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

Level 28: Ingenious
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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 slight_smile


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

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.