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What is 2G, 3G, and 4G? ** New Update 21st Sept 2015 **

by on ‎15-09-2012 20:17 - last edited on ‎31-10-2017 17:21 by (204,370 Views)

Smiley Happy


So when I originally wrote this, was many moons ago and I thought that since 4G has been here for a while then its time to update the information on here as well.


What is 2G, 3G, and 4G?

I've been on the forum now for many years and questions about the signal, frequency and the Network info are asked on many occasions. So I've written this to try and make it as understandable as possible.


What is meant by 2G, 3G and 4G?

2G stands for 2nd Generation Network, 3G is 3rd and you guessed it 4G is 4th Generation.


Other acronyms that you may have heard them being called are

2G = GSM           (Global System for Mobile)

3G = UMTS         (Universal Mobile Telecommunications System)

4G = LTE             (Long Term Evolution)


2G was introduced in the 90s in the UK and allowed us to use Text Messages (SMS), Picture messages (MMS) and Internet (WAP) all though it is rather slow.

Now if you look at your mobile phone / Smartphone. You may notice either a letter E, G or possible the circle on the iPhone.


For example, G stood for GPRS (Dial-up modem speeds. Real Slow Internet)

O2 – UK  o (Apple IOS 6.x and below), (Apple IOS 7.x and above now displays GPRS)

O2 – UK  G


E Stood for Enhanced, So you got a little faster Internet in theory!

O2 – UK  E


However, the 2G network was not fast enough for the consumer so 3G came about.

3G was introduced in around 2003 and brought us Video Calling and Faster Internet. Broadband speeds at the time, but again we wanted more.

So 3G started its upgrade path and was upgraded to the HSPA Family

HSPA = High-Speed Packet Access

There has been a few upgraded to the HSPA family and yes they are calls different names, but all they are is enhancements and faster speeds for us to use.

The latest upgrade going on is DC-HSPDA which is speeds of up to 42 Mbits (Megabits per second)


So you may see on your phone

O2 – 3G (On an iPhone's)

O2 – 3G or H or H+ (Other phones)

So if you see any of the above symbols, you know you're on a 3G Network (or 3rd Generation)


So then what is 4G.

4G is 4th Generation Network which will enable us to go even faster on our mobiles and mobile dongles. Possible speeds achievable are 1Gbit/s download and 500Mbit/s Upload. This is whats possible. However, the network has to support LTE-A and have the bandwidth to do the speeds mentioned. Also, your devices have to be able to support them as well. We are a long way at these speeds at present, but you never know what the future holds.


Going Forward...

The Devices themselves ie Mobiles are categorised. I.e. iPhone 6 and 6+ are Cat 4, so there max speed on LTE networks will never go any faster than 150Mbit/s down and Upload of 50Mbit/s.

Cat 6 Devices like Galaxy S6 and iPhone 6s and 6s+ can go to 300Mbit/s Down and 75Mbits Up.

However at present o2 network doesn't support Cat 6 just yet. (Please correct me if I'm wrong, but I've checked this recently and cant see Cat6 Listed for O2 Uk)

Cat 6 is also known as LTE-A (Long Term Evolution Advance)


4G can go faster with later Technology, but at present, the above is what can be achieved if the networks allow it.

The Max I've had downloaded on O2 was 67Mbs and upload was 32Mbps. on my iPhone 6+. Will try the same areas with I get the 6S+ shortly Smiley Happy


So why can some phones work on 4G, 3G and 2G,

Well, it's all to do with the frequency they are run on and your Receiver Microchip on your phone.

Is the way to explain is like a radio in the house or in the car?


There is FM, MW(AM), LW, SW (and others)

Some Radios can only pick up FM, MW(AM)

Some Radios pick up them all.


Mobile phones are no different, but they are called frequencies or Airwaves.


