> The bidirectional connection is symmetrical. It doesn’t matter if the AP has a better antenna or is located higher up. The antennas and amplifiers work symmetrically in both directions.
It does matter if antenna is located higher up. This will allow it to pickup weaker signal from clients. Better antenna is also probably more sensitive.
I think what the author meant to express is that the situation is symmetrical, even if one of the antennas is "better" (eg larger, or located higher up). So, author probably meant: "The bidirectional connection is symmetrical. It doesn’t matter (in terms of symmetry) if the AP has a better antenna or is located higher up".
So, even if the antenna on one side is "better" in some way, it affects both directions the same, and as such it still makes sense to use the same transmit power from both ends.
Not only that but APs usually have more antennas, which makes a huge difference. The antennas can also be spaced out more (for better diversity) and be physically larger (typically you get more gain the closer your antenna length is to the wavelength of the signal).
You can also have better analog RF components with more space (filters, LNAs, PAs, etc).
It's not necessarily true that the "advantage" of the AP is symmetric as well. The tx power is limited by FCC part 15 so the difference in tx power between AP and client is probably less than the difference in Rx sensitivity between the AP and client.
Even if the uplink and dowlink are symmetric, the traffic profiles are probably not - there's probably a lot more data going to the client.
Yeah, that sticks out like a sore thumb in an otherwise accurate article. Antennas have a certain radiation pattern for transmitting, but there is also improved reception in the directions it radiates strongly in.
With wifi, there is usually little you can do since you probably want a spherical radiation pattern, which prevents you from getting any significant gain over a perfect isotropic radiator, but that's a different story.
Probably also giver you higher probability to have line-of-sight, especially in a crowd.
Less walking bags of absorbent human bags of water in the way.
Exacty, that is why we have cell towers, not streetside cabinets. Both indoors and outdoors people and other obstacles try to clutter around ground/floor level more.
It does matter if antenna is located higher up. This will allow it to pickup weaker signal from clients. Better antenna is also probably more sensitive.