthogonal frequency-division multiplexing (OFDM), a more efficient coding technique. 802.11a transmits at 5GHz and can move up to 54 megabits of data per second. It also uses OFDM coding.
- Newer standards like 802.11n can be even faster than 802.11g. However, the 802.11n standard isn’t yet final. (Industry insiders say the final standard may not be approved until 2008.)
WiFi radios can transmit on any of three frequency bands. Or, they can "frequency hop" rapidly between the different bands. Frequency hopping helps reduce interference and lets multiple devices use the same wireless connection simultaneously.

Now back to how it works: The wireless Internet "signal" is sent from your provider’s wireless Internet transmitters or relay stations to your rooftop receiver (CPE). From there, the signal travels through a CAT5e network cable to your router. Unlike dialup Internet access, your wireless Internet connection is "always on" and does not require you to login to the network each time like dialup Internet.

Wireless Internet access is basically what it says "wireless." A small antenna (usually around 1' x 1') is installed at the customer’s location. The small antenna is placed somewhere outside near the top of the building. The customer’s antenna communicates with the provider’s access point that connects the client to the Internet through the provider’s high-speed backbone. A coaxial cable is run from the antenna at the client's location to a broadband radio. The radio connects the customer's computer. If the customer has a network card, no additional equipment is required.

Wireless Internet technology is basically very similar to Cell Phone Technology. Your Wireless Internet Provider has a high-powered Broadcast Antenna placed at a very high location, and it sends or broadcasts signals to receiving antennas. The receiving antenna is placed at your home or business location, mounted at the best location determined by your provider. It is very simple. The only actual wire involved is the one Cat5 Cable that runs from the antenna, into your home, and is plugged into an existing outlet right near your computer.