KEY TAKEAWAYS
  • Photonic technology, using optical wavelengths to transmit information at a much-reduced rate of power consumption, provides the basis for NTT’s new green infrastructure – an Innovative Optical Wireless Network, or IOWN.
  • Core the IOWN concept is an All-Photonics Network, which will allow such new services as a hyper-realistic, hyper-reliable remote communications network, using multipoint connection technology (Photonics On-Demand).
  • Certain key technology services support the coordination needed for all the service partners involved in creating hyper-realistic remote connections, such as varied protocol support, flexible bandwidth selection, disaggregation and multi-vendor interconnection.
  • Also needed is an improvement of network utilization efficiency, high-speed distribution of large-volume content to multiple locations, and on-demand connection with Function Dedicated Networks (FDNs – dedicated logical networks that are independent for each user).
  • To improve usability and make Photonics On-Demand available to as many service providers as possible, NTT is developing a high-presence communications platform: a video platform to provide more convenient user interfaces.
  • We’re working with partners to research and develop fundamental technologies to achieve the Remote World. Going forward, we will improve the real-time functionality of service delivery and scale of concurrent usage to bring more affordable services to more people.

The near future will see the world needing more expansive, more reliable internet connectivity, as well as a significant reduction in the environmental impact of technologies and infrastructure. NTT’s IOWN concept – an Innovative Optical Wireless Network – is aimed at transforming existing systems and realizing a new infrastructure that goes beyond the limitations of current ICT. The ambition of this ten-year program is to radically increase the capacity of the internet, whilst radically reducing the energy consumption of computing resources and facilities – creating a new, green internet by 2030.

IOWN, described in more detail in this article on the network of the future and this video, is composed of an All-Photonics Network for ultra-high capacity, ultra-low latency and ultra-low power consumption, Digital Twin Computing that creates predictions by combining the real and digital worlds, and a Cognitive Foundation® that connects and controls everything.

Photonic devices – which use photonics-electronics convergence technologies (i.e. comprising both optical and electrical components and capable of achieving performance that far exceeds that of discrete devices) – are the basis of IOWN, and we want to use such devices to expand the capabilities of terminals, devices, and applications supported by networks.

One such example of the network-service technologies enabled by the All-Photonics Network (APN) for IOWN is Photonics On-Demand, which enables hyper-real virtual communications to help everyone be better connected, even when physically apart.

Making the Remote World a reality with Photonics On-Demand

The world where people used to meet each other, gather in large groups, and enjoy on-the-spot conversations and events is changing to one where people gather remotely from various locations to participate in meetings and events. People separated by distance (or other restrictions) can easily meet via a screen, and events that used to be difficult to experience due to capacity limitations are now easier to participate in, offering new ways to enjoy time together. However, many people still feel a lack of realism – likely due to unstable and highly variable communications quality, such as poor or interrupted connection when talking to a friend.

High-quality communications are also expensive, take several months for services to become available, and are a privilege only for a limited number of people, due to the limitations of current communications network technologies (Fig. 1).

“We will add service technologies, such as our next-generation video service platform, to deliver high-presence communications to a large number of customers even in remote environments – and make the Remote World a reality.”

To overcome these challenges and achieve high-speed and broad bandwidth as well as low cost and immediate use, NTT is collaborating with partners and using APN technology to research and develop on-demand photonic multipoint connection technology: Photonics On-Demand.

We will add service technologies, such as our next-generation video service platform (Photonic Direct Multipoint Connection) to this communications technology, to deliver high-presence communications to a large number of customers even in remote environments – and make the Remote World a reality.

Fig. 1. Relationship among current services and target area for new technologies.

Connecting the world

The key to solving network issues with remote communications, using Photonics On-Demand, is how to make the smallest unit of an optical communications path (one optical wavelength, commonly known as λ) – which is high-speed but expensive and has limited applications – available to a large number of people at low cost.

To achieve this, it’s necessary to increase the number of λs that can be used with a single optical fiber, and using the optical resources only when necessary, i.e. on-demand, minimizing use to only the amount of time needed.

It is also important to greatly expand service menus, which currently have little variety, to meet a wide range of user needs on the same network, and superimpose networks that can be provided to each user. For example, for an immersive-feeling live event, multipoint connection technology must work for the video communications provider, the event planning company, those viewing at home, those at a cinema or other public viewing venue, and so on.

Certain key technologies and services support this multi-entity coordination, such as interfaces, vendor-agnostic photonic device connection, multipoint simultaneous connection, network improvements, high-precision synchronization and a direct high-presence communications platform.

Enabling a variety of interfaces

To enable users to use their own assets and the network freely, it is important to have a variety of interfaces to connect devices, such as uncompressed video transmission (e.g. via serial digital interfaces) and analog optical signals, essentially without the need for conventional protocols such as Ethernet or TCP/IP (Transmission Control Protocol/Internet Protocol). Using technology that divides a λ into time-domain elements, and/or treats multiple λs as a group, will provide communications with optimal quality and speed at all times.

To enable users to use various interfaces, it will be necessary to expand the choice of connectible devices and guarantee a variety of network combinations. However, since optical transmission equipment is conventionally provided by a single vendor in an end-to-end (E2E) manner, it will be necessary to disaggregate such equipment by function and freely interconnect different vendors.

