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11/06/2025, 09:38 PM
(This post was last modified: 11/06/2025, 09:41 PM by Seán.)
The main difference between these is band congestion, mainly as a result of Eir's RSRP cut-off thresholds. I'll try to explain. 
From my past testing, Eir's network requires a band 1 carrier to have an RSRP of around -103dBm to aggregate it and will drop the carrier if it falls below around -108dBm. The same applies when handing over to band 1 as the primary (upload) band. With band 1 being a high frequency band (2100MHz), it does not have as great penetration capability as the lower bands, the reason it is much weaker than band 20 (800Mhz) despite coming from the same tower.
Between band 1's poor penetration capability through vegetation, building walls, etc. and the high RSRP cut-in threshold, there are far fewer users on that band, so in turn much less congestion.
As you had no signal on band 28, Band 20 has the highest congestion due to the majority of users using that band and likewise with band 3 due to Eir using 5G DSS to share its bandwidth between 4G and 5G connections. While I think the 4G RSRP thresholds for band 3 are still similar to band 1, it allows 5G connections with much weaker RSRP levels.
With the router locked on 4G band 1, connect the router to a long extension lead and try moving the router about the house including the attic to see if you can get the RSRP level better than -103dBm. If you can find a spot where the band 1 signal gets this high, preferably within -100dBm, you can enable all the bands and it should aggregate band 1 along with the rest, potentially getting well over 100Mbps, especially with the speeds you were getting with such a weak signal.
Unfortunately, the Deco X50-5G's antenna connections only work with 5G band n78 on Eir. If you are not able to find a spot where band 1 is strong enough, I suggest testing the router outside on the side facing the mast direction on a clear day. If band 1 performs much better outside, another option would be to get a weatherproof plastic electrical box to mount the router outside and get a another Deco X50 node or a separate Wi-Fi mesh kit to provide indoor Wi-Fi.
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Thanks Sean,
You are good! Not only do you seem to know what you are talking about, but you are also able to explain it intelligibly.
I'll report back once I had a chance to go looking for that magic spot.
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Hi Seán,
I finally got around to go walk-about with my modem. It appears so far that I have managed to find a better spot, and it's even inside. Still, it's all very puzzling.
First I tried close to the house. Despite a full view of the mast, it wasn't as good as the spot I finally found inside the conservatory.
Here is a pic I took with a zoom lens. the white blob in the foreground is the modem. The mast is 4km away. It's the zoom that makes it look that close. Could the power lines in front of the mast interfere with the signal? Those are no more than 500 yards away.
From inside the conservatory position I can't see the mast at all. It is covered by the trees.
Here are a couple of readings. All of them better than the readings outside 
They go up and down a lot, and the bands pop in and out continuously, quite frequently using B1 only.
But for a Sunday evening they are still very decent.
As you suggested, I searched with the modem fixed on 4G and B1. Now it is fixed on 4G and B1, B3, B20.
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Power lines, telephone wires, etc. can have a large impact on the signal. I had this issue when we originally installed LPDA antennas on our gable only to find the signal to be about 10dB lower than on a tripod. It turned out to be the telephone line along our lane being in the line of path. We had to raise the antennas by over a metre above the telephone wire to get the full signal.
If those wires are nearby, your router is likely at a different height in your conservatory. I suggest try different height levels, such as a few steps up a ladder.
If you find the speeds to be dipping too much such as causing streaming to drop resolution or buffer, another option would be to consider purchasing something like the MikroTik ATL LTE18 which is a combination of a router and high gain antenna in the one unit. This is an outdoor router that you can mount on a standard outdoor TV aerial mount and ran an Ethernet cable inside and configure the TP-Link router as a wired WAN router. With you current readings, I reckon the ATL would get band 1 and 3 into the low -90's.
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Hi Seán, I haven't done any 'Sweet Spot' searching since. As of now, thanks to your 4G-Only/B1 search suggestion, I have definitely got the most stable connection since using mobile data. But sure, we keep on searching.
Before I go at it again:
I still had a 48 sim in the drawer for emergencies (like no Meteor connection all day). So for curiosity's sake, I just activated it for a month of 5G.
