You’ve probably heard of it, but what is 4G? In short, it’s the name given to the fourth generation of mobile networks, just as the previous generation is called 3G.
Another piece of jargon, which you will see tagged onto the end of 4G is ‘LTE’. This stands for Long Term Evolution and is a type of 4G technology. It’s arriving in the UK for the first time at the end of October and will be available to around a third of the population by Christmas 2012. See also: iPhone 5 review
4G LTE aims to offer users faster, more reliable mobile broadband internet for devices like smartphones, tablets and laptops.
Loosely speaking, 4G is around five times faster than existing 3G services. Theoretically it can provide download speeds of up to 100Mbps but you won’t achieve this in real-world use.
Unless you’ve just bought an iPhone 5, a Samsung Galaxy S3 LTE (not a regular S3) or one of the other brand new 4G-capable smartphones, your existing handset won’t work on a 4G network.
4G technology allows us download content at superfast speeds and has transformed our handsets into complete entertainment hubs.
4G is so quick that when exploited fully it is can match the fastest fibre-optic home broadband connections in the speed stakes.
4G phones are supposed to be even faster, but that’s not always the case. There are so many technologies called “4G,” and so many ways to implement them, that the term is almost meaningless. The International Telecommunications Union, a standards body, tried to issue requirements to call a network 4G but they were ignored by carriers, and eventually the ITU backed down. 4G technologies include HSPA+ 21/42, the now obsolete WiMAX, and LTE (although some consider LTE the only true 4G of that bunch, and some people say none of them are fast enough to qualify.)
When to go for 4G
If you like to surf the Web and especially stream video, 4G can be heaven. If you connect a laptop to your mobile link, 4G makes a huge difference. In general, anything involving transferring large amounts of data gets a big boost from 4G. Watch out for the data limits on your service plan, though; it’s easy to use up a lot of data very quickly with 4G.
If you have a 3G phone and you’ve been frustrated with slow data, 4G may be the solution. 4G won’t solve any dropped call problems, though, as all calls will be made over older networks until carriers switch to voice-over-LTE during the next few years.
Finally, if you want to future-proof yourself, get a 4G phone. 4G coverage is only going to get better, and that’s where the carriers are spending most of their money right now. You can assume that all 4G phones also support your carrier’s 3G and 2G networks as well.
What is 4G: technology
The main reason 4G is faster than 3G is because of Orthogonal Frequency-Division Multiplexing (OFDM). It sounds complicated, but it’s the same technology used in Wi-Fi, ADSL broadband, digital TV and radio.
OFDM is a technique for squeezing more data onto the same amount of radio frequency. It also reduces latency and interference. Data is split up and sent via small chunks of frequency in parallel, therefore increasing the capacity of the network.
Multiple-input and multiple-output, or MIMO, is another reason 4G is able to provide faster speeds. It is simply the use of multiple antenna arrays at both the transmitter and receiver to improve communication performance.
This allows more data to be transferred without requiring additional bandwidth or drawing more power. The most common configuration currently is a 2×2 MIMO, found in many smartphones and some tablets. A 4×4 setup is also possible and promises even faster speeds but is still a little way off making its way onto devices. Since different setups are possible, one phone could provide faster 4G speeds than another.
With 3G handsets, most of us take roaming for granted. We take our phones travelling around the world, and expect to be able to pick up emails and browse websites as soon as we land. Things are different with 4G.
Although there are 4G networks in many countries around the world, your UK 4G smartphone won’t necessarily work wherever you go. The reason is that 4G doesn’t operated on the same frequencies in every country.
If your phone’s 4G modem doesn’t work on the same frequencies as those used in the country you’re visiting, then you’ll have to live with 3G instead. Even if the numbers do match, there needs to be a 4G roaming agreement between operators. Currently, there is no such agreement in place and even when there is, expect data prices to be high.
What is 4G: UK frequency bands
|Technology||Frequency spectrum (UK)|