Transmission and Multiplexing (TM); Sub-STM-1 Digital Radio Relay Systems (DRRS) Operating in the 13 GHz@ 15 GHz and 18 GHz Frequency Bands with About 14 MHz Co-Polar Channel Spacing
This ETS specifies the minimum performance parameters for terrestrial fixed services radiocommunications equipment@ as given below@ for operation in the 13 GHz (12@75 GHz to 13@25 GHz)@ 15 GHz (14@5 GHz to 15@35 GHz ) and 18 GHz (17@7 GHz to 19@7 GHz) frequency bands. This ETS covers equipment for the transmission of sub-STM-1 digital signals with a VC3 payload capacity. The standardization of sub-STM-1 radio systems for 13 GHz@ 15 GHz and 18 GHz bands has been prepared to ensure the compatibility with the existing plesiochronous and the new synchronous systems concerning frequency plans and performance. The application of these digital radio-relay systems is anticipated to be for point-to-point links in local@ regional and national networks@ mobile base station connections@ customer and access links. Consideration has to be given to special requirements of the local and access network@ e.g. simple towers with less space for antenna@ different network structures with high density nodes. The systems considered shall operate in these networks having regard for existing hop lengths@ which mainly depend on the frequency band envisaged@ the performance objectives set by relevant ITU-R Recommendations or national Network Operators requirements and existing propagation characteristics. The hop lengths are considered to be normally up to 37 km in the 13 GHz band@ up to 30 km in the 15 GHz band and up to 20 km in the 18 GHz band. The parameters to be specified fall into two categories: a) Those that are required to provide compatibility between RF channels occupied by different sources of equipment on the same route connected either to: - separate antennas; or - separate polarization of the same antenna. NOTE: Equipment supplied by different manufactures on the same path and using different polarizations shall operate on different frequencies. b) Parameters defining the transmission quality of the proposed system. The standardization deals with IF (Intermediate Frequency)@ RF and baseband characteristics relevant to Sub-STM-1 SDH transmission. Spurious emissions and EMC (ElectroMagnetic Compatibility)requirements are also included in the ETS. Safety regulations are outside the scope of this ETS.