TM-AC1900 (RT-ac68U) 5ghz transmit power on channels 36->48

[Marc Aronson]

I've read through a bunch of threads about adjusting transmit power but have not yet found an answer to my question.

Background:

• I have no interest in doing anything that violates FCC regulations.
  
• Somewhere in the 2014 / 2015 timeframe the FCC in the US updated the regulations to allow higher transmit power on channels 36->48 of the 5ghz band.
• I purchased my TM-AC1900 in December, 2016 and it is running Merlin firmware 380.64.

My questions:

1. With the change in regulation, has the transmit power for the lower 5ghz channels been increased through a firmware or other update on the TM-ac1900 or any other variation of the Asus RT-AC68?
   • Based on various tests I have run, I suspect the answer is "no" for the TM-AC1900, but want to double check.
2. If the answer is "no", does anyone know which Asus router models are taking advantage of the higher transmit power allowed on those channels?

Thanks!

Marc

 

[bandit8623]

I've read through a bunch of threads about adjusting transmit power but have not yet found an answer to my question.

Background:

• I have no interest in doing anything that violates FCC regulations.
  
• Somewhere in the 2014 / 2015 timeframe the FCC in the US updated the regulations to allow higher transmit power on channels 36->48 of the 5ghz band.
• I purchased my TM-AC1900 in December, 2016 and it is running Merlin firmware 380.64.

My questions:

1. With the change in regulation, has the transmit power for the lower 5ghz channels been increased through a firmware or other update on the TM-ac1900 or any other variation of the Asus RT-AC68?
   • Based on various tests I have run, I suspect the answer is "no" for the TM-AC1900, but want to double check.
2. If the answer is "no", does anyone know which Asus router models are taking advantage of the higher transmit power allowed on those channels?

Thanks!

Marc

I am also curious about this. The higher bands are crowded in my area and it seems the lower bands have less signal and speed even though all settings are the same.

 

[sfx2000]

Background:

• I have no interest in doing anything that violates FCC regulations.
  
• Somewhere in the 2014 / 2015 timeframe the FCC in the US updated the regulations to allow higher transmit power on channels 36->48 of the 5ghz band.
• I purchased my TM-AC1900 in December, 2016 and it is running Merlin firmware 380.64.

That would require the device to be re-submitted to the FCC (and possibly other regulatory agencies) for full testing, which is quite expensive - this is different than a permissive change (changing out a RAM chip for example), which is generally a paper submission.

And with Asus' 2016 product lineup - the RT-AC3100/RT-AC88U/RT-AC5300... it becomes an easy business decision for them.

 

[joegreat]

1. If the answer is "no", does anyone know which Asus router models are taking advantage of the higher transmit power allowed on those channels?

Hi Marc,

The answer is simple: None of the actual Asus routers follows the allowed transmission power (above the minimum)!

Unfortunately the FCC rules from US forced the router manufacturers to limit the transmission to the absolute minimum. Regardless of the fact the some countries/regions allow up to 5x more transmission power for 5 GHz - see Wikipedia for details.

 

[sbailey4]

There has been discussion regarding this in other threads. But it seems Merlins (and a lot of others) consensus is the transmit power doesn't really do a lot due to the fact that the receiving devices remain at a lower power. Equivalent to you shouting across the room at the top of your lungs but the person you shout to responds in a normal voice. Even potentially the extra power adds noise that effectively could make things worse in some cases.

 

[bandit8623]

There has been discussion regarding this in other threads. But it seems Merlins (and a lot of others) consensus is the transmit power doesn't really do a lot due to the fact that the receiving devices remain at a lower power. Equivalent to you shouting across the room at the top of your lungs but the person you shout to responds in a normal voice. Even potentially the extra power adds noise that effectively could make things worse in some cases.

Well Tru in some ways. Higher transmit from router would allow faster downloads.

 

[Deleted member 22229]

I can confirm the ac3100 does have the higher power on the lower 5ghz channels. i have tested this many times and its confirmed. Not sure about any older asus routers.

 

[trentm1]

Well Tru in some ways. Higher transmit from router would allow faster downloads.

A download still requires responses to every packet

 

[John Navas]

A download still requires responses to every packet

True, but not relevant (a common misconception). The issue here is speed, not range:

• Higher power can enable higher speed for the big download packets.
• Response packets are not affected, but that doesn't matter, since they are tiny.

So while higher router transmit power may not increase range,
it can indeed boost download speed.

 

[octopus]

I purchased my TM-AC1900 in December, 2016 and it is running Merlin firmware 380.64.

https://www.snbforums.com/threads/a...d-forks-on-non-asus-devices-is-illegal.44636/

 

[CaptainSTX]

The OP never states that they are running Merlin's firmware or that the router has been hacked. As far as we know he is running the firmware native to his TM AC1900.

Therefore his questions are legitimate and worthy of discussion on this forum.

 

[thiggins]

The question was valid and allowed. But this is an old thread. @John Navas please check post dates before posting to old threads. Thank you. Closing thead now.