Nokia, NTT, Anritsu validate Elastic networking to cut mobile fronthaul energy use

Nokia, Nippon Telegraph and Telephone (NTT), and Anritsu Corporation have successfully conducted a proof of concept (PoC) demonstrating the effectiveness of Elastic networking in reducing energy consumption in mobile networks.

Developed under the Innovative Optical and Wireless Network (IOWN) Global Forum architecture, the All-Photonics Network (APN) was successfully applied to the mobile fronthaul between the antenna unit (Radio Unit, RU) and the control unit (Distributed Unit, DU) of a 5G RAN base station. “This demonstrated that dynamic rerouting of the mobile fronthaul is possible by using the IOWN APN,” NTT stated in its press release.

“The validation paves the way for the widespread adoption of Elastic networking to help telecom operators ensure more energy-efficient networks,” Nokia stated. When deployed, Elastic networking reallocates network resources on demand, helping operators reduce energy costs by switching off network resources from a secondary to a primary destination. This approach effectively enables the hibernation of radio and optical equipment when not in use.

Similarly, network resources can be switched dynamically to accommodate high traffic demand. This will also help operators to effectively address future bandwidth demands driven by AI while lowering energy consumption. The intelligent network architecture ensures that end users, particularly in densely populated urban areas, do not experience service degradation.

Founded in January 2020, the IOWN Global Forum has over 150 members, including telecom players and companies from other industries. The Forum aims to accelerate innovation and create next-generation communication and infrastructure technologies to meet evolving data and computing needs.

Addressing Rising Energy Demands in Telecom

The growth of 5G technology and the expanding digital economy are driving increased mobile traffic, leading to higher power consumption in base stations and communication infrastructure. The advent of 6G is expected to accelerate this trend, necessitating even greater energy efficiency in mobile networks. To address this challenge, telecom operators and vendors are implementing various solutions, such as optimising base station power consumption and leveraging virtualisation technology.

The PoC by Nokia, NTT, and Anritsu establishes that dynamic routing can further reduce power consumption in base stations while improving network reliability. Since mobile traffic fluctuates based on human movement and time of day, business districts experience peak demand during working hours, while nighttime traffic is significantly lower. Under the current fixed, point-to-point optical fibre connection (dark fibre) between RU and DU, operators must maintain more DUs than necessary, with all connected DUs remaining operational regardless of actual demand.

By leveraging the IOWN APN for mobile fronthaul, RUs can dynamically reroute connections to DUs, replacing fixed point-to-point connections with a more flexible approach. This allows all DU bases to function during peak hours while enabling consolidation when traffic is low, reducing energy consumption. Additionally, DU bases that are temporarily unnecessary can be shut down, leading to power savings not only for communication equipment but also for supporting infrastructure such as air conditioning.

In case of a failure between a RU and a DU, dynamic rerouting ensures seamless service continuity by redirecting traffic to an operational DU base. This enhances overall network reliability and minimises service disruptions.

NTT highlighted that in an environment where user traffic flows through two mobile fronthaul links using the IOWN APN, dynamic route changes can occur in under eight minutes over a transmission distance of 30 km without impacting user traffic. The PoC demonstrated a nearly 20% reduction in power consumption after rerouting, though NTT clarified that this figure is an estimate based on minimal user traffic and stable conditions.

The PoC initiative leveraged the expertise of each participating company. NTT provided a test environment to verify and measure the quality of 5G mobile communications, including devices, RUs, Dus and Central Units, and conducted demonstration tests. Nokia supplied key IOWN APN equipment such as the Flexible Bridge, APN-Terminal, APN-Gateway, and APN-Interconnect, playing a critical role in the testing process. 

Anritsu contributed measuring instruments to assess APN delay and confirm the normal operation of Precision Time Protocol (PTP) and Synchronous Ethernet (Sync-E), ensuring the integrity of the network performance. PTP helps synchronise clocks throughout a computer or telecom network, enabling nanosecond-level accuracy, critical for applications requiring precise timekeeping, such as mobile networks, financial transactions, and industrial automation.

Sync-E provides frequency synchronisation over Ethernet networks by distributing a highly accurate and stable clock signal. Unlike PTP, which synchronises time, Sync-E focuses on frequency stability, ensuring minimal drift across network elements.

Nokia’s TPS and PSS Solutions

Nokia’s high-performance optical solutions, including the 1830 Time-Sensitive Packet Switch (TPS) and 1830 Photonic Service Switch (PSS), played a key role in conducting the PoC.

The Nokia 1830 TPS portfolio enables cost-effective scaling of optical networking capacity to support increasing connectivity demands. Designed as a compact, carrier-grade Ethernet time-sensitive network switch, the TPS facilitates the converged transport of real-time services, making it ideal for applications like mobile fronthaul, carrier Ethernet, industrial Internet of Things, and residential broadband. With ultra-low latency and high reliability, the TPS enhances real-time communications for various industries.

Meanwhile, the 1830 PSS is a family of DWDM multiservice, multilayer Packet Optical Transport Network (P-OTN) transport platforms that provide scalable transport solutions across access, metro, and core networks. By leveraging advanced coherent transport through Nokia’s Photonic Service Engine (PSE), agile line systems, and ultra-scalable P-OTN switching, the 1830 PSS allows operators to adapt their optical networks to meet unpredictable traffic demands. 

The platform supports a range of applications, including metro edge transport, long-haul networking, broadband backhaul, data centre interconnect, and wavelength services.

Going forward, the companies plan to conduct a demonstration experiment on the power reduction effect of IOWN's dynamic route changes and shorten the time required for dynamic rerouting to minimise the impact on service. “These experiments will simulate real-world base station configuration, number of users, traffic, and automatic route change decisions based on traffic prediction, aiming to achieve a highly power-efficient and resilient network,” NTT stated.