Hey guys, thanks for coming back to Wi Fi fundamentals with location and analytics. This course will help you to muster the air. It's time to take a deep look at waves properties and trust me, it is a key topic. Why? Because everything in Wi Fi is somehow related to waves properties. Let's start.
Our first property is actually a measure of time. How long does it take for a wave to complete one cycle. Our second property wavelength is the distance between the peaks, or one trough of the wave to the other. It is expressed as the Greek letter lambda. Frequency is the amount of cycles a wave finishes in one second. We measure it using the unit hertz.
So 10 hertz wave is actually a wave that finishes 10 cycles. A second, you will see that the high frequency wave results in a short wavelength and vice versa. amplitude is the amount of energy the signal has. Or in other words, how strong is my signal, it is measured from the resting point towards the peak. And as the wave moves along over time and distance, it loses energy and its amplitude its power decreases due to free space path loss and interferences. We measure amplitude in absolute units such as a VAT or a minute VA or in a dBm scale which we will look into very soon.
Last property is phase. Remember that a sine wave is a periodic wave that repeats itself over time. In its nature form, it starts in zero degrees and finishes the full cycle. When it reaches 360 degrees, we say a wave is in phase if it is either zero degrees or 360 degrees apart. When two waveforms are not synchronized, there is a phase shift there picks and zero points do not match up the same points in time and this is this truck tip. The result is a loss or even zero amplitude zero power.
On the other hand, when both of the waves are in phase and in the same amplitude and friction See, the two waves reaching the antenna will look like a single wave. It is what we know as a gain a constructive interference. Our access point believes that it is receiving a stronger wave. Stuff Time To summarize, as our access point and station transmits RF energy into the air, it is represented graphically as a sine wave. A sine wave has all the properties to represent RF signal. As we meet obstacles in their space, they lose power amplitude, in several cases reflect back and different phase which sometimes called phase shift.
In real deployment, our access point antenna will get different types of wave Some of them destructive and some in faith. All right, that's all for today. Next up RF loss