Transport, access & home
The international standards (ITU-T Recommendations) developed by Study Group 15 detail technical specifications giving shape to global communication infrastructure. The group’s standards define technologies and architectures of optical transport networks enabling long-haul global information exchange; fibre- or copper-based access networks through which subscribers connect; and home networks connecting in-premises devices and interfacing with the outside world.
This includes the development of standards for the optical transport network, access network and home network infrastructures, systems, equipment, optical fibres and cables and the related installation, maintenance, management, test, instrumentation and measurement techniques, and control plane technologies to enable the evolution toward intelligent transport networks.
Particular emphasis is given to providing international standards for a high-capacity (terabit) optical transport network (OTN) infrastructure including the support of IMT-2020 and beyond, and for high‑speed (multi‑Mbit/s and Gbit/s) network access and home networking. This includes the related work on modelling for network, system and equipment management, transport network architectures and layer interworking.
Access network technologies addressed by SG15 include passive optical network, point-to-point optical, and copper-based digital subscriber line technologies, including ADSL, VDSL, HDSL, SHDSL, G.fast and MGfast. These access technologies find application in their traditional uses as well as in backhaul and fronthaul networks for emerging services such as broadband wireless and data centre interconnect. Home networking technologies include wired broadband, wired narrowband, wireless narrowband and free space optical transmission (visible light communication). Both access and home networking for smart-grid applications are supported.
Network, system and equipment features covered by SG15 include routing, switching, interfaces, multiplexers, cross-connect, add/drop multiplexers, amplifiers, transceivers, repeaters, regenerators, multilayer network protection switching and restoration, operations, administration and maintenance, network synchronization for both frequency and precision time, transport resource management and control capabilities to enable increased transport network agility, resource optimization, and scalability (e.g. the application of software-defined networking to transport networks, together with enabling the use of artificial intelligence and machine learning to support the automation of transport network operations). Many of these topics are addressed for various transport media and technologies, such as metallic and terrestrial/submarine optical fibre cables, dense and coarse wavelength division multiplexing optical systems, and OTN, including the evolution of OTN beyond 400 Gbit/s rates, Ethernet and other packet-based data services.
Within its framework, SG15 handles the entire range of fibre and cable performance, field deployment and installation, taking into account the need for additional specifications driven by new optical fibre technologies and new applications. It is also studying the use of submarine cables for ocean and climate monitoring as well as disaster warning. The activity on field deployment and installation addresses reliability, security aspects and social issues, such as the reduction of excavation, the problems caused to traffic and the generation of construction noise, and includes the investigation and standardization of new techniques allowing faster, cost-effective and safer cable installation. This work also includes deployment considerations of particular relevance to developing countries. Planning, maintenance and management of the physical infrastructure take into account the advantages of emerging technologies. Solutions for improving network resilience and recovery against disasters are studied.
In its work, SG15 takes into account related activities in other ITU study groups, standards-developing organizations, forums and consortia, and collaborates with them to avoid duplication of effort and identify any gaps in the development of international standards. Its activities relate to the WSIS Action Line C2 “Information and communication infrastructure” and the UN Sustainable Development Goal SDG 9 “Industry, Innovation and Infrastructure”.