ETSI - EN 302 878-2
Access, Terminals, Transmission and Multiplexing (ATTM); Third Generation Transmission Systems for Interactive Cable Television Services - IP Cable Modems; Part 2: Physical Layer; DOCSIS 3.0
|Publication Date:||1 November 2011|
The present document is part of a series that defines the third generation of high-speed data-over-cable systems. This series was developed for the benefit of the cable industry and includes contributions by operators and vendors from North America, Europe and other regions.
There are differences in the cable spectrum planning practices adopted for different networks in the world. Therefore, two options for physical layer technology are included, which have equal priority and are not required to be interoperable. One technology option is based on the downstream multi-program television distribution that is deployed in North America using 6 MHz channelling. The other technology option is based on the corresponding European multi-program television distribution. Both options have the same status, notwithstanding that the document structure does not reflect this equal priority. The first of these options is defined in clauses 4 and 6, whereas the second is defined by replacing the content of those clauses with the content of annex B. Correspondingly,  and  apply only to the first option and  only to the second. Compliance with the present document requires compliance with the one or the other of these implementations, not with both. It is not required that equipment built to one option will interoperate with equipment built to the other.
These optional physical-layer technologies allow operators flexibility in mandated areas of operation, including any frequency planning, EMC (electromagnetic compatibility) and safety requirements. For example, the 6 MHz downstream based option defined in clauses 5 and 6 might be deployable within an 8 MHz channel plan. Compliance with frequency planning and EMC requirements is not covered by this specification and remains the operators' responsibility. In this respect,  and  are relevant to North America and [i.1], , , , , ,  and  are relevant to the European Union.
Backwards compatibility with earlier versions of that technology  is only ensured within the same technology options referred to above and not between the two options.