Transmission and Multiplexing (TM); Digital Radio Relay Systems (DRRS); High Capacity DRRS Transmitting STM-4 or 4 x STM-1 in a 40 MHz Radio Frequency Channel Using Co-Channel Dual Polarized (CCDP) Operation (V1.1.1)
The present document defines technical parameters for a high capacity Digital Radio Relay System (DRRS) operating in frequency bands with 40 MHz channel spacing e.g. the 4 GHz@ 5 GHz@ U 6 GHz and 11 GHz bands. The capacity should be STM-4 or 4 ?? STM-1 per 40 MHz RF-channel by using both polarizations in the co-channel dual polarized (CCDP) mode of operation. The area of application of these DRRS is foreseen to be in regional and trunk networks forming part of a SDH-network including STM-4 rings. Systems considered in the present document should be able to respect ITU-R high grade performance objectives. The systems considered should operate in these networks having regard for existing hop length@ which are considered to be normally up to about 30 km to 40 km for regional and about 60 km for trunk networks@ respectively. Hop lengths greater than this latter length are used in special applications. For information about compatibility with other systems see clause A.3. The parameters 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 to separate antennas. NOTE: Equipment supplied by different manufacturers on the same path or existing radio-relay systems operate on different frequencies. b) Parameters defining the transmission quality of the proposed system. The standardization deals with baseband and RF characteristics relevant to SDH. Antenna/feeder system requirements are also considered. Baseband interfaces have to be considered for STM-1 signals and STM-4 signals in accordance with ITU-T Recommendations G.707 [6] and G.957 [21] respectively.