SoftBank And Ericsson Have Partnered To Launch Support For 'Uplink Tx Switching,' Which Enables Faster Uplink Communication For 5G SA

Advanced carrier aggregation and MIMO technologies accelerate uplink communication, crucial in the AI ​​era

SoftBank Corp. (hereinafter "SoftBank") has partnered with Ericsson Japan K.K. (hereinafter "Ericsson") to begin supporting the " Uplink Tx Switching " technology , which enables faster uplink communication for 5G SA^*1 , on its network ^*2 . By enhancing carrier aggregation ^*3 and MIMO^*4 , this technology will achieve even faster and more stable uplink communication. This technology will be gradually made available on some smartphones released by SoftBank from summer 2026 (planned ) onwards ^*5 .

• Background
  In recent years, with the spread of AI (artificial intelligence) and the expansion of social media use, uplink traffic from users has increased, and there is a demand for more stable and faster uplink traffic ^*6 . Anticipating a further increase in uplink traffic in the AI ​​era , SoftBank and Ericsson have been working with smartphone chipset vendors since 2024 to introduce " Uplink Tx Switching " . They have jointly conducted performance verification from the chipset development stage, and have now realized its introduction into SoftBank's network

• Details and effects of " Uplink Tx Switching "
  Traditionally, when performing uplink communication using radio waves in the frequency band used by the TDD method ^*7 , communication speed was increased by performing carrier aggregation with radio waves in the frequency band used by the FDD method ^*8 . " Uplink Tx Switching " is a technology defined in 3GPP Release 16 that temporarily stops FDD communication during TDD uplink communication and performs MIMO communication using multiple antennas with the wider bandwidth TDD method, thereby achieving even faster uplink communication . SoftBank expects that the introduction of " Uplink Tx Switching " will theoretically improve uplink throughput by approximately 1.5 times ^*9 . This will improve the perceived speed when uploading videos and images, making it possible to transmit large amounts of data in the AI ​​era more comfortable .

• Future Outlook
  SoftBank will continue to expand the range of compatible devices and coverage areas for " Uplink Tx Switching . " Furthermore, in cooperation with Ericsson, SoftBank aims to further improve uplink performance by considering MIMO support, including the frequency bands used by the FDD method defined in 3GPP Release 17. SoftBank will continue to strive to improve communication quality and customer satisfaction through the advancement of its 5G services utilizing the latest technologies .

About Ericsson:
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^*1 Stand Alone 5G ( 5th Generation Mobile Communication System) . High-speed , high-capacity 5G SA communication is available in limited areas. Please see the area map for details.

^*2 Supported frequencies: 3.4GHz band, 3.5GHz band, 3.7GHz band

^*3 Technology that uses radio waves 　from multiple frequency bands simultaneously

^*4 MIMO ( Multiple Input Multiple Output ): Technology that improves communication speed by sending and receiving data simultaneously using multiple antennas

^*5 Service will start in some 5G SA areas and will be gradually expanded.

^*6 Ericsson's regularly published "Ericsson Mobility Report," November 2025 edition , points out that AI- enabled devices and AI agents will be factors that will drive future increases in uplink traffic .

^*7 TDD ( Time Division Duplex ): A communication method that uses radio waves in the same frequency band to switch between uplink and downlink based on time.

^*8 FDD ( Frequency Division Duplex ): A communication method that uses radio waves in different frequency bands for uplink and downlink.

^*9 Theoretical value verified by SoftBank in a configuration that uses radio waves in two frequency bands, n1 and n77 , simultaneously for uplink communication.