I stuck it in the modem on 4G Only/Auto and and it gives some pretty nice reading.
The display looks a bit funny, but this is actually 110 and 130.
The strange thing is that it won't let me set the Bands manually. It just won't display the list.
If I do manage to get the list, is it 4G Only/B1 for 48 as well? I've never seen B1 show up in the auto setting. It's usually B3 or B20,B3.
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With 48 which operates on the Three network, they use 4G bands 3, 7, 20 and 28. Three previously operated 4G on band 1, but converted it into a 5G-only band around July 2024. I have only seen band 7 in use in larger urban areas such as Letterkenny, Cavan, Dublin, etc. and they don't seem to have have as many band 28 enabled towers as the other two operators. Three actually has two band 3 carriers with the second one showing up as EARFCN 1275, however, the second one is usually switched off as part of their energy saving measures.
I am surprised the band list does not show the full list of bands with the 48 SIM as I would expect the same selection regardless of the SIM. On the other hand, getting over 100Mbps is very good for Three, particularly if this speed holds up in the evening. Before I left Three, I could only get over 100Mbps early in the morning or after midnight and it often dropped under 20Mbps in the evenings, mainly due to the second band 3 carrier rarely coming online.
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Hi Seán,
...and more confusing it's getting. For no apparent reason, I got the bands-list up all of a sudden for 48. And because I kept getting connected to B3 most of the time when on Auto, I selected B1,B7,B20,B28. Now I seem to be constantly connected to B7.
Every now and then it shows B7,B7. No idea what that means.
All the same — quite promising for a Friday night.
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It looks like band 7 may be from a tower that is only operating that band. Its eNB ID (6044) is different to the tower that you got bands 3 and 20 from (6043), so this is likely why you don't see band 7 combined with any other band. This is its approximate location on CellMapper with the "Show low accuracy" setting enabled:
Three operates two carriers on band 7 (EARFCN 2850 and 3025) so when you saw B7 appear twice, it has aggregated the second band 7 carrier.
With that speed on a Friday evening, particularly with the weak RSRP, that is one band well worth trying to improve. Due to its high frequency (2.6GHz), this may be worth considering getting an outdoor router for, such as the MikroTik ATL LTE18. Like GoMo, try an outdoor test around the house just to rule out its signal coming from another direction with band 7 appearing to be served on a separate tower / mast.
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29/06/2025, 09:54 PM
(This post was last modified: 29/06/2025, 09:59 PM by Paddy.)
I have done my walk-about first on ground level and than with the modem on top of a 5mtr latt, but without much success. The only readings that were better than the ones in the conservatory were too far from the house. My guess is that there are simply too many trees in the way, and there are even more leaves on them this year than what I have ever seen before. It still doesn't explain why the reception is that good in that very spot. Maybe reflections from all that glass.
The next time I have the roof ladder in place I'll give it a go on top of the chimney.
But I wouldn't dream of complaining about my latest results. I haven't seen less than 50Mbps during the whole weekend. Average around 70-80Mbps, plus the occasionally 120-130Mbps. I will definitely use 48 for the modem from now on. But I will keep GoMo for the phone, because 48 was always useless for roaming abroad. Extra benefit: It'll cost me just 7.99 a month for 4G instead of 14.99 for 5G with GoMo. Thanks Seán 
I have very little experience with CellMapper. On the map, same as your image, I get the 6043 displayed, but no sign of the 6044. Has that got anything to do with your "Show low accuracy" setting? I haven't been able to find that setting anywhere in the app.
And with the NetMonster map I get nothing but my own position displayed. No masts at all?
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That's great maintaining those speeds as 50Mbps can handle 2 to 3 simultaneous 4K streams. That is the speed I used to get on Three a few years ago before they started cutting their 4G capacity here.
To see the low accuracy towers in CellMapper, go into the Menu and click "Filters". The checkbox is near the top:
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Thanks Seán, found it. I looked up and down that menu last night several time. It must have been right under my nose.
I wonder why this tower is listed on the Comreg Site Viewer as 'Site EIR_CE_2911' only. No mention of THREE.
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