2G GSM have 4 bands in the world (For Mobile phones)

900 MHz used by O2 and Vodafone

1800 MHz used by Orange, T-mobile (Now EE), O2 and Vodafone

850 MHz, 1900 MHz bands are used in USA, Canada and some South American Countries only. (Also CDMA (Code division multiple access) which is another frequency completely different to GSM)


3G UMTS has 5 Bands that I used for Mobile phones

900 MHz is currently been used by O2 and Vodafone

2100 MHz is used by all the UK carriers

850 MHz, 1700 MHz and 1900 MHz are again bands that are used in USA, Canada and some South American Countries only. (And again enhanced CDMA (CDMA 2000) another difference to UMTS)


So why will 4G (LTE) be problems for manufacturers.

First problem is that 4G can be known as 4G or LTE (Long-Term Evolution).

2G and 3G had a set amount of frequencies that were utilised and that the mobile manufacturers were told they could only use. (It was Harmonised)


4G however hasn't had that sort of guidance and it become a free for all in the Mobile industry.

This is where the problem lies.

2G has 4 different bands, 3G has 5, 4G has 35+ frequencies and is still counting.

And this is causing issues.


UK is allowed to use 800 MHz, 1800 MHz and 2600 GHz. (1800 MHz used to be used for EE and O2 2G networks, but have been allowed to refarm some of the spare frequency for 4G)


800 MHz and 2600 GHz was sold by Ofcom in 2014. But not all operators bought 800 / 2600GHz Frequency.


O2 purchased 800 MHz and is obliged to provide 98% UK population indoor coverage by 2017 (O2 is now refarming spare 1800 Mhz it already owns from 2G to 4G (So the iPhone 5 that didnt used to work, now will when on a 4G 1800 Mhz frequency) London, Slough and other Cities are now using or tunring on 4G 1800 Mhz

Vodafone purchased 800 MHz and 2600 GHz

EE used spare 1800 MHz from 2G and purchased 800 MHZ and 2600 GHz

Three took 1800 MHz requested by Ofcom from EE (When T-Mobile and Orange Merged and had too much 1800Mhz band) and purchased 800 MHz as well


Also Note that the UK to France part of the Chanel Tunnel support 4G on O2, Voda and EE. All 1800Mhz Freq. 2G and 3G again on O2, Voda and EE.  No Three network at all though.


Now before you start to say, well some networks have more than others, It doesn't work like this. Each network purchased Chunks of the Frequency and some purchase more than others. Also Some are better chunks than other you can say as well


EE started 4G in October 2012

O2 and Vodafone Started 4G on August 2013

Three Started officially March 2014


Most of EU and Asia, are using 800 MHz, 1800 MHz and 2600 GHz, however you also have 850 MHz, 2300 MHz, 900 MHz for some parts of the world and again

Americas use a completely different frequency (700 Mhz 2 different bands, 2100 MHz, 1700 MHz and At&t are using 2300 MHz) and also use can use another different technologies completely (Again another different structure of frequency called Mobile WiMAX)


List of Networks on Wikipedia http://en.wikipedia.org/wiki/List_of_LTE_networks

Beleive me when I say its a Eye opener or confusion.


The iPhone 5 for the UK will use 2G and 3G on Vodafone only. (Update 4G will now work on O2 as long you are in a area with the 4G 1800 Mhz

So now O2, EE and Three will all support 4G on the iPhone 5 4G as we speak.

There is no mention that Vodafone are converting any spare 1800MHz into 4G


Note that the iPhone 5 in the EU utilises the 850 MHz, 1800 MHz and 2100 MHz frequency only.

iPhone 5 in USA utilises different frequencies as US networks are on different ones to us.

(To also make matters worse, US and some countries again chooses a different technology to LTE. They choose Mobile WiMAX)

iPhone 5S / 5C upwards are able to utilise all the 4G frequencies in the UK


Now you may have recently taking you phone to the USA and you don't have a LTE phone (4G), but noticed the phone may have said 4G? (More on the iPhone 4 and iPhone 4s)

Well you weren't really on 4G. Some American Networks says that there old 3G network is just as fast or nearly as fast as there 4G LTE network and therefore it should be called that. As there is no harmonised regarding 4G, this was agreed and so in the USA Some have named there old 3G to 4G (Due to the speeds and nothing else) So you can see its really confusing for customers.


