全球无线电数字传输（DRM).第一部分:系统规范

[中文适用范围]： 描述用于 30 MHz 以下广播的频段： 低频 (LF) 频段 - 从 148.5 kHz 到 283.5 kHz，在 ITU 1 区 1；仅有的;中频（MF）频段 - 在 ITU 1 1 和 3 1 区域中从 526.5 kHz 到 1 606.5 kHz，以及从 525 kHz 到 1 [外文原描述]： Describes the frequency bands used for broadcasting below 30 MHz: Low frequency (LF) band - from 148,5 kHz to 283,5 kHz, in ITU Region 1 [1]* only; Medium frequency (MF) band - from 526,5 kHz to 1 606,5 kHz, in ITU Regions 1 [1] and 3 [1] and from 525 kHz to 1 705 kHz in ITU Region 2 [1]; High frequency (HF) bands - a set of individual broadcasting bands in the frequency range 2,3 MHz to 27 MHz, generally available on a Worldwide basis. These bands offer unique propagation capabilities that permit the achievement of: Large coverage areas, whose size and location may be dependent upon the time of day, season of the year or period in the (approximately) 11 year sunspot cycle; Portable and mobile reception with relatively little impairment caused by the environment surrounding the receiver.