Question

Horrible signal to noise ratio

  • 30 August 2021
  • 15 replies
  • 4411 views
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So my signal to noise ratio is really terrible. So much in fact that my Internet speeds can be 1 to 5 Mbps if lucky. Looking through my gateway settings as well as the app settings I see that the signal to noise ratio is not where it should be. This is causing the connection to drop or even the modem to reboot on its own. As you can see in the attached screenshots the signal to noise ratio is really horrible on the primary signal as well as represented on the app but the signal to noise ratio on the secondary signal is actually quite good. Unfortunately that’s not being reflected because I’m still getting a terrible connection as I had mentioned.

I’m also getting a crazy thing happening where I’m getting locked out of my gateway page(192.168.12.1) but that might be a different problem.


Is there any way for the secondary signal to kick over and stay basically making it my primary signal?

and by the way this cannot be a heat issue since I have a fan underneath the modem and a fan on top of the modem.

15 replies

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Userlevel 5
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Odd I wish my reading looked half as good as yours you have great signal compared to me.

I am averaging 50-80 at best so no idea why you have such slow speeds. But these things are finicky moving them even a very small amount yields big gains in speed.

 

I don't see you listing it what are both your primary and secondary signals? I see the B2 but you should have 2 like this.

 

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This is what I have. I honestly don’t know if it’s good or bad. I just can’t understand apart from the terrible signal to noise ratio why my connection is so bad.

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You are very close to the 5G what you need to do is put the can on a long ext cord move it around even inside your home. Test many spots sometimes you will get much better speed with a little less signal bing inside. I mean you have such good signal strength you should find a spot where you get 100+ off that n71.

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I really hope so my friend. Right now as you can see in the attached picture my router is up in a ceiling window that is facing the tower which is the next street over. I don’t believe it’s a 5G tower though. That is why I cannot understand the whole signal to noise ratio problem. I’ve got two fans running one on top one of the bottom. I even have a black out shield on the window so the sun doesn’t hit it and it doesn’t get hot up there. It looks pretty messy and butt ugly! But when I try to make it nice and neat the signal was even worse. If I move around my apartment like you suggested I will be going away from any windows and going more towards the hallway of the apartment complex. This will be going in the opposite direction of the tower. But I will take your suggestion and give it a try.

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This is my set up. It’s in a window that is as high as the ceiling. And that window is facing the tower. As much as I moved the router ever so slightly in that window it would either make no difference or would make the connection worse. The window is blocked so no heat can come through. And there are two fans one on the bottom and one on the top of the router. It looks pretty ugly. I tried to make it nice and neat but that only made the signal worse. I will definitely try your suggestion though. Although any other location in my apartment is going to be further away from the tower and closer to inside the apartment complex which will be closer to the hallway.

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Looks nice.

 

Do keep in mind that there are 4 antennas on the unit so rotation can Improve download speed. Look you will find many post that say signal is not the best indicator download speed is. Also many post that say moving the unit indeed did make the signal worse but somehow made download speed faster. Since you have great signal and are complaining about speed why not give rotation a try you have nothing to lose and all to gain.

I am in a second fl window facing the tower. Just did some more speed testing (don't care about signal) rotation changed download speed in a range of 25 to 80. So when I find the spot that gives 80 I fine tune it. I have tape with marks so I can move one tick at a time and test.

So just give it a try.

Also you will find post where again no one knows why but they get much better speed with the can inside and less signal. So don't get hung up on the signal if you want speed try moving it.

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Attempted to move my router all around my apartment and unfortunately the speed got progressively worse as I tried. So I put it back to where it was before and unfortunately now the speed is much slower than it was before I moved it!

My signal to noise ratio on my primary signal is 0 dB!  Obviously you can’t get any worse than 0 db for signal to noise ratio! I also noticed that my band on my primary signal has now changed to be B66, where this afternoon it was B2. I don’t know if that change was what made things worse.

 

You had mentioned that I’m very close to the 5G. How were you able to determine that and is there anything I can do on my end besides moving my router? Does the secondary single even matter? The reason I’m asking is it seems I’m not even using the secondary signal despite it being there so is everything relying on the primary signal? It sure seems that way because I get the feeling the secondary single is not even being used. I wish there was someway I could get them to have the point at the secondary signal and make that the primary one.

scottjd

First I would only run one fan and make sure its blowing bottom to top and you have spacers under the fan so it can draw air in from under it. Fans can cause interference noise sometimes, one at the bottom blowing up is more then enough to help push the passive heat dissipation faster. You can out a piece of single layer tissue on top to see if the fan is pushing enough.  I noticed sometimes if you turn the fan a certain way it can push more.  If this is a 12V fan you wont need to run it at 12V as that could just cause more noise interference so I suggest running it at 5V from a USB power supply. 

Have you done a full default reset on the unit since you found a good spot with the good secondary signal? I have also seen others mention that it needs to be unplugged for 3 minutes before plugging back in. Maybe the secondary signal is active but not fully online yet?  You could call T-Mobile and ask, or maybe they dont know the tower is having any issue unless you report it.

