Hey everyone, thanks for joining back to Wi Fi fundamentals will location and analytics. This course will help you to master the air work part four of our antennas series and this one is the last chapter. What are we up to? Well, we will look at antenna types we will learn how to calculate Ei RP, which is the effective power transmitted from your Wi Fi access point. We will also take a look at antennas beam factors, which is something you need to know it influences your coverage area and why hackers are using high gain antennas. There are several types of antennas but in general, there is the omni directional and the directional antenna.
Different Types different focus omnis has 360 degrees coverage when you look at it's been from the top view. But take a look at it side view. It's far from being spherical. Reminds me of something. Yep, it's a doughnut shape. omnidirectional is vertical coverage we rise with its antenna again.
Usually it is between 70 to 80 degrees. Their power their gain is usually between two DBI for 2.4 gigahertz access point, and five DBI for a five gigahertz access point. directional antenna is another story look at its main low. Its beam is cool. whizzed into one narrow direction. The pros, its signal coverage and sensitivity are way bigger than omni directional antennas.
The cons because of the narrowness of the signal, the area beside and above stays on cover. A Yagi is a known directional antenna. And so is the dish antenna. antennas coverage various different types different coverage areas, we can represent the courage to it's been patterns from above, which is the age plane and only has a full coverage 360 degrees. From the side view, the vertical view we can see that not all of the area is covered So we have our access point power it is connected to an electrical source and we have our antenna gain which is also something that adds to its power. And in some cases when we use external antennas we also have cables and connectors.
How much power do we send out of our access point? Well that is the effective is tropic radiated power. The bottom line quite simple equation is simple. Ei RP in dBm is the transmission power minus the cable loss plus the antennas. Okay, so if we have a 14 dBm access point, power and a connector or a cable that makes it close another two DB antennas gain that is equal to four DBI. The sum of all is 16 dBm power.
And if we're into equations and other equations, which is quite interesting, although we will not get into the numbers, this is the equation that shows us that there is a relationship between the effective area or the size of the antenna and its gain. gain is equal to four pi the effective area divided by lambda squared. The bottom line. If you want more gain, use bigger area and tennis and use lower frequencies. This course is not about hacking, but know that high gain and directivity are used by hackers to attract to WiFi stay To connect to them. They do it usually in two steps.
One, dissociate the user from their safe access point. And reassociate them using a soft AP a virtual one with the same SSID, the same Wi Fi network name and a stronger signal due to their high gain antenna. All right, next up the needy greedy we will learn a basic Wi Fi process. See you there.