In setting out the next phase of its network evolution plan, UK incumbent BT was cautious about emerging trends such as disaggregation, and in fact, focused as much on legacy networks as on 5G and advanced fiber. The company believes it can reduce its operating costs by £500m by sunsetting legacy platforms and going through a large-scale network modernization program, a move that would also reduce energy consumption. The first networks due to be decommissioned are the 20-year old 3G system and the public switched telephone network (PSTN). Such moves will be important to allow the inherent efficiencies of new architectures, including those surrounding 5G and FTTx, to be fully exploited, without drag from legacy infrastructure. And BT’s shareholders will…