Fixed Radio Systems; Point-To-Point Equipment; Parameters for Radio Systems for the Transmission of Sub-STM-0 Digital Signals Operating in the 18 GHz Frequency Band (V1.1.1)
The present document specifies the minimum performance parameters for terrestrial digital fixed service radio communications equipments operating in the 18 GHz frequency band and provides for the following: - technical specifications relevant to the EMC Directive@ detailed in annex B (normative); - system types codes for regulatory unique reference to the various system types detailed in the present document@ refer to annexC (normative). Digital systems are intended to be used for point-to-point connections in local and regional networks at data rates of Synchronous Transport Module. Digital systems considered in the present document will be able to meet the performance objectives of the ITU-R national portion of the reference path@ i.e. ITU-R Recommendation F.1189-1 [23] and the performance objectives detailed in ITU-T Recommendation G.826 [30] and in ITU-T Recommendation G.828 [31]. The parameters to be specified fall into two categories: a) those that are required to provide compatibility between channels from different sources of equipment on the same route@ connected either: - to separate antennas; or - to separate polarizations of the same antenna. b) parameters defining the transmission quality of the proposed system. The present document deals with Radio Frequency (RF) and baseband characteristics relevant to Sub STM-0 Synchronous Digital Hierarchy (SDH) transmission systems. Antenna/feeder system requirements are covered in EN 300 833 [13]. These digital systems capacities shall be in accordance with ITU-T Recommendation G.708 [27]. The present document does not contain aspects related to test procedures and test conditions@ however they are to be found in EN 301 126-1 [14]. As the maximum transmission rate in a given bandwidth depends on system spectral efficiency@ different equipment classes are defined: Class 1: equipment spectral efficiency based on typically 16 or 32-states modulation scheme (e.g. 16-QAM@ 32-QAM@ or equivalent); Class 2: equipment spectral efficiency based on typically 64 or 128-states modulation scheme (e.g. 64-QAM@ 128-QAM@ or equivalent). The above classes are indicative only and do not imply any constraint to the actual modulation format@ provided that all the requirements in the present document are met. Safety aspects are outside the mandate of ETSI and they will not be considered in the present document. However compliance to EN 60950 [1] will be required to comply with EC Directive RTTE. Technical background for most of the parameters and requirements referred in the present document may be found in TR 101 036-1 [17].