The pace of development of mobile communications technology continues to increase. Even before the long-awaited 4th Generation 4G systems are rolled out across the UK, news comes through of the start of work on its successor, unsurprisingly named 5G.
Where 4G promises more of everything: more data being moved more quickly and hence more application programs offering more features; 5G addresses an inevitable consequence of that: the fact that there are limits to this expansion.
All networks – whether cable or wireless – exist to move information in the form of electrical signals. From 2G onwards, these signals have been digital, with information being represented as strings of binary digits (each of which is either zero or one). Binary digits, or bits, are the basic unit of data in computers, mobile phones and digital TV. When you access a web page on your smart phone, the words and images you see are transferred as a sequence of bits, which your phone is able to interpret as the patterns and images you see. When you have a phone conversation, your voice is converted into a sequence of bits by your phone, these bits are sent to the receiver’s phone, which interprets them as the sound of your voice to be fed out through the earpiece. When you watch digital TV, the transmission is a sequence of bits, which your TV converts into the sound and pictures you hear and see. More complex messages need more bits, as do higher quality signals, so TV uses more bits than radio and HDTV needs more bits than “normal” TV.
Bandwidth cannot be expanded forever: physics limits the number of bits which can travel in a wire, fibre optic or radio signal. Much time and effort has been spent on squeezing as much data as possible into a smaller space, but there are limits to this process as well.
In addition, all this activity consumes electricity. It is believed that telecommunications networks are among the UK’s biggest users of electricity. This has consequences for cost of operation – usually passed on to the consumer – and in the wider environmental impact of information technology and communications. Work at Leeds Met’s School of Computing, Creative Technologies and Engineering and in the Sustainability Research Institute has explored the energy use of IT, we have worked on measuring and reducing energy use, an also on the effects that this power saving might have on the way the systems operate.
Colin Pattinson is Professor of Mobile and Converging Technologies and former Dean of School of Computing and Creative Technologies at Leeds Beckett; his research focuses on sustainable 'green' IT and computer network management.