Question

Hello,

I installed my RUT955 in my cellar (for a particular reason) and I note that the Mobile signal strength is -109dBm.

In the living room the wifi signal is -60 dBm. Impossible to have a stable connection with Internet.

Weak signals.

The floor is in ferro concrete: this explains probably that.

How to improve all these stuff ? positions of the antenna ? other types of antennas ? do you have experience (models,...) ?

Thank's you,

Comments

@bigbloke

Yes, your analysis helps me !

Two small black with magnetic mount came with the RUT955. In a first step I could try to add a sma extension.

I moved the RUT955 in my living room just for testing (compare the values of the signals).

Yes my home has 2 floors and cellar.

If I can fix (more or less) the LTE problem, I must also find solutions for wifi: I want to use the RUT955 for the heat system AND for normal access to Internet thru wifi.

Best regards,

Answer 1

Hi,

Seems like only way will be to place antenna to outside.

Comments

The lenght of the cable is only 3m !

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You can always use other antennas than Teltonkas's, just check recommendations: https://wiki.teltonika.lt/view/Can_I_use_LTE/3G/Wi-Fi_antennas_other_than_Teltonika%27s%3F

Answer 2

I gave up on RUT955, I tried new antennas even Teltonikas latest panorma antenna and it stuck at max 20Mbit download speed. ( I have antennas outside)
I order the new X11 and hope its better, else I just change platform to other brand for the company needs. ( not going to order a few hundred of  RUT955 when the performance is this bad for sure, even older 4G routers that is a few years old are performing a lot better even with less potent WWAN chip. Something must be very wrong with the design of RUT955)
I guess its something with connectors or interfering form other component that make the RUT955 to be ultra slow)

Sorry to sound negative, but I got very unhappy.

Comments

Thank you for this negative point of view.

In my case the speed is not important. The coverage shall be optimal, I mean reception of the wifi in my house, but the RUT955 shall be in the cellar, indoor, in concrete walls.

Standard wifi antennas have a 2dbi gain. Shall I change for the 5dbi model ?

Answer 3

There are two factors.

1) Antenna locations
2) Feeder losses.

1) -109 dBm is - in cellular terms - a very small signal - in the original GSM system you would not
register on the network if you were smaller than -108dBm.

Conversely, -60dBm is quite a large signal - do you truly mean that the WIFI signal is -60?
as I would have expected your steel re-inforced concrete floor to have reduced this quite a bit
more.

So to get your SOURCE (i.e. INTERNET IN)  signal strength up you need an external LTE / 3G
antennas (2 of them) at least at living room level, but outdoors would be better again - theyre
quite small.

However, it begs the question, Why are you installing your router in the cellar? 
If your using your RUT955 WIFI it too will be impacted by your steel re-inforced concrete floor?

Perhaps you can share more information about your installation choices? then we can make better
reccomendations!

2) Feeder losses (signal drop in the co-ax cable between an external antenna and the RUT955
unit) become significant at cellular frequencies. Down at (say) the CB radio bands you can get
away with cheap 50 ohm co-ax cable  like RG-58. But at cellular frequencies you need cables
that permit less loss. I would go for Times LMR-200 of one of the cheaper HDF-200 "clones"
as theyre ok for up to 2GHz in short runs .

Also, you dont say how thick the living room floor / cellar ceiling is - so its very difficult to make
considered opinions

Your simplest solution would be not to install the unit in the cellar but put it near a ground floor
window - its not exactly a big unit and I have seen people hide small routers (in fake hardback
books on bookshelves for example) so you dont have to look at it.

I think for a more detailled reply I would need to know a LOT more about your installation choices

Regards

BB

Comments

Hello,

-109dbm is given by the RUT955 (status): I am localize in mountain

-60 dbm is given by the Android app "WiFi analyser" : I suppose the application can measure correctly ...

when the RUT955 is in the living room, the wifi signal strength is -35dbm

You preconize an external 4G antenna: this will increase my budget ! or may I modify the provided antennas ?

I installed my RUT955 in the cellar because I want to use the relay output (10 and 5) in order to command/control my heat during the winter.

The living room floor is in ferro concrete.

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Hi JPC

What we do not understand at this time is what the Mobile network dBm figure would be in your living room .

what we seek to obtain is a good (-80dBm to -40dBm) Signal strength on your LTE side as it is this side where the 
signal weakness is most present. You do not say how many floors your home has - I will assume therefore 2 + cellar
therefore the first floor is dropping about 25dB , and if you have an upper floor your wifi will be getting quite weak.
If no-one else around you has wifi this may not be a problem - if there are many wifi base units - it may become one 

From the limited knowledge of your situation and engineering figures you have provided I would say that the biggest
improvement to be made will be two external LTE antennas. 

Yes it will increase your budget - not by too much I would hope - but how much depends on many factors, all of which 
require a detailled knowledge of your location (top of valley?, bottom of valley? , height of hills?, the distance between
the LTE operator's masts and your home?, what is in between your home and the LTE operator's masts? and so on...)

Those factors require experimentation by yourself or another mobile network expert in your country (if you know of one).  

You ask "can you adapt the existing antennas" - well the short answer is yes - but much depends upon which antennas came with 
your RUT955. I have seen some with small black antennas directly attached, others I have seen with magnetic mount antennas

You can purchase SMA to SMA cable extensions which would go like this: 

<--------------------INDOORS------------------------------------------><-----------OUTDOORS----->
<LTE SOCKET1><SMA PLUG1>---------Cable extension1------<SMA SOCKET>ORIGINAL ANTENNA
       RUT955
<LTE SOCKET2><SMA PLUG2>---------Cable extension2------<SMA SOCKET>ORIGINAL ANTENNA 

But you must be careful where, and how, you  attach the antennas outdoors to maximise your signal

Adding the cable extensions means signal loss inside the extension parts. Your goal in moving the antennas 
is to boost the LTE (not wifi) Signal to a place where the incoming signal is better than the loss experienced 
in the cables - for example:

LTE signal improves from -109 to -90 when you move the router upstairs
Cable introduces 20 dB of loss 
actual signal at RUT955 = -90-(+20) = -110dBm

In that scenario you have outdoor antennas and would be one dB worse !! 

ideally find a good place where your LTE signal is as large (i.e. least minus figure -40 is MUCH bigger than -109)
as you can make it , then use VERY good quality extension cable like LMR 200/400 or HDF 200/400 so that as much
of the LTE signal as possible arrives at the back of your RUT955. That will guarantee you a good 
Internet feed

Then - and only then - start looking at the wifi dBm figures 

If your LTE signal is very weak outside you might need new outdoor directional antennas (like a smaller TV antenna) to get the
LTE signal up to a high enough level. this will cost more, but there is nothing I , nor Teltonika, nor anyone else on the 
forums can do about where you have chosen to live! :-)

A good source of cheap LTE directional antennas is Ebay

Hope this helps

regards 

BB