Guidelines for implementations and deployment of transmission of multichannel digital television signals over optical access networks and Hybrid Fibre-Coaxial (HFC)
(Continuation of Question 4/9)
MotivationRecent fibre optical transmission technology allows extending fibre networks to the curb, the building or the home.
Fibre networks can be brought closer to users' premises than hybrid fibre-coaxial (HFC) networks, although HFC is still widely used in developed countries and expected to be used in some developing countries as the primary cable access infrastructure.
Fibre technology enables transmission of multichannel digital television signals in the form of RF as in the HFC networks. It can also provide high capacity (10Gbps or more) in the forward and return channel in the form of high-speed digital signals such as IP, which is required for the provision of typical cable television services, including interactive ones.
Although several Recommendations on optical access networks have been developed to transmit high quality television signals, further study on the interworking and interfaces between digital video systems and fibre networks is needed.
QuestionStudy items to be considered include, but are not limited to:
- Which mechanisms can be used to transport multichannel digital television signals over fibre networks and hybrid fibre–coaxial (HFC), in view of the high loss of optical splitters used for PON (passive optical networks)?
- Which mechanisms can be used to ensure the low composite distortion and high carrier-to-noise ratio (CNR) that are required for frequency division multiplex (FDM) transport of digital television signals over fibre networks?
- Which mechanism can be used to transport multichannel digital television signals over fibre networks in the form of a high-speed digital communication link or IP packets?
- Which mechanism can be used to compensate the jitter arising from transporting over asynchronous communication links over fibre networks?
- Which mechanism can be used to compensate the packet loss arising from transporting over best effort communication links over fibre networks?
- Which mechanism or interface can be used between content providers, core networks and optical access networks/HFC?
- Which mechanism can be used to control access to the traffic in term of traffic management and security?
- How ITU-T SG9 can support developing countries to deploy digital television services on optical fibres and HFC, taking into account their limited resources as well as other specific needs?
TasksTasks include, but are not limited to:
- Preparation of new Recommendation(s) regarding the above study items listed under “questions” as well as maintenance of existing Recommendations such as ITU-T J.185 and J.186;
- Publish useful information (e.g. Reports, Surveys, Supplements, Guidelines or Handbooks) to support the deployment of digital television services on optical fibres and HFC in developing countries.
An up-to-date status of work under this Question is contained in the Study Group 9 work programme (
https://www.itu.int/ITU-T/workprog/wp_search.aspx?sp=16&q=4/9).
Relationships
Recommendations
- ITU-T J.83, J.185, J.186 and other relevant J-series Recommendations;
- ITU-T G.984-series, G.987-series, G.9807-series and other G-series Recommendations addressing optical fibre networks, systems and interfaces.
Questions
Study groups
- ITU‑T SG15 (optical network architectures, particularly those related to PON systems, and optical interfaces)
- ITU-D SG1 and SG2
Standardization bodies