The appropriate frequency band is in the 863-928 MHz range, specifically the AS923 frequency plan. Southeast Asian countries such as Malaysia, Singapore, Brunei, Cambodia, Indonesia, Laos, Thailand, and Vietnam typically use the AS923-925 frequency plan, with uplink channels around 923.2 MHz to 924.8 MHz. Devices usually supports frequencies from 470-510 MHz and 863-928 MHz, with the high-frequency (HF) model covering 863-928 MHz, which includes the AS923 band used in Southeast Asia.