RES517 – 328 – 3 that whenever an administration replaces a DSB emission by an emission using digital modulation techniques, it shall ensure that the level of interference is not greater than that caused by the original DSB emission, and shall use the RF protection values specified in Resolution 543 (WRC-03); 4 that the continued use of DSB emissions may be reviewed by a future competent world radiocommunication conference based on administrations’ experience with the introduction of digital HF broadcasting services, instructs the Director of the Radiocommunication Bureau to compile and provide to the future competent world radiocommunication conference referred to in resolves 4 the latest available complete statistics on the worldwide distribution of digital HF broadcasting receivers and transmitters, invites ITU-R to continue its studies on digital techniques in HF broadcasting with a view to assisting in the development of this technology for future use, invites administrations to encourage the inclusion in all new HF broadcasting transmitters put into service after 1 January 2004 of the capability to offer digital modulation, further invites administrations 1 to assist the Director of the Radiocommunication Bureau by providing the relevant statistical data and to participate in ITU-R studies on matters relating to the development and introduction of digitally modulated emissions in the HF bands between 3 200 kHz and 26 100 kHz allocated to the broadcasting service; 2 to bring to the notice of transmitter and receiver manufacturers the recent results of relevant ITU-R studies on spectrum-efficient modulation techniques suitable for use at HF as well as the information referred to in considering d) and e), and encourage the availability of affordable low-cost digital receivers.