[SOLVED] Upper 5Ghz channels unusable at 80Mhz bandwidth

[DarnellG]

I have been troubleshooting my RT-AC5300 for several weeks. The 5Ghz-1 band is manually set to use ch36@80Mhz and I get up to 750Mbit/sec transfer between my wired pc and my samsung s10+. I was having issues with my 5Ghz-2 band. I tried every channel @ 80Mhz using the stock ASUS firmware and the Merlin firmware and both do the same thing. The signal strength on any channel (149-163) @80Mhz drops out completely or is detected very weak. Clients can connect but struggle to get anything over 1Mbit/sec. As soon as I lower the bandwidth to 40Mhz boom the signal strength returns to normal and I get a transfer rate of about 250Mbits. Still this is almost half the transfer rate I would get running the 5Ghz-1 band on the ch36@40Mhz but none the less useable. Again I am not detecting any other APs using the upper channels. All my channels are manually set, I do not use smart connect, I've disabled universal beamforming and fairness but no change.

I figured it must be hardware related so I bought a new RT-AX88U and did some testing on the upper 5Ghz channels and it does the exact same thing as my AC5300. Using any upper channel (149-163) @ 80Mhz causing the signal strength to drop below -80db. Using the lower channels (36-48)@80Mhz is blazing fast. I've read others have the same problem. I need help trying to determine the problem because I can't use AIMESH because it forces both my AX88U andAC5300 to the upper 5Ghz channel for the backhaul. I need to fix the problem using the upper 5Ghz channels @ 80Mhz.

 

[L&LD]

Have you tried using new SSID's in your testing? When testing one router, is the other one, off?

Have you reset the routers to factory defaults, fully? What other features and non-default services are you running on the network and/or routers?

The easiest way to get to the bottom of these issues, if possible, is to follow the link in my signature below to the M&M Config and the Nuclear Reset guides to get your routers to a good/known state first. Add one client and/or feature at a time and see where the issues start.

 

[OzarkEdge]

I figured it must be hardware related so I bought a new RT-AX88U and did some testing on the upper 5Ghz channels and it does the exact same thing as my AC5300. Using any upper channel (149-163) @ 80Mhz causing the signal strength to drop below -80db. Using the lower channels (36-48)@80Mhz is blazing fast. I've read others have the same problem. I need help trying to determine the problem because I can't use AIMESH if I can't fix the problem using the upper 5Ghz channels @ 80Mhz.

The AX88U is dual-band. My AC86Us are dual-band. I use 5.0 GHz, n/ac-mixed, 80 MHz, ch 149; and measure ~28 dBm signal strength at ~5 feet from the router using a WiFi Analyzer app. I've only ever measured speed/thoughput using laptop WiFi and speedtest.net (or DSLReports) and measure ~115 mbs at a typical working distance... cable ISP service is 100 mbs down.

So, how are you measuring your 5.0 GHz signal below/more negative than -80 dBm?

And, how do you measure WiFi speed?

OE

 

[DarnellG]

L&LD when I was testing the AC5300 in the beginning that was the only router I had. I tried many ways of resetting it, using the reset button, then after going into the administration,restore with the little box ticked to initialize, and tried the holding the WPS button on. I used unique SSIDs. I've been using your guide. The AX88U new out of the box did the same thing again using unique SSIDs. Last night I only had the AC5300 on and reset it to defaults. I had unique SSID for the 5Ghz-2 band and its very repeatable, 80Mhz weak signal, 40Mhz great signal

OzarkEdge I'm using an open source wifi scanner on samsung S10 and it goes down to -80 and sometime disappears. When I use the upper channels it drops from -40 @6' from the router to below -80. For my speed tests I'm running an iperf server on my wired desktop and iperf on my samsung s10.

 

[DarnellG]

I'll make a video and post it on youtube tonight showing what I observe

 

[OzarkEdge]

OzarkEdge I'm using an open source wifi scanner on samsung S10 and it goes down to -80 and sometime disappears. When I use the upper channels it drops from -40 @6' from the router to below -80. For my speed tests I'm running an iperf server on my wired desktop and iperf on my samsung s10.

I assume the wired desktop is not measuring WiFi.

So, the S10 is common to your poor signal and speed test results across two routers.

Assuming no contributing ambient conditions/factors, and given my 86U results, I wonder if your S10/testing method should be suspect and not your two routers...

OE

 

[OzarkEdge]

I'll make a video and post it on youtube tonight showing what I observe

We believe you.

OE

 

[drabisan]

What is the region of your router?

 

[DarnellG]

OzarkEdge, I know you believe me , its more so you can see if I'm doing anything wrong that I obviously cannot see.

What do you mean my desktop isnt measuring wifi? I'm measuring the throughput using an iperf on my desktop wired to my AC5300 and I connect my s10 to the SSID running on 5Ghz-1 (ch36@80Mhz) and I get 750Mbits/sec max. I switch to the SSID on 5Ghz-2 running on ch149@80Mhz I get below 10Mbits/sec and ch149@40Mhz I get 250Mbits/sec.

 

[OzarkEdge]

What do you mean my desktop isnt measuring wifi? I'm measuring the throughput using an iperf on my desktop wired to my AC5300 and I connect my s10 to the SSID running on 5Ghz-1 (ch36@80Mhz) and I get 750Mbits/sec max. I switch to the SSID on 5Ghz-2 running on ch149@80Mhz I get below 10Mbits/sec and ch149@40Mhz I get 250Mbits/sec.

I'm not familiar with how iperf works, so I simply assumed a wired desktop was not making WiFi measurements.

OE

 

[DarnellG]

@drabisan
I'm assuming its running on the US region because I'm in Canada and I downloaded the firmware from the US site. I didnt see any setting to change this. In the AC5300 I only can manually select ch36-48 and ch149-165 IIRC. On my AX88u I get more channels I'm not at home so I cannot state which they are.

