Situation:
I am using a RUT955 on a Site in Switzerland, but very close to the german border. The Swiss Signal (Swisscom) is quite weak; RSRP LTE ca. -80dB, RSRP UMTS ca -105dB. All other swiss carriers are weak. All german carriers are quite strong. I don’t want to use a german SIM-Card. Roaming is switched off.
Antenna is a X-Pole MiMo for LTE with approx. 6dB gain. I already spent a lot of time to align the antenna as good as possible.
Issue:
The RUT connects to Swisscom LTE for a few minutes, then it switches back to UMTS and finally looses the connection. After a few Minutes, this is repeated.
Finally, after a few Days, constantly no connection anymore.
Questions:
I’m afraid that the german Signals interfere heavily with the swiss signals. Unfortunatly I’m not able to give any statement about Singal-Quality SINR. Is there any possibility to filter out german signals and if yes, how? Are any external filter available?
There’s no option within the RUT955 itself to hardware-filter out german operators’ frequency bands. Preventing interference from german carrier signals would require the use of external RF filters, such as band-pass filters, which allow only specific frequency bands (e.g., Swisscom LTE bands) to pass through, or notch filters, which are designed to block out specific unwanted frequency bands.
In this case, one potentially effective step is to try band locking on the RUT955. You can perform this directly through the WebUI page by:
Navigating to Network → Mobile → General;
Setting Network type to 4G only or Auto (default).
Enabling Manual band selection;
Specifying the most stable LTE bands that Swisscom uses in your area (typically Band 20, Band 3, or Band 7 in Switzerland, depending on the region).
A video guide is available here to assist with this:
Also, since the XPOL antenna is directional, it’s critical to aim it as precisely as possible toward the correct Swisscom cell tower. You can locate that tower using opencellid/cellmapper using Cell ID, TAC, MCC, MNC parameters found on Status → Network → Mobile page.
Additionally, if possible, please share a screenshot from the Status → Network → Mobile page with any sensitive/private information, such as IMSI, ICCID, etc hidden/blurred.
Unfortunatly Band 20 is used in Germany and Switzerland. Because of national limitations, swiss carriers are only allowed to send with a 10x lower level than in other courties (so called NIS-V). Not good at all.
Other Bands (higher frequency) are not available or its reliablity is even worse.
However, this is what I get the best after spent again some hours of try and error yesterdays:
RSSI seems to be quite good, but RSRP is very low, while RSRQ and SINR are ok. What can be done to improve that? The RUT was looked to band 20. Band 1 is the same but even worse, other bands are not available.
To give you an idea, how the geographically situation is, see 47°35’02.5"N 7°51’30.2"E. The area is quite steep towards gemany.
Switching back to UMTS is about -105dBm, slow, but more stable than LTE - summarised not satisfyable.
In this case, it’s difficult to suggest any additional improvements beyond those already outlined in the mobile signal strength recommendations wiki article here:
Additionally, judging from cell information, it appears that the modem is connected to a cell on Germany’s side, which is a bit weird.
Furthermore, a higher gain directional antenna, mounted at the highest feasible point and aimed precisely toward the mobile tower, might give a noticeable improvement.
That said, it’s worth noting that the RUT955 is a relatively older LTE Cat4 device, meaning it does not support carrier aggregation. Given its end-of-life status, upgrading to a higher LTE category device (like RUTX11 or RUTX50) will definitely bring better signal metrics, increased stability, and data throughput.
…yes, I noticed the fact about being connected to germany (data-roaming is off).
However, I checked out opencellid and cellmapper in the meantime, witch give me some inputs about possible bands and antenna-directions.
I’ll make some more tests to get the latest dB’s.
