A small handful of operators is seizing the initiative in open, software-defined platforms so decisively that they stand a good chance of transforming their own operational base, and raising the drawbridge once again to keep out newcomers. There are not many names on this list, and some are helped by a relatively closed commercial environment, as in China. In the USA, however, the most competitive telecoms market for many years is developing, thanks to the convergence of fixed, mobile and video/media services; and to the high mobile ambitions of the leading cable operators. These developments, coupled with the prospect of an enlarged third player, should Sprint and T-Mobile USA be permitted to merge, are putting the pressure on AT&T and…