1、 1 - Place des Nations Telephone +41 22 730 51 11 Telex 421 000 uit ch E-mail: itumailitu.int CH-1211 Geneva 20 Telefax Gr3: +41 22 733 72 56 Telegram ITU GENEVE www.itu.int Switzerland Gr4: +41 22 730 65 00 QUESTION ITU-R 52-1/6 Coverage in LF, MF and HF broadcasting (1990-1994-2006) Q. ITU-R 58-1
2、/10 The ITU Radiocommunication Assembly, considering a) the need to ensure efficient spectrum utilization when planning LF, MF and HF broadcasting services, decides that the following Question should be studied 1 What is the dependence of ground-wave and sky-wave sound broadcasting coverage on: the
3、systems used and their characteristics; the type of modulation in digital and analogue broadcasting; the radio-frequency protection ratios; the channel spacing; the minimum usable field strength; the radiated power; the geographical distribution of the transmitters; the distribution of population de
4、nsity; the use of directional transmitting antennas; the use of groups of synchronized transmitters and single frequency networks; for bands 5 (LF), 6 (MF) and 7 (HF)? 2 What methods are required (including the use of computers), for calculating the minimum number of channels for the coverage for br
5、oadcasting in bands 5 (LF) 6 (MF) and 7 (HF), for each of the systems envisaged, taking into account the points listed under 1? NOTE 1 See Recommendations ITU-R BS.598, ITU-R BS.1514, ITU-R BS.1615. further decides 1 that the results of the above studies should be addressed to: update existing Recommendation(s); prepare (a) new Recommendation(s); 2 that the above studies should be completed by 2007. Category: S1
