Dynamic spectrum sharing (DSS) has been billed as an important way for operators to improve spectral efficiency and increase the frequencies available for 5G. However, as it becomes commercially deployed, operators are taking different views of its advantages. DSS allows 4G spectrum to be used flexibly for either 4G or 5G signals. This has allowed some MNOs, such as VodafoneZiggo in the Netherlands, to launch 5G before they were allocated specific licences. It also enabled operators such as Verizon to extend coverage before it secured the midband spectrum that is generally ideal for 5G. Even in the USA there were differences of opinion. T-Mobile USA has been critical of the claimed performance trade-offs of DSS, partly (of course) because it…