To make Matters worse for example. 2600mhz is band 7 and 38. Even tho you phone may support 4g 2600mhz, it also has to support its band number as well.



So What was missing when they created 4G. You have heard me talking alot about Data speeds, well when they created 4G, they completely forgot about Phone calls (Yep what the Mobile was first made for)

So now they have had to create a new technology called VoLTE.

And if you guessed right, VoLTE stands for Voice over LTE (4G Network)


As the time of writing, VoLTE is currenlty supported on Three (Certian areas), Vodafone and EE will be before end of 2015 and O2 will be Q2 in 2016.


If you make a call now, you may have noticed that you phone will switch to 3G and 2G. (Good fun isnt it)

Also your phone has to also support VoLTE and again not all of them do.


Why can't mobile phones use them all. Technology, price and size of the Chip.

One day as new Micro Chips come out, we may be able to use more 4G networks, but until the time comes, we have to make do with what we have. At present the iPhone 6s and 6s+ support the most LTE networks in the world. but doesnt support them all.

Phones in the USA support there frequenices and again differ to those from EU and other areas in the world


I really hope the above is helpful and has been somewhat useful. I have tried to make it understandable as I know that the world of mobile phones is somewhat confusing.


 If you have any questions please ask and I will do my best to answer them.

on ‎31-08-2015 23:01

Thanks @Cleoriff. I'll give Toby a PM


ive not been on here a while since being ill.  I do keep looking at it

on ‎31-08-2015 23:05

@darrengf wrote:

Thanks @Cleoriff. I'll give Toby a PM


ive not been on here a while since being ill.  I do keep looking at it

Hope you are feeling better now @darrengf. Lovely to hear from you anyway...Smiley Wink

on ‎31-08-2015 23:06

Thanks @Cleoriff. Hope your well.?

on ‎31-08-2015 23:09

@darrengf wrote:

Thanks @Cleoriff. Hope your well.?

Doing good thanks....Must be ok...I spend half my life in Spain...(would be rude not to really) Smiley Very Happy

on ‎21-09-2015 19:51

Well I thought it was time that this article had a bit of a make over so, its been fully updated with new information and the new 1800Mhz freq that o2 are now using on 4G


Enjoy Reading


Thanks Daz

on ‎21-09-2015 19:58
Good info and links to the 1800mhz thread I started a little while back http://community.o2.co.uk/t5/Other-Products-Services/O2-1800MHz-Spectrum-And-Wi-Fi-Offloading-Will-B...
on ‎21-09-2015 20:00

Thanks for updating @darrengf and good to hear from you again...Smiley Wink

by Anonymous
on ‎23-09-2015 15:46

Hi, I've been looking at new phones for my wife and I wanted to find what the difference is in the 800Mhz bands. From looking at the phones some are capatible with LTE Bands 18, 19, 20, and 27. When finding out which phone will have 4G connectivity in the UK which Band should I be concerned with?



by Anonymous
on ‎23-09-2015 16:27
I managed to find out what these were. Sorry for the inconvenience.
For anyone else looking for this information - If the 4G LTE Bands are quoted in the phone spec as numbers then these are the ones that apply to the UK.

Band 3 for 1800 MHz
Band 7 for 2600 MHz
Band 20 for 800 MHz
on ‎23-09-2015 19:29
Only band 20 for broad-brush o2 4g but some areas will get band 3 on 1800mhz.
There is no 2600mhz for o2 at all currently.
by Anonymous
on ‎16-01-2016 06:33

Hi Darren

As you obviously know so much about the mobile networks can you answer this for me?


I am moving to Wiveliscombe in Somerset where coverage is patchy for some providers which is fine I expected it. Although I don't want to leave 02 I have no choice unfortunately as they have no coverage.


