Just because the devices support VoLTE doesn't mean that the networks will support it. There is many VoLTE compatible devices around most won't be supported. Look at America 3 of the big 4 networks have VoLTE now and each support less than ten devices. AT&T supports less than 5 devices in total.

Honestly I don't think it's possible to restrict 800MHz LTE to particular devices if they did it could only be carrier devices or iPhones perhaps could do by IMS. Would mean Sim-only customers would have no chance.


If Three are doing that many software updates then they will be the only network that does. Most of the VoLTE networks are updating very few of the older VoLTE compatible devices.

so let me get this confusion out of my mind.

Three customers on sim only contracts wont be getting the VoLTE software update?

And anyone know If the Nokia Lumia 930 will support this?

Bear in mind that more than 50% of Three's userbase will hav an lte handset and this number is less than half that. Plus, three ha. more than 3 million iPhone users so I would imagine thst quite a number of users will be using VoLTE on an iPhone

How the hell did you get to that conclusion? That's not true

Only certain phones will support VoLTE to begin with. On all networks.

I suppose the main annoyance with the current implementation of low density 4g masts (I must admit it sounds more likely than low power but I'm still confused) is that even with a perfectly usable 4g signal the handset is told by the sim to change to the 'stronger' 3G signal from a closer mast.

So it sounds like VoLTE won't solve this problem and time will, when all (but 30) masts are upgraded 2,3 & 4g.

I had a short stint on O2 4g and the coverage did seem stronger with lots of bars consistently within a 4g area only dropping off when going out of a coverage zone.

True enough will be interesting see how it goes I'm moving to EE and getting an iPhone 6 so I think I should be when EE launches VoLTE.


I think he means because carriers are going have to release software updates to allow VoLTE how is that going to work on Sim Free. He has a point apart from iPhone 6/6Plus users it likely will be that way.

Lower frequency.


Not really, other SIM free phones will get the update.

Well 3 should make the 4G phones they sell compatible.

well Microsoft did release the update to enable VoLTE in WIndows Phone 8.1 so now its up to Three.

I've done a bit of testing today and 4G is definitely broadcasting at a significantly lower dBm than 3G from the same mast.

Why on earth is this?

Bear in mind I used dBm not bars for these tests, but that got me thinking that someone on here said that 4G bars are calculated differently? Is this a definite?

There is lots and lots of lovely strong 2G signal out there on EE, so come on EE pull your finger out and turn the juice up!

If you look at your results, there should be a difference of ~20dBm between 3G and 4G.

This is due to the way 4G signal is calculated.

I was getting 30 difference at the mast and perhaps 10 less further away.

dBm surely is a scientific number and it is what it is, just as a metre is a metre?

I dont suppose you have any references to this scale please? I Googled but didn't really find much.

Have a read here http://en.wikipedia.org/wiki/DBm

Perhaps calculated was the wrong word to use.

It's to do with the way the reference signal is transmitted. It'll always result in around a ~20dbm lower number compared to 3G. (Obviously so many real world factors affecting that but a closed test should have ~20dbm difference)

It's the same reason why signal appears to be better on 3G 900Mhz vs 2G 900MHz.

You have to remember that 4G is a different technology to 3G so cannot be compared directly.

Do some googling around RSRP and you should get some stuff.

It does appear that dbm is measured differently for each technology.
It's really complicated but I found this page that helps a bit.
http://en.wikipedia.org/wiki/Mobile_phone_signal
Look at the ASU section, Arbitrary Signal Strength.
This calculated differently for 2G, 3G and 4G.

"Arbitrary Strength Unit (ASU) is an integer value proportional to the received signal strength measured by the mobile phone.

It is possible to calculate the real signal strength measured in dBm (and thereby power in Watts) by a formula. However, there are different formulas for 2G and 3G networks.

In GSM networks, ASU maps to RSSI (received signal strength indicator, see TS 27.007[1] sub clause 8.5).
dBm = 2 × ASU - 113, ASU in the range of 0..31 and 99 (for not known or not detectable).

In UMTS networks, ASU maps to RSCP level (received signal code power, see TS 27.007[1] sub clause 8.69 and TS 27.133 sub clause 9.1.1.3).
dBm = ASU - 116, ASU in the range of -5..91 and 255 (for not known or not detectable).

In LTE networks, ASU maps to RSRP (reference signal received power, see TS 36.133, sub-clause 9.1.4). The valid range of ASU is from 0 to 97. For the range 1 to 96, ASU maps to

(ASU - 141) ≤ dBm < (ASU - 140).
The value of 0 maps to RSRP below -140 dBm and the value of 97 maps to RSRP above -44 dBm."

This might help...

http://copter.ardupilot.com/wiki/common-db-watt-dbm/

One thing I have noticed though is that although 4G seems to be weaker (in bars), whereas it's perfectly possible to have an unusable 1 bar 2G or 3G signal, it appears that 4G will only show 1 bar if you can actually use it.
I much prefer this.

I would guess that's more to do with the fact we haven't seen 4G saturation yet (except maybe in London).

Given there are significantly more sessions per mast sector on LTE than on UMTS or GSM it will take a lot longer for us to experience saturation effects.

How the handset firmware copes will be interesting - but maybe the handset can't do much, except transmit and hope for a reply.

I wouldn't have thought it was anything to do with saturation really.
I think it's simply that 2G/3G will show a bar when the signal is effectively just hanging on.
Whereas 4G won't show anything unless it's over a certain usable threshold.
I could be wrong though... you could be right..

You could be right too! I notice iOS is different to Android (Moto G 4G) in showing 4G bars/dots, as they are different in 2G and 3G.

reminds me of this:
http://www.cel-fi.com/phonebars

Each phone displays bars slightly differently (as there is no standardised version tbh) so it doesn't mean much when one phone has 1 bar and the other may have 2.

Yeah I know that already.. God you do go on don't you.....
I tell you, you keep on like this and you'll find divorce papers on your mat!!!
Hahahahahahaha
All I was really saying is that on my iPhone 4G will only show 1 bar if you can actually use it.
I have never had 1 bar 4G and not been able to connect or do a decent speedtest.
With 2G/3G I often get a 1 bar signal I can't use.
Has or can anyone test this on an Android handset to see if it is the same?
Would be interesting to know if this is an LTE thing or a handset thing.
I feel an animated PNG coming now.........

Thanks. I found this which confirms your 20.

http://communicationanddsp.blogspot....n-lte.html?m=1

I've just downloaded lte discovery on my android phone. I'm trying to find the old orange mast (it's edge 2g and slow 3G so I guess orange) near to me to see if there are any cabinets ready for 4g back haul.

I think the actual number is 19 point something but I can't remember the actual number. And tbh it can vary as well depending on network parameters.

It is the same on the Moto X (2013) on what you said for 3G and 4G.