Many operators in Asia and the USA have rushed to switch off their 2G and 3G networks and make more spectrum free for 4G and 5G. Freeing up sub-2 GHz 2G frequencies helps extend coverage and may even save an operator from bidding in often expensive auctions for low band spectrum. And the 2.1 GHz band most commonly used for 3G can add useful capacity to 4G/5G options like 1.8 GHz and 2.5 GHz. Japan, Korea, Singapore, the USA, Taiwan, Australia and New Zealand are among the countries that have been through 2G and 3G sunsets, or are due to complete them in the coming year. In Europe, the pace of sunsetting legacy networks is far slower, and most commonly,…