I need to buy a new phone and am looking at the Samsung Galaxy S6 which everyone advertises as 4G blah blah blah......... if 4G isn't available in Wiveliscombe will it automatically use 3G/2G and just be slower or doesn't the SIM/phone have the ability to use the slower more widely available network?


Am I looking at having to find an older 2G/3G phone until someone delivers 4G to Somerset?


My existing Samsung S3 will be replacing my husband’s LG Cookie which is slowly dying by the day so I have to do something.



on ‎16-01-2016 06:57

Hi @Anonymous Not sure how soon Darren will be back on so I will answer as best I can. It doesn't matter if you have a 4G capable phone with a 4G sim in it.... it will still work on 2G/3G as it will seek out the strongest signal.

Similar to my own story. I had a 4G capable phone which I used with a 3G sim in for 2 months (4G wasn't even in my area at the time). I swapped to a 4G sim and could get 4G 8 miles away.....but still not in my home town.

We have it now but it is patchy in places so I often see my phone switching between 3G and 4G depending on where I am. The S6 is a lovely phone and if you want it then go for it. It will work well on 3G.

Have you ever thought of getting TuGo which works well over wifi in areas that have limited signal? http://www.o2.co.uk/apps/tu-go

by Anonymous
on ‎16-01-2016 08:22

Thanks @Cleoriff for this and I'll investigate TuGo as well........ now I just have to choose which colour to buy.... decisions decisions

on ‎16-01-2016 08:45

@Anonymous wrote:

Thanks @Cleoriff for this and I'll investigate TuGo as well........ now I just have to choose which colour to buy.... decisions decisions

You sound like me @Anonymous I wanted a Samsung Note ...but it had to be red. The Note 4 never came in that colour so I went for the Note 3 instead...LOL Mind you the S6 looks nice in Platinum Gold...or even Blue Topaz...Smiley Wink

on ‎16-01-2016 09:10
The wife the S6 Edge. Beautiful phone.
by Anonymous
‎18-01-2016 12:02 - edited ‎18-01-2016 12:42

Hi Darren or whoever available:


I am very confused about the LTE band provided by O2 in UK, so if someone could clear it up for me it will be great.


I chatted with online help and also 202 in three different sessions and I get three different answers regarding what LTE band O2 use, particularly in London.


First I used online chat:

O2 uses 800MHz and the 1800MHz is now available in London "100% sure" (quoted)


Then 202:

O2 only have 800MHz not 1800MHz


Then online chat on a different day with a different person:

O2 uses 2100MHz (?) and not support 800MHz and 1800MHz.


Which one is telling the truth, if at all?

on ‎18-01-2016 12:10
800 (everywhere) and 1800 (in some areas only, mainly around London).
on ‎18-01-2016 12:12


How to tell whether a phone is supported by your network: O2

As you can see from the table, O2 has the least amount of frequencies on offer with just 800 MHz – this is what caused controversy when the iPhone 5 launched as it didn't come with support for this frequency. You'll need to buy a phone which supports 800 MHz otherwise it won't work with O2's 4G network.

Virtual networks Tesco Mobile and GiffGaff both use O2's 4G network so also use the 800 MHz spectrum.

by Anonymous
on ‎18-01-2016 12:14

If this is true then great.



FYI I am still in chatting with the third guy and here's his/her story...


"I'm sorry for the information given to you from my fellow colleague but O2 4G works on 2100 MHz and and that's the reason iphone 5 being a 4G phone doesn't support O2 4G.


Iphone 5 has 1800 MHz band limit whereas o2 4G works on 2100 MHz band.


I hope now it is clear to you."

on ‎18-01-2016 12:15
2100 is the 3g frequency !
on ‎18-01-2016 12:18

I can imagine live chat told you it was Tuesday today....Smiley Frustrated

by Anonymous
‎18-01-2016 12:23 - edited ‎18-01-2016 12:25

That's what I believe to be true too (I have basic understanding on what band refers to which service).


Perhaps it is better to ask here...


