John O’Sullivan has made significant contributions to the field of digital signal processing relating to the application of Fourier Transforms in the Telecommunications, Electro-acoustic and Radioastronomy fields. He is more generally known as the primary inventor of two technologies that led to significant areas of application and start-up companies — a FFT chip that led to Lake Technologies and the 802.11a/g wireless LAN, where he solved problems considered intractable by the major companies in the space globally. This led to the formation of Radiata which was acquired by CISCO. John has a global reputation for his significant contributions in radioastronomy.