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daviddondero's avatar
daviddondero
Newbie Caller
Hace 4 años

Horrible signal to noise ratio

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.

  • djb14336's avatar
    djb14336
    Bandwidth Buddy

    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.

  • 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. 

  • daviddondero wrote:

    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.

     

    Hola 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.

  • copz1998's avatar
    copz1998
    Connection Curator

    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.

     

  • copz1998's avatar
    copz1998
    Connection Curator

    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. ¡Buenas noticias!

    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.