Timothy Pratt is Emeritus Professor of Electrical and Computer Engineering at Virginia Tech, USA. He is a life senior member of the Institute of Electrical and Electronic Engineering. After industrial experience in UK industry, he taught at the University of Birmingham for ten years and at Virginia Tech for thirty years. He retired from Virginia Tech in 2013 and lives on a farm in Blacksburg, Virginia. Jeremy Allnutt is Emeritus Professor of Electrical and Computer Engineering at George Mason University, USA. He was a telecommunications research scientist in England and Canada and then Intelsat in Washington, DC, USA. After Intelsat, he spent four years as a professor in ECE at the Northern Virginia campus of Virginia Tech before joining George Mason University, from which he retired in 2014. He is a fellow of the Institute of Electrical and Electronic Engineering and a fellow of the Institution of Engineering and Technology (UK).