Networks

By the end of this lesson, you will be able to:

• Identify what a network is and how devices in our home connect
  • Create networks for a given scenario
    • Understand basic network hardware and their uses

What Is WiFi?

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.

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. The router 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.

Frequencies

The radios used for WiFi 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 WiFi radios have a few notable differences from other radios:

They transmit at frequencies of 2.4 GHz or 5 GHz. 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.

2.4 GHz connections are now considered somewhat obsolete because they carry lower data speeds than 5 GHz. The 2.4 band continues to see use, however, because the lower frequency can carry over several hundred feet. In ideal conditions, the 5 GHz band has a max range of about 61 metres, but in the real world, it is much more prone to interference from walls, doors and other objects. The 2.4 band may be faster for a user connecting to a router several rooms away, while 5 GHz will definitely be faster for a close connection.

WiFi uses 802.11 networking standards, which come in several flavors and have evolved over the decades:

802.11b

Firstly introduced in 1999, is the slowest and least expensive standard. For a while, its cost made it popular, but now it’s 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 complementary code keying (CCK) modulation to improve speeds.

802.11ax

also known as WiFi 6, came to the industry in 2019. This standard extends the capabilities of 802.11ac in a few key ways. First of all, the new routers allow an even higher data flow rate, up to 9.2 Gbps (gigabits per second). WiFi 6 also lets manufacturers install many more antennas on one router, accepting multiple connections at once without any worry of interference and slowdown. Some new devices also connect on a higher 6 GHz band, which is about 20 percent faster than 5GHz in ideal conditions.

802.11be

is projected to be the standard by 2024, and should offer even better range, more connections and faster data rates than any of the previous versions.

WiFi radios can transmit on any frequency band. 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.

As long as they all have wireless adapters, several devices can use one router to connect to the internet. This connection is convenient, virtually invisible and fairly reliable; however, if the router fails or if too many people try to use high-bandwidth applications at the same time, users can experience interference or lose their connections, although newer, faster standards like 802.11ax will help with that.