What exactly is a 4G mobile data network?

Posted on By Mark Wilson
This content is 13 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I’m not a telecoms expert but, every now and again, new technologies come along that cross over into my world. One of those is the evolution of mobile telecommunications networks and there’s a lot of talk right now about “4G”. So what is it all about? Well, I’m sure there are a lot of detailed technical references available on the ‘net but I recently heard Ben Roome from Nokia-Siemens Networks being interviewed on the Guardian Tech Weekly podcast and he gave a quick overview, which I’ve reproduced here:

  • First generation mobile networks were analogue – that is to say that the signal could vary, a bit like tuning in to get a (broadcast) radio signal.
  • Second generation (2G) networks came on stream in the 1990s and used digital signals for communication.
  • There were various “interim” generations (2.5G for example) to try and squeeze more data over networks but the advent of 3G allowed mobile broadband data access, although many 3G handsets still use 2G for voice communications (modern radio networks can handle 2G, 3G and 4G using the same hardware – all that is required is a software update).
  • There are different standards for each generation of network, and 4G networks use LTE (Long Term Evolution) or WiMax (since the ITU relaxed standards to allow other technologies than LTE Advanced as LTE was not originally considered a fourth generation network technology but is now regarded as a sufficient improvement over 3G to be called 4G). To achieve duplex transmissions (i.e. send and receive at the same time) channels may be divided by time or spectrum (frequency) – WiMax uses time division (as do some LTE variants) and was effectively an interim 4G technology that was good for fixed wireless access (i.e. wireless connections, to a fixed location, cf. mobile networks). 4G networks have the potential to offer big improvements in latency (round trip speed between asking for something and getting a response delivered) but high speeds also need a high speed backhaul between cell towers (i.e. the core network). Most backhaul is microwave, but the core architecture does makes a difference and LTE networks are “flatter” (all IP from handset to cloud and back again) so they have simpler routes and improved management (hence improved latency).

Commercial 4G networks are in operation in Germany, with trials in UK. Broadband is a huge driver of economies and society so coverage requirements may be greater (i.e. 98% in place of 95%) when the UK governement auctions the radio spectrum next May as 4G is a technology that can genuinely offer universal access. The UK 4G trial in Cornwall is intended to see if 4G offers an alternative to fixed line broadband. Fixed lines currently averages 6.4Mbps, with 3G offering 1.6Mpbs – so the question is “can 4G beat offerings and offer a solution for people in areas with poor copper infrastructure.

Whilst the increased coverage requirements may mean that less money is raised by the spectrum auction, Ben Roome commented that those countries who are leading the world in this area make the most of the infrastructure with “beauty contests” for spectrum rather than charging. The UK has gone down the charging route – hopefully that doesn’t mean that we’ll all have to pay too much in years to come for something that people really value.