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In this video, we break down the basic components of a wireless network.
Basic Service Set
A Basic Service Set, or BSS, is where we have an access point connecting multiple devices, which are known as members of the BSS.
Most wireless networks will connect back to the wired network. The upstream connection from the access point that connects back to the wired network is called the Distribution System or DS.
BSSID and SSID
The Access Point is periodically advertising the network details using radio waves. These advertisements are called beacon frame
Beacon frames contain several bits of information, but the two main bits are the Basic Service Set Identifier (BSSID) and the Service Set Identifier (SSID)
The BSSID is a unique identifier for the wireless access point, and it’s based on the MAC address.
The SSID is something I’m sure you have seen and used before. It’s essentially the wireless network name.
Extended Service Set
For bigger wireless networks, we often need to extend our wireless network using multiple access points. When we use multiple access points like this, it’s called an Extended Service Set.
Each access point in an extended service set will have a unique BSSID to identify the device.
The same SSID, however, can be used on multiple access points to extend the range of the wireless network.
The way our devices can talk to each other without the need for physical cables is by using electromagnetic waves.
This works by sending an alternating current into an antenna which creates magnetic fields that propagate out as waves.
You have probably heard of radio frequencies before, things such as radio and TV use radio frequencies.
Wireless uses two main frequency bands 2.4 and 5GHz
Now to make things a bit more complicated, these bands are split into separate channels.
If we look at the 2.4 GHz band, which is actually 2.400 to 2.4835 GHz, we can see that it’s split into different channels.
The reason we use channels is to split the wireless bands into smaller, more management pieces allowing us to control things like congestion and interference.
The 2.4 GHz band has 14 channels, however a lot of these overlap which can cause interference. So instead, it is recommended to use channels 1, 6, and 11 to avoid any problems.
Everything we just looked at is part of the IEEE standard 802.11
As wireless technology evolves and improves, amendments to the 802.11 standard are made.
It’s important to note that for two devices to talk to each other, they both need to support the same amendments. Luckily, devices can be compatible with multiple amendments so you shouldn’t run into many problems.