Nouvelles de l'industrie

SoftBank Group, in collaboration with Ericsson and Qualcomm, successfully completed a field test of low-latency communication on SoftBank Group's 5G SA commercial network in Tokyo. This test validated several 5G and 5G-A technologies, including low latency, low loss, and scalable throughput (L4S).

The test results showed that compared to scenarios without 5G and 5G-A technologies (such as L4S), wireless link latency was reduced by approximately 90%, successfully achieving consistently low latency and stable communication.

The three companies conducted field tests of low-latency communication on a 5G SA commercial network in the Tokyo metropolitan area by integrating multiple 5G and 5G-A technologies (such as L4S, configured uplink grants, and rate control scheduling – 3GPP standardized technologies).

As an application case, the three companies used smart glasses for streaming XR content, which has extremely high real-time performance requirements. Specifically, the smart glasses were connected to a smartphone via Wi-Fi, and the smartphone then accessed the commercial mobile network through a designated 5G base station. The smart glasses and smartphone interacted with the application server via the internet.

In applications such as XR, even slight communication delays can affect the quality of the user experience; therefore, this application scenario was used to verify low-latency communication.

The field test results confirmed that compared to scenarios without 5G and 5G Advanced technologies such as L4S, wireless link latency was reduced by approximately 90%, successfully achieving consistently low latency and stable communication. Furthermore, network slicing technology was used to limit the application of 5G/5G Advanced technologies to the equipment used in this test, creating a communication environment optimized for low-latency XR content streaming.

The main 5G and 5G Advanced technologies used in this field test were:

L4S (Low Latency, Low Loss, Scalable Throughput Data Transmission)

1. • A technology for reducing communication latency
2. • Utilizes Explicit Congestion Notification (ECN) bits to provide real-time notification of network congestion and control transmission rates
3. • Adjusts communication conditions before congestion intensifies, preventing packet congestion and ensuring stable low-latency communication. Configuring Uplink Authorization
4. • Simplifies the transmission process from mobile terminals to base stations.
5. • Enables mobile terminals to immediately begin sending data according to pre-set arrangements and conditions.
6. • Suppresses uplink communication latency in applications requiring real-time performance, such as XR technology.
7.  

Rate Control Scheduling

1. • The base station dynamically controls wireless resources to maintain the configured throughput.
2. • Stabilizes video display and operational response in XR applications.
3.  

Network Slicing

1. • A technology that virtually divides the network into multiple slices, providing optimized communication quality for various services.
2. • Can simultaneously and stably support a variety of needs, ranging from control applications requiring low latency and high reliability to video services requiring high-capacity communication.
3.  

In this test, SoftBank selected the site for the field trial, studied the evaluation metrics and methods for the trial, and investigated the current communication status of 5G base stations in the Tokyo area; Ericsson provided several 5G and 5G Advanced technologies, including L4S, conducted pre-test verification, and configured relevant functions at the target trial site; Qualcomm provided smart glasses based on the Snapdragon® AR2 Gen 1 platform, smartphones equipped with the Snapdragon® 8 Elite mobile platform and integrated with the latest Qualcomm® 5G modem-RF platform, and the AR application used in this proof-of-concept trial. Hideyuki Tsukuda, Executive Vice President and Chief Technology Officer of SoftBank Group, said: "This field test demonstrates that SoftBank's 5G SA network can fully leverage the potential of 5G/5G Advanced technologies such as network slicing and low-latency technology. Based on these results, we will continue to strengthen our network infrastructure to provide our customers with a leading communication experience."

Jawad Mansour, President and Representative Director of Ericsson Japan, said: "This field test is very important, proving that we can provide the ultra-low latency and high-reliability communication required for next-generation XR experiences. XR technology is expected to revolutionize the way we work in many fields, including industry, social infrastructure, and entertainment. Ericsson will continue to support our customers in upgrading their networks to deliver new digital experiences and address social challenges."

Hemanth Sampath, Vice President of Engineering at Qualcomm Technologies, said: "We are very pleased to collaborate with Ericsson and SoftBank on this field test. This test demonstrates the potential of the convergence of XR and 5G technologies, and the potential created by the distributed spatial computing and low-latency on-device processing capabilities of the Snapdragon XR platform. Qualcomm will further expand the possibilities of AR and smart glasses based on distributed spatial computing capabilities and low-latency features."

Based on the results of this field test, SoftBank will continue to advance the commercial deployment verification of 5G/5G Advanced technologies. In the future, we will use these technologies to improve the convenience of communication services at large events such as sporting events, and provide new services based on network slicing, bringing new experiences to users.