I *know* that O2 uses 800 nationwide, and heard that it's refarming 1800 for LTE use. I just wonder if 1800 is ready in big cities, mainly London.


And it seems strange they did not make any press release on 1800 update


EDIT: are you suggesting the Gurus are incompetent in giving the answer? He seems confident in giving his answer that 2100 is the only 4g available.

on ‎18-01-2016 12:29
They did release some info.
I'm sure there was an announcement on The Blue?
We reorted it here too https://community.o2.co.uk/t5/Other-Products-Services/O2-1800MHz-Spectrum-And-Wi-Fi-Offloading-Will-...
on ‎18-01-2016 12:29

@Anonymous wrote:


EDIT: are you suggesting the Gurus are incompetent in giving the answer? 

Yes Smiley Wink

by Anonymous
‎18-01-2016 12:33 - edited ‎18-01-2016 12:37

@MI5 I was reading the same report and that gives hope to me that 1800 is being supported, but it didn't have any update on whether the refarming is "finished".


My current phone just broke and I have the opportunity to bring in a cheaper one from Asia (I know the bands are different over there) so I wanted to see if 4G is available. 800 is not available on those handsets so here comes the trouble in finding if 1800 exists for O2. Mostly residing in London, Birmingham and Manchester.


Here's a couple of phones I am looking at, and their FDD-LTE bands (from GSMArena):

Sony C5 Ultra Dual

4G bandsLTE band 1(2100), 3(1800), 5(850), 7(2600), 8(900), 20(800) - E5533


OnePlus One

4G bandsLTE band 1(2100), 3(1800), 4(1700/2100), 7(2600), 17(700), 38(2600), 40(2300)


EDIT @MI5 I found the Gurus and 202 quite non-technical... perhaps I should have hit here first Crazy

on ‎18-01-2016 12:37
Get a Leagoo Elite 1 for around $150 (£100).
Works on all UK 4G bands currently in use and will support Band 3 too, but there is no guarantee that O2 will drop Band 3 everywhere.
At the moment they are only using spare 2g capacity.
by Anonymous
on ‎18-01-2016 12:41

Never heard of Leagoo before but I assume this applies to a lot of Chinese/Asian phones anyway Smiley Wink


Good to hear band 3 is available in big cities, can't thank you more @MI5 @jonsie

on ‎18-01-2016 12:44

I've just ordered a Leagoo Elite 1 myself two days ago....

on ‎18-01-2016 12:48
Can't do better for the money.....
by Anonymous
‎02-02-2016 17:24 - edited ‎02-02-2016 18:01

A little update - I am back UK with a new phone with only 1800 MHz LTE band, and managed to pick up a brief signal of 4G near Stratford. Speedtest showed 17.76Mbps DL and 5.64 Mbps UL which was reasonable. Hopefully I would be able to pick up the signal later in Central London.


Thanks to @MI5 and @jonsie for the help, and no thanks at all to the O2 Gurus that gave wrong and inconsistent answers every single time I approached them. If you read this thread from page 1 you would see how they contradict the facts from the message history attached.


As for the incompetent official support, I am actively considering a move to other networks. O2, in a few months time your revenue would go down by around £20 per month, but I guess you wouldn't mind/care.


Screen Shot 2016-02-02 at 17.15.34.png



Screen Shot 2016-02-02 at 17.15.34.png

Screen Shot 2016-02-02 at 17.23.02.png

on ‎02-02-2016 17:28
We can only apologise for the others!
on ‎02-02-2016 17:32

The knowledge of Gurus leaves me speechless. What knowledge and common sense qualifies as a guru? seemingly very little!

on ‎02-02-2016 18:03

@Anonymous I hope @Toby can pass the feedback regarding the poor advice to the correct people.


Toby yet again this shows the very poor advice being given.

on ‎02-02-2016 19:44
At least we will never be out of work Smiley Wink
on ‎03-02-2016 10:55

Hi @Anonymous,

Sorry to hear that you received inconsistent info from gurus and I'll feed this info back so that we can improve.

