On 2 June 2021 the National Communications Commission (NCC) announced that it is considering share use of the 2100MHz band exclusively for circuit switched fallback (CSFB) 3G voice service but not for further share use in 4G or 5G services. A 60-day public consultation will begin in July 2021.
The 3G service in Taiwan officially closed at the end of 2018. However, the 3G voice service in the 1800MHz and 2100MHz bands remains available while the data service moves up to 4G long-term evolution (LTE). It is reported that up to 6 million mobile users – approximately 25% of total mobile phone subscribers in Taiwan – are not equipped with voiceover LTE smartphones. The incumbent 4G operators have proposed to close the 3G voice service from 2024 and have explored the possibility of share use in the 2100MHz band or, alternatively, a roaming arrangement in CSFB on the rival 3G networks.
It will be another successful case of spectrum sharing, further to the NCC's permission grant in March 2021 for FET and APT alliance on shared use of 3340 to 3520MHz (n78 New Radio), which is currently assigned to FET (for further details please see "NCC approves first application for 5G spectrum sharing"). The NCC nevertheless reaffirmed its statement that, for the sake of fair play, it plans no spectrum sharing for 4G and 5G services in the 2100MHz band.
