SIST ETS 300 147 E3:2003

SIST ETS 300 147 E3:2003 is the Slovenian adoption of ETS 300 147 Edition 3 from ETSI. It specifies the SDH multiplexing structure for transmission networks, including hierarchical bit rates, mapping schemes, pointer processing and overhead bytes. The standard is intended to support inter-vendor and inter-operator compatibility for SDH interfaces and equipment.

What does SIST ETS 300 147 E3:2003 specify?

SIST ETS 300 147 E3:2003 specifies the hierarchical bit rates, multiplexing structure and mapping schemes used in transmission networks based on the Synchronous Digital Hierarchy (SDH).

The document is organized into scope, normative references, definitions/abbreviations/conventions, basic multiplexing principles, multiplexing method, pointers, overhead bytes description, mapping of tributaries into VC-n, conformance testing, and an informative bibliography.

• Annex A - Informative bibliography

What are the key requirements of SIST ETS 300 147 E3:2003?

SIST ETS 300 147 E3:2003 takes the relevant parts of ITU-T Recommendation G.707 and marks each item as normative or not relevant. In practice, that means an implementation only needs to follow the parts that apply to the SDH subset covered here, but any implemented function has to match the stated SDH behavior.

Basic multiplexing structure

Clause 4 states that the SDH multiplexing structure shall follow figure 1, and that this structure is a subset of the SDH multiplexing structure defined in G.707. For users, this is the core hierarchy they need to design around when building or checking SDH transport paths.

Clause 4 also makes the section overhead, administrative unit pointers, maintenance signals, hierarchical bit rates, interconnection of STM-Ns, scrambling, physical specification of the NNI, and the 51 840 kbit/s interface part of the normative SDH framework. That matters because these are the interface and framing items that determine interoperability.

Multiplexing method and numbering

Clause 5 covers multiplexing of administrative units into STM-N and tributary units into VC-4 and VC-3. It also defines numbering for AU-4s, TU-3s, TU-2s and TU-12s in the relevant containers, which is what implementers use to place signals consistently and to avoid incompatible channel ordering.

Several G.707 items are marked not relevant here, including AU-3-related items and some VC-3, TU-11 and TU-2 paths. In practice, this shows which mapping options belong to this ETS and which are outside its SDH subset.

Pointers and concatenation

Clause 6 specifies AU-n and TU-3/TU-2/TU-1 pointer location, value, frequency justification, New Data Flag, generation and interpretation. That is the mechanism used to align payloads when clocks are not exactly synchronous, so equipment designers need to implement the pointer rules exactly.

The clause also addresses concatenation. Contiguous AU-4 concatenation is normative, virtual concatenation of AU-4s is noted as under study, contiguous TU-2 concatenation in the higher-order VC-3 is not relevant, and virtual concatenation of TU-2s in the higher-order VC-4 is normative.

Overhead bytes and supervision

Clause 7 describes SOH and POH bytes by location and function. It covers framing, trace, parity, orderwire, user channels, the Data Communication Channel (DCC), Automatic Protection Switching (APS), synchronization status, path status and network operator bytes, so operations teams can identify what supervision and management information is carried in the frame.

The clause also notes that Enhanced RDI is not supported in the G1 and K4 contexts, and that the V5 byte RFI bit is not used within European countries. For readers, that means those bits should not be relied on for functions outside the document’s stated behavior.

Tributary mapping

Clause 8 covers mapping of tributaries into VC-n, including asynchronous, bit synchronous and byte synchronous mappings for the listed SDH and PDH rates. It also covers VC-11 to VC-12 conversion and ATM cell mapping into VC-4-Xc, VC-4/VC-3, VC-2-mc, VC-2 and VC-12/VC-11. This is the practical part that tells a designer which traffic types can be carried and how they enter the SDH hierarchy.

Conformance testing

Clause 9 says conformance testing is carried out on functional blocks within a network element, using SDH interfaces to exercise those blocks. That means equipment testing is organized around atomic functions, not around one fixed end-to-end product profile.

What terms does SIST ETS 300 147 E3:2003 define?

• SDH - Synchronous Digital Hierarchy, the transport hierarchy addressed by the standard.
• STM-N - Synchronous Transport Module (-N), the SDH line signal that carries multiplexed payloads.
• AU-n - Administrative Unit-n, a payload unit placed into STM-N.
• TU-n - Tributary Unit-n, a lower-order unit used when mapping tributary signals.
• VC-n - Virtual Container-n, the container that carries tributary information through the SDH network.
• SOH - Section OverHead, the bytes used for section framing, management and protection.
• POH - Path OverHead, the bytes used for end-to-end path supervision.
• APS - Automatic Protection Switching, the protection mechanism carried in dedicated overhead bytes.

Who uses SIST ETS 300 147 E3:2003?

SIST ETS 300 147 E3:2003 is used by SDH network equipment designers, transmission engineers, test laboratories, operators and buyers who need to check SDH compatibility.

It is especially relevant when selecting supported tributary rates, defining multiplexing chains, checking pointer handling, or building conformance tests for SDH network elements. The foreword states that it is intended to provide inter-vendor and inter-operator compatibility.

What changed in SIST ETS 300 147 E3:2003 from the previous edition?

SIST ETS 300 147 E3:2003 is the third edition and supersedes the second edition of ETS 300 147 (1995).

The scope says this edition takes account of changes resulting from ITU-T Recommendation G.707 (3/96), which replaced former ITU-T Recommendations G.707, G.708 and G.709.

Which standards are used with SIST ETS 300 147 E3:2003?

• ITU-T Recommendation G.707 (1996) - the base reference for SDH network node interface, and the source of the definitions and clause structure reused here.
• ITU-T Recommendation G.702 - provides the digital hierarchy bit rates and signal rates used in the tributary mappings.

What does the SIST ETS 300 147 E3:2003 document contain?

The document contains a figure showing the SDH multiplexing structure from tributaries through VC-n, TUGs, AU-n and STM-N. It also contains Tables 1 to 5, which align this ETS with G.707 sections on multiplexing principles, multiplexing method, pointers, overhead bytes and tributary mapping.

For practical work, the tables indicate which SDH functions are normative, which are not relevant, and which functions are under study. Annex A then gives a short bibliography for related ITU-T recommendations used as background or context.