NTT Low-Latency Network Connects Urban and Suburban Data Centers in U.S. and U.K.

IOWN All-Photonics Network (APN) demonstration achieves very low communication delay for connected data centers, with applicability for AI analysis and financial services

April 12, 2024

NTT DATA Group Corporation

News Highlights:

  • NTT DATA and NTT demonstrates APN-connected data centers in U.K. nearly 100 km apart with less than 1 millisecond of network delay.
  • APN-connected data centers in U.K. and U.S. reduce delay variation to a tiny fraction of what prevails in conventional networks.
  • Network performance can unite geographically distributed data centers, addressing real-estate constraints and green-energy requirements.
  • Potential applications include real-time AI analysis and financial services.

SAN FRANCISCO and TOKYO – April 12, 2024 – At Upgrade 2024, NTT DATA and NTT Corporation (NTT) announced the successful demonstration of All-Photonics Network (APN)-driven hyper low-latency connections between data centers in the United States and United Kingdom. In the U.K., NTT DATA and NTT connected data centers north and east of London via NTT's Innovative Optical Wireless Network (IOWN) APN, and communication between them was realized with a round-trip delay of less than 1 millisecond. In the U.S., data centers in Northern Virginia achieved similar results. The goal of this initiative is to transform geographically distributed IT infrastructure into the functional equivalent of a single data center.

The data center market is under severe local constraints. Carbon dioxide emission restrictions and land shortages have made it difficult to build data centers in urban areas, forcing operators to turn to the suburbs. Yet with geographically distant data centers, delay of communication, or latency, can be very high, making it difficult to meet customers' needs for low latency. In separate demonstrations, NTT DATA and NTT connected data centers in the U.K. (HH2 in Hemel Hempstead and LON1 in Dagenham) and in the U.S. (VA1 and VA3 in Ashburn) using APN equipment from NEC. These U.K. and U.S. data centers are 89km and 4km apart, respectively. (See Figure 1.) Measurements in tests conducted over 100 Gbps and 400 Gbps links showed the two APN-connected data centers in the U.K. operated with less than 1 millisecond (approximately 0.9 milliseconds) of latency, and with a delay variation (sometimes called jitter) of less than 0.1 microseconds. (See Figure 2 and Table 1.) According to cloud connectivity provider Megaport, typical delay between data centers at an equivalent distance exceeds 2,000 microseconds (2 milliseconds). In the U.S. case, delay over the much shorter span was approximately 0.06 milliseconds; and delay variation was less than 0.05 microseconds. By contrast, conventional networks with general Layer 2 switches experience delay variation of several microseconds to tens of microseconds. In other words, the APN cuts latency in half, and jitter by orders of magnitude.
The APN delivered very low latency required by current and emerging use cases. These include distributed, real-time AI analysis, such as industrial IoT and predictive maintenance, smart surveillance systems, smart grid and energy management, natural disaster detection and response and more. NTT DATA is also conducting demonstrations in the financial sector, where low latency is required for remittances, settlements and transactions. Another advantage of the IOWN APN is that it enables line activation simply by adding wavelengths, without needing to install new dark fiber. As a result, data center operators can respond very quickly to customer demand.

Figure 1: Data Centers Used for Demonstration

Figure 1: Data Centers Used for Demonstration

Figure 2: Demonstrated Network Configuration

Figure 2: Demonstrated Network Configuration

Delay Delay Variation
U.K. 0.893 milliseconds 0.035 microseconds
U.S. 0.062 milliseconds 0.045 microseconds

Table 1: APN-Connected Data Center Results

About NTT

NTT contributes to a sustainable society through the power of innovation. We are a leading global technology company providing services to consumers and businesses as a mobile operator, infrastructure, networks, applications, and consulting provider. Our offerings include digital business consulting, managed application services, workplace and cloud solutions, data center and edge computing, all supported by our deep global industry expertise. We are over $97B in revenue and 330,000 employees, with $3.6B in annual R&D investments. Our operations span across 80+ countries and regions, allowing us to serve clients in over 190 of them. We serve over 75% of Fortune Global 100 companies, thousands of other enterprise and government clients and millions of consumers.


NTT DATA is a $30+ billion trusted global innovator of business and technology services. We serve 75% of the Fortune Global 100 and are committed to helping clients innovate, optimize and transform for long-term success. We invest over $3.6 billion each year in R&D to help organizations and society move confidently and sustainably into the digital future. As a Global Top Employer, we have diverse experts in more than 50 countries and a robust partner ecosystem of established and start-up companies. Our services include business and technology consulting, data and artificial intelligence, industry solutions, as well as the development, implementation and management of applications, infrastructure, and connectivity. We are also one of the leading providers of digital and AI infrastructure in the world. NTT DATA is part of NTT Group and headquartered in Tokyo. Visit us at


NTT DATA Group Corporation
Research and Development Headquarters, IOWN Promotion Office
Contact persons: Kohei Takeda, Rajiv Saavedra Rivano, Hiroshi Miura

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