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networkn:sbiddle:networkn: Doesn't AC have much less range than ABG and N?
It's not do with AC - it's the fact 5GHz has less range than 2.4GHz. N works on both 5GHz and 2.4GHz.
So 5Ghz N has the same range as AC (Which is only 5Ghz if I am reading correctly)?
Sortof
I'll try to explain each point and then you will see how it all gets put together.
- Signal is measured in decibels and a good signal is between -60db and -70db with a margin of about 30db above the interference noise floor.
- Your AP transmits the signal and the antenna in your laptop recieves it. Better antenna in the client device = better captured signal and better range. This is why cellphones are crap with wifi range.
- However working against you is free space path loss (the air) and any objects in the direct path such as walls, cabinets and plates, books etc in the cabinet.
Different objects or masses have different absorbtion characteristics.
Air wont absorb much of the signal and lets most of it pass through. A drywall for example will absorb less signal than a wall made of concrete as there is more mass in the concrete wall where as the drywall is typically hollow with maybe some insulation inside it.
- 2.4ghz can get through mass better than 5ghz. That is if the AP transmits at the exact same power level, you might be able to get a -70db signal through two walls at 2ghz, but at 5ghz it might be down at -80db. The mass making up the walls have absorbed more of the 5ghz signal.
- The signal level above the noise floor is what determines the clarity and your client device's capability to decipher the radio waves. Better signal = more clarity and therefore more speed can pass through. If there is a low signal or noise causing interference then the speed is automatically stepped down so the signal remains clear enough for the client device to decipher from the noise.
- A single chain A/G radio will typically operate at full speed (54mbits) at -75db. A single chain N radio can operate slightly faster if you give it a signal of -73db and its capable of 65mbits. They also added dual chain capability to N so you could get up to 150mbits but thats beside this point.
AC took it even further. They added some more speed levels to the single chain so it could operate at its full speed at a signal level of -65dbm
But like N they did some other things like adding multiple chains to increase the speed - two chains in parallel = double speed etc.
However if your AC signal happens to be down at -73db then you are only going to connect at N speeds. There is no general advantage of having AC unless your signal is better and your noise floor remains the same.
So to summarise
5ghz has a shorter range than 2.4ghz
AC doesnt typically give you a performance increase over 5ghz N unless you are 1 wall or less away from your router
In some situations, 2.4ghz can penetrate more walls and give you a better signal than a 5ghz one so it could possibly perform faster,
But this is unlikely in an urban area because you will suffer from noise throughout the neighbourhood.
5ghz has the disadvantage of shorter range, but that is also its biggest advantage as there is less noise from neighbours.
Therefore its a mixed bag - would better penetrating 2ghz signal perform better than less 5ghz signal (but also less noise) ?
I am reminded of WDECT cordless phones that advertise more range at 5ghz than standard 1.7ghz DECT which technically can give more range but the box still likes to tout 5ghz as better but i can only think they claim that due to less noise which in reality isnt really a problem for cordless phones and it just makes me angry.
I see now as I click reply I have probably not given a definite answer.
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