5G speeds and reliability

MichaelR

Hello,

I am on Eir, but I suspect this might apply to any 4G+5G network. I have a 5G phone and this is why I stay on Eir not the cheaper GoMo.

In some places, usually cities, 5G is lightning fast, 200+ Mbit/s.

In other places, somewhat more rural, 5G - with good coverage too, full or nearly full bars - can be slower than 4G in that same location. Moreover, a handover issue seems to exist close to my home; when I walk a certain point with 5G enabled I lose data for a few seconds.

I have installed a cell info app but don't see a correlation between the cell info and the speed. Yes, there are differing frequencies, but all of them are either 700-800 or 1800-2100 MHz - and no clear link of the speed I get to the frequency. (And it's always 5G NSA, though to be fair I have not tried this in Dublin, and maybe SA makes no sense outside Dublin city centre).

So what explains this difference in speeds? And also, should I report that handover issue to Eir and if so, what's the best way of doing it?

Cork981

Eir are using 5G DSS (Dynamic spectrum sharing) on many sites which can give less speed than 4G as is it just shares 1800mhz (n3) and 800mhz(n20) with 4G LTE. While you have access to B20+B28+B3+B1 when on 4G.

In cities Eir have NR deployed on 85mhz of 3.6Ghz so you see much better performance.

Vodafone are using DSS on N1 (2100mhz) but can aggregate with more 4G bands.

3 are the only 5G network with dedicated spectrum on all 5G sites. 100mhz in the 3.6ghz range and 15mhz n3 (1800mhz) on quieter sites.

MichaelR

Aha, so in a city I can have a "serving cell" identified by the cell info app (something in the 700 or 1800 or 2100 MHz are), then when I actually start downloading in 5G, the 3.6GHz NR kicks in? This would explain the speed, yeah.

AllForIt

https://www.boards.ie/discussion/comment/119171480#Comment_119171480

3 are the only 5G network with dedicated spectrum on all 5G sites. 100mhz in the 3.6ghz range and 15mhz n3 (1800mhz) on quieter sites.

Are you sure about that? I looked at the towers in my area, and according to it 3 are using 1800mhz for 5g in my locale.

Cork981

https://www.boards.ie/discussion/comment/119177111#Comment_119177111

Sorry yeah that's what I meant. The 15mhz in 1800 band (n3) is dedicated to 5G but Eir is sharing the 15mhz with 4G customers using DSS so much more congestion in the band. Three have a separate B3 band for 4G that we acquired when they took over 02.

pawrick

This may explain why my mobile router speeds have dropped since i "upgraded" to 5G so?

Cork981

When using 4G, it uses carrier aggregation with bands 1(15mhz), 3(15mhz), 20(10mhz) and 28 (10mhz). That’s a total of 50mhz of LTE bandwidth.

With Eir 5G it only connects to 4G (band 20) and 5G n3 15mhz. That’s only 25Mhz of bandwidth.

Micky 32

So if you’re on Eir you are better off staying on 4G?

Cork981

Only if your in an area thats using DSS instead of n78 which gives 85mhz in the 3.6ghz band.

You can check which is in use on comreg site viewer.

Cork981

This is an example of n78 on Eir

https://www.speedtest.net/my-result/i/5123678219

Micky 32

https://www.boards.ie/discussion/comment/119180476#Comment_119180476

How do you tell on the site viewer? It says NR for all 5G masts?

Cork981

Sites that have two meteor sites with one with just LTE and NR and generally n78 sites.

This one for example

https://siteviewer.comreg.ie/#site/CK_3702/51.8805340368/-8.4710368144/1/Site%20CK_3702

MichaelR

How far can an n78 connection go, as in distance between the cell and the phone? And why would a cell info app on the phone show a non-n78 serving cell?

Cork981

I think it’s around 10km in super ideal conditions.

n78 is 3.6ghz so very susceptible to buildings and walls etc.

On eir you’ll see b20 800mhz as an anchor band and n3 1800mhz as a CA band.

Good write up here by Sean.

https://confusedbird.com/thread-145.html

MichaelR

Could you please clarify what "anchor band" and "CA band" mean?

Also, if the big speeds in cities ate the n78 band and impeded by walls, why did I get the big speed inside Lidl?

BArra

CA=Carrier Aggregation, it bonds frequency's for higher throughput/output

MichaelR

I installed two more apps, NetMonster and LTE Discovery. NetMonster is universally praised but somehow does not display the 4G band number, just the frequency. LTE Discovery crashes but does display the band.

And both of them display just "5G NSA" when a 5G signal is also used. Somehow the 5G band or frequency is not seen in either app. I wonder if there is a way to see it.

Cork981

Eir 5G DSS

Eir 4G LTE

Same mast, location and time.

Cork981

And this is an Eir n78 5G site just down the road.

dannijuno

I'm with Eir - 5G can actually be brutal at times. Often the case of 5G being slower than 4G, well .. in my case at least and I am not too far from Dublin

Gus75

https://www.boards.ie/discussion/comment/119181144#Comment_119181144

Looks like most of the NIR surveys were performed between 2010 and 2012, when Mobile traffic was a tiny fraction of what is there today.

Around Cork you are "lucky" to have reports from 2019, still without information on 5G bands usage.