Answering A Wi-Fi Question With Analogies – Analogy #1

How far can your AP reach?

Giving examples and telling stories are a few of the best techniques to send a memorable and impactful message across. Let’s try to put in simple examples, real-life analogies that would help clarify the question pitfalls and answer it.

Analogy#1: Wi-Fi coverage is like bouncing a pebble across water – Attenuation

Known as pebble skipping or skimming, have you ever noticed the effect of a pebble you try to skip across a surface of water? There are many factors that affect how many skips or jumps the pebble can make. Those include the pebble shape, smoothness, weight, water calmness, throw strength, throwing technique…etc. There’s a whole science and practice behind pebble skipping competitions and even a Guinness World Record of 51 skips across the water surface!

The first skip that the pebble makes gives you the biggest ripples in the water. This is your Wi-Fi data rate at your nearest connected client, or station (STA). The second skip that the pebble makes gives another set of ripples, still big, but not as big as the first one. This is your Wi-Fi data rate at your second nearest connected STA. And this goes with the pebble making ripples, the farther it goes, the smallest they are, until it plops to sink down in the water.

Stone Skipping – “Patagonia” by Killy Ridols is licensed under CC BY 2.0

I would like to simply think of this effect as transfer of energy. Remember how they taught us the change (and conservation) of energy forms between Kinetic and Potential Energy? When you threw the pebble, your arms Kinetic Energy charged the pebble with Potential Energy, while still at rest in your hand. Once you release it, the pebble’s energy will change into Kinetic Energy used to fly and bounce. At the beginning, the pebble will have more energy to convert and transfer in the shape of flying and bouncing, hence, bigger ripples will form at the first few and nearest bounces. If you have never done that before in your life, please try it, or watch a video of pebble skipping online on YouTube. Here’s a slow-motion video that will portray the discussion above:

The strength of a Wi-Fi signal at a specific distance to an AP, is like the size of the ripple to a skimming pebble. This is how a Wi-Fi signal is a form of traveling energy, slowly losing power as it travels farther due to the distance travelled and attenuated by other reducing factors in the medium it is traveling through, but more on that in a different analogy below.

Next:

Analogy #2: Even in a one-sided conversation, you still need a listener.

Analogy #3: A Prius and a Ferrari are racing on the highway, which car can speed the most?

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