Mine is running the same channels of B2 primary and n71 secondary (see attached picture).  I have attached my speed test results also. I found that because of the way speedtest does the test sometimes the servers cut back on the upload speeds, so I started running it from my router that's that I use off the ethernet. My router is 22 feet away on the other side of the room. I did this to also avoid unwanted interference as listed with the FCC Part 15.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

 

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Thank you, Scott
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The other metrics are not bad... putting you in fair/good range or better--so it is putting you at the higher quality range, which allows for higher QAM and such.

 

The problem may well boil down to a capacity issue... either at the tower or the backhaul.  Something TMO would need to be made aware of and address somehow.

 

If you could find another tower nearby to latch on it might help.  Used to be able to do that in my market... move to the other side of the wall and I had two other bands to work with.  But they have since increased power on the primary tower, so it always picks the same B2 or B66 to the east of me.  If I ever see the tower to the northwestt, it is usually only briefly after a reboot now.

iTinkeralot
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From looking at the small window you have the router situated in with the metal frame it could be you are getting multipath propagation due to radio wave diffraction. This would be difficult or impossible to prove without equipment to analyze the signaling. I am just speculating. The router may be directly facing the tower where the signals come from but if the small window results in interference resulting in the diminished SNR. The RSRP and RSRQ values look pretty good but the noise is probably resulting in some packet damage and diminished speed due to retransmissions. It could be a capacity issue or backhaul issue but T-Mobile engineering should be able to determine the actual loads on the equipment. 

Using the external “router” for WIFI and disabling the WIFI in the Nokia router might help a bit but if the cellular signals are suffering from external influences that might only improve local wireless connectivity. If you do indeed have line of sight to the tower then a YAGI external MIMO antenna directed right at the tower would probably help reduce noise and improve performance. Instead of locating an external antenna on the exterior wall directly facing the tower it might be necessary to leverage other building surfaces to shield the antenna from unwanted signals to allow the antenna to have cleaner signal wash from the desired tower. The downside of an external antenna is the added cost. With lightning arrestors and a 2x2 MIMO external YAGI antenna you would be looking at $300-$375 to do that. 

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Attempted to move my router all around my apartment and unfortunately the speed got progressively worse as I tried. So I put it back to where it was before and unfortunately now the speed is much slower than it was before I moved it!

My signal to noise ratio on my primary signal is 0 dB!  Obviously you can’t get any worse than 0 db for signal to noise ratio! I also noticed that my band on my primary signal has now changed to be B66, where this afternoon it was B2. I don’t know if that change was what made things worse.

 

You had mentioned that I’m very close to the 5G. How were you able to determine that and is there anything I can do on my end besides moving my router? Does the secondary single even matter? The reason I’m asking is it seems I’m not even using the secondary signal despite it being there so is everything relying on the primary signal? It sure seems that way because I get the feeling the secondary single is not even being used. I wish there was someway I could get them to have the point at the secondary signal and make that the primary one.

 

Hi David,

Your SNR can certainly drop below 0 dB to negative values - it is not a linear thing with zero being no signal.  SNR is 10 times the log (base 10) of the ratio of powers of the signal to the noise in the receiver bandwidth.  So when they are equal, that ls 10 times the log of 1, which is 10 times zero, or zero.  When the noise exceeds the signal, you get negative values.  You can still get reception with negative values, but it’s not a great place to be.

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My signal to noise ratio on my primary signal is 0 dB!  Obviously you can’t get any worse than 0 db for signal to noise ratio!

 

 

I CAN!!!!

 

 

copz1998
Userlevel 5
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Hello all,

I am providing the following post to those who like me have a low SINR and slow 5G speeds. On another forum, I learned that one user found that using tin foil to block out unwanted signals works. So, due to the lack of technical support from T-Mobile, I gave it a try.

First, your mileage may vary. For me, I started with an SINR of 1. As I progressed I am at 11. I hope tomorrow to get some thicker tin foil and block out the other signals to get close to 20.

See the pics. For me the gateway is facing towards the south, the direction of my 5G antenna. There are antennas to the north (right of the gateway) blasting signals out, which my gateway is receiving and causing my low SINR. The tin foil is blocking those signals. 

This experiment has taken several hours to figure out, but now I have evidence the concept works; block out the unwanted signals with tin foil. I will clean up the wiring and setup once I finish the tin foil work.

I hope this helps.

 

I am not a T-Mobile employee, but like helping others.
copz1998
Userlevel 5
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I want to follow-up with this post regarding SINR and signal reception. I went to T-Mobile and exchanged my Arcadian with the new Sagemcon gateway because it looks easier to open and add antenna leads.

I placed a 2X2 Waveform antenna in my attic pointing at my n41 antenna. But, I was getting a lot of cross signal interference from south and east of me. I wondered if the cheap windshield screens from my local Walmart would reflect unwanted signals with the goal of increasing my SINR. Good news!

Band: n41

SINR before 4 / after 14

RSRP before -89 / after -87

RSRQ no change

My page loadings from YouTube and websites is much quicker. If you are in a similar position, you may want to give this a try. I hope this helps.

 

I am not a T-Mobile employee, but like helping others.
iTinkeralot
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Userlevel 7
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To take full advantage of the n41 the 4x4 MIMO antenna is best. When researching the external antenna solutions one of the techniques to reduce noise is to use the structure as a shield from unwanted signal interference. With my solution I found that to be helpful. Installing at a higher point is not always the best solution. Improving results does take a bit of experimenting for sure. 

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