ETSI - PRETS 300 430
Transmission and Multiplexing (TM); High Capacity Digital Radio-Relay Systems Carrying 1 x Synchronous Transport Module-Level 1 (1 x STM-1) Signals Operating in the 18 GHz Frequency Band with Channel Spacing of 55 MHz
|Publication Date:||1 January 1994|
The present document specifies parameters for digital radio-relay systems with a capacity of 1 x Synchronous Transport Module-1 (1 x STM-1) designed to operate in the 17,7 GHz to 19,7 GHz band. The channel spacing between adjacent co-polar channels is 55 MHz. Operation in the Co-Channel Dual Polarized (CCDP) mode with orthogonal polarizations is also foreseen.
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
- separate polarizations of the same antenna; or
- one polarization of one antenna at a frequency separation of twice the basic co-polar spacing (2 x 55 MHz), enabling interworking of different manufacturers equipment at the same Radio Frequency (RF) branching.
This category also includes parameters providing compatibility with the existing radio-relay network;
b) parameters defining the transmission quality of the proposed system.
The standardization deals with Intermediate Frequency (IF), RF and baseband characteristics relevant to Synchronous Digital Hierarchy (SDH). Antenna / feeder system requirements are also considered.
Two possible baseband interfaces have to be considered: one for STM-1 signals in accordance with ITU-R Recommendation F.750  and another for 140 Mbit/s signals.
Safety aspects are outside the mandate of ETSI and they will not be considered in the present document.