“The Internet Is Not A Luxury, It Is A Necessity.”
Those are the words of former US President Barack Obama, whilst research commissioned by Disney has ranked internet access as the number one bare necessity of life for Britons. It is clear we are becoming more and more reliant on internet access with 9 out of 10 adults accessing the internet weekly and 8 out of 10 accessing it daily “on the go”. But are the systems that are designed to connect us to the internet capable of living up with the demand? Do we have the tools to design networks and systems that can connect us seamlessly to the world?
Despite our ever growing reliance on the internet and a connected world, it can often be a struggle to get a reliable WiFi or 4G signal. Most people have experienced a situation where they are watching a programme on Netflix, streaming music or browsing social media when they lose their internet connection. For some, it is a very common occurrence with many people having poor WiFi signal in their home who resort to having to buy WiFi boosters or build their own home DIY reflector out of tin foil. At the best of times, this is mildly irritating but what can we do about it?
All wireless communication systems like WiFi, 4G and Bluetooth communicate using radio or electromagnetic waves. Radio waves are similar to light but occur at lower frequencies than light and aren’t visible to the human eye. They are for the most part governed by Maxwell’s equations, a set of four equations that describe how electric and magnetic fields are generated as well as how fluctuating electric and magnetic fields propagate. These equations were first published together in complete form by James Clerk Maxwell in 1861. ‘So, if we know how electromagnetic waves and thus radio waves propagate why do we still seem to have issues acquiring a reliable wireless signal?
Maxwell’s equations are very difficult to solve. In the past empirical models have been used to model wireless communications but these aren’t very accurate as they simply fit a curve through measurements from a particular environment and are specific to that environment. These measurement campaigns are also very expensive and time-consuming to perform. More recently, research has focused on developing approximate methods to solve Maxwell’s equations and whilst these are more accurate than empirical models they still aren’t accurate enough especially with the trend towards more advanced communication systems like 5G.
In the School of Electronic Engineering, I am attempting to bridge the gap between the desired accuracy by radio engineers and us, the users, and that offered from empirical and approximate models by solving Maxwell’s equations exactly. Using mathematical tricks and some small approximations it is possible to solve Maxwell’s equations to a high degree of accuracy and develop useful models that can provide a solution very quickly.
By Ian Kavanagh