Fixed Radio Systems; Point-To-Point Equipment; Parameters for Radio System for the Transmission of Digital Signals Operating in the Frequency Range 24@50 GHz to 29@50 GHz (V1.2.1)
"The present document specifies the minimum performance parameters for terrestrial fixed service radio communications equipments operating in the frequency range 24@50 GHz to 29@50 GHz and contains a revision from the previous version@ in the areas of: - introduction of unique system type codes for regulatory reference to the various system types detailed in the present document@ refer to new Annex C and related categories of equipment classes of spectral efficiency; - additional systems with higher spectrum efficiency in the new class 4 systems; - change of spectrum mask and adjacent channel selectivity of STM-0 systems in 28 MHz channel spacing to align to EN 300 639 [34]; - introduction of new spectrum efficiency class 5 for STM-1 capacity for 28 MHz Adjacent Channel Alternate-Polarization (ACAP as class 5a) and Adjacent Channel Co-Polarization (ACCP as class 5b)@ see examples of the spectrum usage in figures 1.1a and 1.1b; - change to spectrum mask for class 4 (140 Mbit/s to 155 Mbit/s) at ""f5"" to align with the mask used in the 23 GHz and 38 GHz standards; NOTE: In a previous version@ of the present document@ there was provision for: - further options for Grade A digital radio systems (with 112MHz Channel separation); - specific antenna radiation patterns (now superseded by EN 300 833 [3]). These options are not reprinted in the present document as they are considered to be no longer of interest for ETSI members. However@ for regulatory purposes@ they may still be referenced from the previous version of the present document]. Digital systems are intended to be used for point-to-point connections in local and regional networks at data rates between 2 Mbit/s and the Synchronous Transport Module@ level 1 (STM-1). 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 low@ medium and high capacity Plesiochronous Digital Hierarchy (PDH) transmission systems@ STM-0 and STM-1 Synchronous Digital Hierarchy (SDH) transmission systems. Antenna/feeder system requirements are covered in EN 300 833 [3]. For digital systems@ with capacities up to 34 Mbit/s@ for class 2 equipment there are also two types of equipment specified: - grade A equipment@ intended for applications where moderate frequency congestion is envisaged; - the deployment of Grade A equipment in new links will be limited and stopped over a period of time. Therefore@ it is likely that provision for Grade A equipment will be removed from the present document during the next revision; - grade B equipment@ intended for applications where higher nodal capacity is required. 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 [2]. As the maximum transmission rate in a given bandwidth depends on system spectral efficiency@ different equipment classes are defined: class 2: equipment spectral efficiency based on typically 4-states modulation scheme (e.g. 4-FSK@ 4-QAM@ or equivalent); class 3: equipment spectral efficiency based on typically 8-states modulation scheme (e.g. 8PSK@ or equivalent); class 4: equipment spectral efficiency based on typically 16 or 32-states modulation scheme (e.g. 16- QAM@ 32-QAM@ or equivalent); class 5: 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 will not be considered in the present document. However compliance to EN 60950 [35] will be required to comply with Directive 1999/5/EC [36] (RTTE). Technical background for most of the parameters and requirements referred in the present document may be found in TR 101 036-1 [21]."