At the time of writing, and to an extent never seen before, there is an expectation that almost any information or service that is available through communication systems in the office or home will be available wherever the user happens to be. This is placing incredible demands on wireless communications and has been the driver for the genesis and deployment of three generations of cellular systems in the space of 20 years. In parallel with this revolution in access technology has come the recognition that any information, whether for communication, entertainment or, indeed, for other purposes as yet unenvisaged, can be stored and transported in a universal digital format. The former technology-driven distinctions of analogue storage and transport for high bandwidth signals, such as video, and digital storage for other content are no more. These changes, together with an increasing international consensus on a ‘light-touch’ regime for regulation to stimulate competition, have enabled the first generation of quad-play multi-national companies to become established. Such companies seek to spread a strong base of content and services across what would formerly have been known as broadcast (cable, satellite, terrestrial), fixed telephony, mobile and broadband access channels. However, the ability for such companies to deliver applications and services that operate reliably and consistently, regardless of user location, is ultimately predicated on their ability to design solutions that deliver an appropriate and guaranteed quality of service (QoS) over what will certainly be a finite and potentially narrow-access data pipe.