 

[drabisan]

Because what you're describing sounds like a low power channels/indoor. In Europe those channels are rated at 25mW and in most equipments is not even an option.

 

[OzarkEdge]

I'm assuming its running on the US region because I'm in Canada and I downloaded the firmware from the US site.

A preliminary search suggests router region (regulated) may be locked into the hardware.

OE

 

[DarnellG]

I have the AX88U in my vehicle and in an area that has no signals accept from my router and whatever my vehicle emits. I resetted the router using the reset button and than reset it once more in the administration section, selected restore to defaults with the initialize all settings box ticked.

I have the router running inside my vehicle connected to a laptop on cat5 and my s10 on unique test2g and test5g SSIDs. I tried the following channels and bandwidth, ch36@40/80/160Mhz and tried ch149@40/80/160Mhz. Its funny on my AX88U with stock firmware I have many more channels to choose from ch 36-64 , 100-112 , 132-161 but I stuck with the ones that are available in my AC5300.

At least now the wireless doesn't crap out when using 80Mhz which is good at least I know the routers are good but all speeds are notably slower than my best speeds at home. This is probably due to the fact I'm inside a vehicle and the signal is probably reflecting alot inside.
Average throughput.
ch36@40Mhz=251Mbits/sec
ch36@80Mhz=485Mbits/sec
ch36@160Mhz after a minute the wifi comes on and it defaults to 80Mhz

Ch149@40Mhz=220Mbits/sec
ch149@80Mhz=495Mbits/sec
ch149@160Mhz after a minute the wifi comes on and it defaults to 80Mhz

I am assuming when I select 160Mhz it defaults back to 80Mhz because of some signal detection or region restriction. In any event 160Mhz was not something I would run because I really do not want to use channels outside of the UNII-1 and UNII-3 allocated bandspace. The power output restrictions in the DFS channels would probably be too low as I want as much range out of my 5Ghz as possible.

I'm going to do more testing in my vehicle as I approach my home. At some point if its interference caused by something inside my home the throughput should go down as I appoach. Any thoughts? How would I know what is causing it to revert from 160Mhz to 80Mhz? If I'm not detecting any APs using the 149-161 channels what could be causing the interference? How to detect if there is excessive noise?

 

[thiggins]

Take 160 MHz out of play. The S10 doesn't support it anyway. It also adds the possibility of DFS radar detection into the mix.

So you moved everything out of your house and you are getting the same throughput on low and high bands. That sure does point to some interference source in (hopefully) or near your home.

Unfortunately, since you aren't seeing any APs (does the scanner tool you're using detect hidden SSIDs?), I suggest you start by powering off everything in your home that has a WiFi radio and see if the high 5 GHz band is ok. Then bring things back up until you find the culprit.

Do you have any old 5 GHz band cordless phones, baby monitors (audio and video)?

 

[DarnellG]

I found the culprit. My Astro A50 wireless headset transmitter/amplifier was causing the interference. My headphones's battery was dead but amp was still powered up. Its always been in the area of my router hiding in plain sight.

How I found the problem. Last night I moved my routers upstairs (for the first time) away from my desktop where I always configured my routers and where the wireless headset was connected. I was doing throughput tests using my desktop downstairs connected with a wired cable to the router upstairs and everything was blazing fast on that level. As I was running the test I walked downstairs and within 15' of my desktop and of my headset amp the throughput dropped to below 10Mbits (from around 500 upstairs) I pulled the power plug to the wireless headphone amp and boom I was getting over 400Mbits which is reasonable with the router upstairs.

I'm not sure why it took me so long to find it, I guess not seeing any APs in that bandspace kinda made me not think of interference right away. All those hours of troubleshooting finally paid off. I hope this help anyone else having wireless issues due to interference.

 

[royarcher]

I found the culprit. My Astro A50 wireless headset transmitter/amplifier was causing the interference. My headphones's battery was dead but amp was still powered up. Its always been in the area of my router hiding in plain sight.

How I found the problem. Last night I moved my routers upstairs (for the first time) away from my desktop where I always configured my routers and where the wireless headset was connected. I was doing throughput tests using my desktop downstairs connected with a wired cable to the router upstairs and everything was blazing fast on that level. As I was running the test I walked downstairs and within 15' of my desktop and of my headset amp the throughput dropped to below 10Mbits (from around 500 upstairs) I pulled the power plug to the wireless headphone amp and boom I was getting over 400Mbits which is reasonable with the router upstairs.

I'm not sure why it took me so long to find it, I guess not seeing any APs in that bandspace kinda made me not think of interference right away. All those hours of troubleshooting finally paid off. I hope this help anyone else having wireless issues due to interference.

You had me wondering what you guys where talking about when you said you had your ax 88 u in the car I was going to suggest that you try your lounge room but seriously good to hear that you worked it out

 

[GuruGuy]

You had me wondering what you guys where talking about when you said you had your ax 88 u in the car I was going to suggest that you try your lounge room but seriously good to hear that you worked it out

I was wondering too, you’re not alone hahaha

 

[royarcher]

I was wondering too, you’re not alone hahaha

Truly but ,it was a great idea to try it out side in the car where the interference would be minimal though,nice "thinking out of the box "

 

[DarnellG]

The reason I had the router in my vehicle was to eliminate any interference that I might have had in my house. After several weeks of pulling my hair out I was going to extreme measures. I could not make sense of the fact that even a brand new router was doing the exact same thing while people here were saying they were having no problems. I'm getting over 500Mbits/sec everywhere in my house with this ax88u and ac5300 in mesh configuration and getting over 750Mbits/sec within 10' of any router.