Cadenza-the first nine months; and beyond

The Cadenza system was first presented as a candidate ATM switch-in-the-sky in 1994. At that time, the viability of the concept had already been demonstrated, but an operational system deriving from it was still only a pious hope-or perhaps a little more than that. Cadenza has now gone on to become the world's first ATM switch in the sky. Since the beginning of March this year, the Cadenza system has been successfully trialled in two of the European Community's ACTS projects. The players have included the Public Telecom Operators in most Member States, and the applications, which have been switched between Oslo, Athens, Ipswich, Brussels and Antwerp, have ranged from slow (keyboard-to-screen) text and management messages, through various types of multimedia, to file and image transfer and high quality MPEG video delivery. These projects are scheduled to continue for a further two years, with increasing switch capacities and increasingly elaborate OAM and signalling. The author describes the Cadenza concept and its implementation and trial results.