Ericsson is to be the dominant supplier of AT&T’s ‘open RAN’, on which the US operator plans to spend up to $14 billion over the coming five years. In the old world of traditional RAN, this would have caused only a small stir. Ericsson has been a powerhouse in the US market since it acquired many of bankrupt Canadian vendor Nortel’s assets in 2009, establishing a strong north American base that had previously eluded it. Now, it is the largest RAN vendor for the big three US operators. But the news of its latest success with its long-standing client caused a furor because it concerns Open RAN, or at least AT&T’s definition of that. Open RAN – which enables operators…