Answering A Wi-Fi Question With Analogies – Analogy #3

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 #3: A Prius and a Ferrari are racing on the highway, which car can speed the most? – Regulatory Domains and Frequency Restrictions

Let’s consider the normal roads and highways, not exceptions, like some roads in Nevada or the Autobahn in Germany. If any two cars are racing, the only way to win on a public road would be due to the difference to the starting time and acceleration. But which car would be able to set the speed record? With speed limits and traffic rules, the answer would be none! Two cars or more would all set the same maximum speed on the road provided they can all perform to that speed limit and are respecting driving regulations.

Police to remove grace speed limit in Abu Dhabi <https://uae.yallamotor.com/car-news/police-to-remove-grace-speed-limit-in-abu-dhabi-5312> Accessed on September 01, 2020

The same goes for Wi-Fi. Laws are to speed limits as regulations are to broadcasting gain/power. You can try to broadcast louder hoping to reach a farther distance at a higher gain, but the AP would always be bound by a set limit in its operating regulatory domain. A regulatory domain is the regulation that gets applied to APs from different vendors are alike. Even if one AP would claim to be more powerful or have more reach, that wouldn’t be possible because we can just raise the gain margin past a set maximum.

Broadcasting power/gain has set limits on the respective Wi-Fi frequency bands (currently 2.4 and 5GHz), channels, and coverage application (eg: indoor versus outdoor). As you can see in the picture above, different applications (car or truck) have different limits. These limits are defined by the respective regulatory and governing bodies. Globally, the FCC and ETSI rules are followed, and region or country-specific regulations are also added by local telecommunication authorities, such as the TRA (Telecommunications and Regulatory Authority) in the UAE and other countries. While the rules are mandated by these authorities, the actual application of those rules is set by the vendors on their equipment and is configured by the wireless network operator or administrator. Wi-Fi equipment can ship to a country once the regulatory authority certifies that it’s compliant with the authority’s rules.

Any deviation from the regulations from any of the stakeholders mentioned above, is considered against the law.

Previous:

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

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

5 comments

    1. Thank you Subhadeep. Will write different topics branching out from this series into other posts. Hoping to cover material that would benefit and broaden the knowledge for all our readers!

Leave a Reply