Transmission and Multiplexing (TM); Digital Radio Relay Systems (DRRS); Plesiochronous Digital Hierarchy (PDH); Low and Medium Capacity and STM-0 DRRS Operating in the Frequency Bands in the Range 3 GHz to 11 GHz (Version 1.1.1)
The present document specifies the minimum performance parameters for low and medium capacity terrestrial fixed service digital radiocommunications equipment operating in the frequency bands between around 3 GHz and 11 GHz but nevertheless such systems should provide the efficient use of the spectrum under any conditions. The present document covers equipment intended to be used at nominal data rates for PDH systems between 2 Mbit/s and 2 ?? 34 Mbit/s and for SDH systems transmitting STM-0 signals with a VC3 payload capacity. Consideration has to be given to special requirements of the local and access network especially different network structures with high density nodes. The systems considered are envisaged to operate in these networks having regard for existing hop lengths which mainly depend on the intended frequency band@ 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 up to about 100 km in the frequency band 3 GHz and 60 km in the frequency band 11 GHz taking into account diversity techniques. Typical applications include: a) point-to-point links in local@ regional and national networks; b) mobile base station connections; c) business networks connections; d) customer access links. The parameters to be specified fall into two categories: a) Those that are required to provide compatibility between RF channels from different sources of equipment on the same route@ connected either to: - separate antennas@ or to; - separate polarization of the same antenna. b) Parameters defining the transmission quality of the proposed system. The standardization deals with RF and baseband characteristics relevant to low and medium capacity PDH and STM-0 SDH transmission. Spurious emissions requirements are also included in the present document. EMC requirements are covered in EN 300 385 [23]. Antenna/feeder system requirements are covered in ETS 300 833 [1]. As the maximum transmission rate in a given bandwidth depends on systems spectral efficiency@ different Classes are defined: Class 1: Equipment based on performances of a typical 4-states modulation scheme Class 2: Equipment based on performances of a typical 16-states modulation scheme Class 3: Equipment based on performances of a typical 32 or 64-states modulation scheme Safety is not considered in the present document.