I am however glad that you got some great advice here! Well done guys Smiley Happy


Is this your first community visit?

by Anonymous
on ‎10-03-2016 13:53

Thanks darren for updating this thread.


Are there any lists of areas that o2 are using 1800mhz band for 4G/LTE?


I was going to upgrade to the Xiaomi Mi5, though it doesn't support the 800mhz frequency (Band 20). So on o2 means I'll be stuck with 3G, unless this 1800mhz frequency is running 4G in my area.



on ‎10-03-2016 13:58
Currently only some areas of London and Reading - No list that we've been able to find so far.
on ‎10-03-2016 14:57

I can understand why o2 would be reluctant to publish a schedule but but an approximate time scale would benefit everyone who can then decide whether to stay with o2 or look at other networks.... oh..... right, now i understand Smiley Wink

by Anonymous
‎26-03-2016 00:00 - edited ‎26-03-2016 00:01

O2 and Vodafone rollout as part of Cornerstone Infrastructure limited ( CTIL) in most areas. I have seen lots of CTIL masts with 1800MHz antennas and cabling fitted, as well as plans for future 1800MHz upgrades.


Take in mind that 4G 1800MHz is below the priority of the 800MHz 4G, so if you have a handset that does not support Carrier Aggregation (CA), you will only see the 800MHz band (in theory at least)

by Anonymous
on ‎20-12-2016 23:40

O2 is now using 2100MHz for 4G in certain areas. The 5MHz on 2100MHz, together with the 10MHz on 800MHz and 5MHz on 1800MHz totals 20MHz of LTE spectrum, which raises O2's maximum 4G speed to around 150mbps.


O2 4G 2100MHz (L21) Video

on ‎21-12-2016 21:22

Any Ideas where this is?


Ive only ever got a max of 68mbs i think which was on a brand new mast in south yorkshire. However that mast is quite used, but still respectable 40-50mbs

on ‎21-12-2016 21:41

@darrengfI think the video stated Lincoln?....

on ‎21-12-2016 22:21

Lol sill me, I've even watched the video as I follow the chap on twitter. 


Mmm  may be a trip with the iPhone 7+ to see if I can get it to work.  @Anonymous where in Lincoln is this, do you have the exact location?  


Ill take both both iPhone and Samsung s7.  See if I can cash in over 100mbs on o2 👍😄

on ‎21-12-2016 22:23

@darrengf wrote:

Lol sill me, I've even watched the video as I follow the chap on twitter. 


Mmm  may be a trip with the iPhone 7+ to see if I can get it to work.  @Anonymous where in Lincoln is this, do you have the exact location?  


Ill take both both iPhone and Samsung s7.  See if I can cash in over 100mbs on o2 👍😄

Good idea x

by Anonymous
on ‎21-12-2016 23:22

I might be the person on Twitter and YouTube - note the Pedro in my screenname on here and Twitter!

L21 is currently live on four masts in Lincoln, which also have L08 and L18:

Deacon Business Park, Deacon Rd, Lincoln LN2 4JB

51 Monks Rd, Lincoln LN2 5HN

Queensgate House, 12 Silver St, Lincoln LN2 1AS

Near LN5 8EL


The masts are also appropriately placed and listed on cellmapper.

on ‎21-12-2016 23:26

@Anonymous Thanks. I'll see if I can get and try to see the speeds I get. You never know.

on ‎22-12-2016 03:17

@darrengf wrote:

@Anonymous Thanks. I'll see if I can get and try to see the speeds I get. You never know.

Yes please update us @darrengf

on ‎22-12-2016 09:32
Exciting news Smiley Happy
on ‎30-12-2016 22:21

@Anonymous Sorry I've not had time to go to Lincoln to check the speeds, but I've been to Rotherham Today and I know o2 have been working on a mast there and upgraded it.

Got some great speeds 👍😄



on ‎30-12-2016 22:35

More than good @darrengf Excellent I would say. Thanks for your continual updates. Smiley Wink