BBF Publishes International Standards Developed by NTT, Chunghwa Telecom to Achieve Modularization of Dynamic Bandwidth Assignment

- Modularization Crucial to QoS in Optical Access System -

TOKYO, Feb. 13, 2019 /PRNewswire/ -- The Broadband Forum ("BBF (*1)"), which is an industry organization focusing on engineering smarter and faster broadband networks, approved standards about modularization of a dynamic bandwidth assignment (DBA (*2)) function on December 3, 2018, which represents a significant impact on quality of service (QoS) in an optical access system. These standards, developed jointly by Nippon Telegraph and Telephone Corporation (NTT) and Chunghwa Telecom Co., Ltd., specify an API (*3) (Application Programming Interface), which enables the replacement of the DBA software module, to realize future optical access systems that can quickly and cost-effectively provide the widest possible range of services.

NTT and Chunghwa Telecom have jointly proposed use cases of the DBA software module at BBF meetings, and developed the API specifications as the international standards. This advance enables carriers to use a common access system for a diverse range of services, including accommodation of base stations for mobile systems of the fifth generation (5G) and beyond, which strictly require low latency.

NTT will promote the developed standards, and push forward its R&D activities which are even now contributing to the expansion of the application area of optical access systems in cooperation with other carriers, system vendors, standardization organizations (SDO), and open source software (OSS) development organizations.

Figure 1 Replacement of softwarized DBA functions to meet each service requirement

Table 1 List of newly developed BBF standards

Looking forward

In addition to this international standard of API specifications, NTT will pursue to modularize the remaining access functions in cooperation with carriers, system vendors, SDOs, and OSS organizations in order to avoid the significant investment of redeveloping hardware-level equipment from scratch. This will result in cost-effective access systems that can quickly meet various requirements.


(*1) BBF

A non-profit industry organization composed of the industry's leading broadband operators, vendors, and thought leaders, the BBF's work to date has been the foundation for global broadband proliferation and innovation.

BBF home page:

(*2) DBA

Dynamic Bandwidth Assignment. This is a dynamic bandwidth control function for point-to-multi-point optical access networks. In order to avoid the collision of upstream data from multiple ONUs, the DBA function in an OLT assigns time to each ONU at which to start upstream transmission and the transmission duration.

(*3) API

Application Programming Interface. This is an interface that specifies how components should interact.

(*4) FASA

Flexible Access System Architecture. "Introducing the New FASA Concept for Future Access Systems" -- NTT news release, Feb. 8, 2016

FASA home page:

(*5) BBF news release, June 20, 2018

"Broadband Forum hits 5G milestone"

(*6) NTT news release, Nov. 20, 2018

"World's First Demonstration of Modularization of Dynamic Bandwidth Assignment; A Crucial Function to QoS in Optical Access System"

Attachments / references
Figure 1: Replacement of softwarized DBA functions to meet each service requirement
Table 1: List of newly developed BBF standards

FASA is a registered trademark of NTT.

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