The IEEE 802.11b Direct Sequence
Now that you’ve had a few basics on radio waves we can take it one step further. The title of this post probably doesn’t tell you a lot, although I’m very sure that you know what it is. Just by a different name: WiFi. This name has been commercially used since 2000, it was used because it just was catchier than the IEEE 802.11b Direct Sequence.
WiFi uses, just like your cellphone, radio, etc, radio waves. As a matter of fact, the transferring of data between a computer and a WiFi device happens very similar compared to send a radio signal. The computer’s wireless adaptor translates data into a radio signal and sends it’s via an antenna. The wireless device (a router for instance) receives the signal and decodes it. The router send the information to the internet by using a wire, the Ethernet cable. Needless to say this process also works the other way around.
Although very similar to radios, there are some significant differences from a “normal” radio. For example, wireless routers for instance transmit at frequencies of 2.4 GHz or 5 GHz. This is a lot higher than the frequencies used for cell phones. This high frequency allows the devices to transfer a lot more data. To give you an idea the 2.4GHz (which is the 802.11b standard, just putting this here as a side note) can transfer up to 11 megabits of data per second. While the 5 GHz version (802.11a standard) can carry up to 54 megabits per second.
And frankly, for the basics.. That’s all their is. Connect your computer to a wifi hotspot and you’re off :).