The Ministry of Information and Communications is preparing to auction the 2.6 gigahertz (GHz) band, which will have higher data-carrying capacity but shorter reach than the current 1.8 GHz.
The ministry said that the bandwidth available in the 1.8 GHz band is lower than actual demand, resulting in lower 4G speeds, and a new band would allow better speeds for telecom firms and national security needs.
The auction will be open to existing network operators and new ones, if any, and winning bidders need to start operating within two years or lose their license.
Existing operators need to have at least 5,000 base transceiver stations in the new spectrum within that timeframe, while a new operator would have to establish at least 4,250.
The current 1.8 GHz band is being used by the three largest telecom operators, Viettel, VinaPhone and MobiFone.
Vietnamobile uses the 2.1 GHz band, and has along with Viettel called for the auction of the 2.6 GHz band.
Vietnam's internet speed ranks 75th in the world, lower than Malaysia and Thailand, according to a report by internet performance database M-Lab released last year.