The Innovative Optical and Wireless Network (IOWN) project has revealed that its all photonic network (APN) has been successfully applied to the mobile fronthaul between the antenna unit (Radio Unit, RU) and the distributed unit (DU) of a 5G radio access network (RAN) base station, demonstrating dynamic rerouting.
Led by NTT, IOWN was created to meet the growing needs of the hyper-connected business world of the future, offering a future global communications infrastructure capable of enabling ultra-high-speed, high-capacity internet services utilising photonics-based technologies. In its mission, NTT is being supported by the likes of Ericsson, Nokia, Sony, Ciena, Intel, Nvidia, Microsoft, Orange, Telefónica and Google.
It aims to address the almost exponentially rising demand for data and a commensurate rise in energy consumption due to the vast amounts of compute power required by future applications, in particular artificial intelligence (AI) and large language model (LLM) use cases. This network and information processing infrastructure includes terminals that can provide high-speed, high-capacity communication using technology focused on optics, as well as large computational resources.
NTT’s IOWN APN infrastructure is being designed to enable high-capacity, low-latency and low-power consumption communications through end-to-end optical connections without converting optical signals into electrical signals.
Explaining the background of the study, IOWN noted that with the rise of 5G technology, mobile traffic is increasing, leading to higher power consumption of base stations and communication facilities. Moreover, it said that the advent of 6G networks is expected to deliver even faster communications and large amounts of data transmission, further amplifying power consumption.
As a result, IOWN stressed that improving power efficiency is an important issue for mobile carriers and mobile vendors. The new initiative aims to further reduce the power consumption of base stations and communications facilities while improving the reliability of the network through dynamic routing.
Under the current fixed, point-to-point optical fibre connection (dark fiber) between RU and DU, operators run more DUs than necessary, and the connected DUs must always remain operational to maintain service. By leveraging the APN for the mobile front haul, IOWN says RUs can dynamically reroute connections to DUs, from a point-to-point physical connection between RU and the DU. This will enable all DU bases to function when the mobile traffic is high and allows the system to switch to fewer DUs when demand decreases, consolidating resources while maintaining service.
Additionally, DU bases that are no longer needed due to the consolidation can be shut down to reduce power consumption – not just for communication equipment but also for the entire base including air conditioning.
In the test, NTT provided an environment designed to enable verification and quality measurement of equipment and communications required for 5G mobile communications, including devices, RUs, and CUs/DUs. Nokia supplied IOWN APN equipment such as Flexible Bridge, APN-T, APN-G, and APN-I. Anritsu delivered measuring instruments to assess APN delay and to confirm normal operation of PTP/Sync-E.
The latest work is said to confirm that in an environment where user traffic flows through two mobile fronthaul using the IOWN APN, the dynamic route change takes less than eight minutes and does not affect user traffic beyond the changed route. Traffic flows normally, even after the change.
This achievement is said to allow flexible DU switching in response to mobile traffic fluctuation, enabling DU base consolidation and activation of only necessary DU base, reducing power consumption, Additionally, in the event of a route failure, routes can be swiftly switched to alternative DU base, thereby reducing the impact on services and contributing to improved network reliability.
IOWN examined a procedure that optimally combines RU changes and APN route changes to minimise communication impact during dynamic route adjustments. It said it verified that dynamic route changes could be performed successfully using this procedure.
For verification, the IOWN APN was applied at 30km between two mobile fronthaul points. The test environment simulated real-time user traffic while modifying the RU settings of the DU device and adjusting the optical path switching of the APN device. It assessed the time required for dynamic route changes, the impact on communication, and post-switching communication quality.
The verification was conducted following the IOWN APN device configuration and transmission method from the IOWN Global Forum’s Proof of Concept (PoC) Reference, IOWN for mobile networks.
IOWN said that verification tests confirmed that dynamic route changes can be completed in less than eight minutes over a transmission distance of 30 km. Communication quality was said to have remained unaffected, including data transfer speed and loss rate after switching. User traffic on the changed route was interrupted, but other routes remained unaffected. Power consumption was reduced by approximately 20% before and after changing the route.
IOWN said the demonstration confirmed that dynamic rerouting can be successfully performed using IOWN APN for mobile fronthaul, enabling dynamic DU base operations during mobile traffic fluctuations and failures, reducing power consumption and service impact.
It now plans to conduct a demonstration experiment on the power reduction effect of 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.
