Transmission and Multiplexing (TM); Generic requirements of transport functionality of equipment; Part 5-1: Plesiochronous Digital Hierarchy (PDH) path layer functions
The present document specifies a library of basic building blocks and a set of rules by which they are combined in order to describe a digital transmission equipment. The library comprises the functional building blocks needed to completely specify the generic functional structure of the European digital transmission hierarchy. Equipment which is compliant with the present document can be described as an interconnection of a subset of these functional blocks contained within the present document. The interconnections of these blocks should obey the combination rules given. The generic functionality is described in the EN 300 417-1-1 [8].