Tag Archives: decibel

The Rule of 10s and 3s

A while back I wrote a blog post explaining how an antenna works when it is connected to a wireless access point. Today I’m going to add to that lesson by explaining The Rule of 10s and 3s. Essentially, you can use this rule to figure out what your transmit power is going to be when you add various connectors, cables, and external antennas to your access points. Without further ado:

Please remember that using The Rule of 10s and 3s does not give you exact figures. It should only be used to perform rough calculations. Also, this video is not intended to be a technical deep-dive into the field of RF mathematics. Instead, my goal is to explain the basics of a complex topic so that almost anyone can understand it. (I’ve assumed knowledge of milliwatts and decibels though).

Dan C.

Bonus marks if you can explain why having this knowledge is important for anyone working with WLANs. Leave your answer in the comments section and share this video with anyone you think might benefit from knowing this rule.