This type of disaggregation between hardware functions is called horizontal disaggregation. NTT is promoting this through global communities such as Metro Ethernet Forum, Open Networking Foundation, Telecom Infra Project (TIP), and OpenROADM. The IOWN program will further accelerate these interconnections.

“The key to providing highly realistic services at low cost is a dramatic increase in the number of users using the network. To do this, we aim for a 125-fold increase in transmission capacity.”

Expanding network capacity and multipoint simultaneous connection

The key to providing highly realistic services at low cost is a dramatic increase in the number of users using the network. To do this, we aim for a 125-fold increase in transmission capacity. This will be achieved by expanding the number of wavelength bands, by increasing the capacity per λ and exploiting the spatial dimension.

To meet diverse user needs, we will also establish technology that divides a single λ into the time-domain elements while guaranteeing long-distance transmission to provide services to even more users.

End-to-end communications leveraging optical transport technology alone are generally point-to-point (P2P), one-to-one connections. By grouping these, and providing frame multiplexing and other features required by users, simultaneous connection of multipoint users can be achieved as Function Dedicated Networks.

A Function Dedicated Networks (FDN) is a dedicated logical network that is independent for each user. These networks enable a large number of separate service levels that do not interfere with each other. It could be said that this is the network slice in which the optical layer is the core, in contrast to the slicing technology currently accelerating around 5G (fifth-generation mobile communications systems).

P2P connections also require servers to provide services and large numbers of optical λs to be handled at all times. However, APN optical components can copy and branch the same data to deliver them to multiple locations at high speed, while maintaining quality.

On-demand services with precise allocation of network resources

The most important technology in Photonics On-Demand – and in all FDN services – is the FDN controller. With facility planning based on network design technology, and usage forecasting based on macro information, which had been mainly adopted by telecommunications carriers, it is assumed that optical paths will be used on a fixed basis. But construction is lengthy, and network resources are occupied even during periods of non-use, resulting in the inefficient use of these resources.

Photonics On-Demand enables high-efficiency usage of network resources by precisely allocating physical and logical network resources only when users need them, contributing to the provision of cost-effective, high-presence services.

The key points are the management of network resources, creation and release of logical networks optimized for the required service level, and provision and maintenance of service levels. NTT is working with the Open Networking Foundation (and the other global communities mentioned above) to demonstrate and promote the use of existing and new transport equipment.

“We are working on the practical application of FDN controllers to shorten the time of providing optical communications paths from several months of construction to just minutes.”

We are working on the establishment of workflows and the practical application of FDN controllers to shorten the time of providing optical communications paths from several months of construction to just minutes, in line with the development of APN technology.

By securely and reliably managing network resources on a per-user basis, an enormous number of services can be provided on a single network (tens of thousands of connection points per service, provision of tens of thousands of simultaneous services, etc.).

Synchronicity and scale

With on-demand resource utilization, it is important to accurately determine the state of the vast amount of disaggregated network resources in real time. Specifically, it is important not only to monitor equipment-failure states, but also guarantee the various network conditions and their strict service levels when each resource is linked.

For this, high-precision end-to-end service monitoring and network control are required. Although NTT has been working on monitoring technology at the transport layer, we are also working on the basic technologies to manage optical resources, measure communication speeds, and adjust latency according to service requirements.

The low-latency network brought about by IOWN and the All-Photonics Network will come into its own with more accurate time management and synchronization between devices. For example, for stock trading and professional remote e-sports, where fairness is key, we are working on high-precision time-synchronization technology to deliver more accurate clock time across the country (without compromising accuracy), and precisely adjust the timing between devices.

Embedding highly accurate timestamps of locations in communication data enables services to conduct highly accurate and fair data timing correction. Increasing the accuracy of frequency sources will also make it possible to provide even more accurate time synchronization in the future.

To make Photonics On-Demand available to as many service providers as possible, we have started to develop a photonic-direct high-presence communications platform: a video platform to provide more convenient user interfaces.

Video communications include functions such as rendering, video composition, video-flow aggregation, compression/decompression, and time-difference adjustment.

These technologies are provided as a platform, through batch control by the controller. Users can combine these functions in the order they want, e.g. to add content such as captured video and audio that they want to use with each function.

Inter-site communications of services and video functions can be combined with a Photonics On-Demand FDN, while connecting to the minimum amount of video equipment makes it possible to provide high-presence video communications, connecting to any point freely at any time.

Deployment and sustainable development

On-demand photonic multipoint connection technology – Photonics On-Demand – is targeted for completion in 2030, and is reliant on the innovative APN technologies being developed as part of our IOWN program. However, the key on-demand connection technologies can be used on existing optical networks.

We are working on using the high-level control and network monitoring functions to provide a more cost-effective optical path, shaping our prospects for the future regarding deployment of usable technologies to the market and sustainable development of services.

This technology, when used in conjunction with IOWN’s new radio technology, will also contribute to increasing the effectiveness of Extreme NaaS. To show the latest technology at Expo 2025 Osaka, Kansai, we will work together with partners to research and develop fundamental technologies to achieve the Remote World. Going forward, we will improve the real-time functionality of service delivery and scale of concurrent usage to bring more affordable services to more people.

 

 

Originally published by NTT R&D, October 2021.