Hey everyone, thanks for coming back to another chapter in Wi Fi fundamentals with location and analytics. This course will help you to muster the air. We've finally laid the foundation we understand now how will wave is created, how it is being propagated in the air, how it reacts to interferences. We will keep on discussing waves and RF theory as we continue, but now it is time to understand the basic WiFi process. Basic Wi Fi connection process is like seeking a job. There's the active job seeker who is always looking continuously for jobs.
And there's the passive one who's waiting for job proposals. We will keep them developing this analogy as we go on. So what is the head we will extend our key terms knowledge. We will also look at the anatomy of a job seeker which is actually our station, our station looking for the access point, we will look at the different discovery techniques the passive scan and the active scan and how do devices connect and share the air everyone in your Wi Fi network wants to talk. We have already discussed what is an access point and what is the station and the group of stations connected to one access point is called a BSS. in your house.
You probably have a BSS. But if you have a bunch of BSS IDs that are connected to the same distribution system To the same switch and gateway, as you probably do in your work or office, you have an extended service set. There is also the SSID, which is the name of the wireless network, and the BSS ID, which is the MAC address of the access point. We will look at MAC addresses as we go on. So we have arrived to an area where access points are all around. And now our station or smartphone needs to discover them.
How do they get acquainted? Well discovery the way a station locates an access point can happen in two ways. The passive way and the active way. The passive way very much like The person who's passive when looking for job is done using a beacon frame. a beacon frame is like job proposals. It is a frame that is sent as a broadcast frame.
A broadcast frame is a frame that anyone can hear in the network. It is sent at the lowest data rate, usually each 100 millisecond. a beacon frame holds information on the access point such as its name, its BSS ID SSID. The supported data rate, its security and encryption capabilities such as WPA two and three. The channel it works in the frequency the AP works on and the channel with 20 or 40 megahertz or even 80 160 megahertz if it is an AC access point and then there's the active way the guy who is always looking for a job in the active discovery phase are station sends another frame the probe request frame, seeing, is there anyone out there? It is sent in every channel that the station supports.
And when it is sent, it waits a while. If there is no answer, it moves to another channel and transmits. Every AP that receives the probe request must respond. There are actually two types of probe request. There's a now probe request that is sent to anyone with no money. Specific SSID and there is the direct one that described contains the SSID name.
So we've had our probe requests sent by our station, asking is there anyone out there and our access point responds, they respond with a probe response, which is a frame that is actually very much like that beacon frame. It contains all of the APS capabilities, supported data rates, frequency views, encryption and security and so on. Up until now, we have seen the discovery process. It started out with a passive scan our station here's a beacon frames sent by the AP describing its capabilities and Active scan this session describes his capabilities and asking is there anyone out there? We will continue with the association process in the next part. See you then.