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A new ITU-T Technical Report places emerging 5G radio requirements in the context of their demands on the optical transport network. The report provides a framework to accelerate 5G transport projects in ITU-T Study Group 15, the standardization expert group for 'transport, access and home'.

The report takes a transport network view of 3GPP and CPRI specifications, capturing ITU-T SG15's understanding of emerging 5G requirements. The baseline document gives direction to new ITU-T SG15 standardization projects aimed at evolving the transport network in support of 5G.

"At ITU, we are working to support enhanced mobile connectivity by defining both the spectrum and the standards for 5G, and the standards for transport networks to support 5G," said ITU Secretary-General Houlin Zhao. "By doing so, we hope to fast-track the global community's access to greater digital connectivity speeds that are more responsive and that can handle the ever-growing number of connected devices."

"Coordinated wired-wireless innovation is key to the 5G vision," said Chaesub Lee, Director of the ITU Telecommunication Standardization Bureau. "This is well recognized by ITU members. We see steady growth in 5G projects in ITU-T Study Groups."

The ITU-T Technical Report – GSTR-TN5G "Transport network support of IMT-2020/5G" – provides a reference model for the 5G transport network, with particular focus on the interfaces between 5G entities and the transport network. The report's primary aim is to identify the 5G architectures and interfaces of importance to ITU-T SG15.

"The report builds a bridge between the transport community in ITU-T SG15 and the wireless community in 3GPP, giving them a common point of reference," said Malcolm Betts, Chairman of ITU-T SG15 Working Party 3. "We have established a framework for 3GPP to talk about what they need and ITU-T SG15 to talk about how we will supply that."

The report identifies four 5G RAN deployment scenarios, describing their influence on the classification of fronthaul, midhaul and backhaul in optical transport networks. It outlines 5G requirements on time and frequency synchronization, highlighting required levels of accuracy defined by 3GPP. It draws attention to the transport network management-control required to support multiservice capabilities and 5G network slicing, particularly in relation to the interaction of 5G network and transport network management systems.

More Information:

ITU-T SG15 leads international standardization work on 5G transport. This leadership received strong support from the administration of China at the closing plenary of the meeting of ITU-T SG15 in Geneva, 29 January to 9 February 2018.

Passive Optical Network (PON), Carrier Ethernet and Optical Transport Network (OTN) are among the technologies standardized by ITU-T SG15 with significant potential to support 5G systems. New standardization efforts continue to emerge as a result, the most recent aiming to define the transport network characteristics required to support 5G fronthaul, midhaul and backhaul.

ITU's programme on "International Mobile Telecommunications for 2020 and beyond (IMT-2020)" defines the framework and overall objectives of the 5G standardization process as well as the roadmap to guide this process to its conclusion by 2020.  

ITU's Radiocommunication Sector (ITU-R) coordinates the international standardization and identification of spectrum for 5G mobile development. ITU's Standardization Sector (ITU-T) is playing a similar convening role for the technologies and architectures of the non-radio elements of 5G systems.  

ITU's 5G standardization programme is led by ITU-R Working Party 5D (IMT Systems) and supported by ITU-T Study Groups 5 (Environment and circular economy); 11 (Protocols and test specifications); 13 (Future networks); and 15 (Transport, access and home).