Recently, China Telecom and China Unicom made a significant breakthrough by successfully completing the industry's first cross-carrier traceable VoWiFi (Voice over WiFi) call in Shandong Province. This milestone offers a cross-carrier solution designed to tackle voice and text messaging problems stemming from poor indoor cellular network coverage.

Back in early 2025, the two telecom giants formed a dedicated team to push forward the pilot project focused on VoWiFi co-construction and sharing technology. The first call was made possible through the 'Cross-Heterogeneous Interconnection' home broadband traceability interoperability solution, a brainchild of the China Telecom Research Institute. This solution has since been adopted as an industry standard by the China Communications Standards Association (CCSA).

During the live network pilot phase, the China Telecom Research Institute stepped in with optimization strategies to simplify processes. They also developed judgment mechanisms to bolster security defenses and carried out thorough verification of routing optimization solutions, thereby broadening the range of service scenarios.

Looking ahead, both China Telecom and China Unicom are set to deepen their collaboration. They aim to extend the reach of their achievements and seamlessly integrate them into the future landscape of 6G development. Notably, China Telecom took the initiative in launching VoWiFi services back in May 2023, effectively addressing the long-standing issue of weak indoor signal coverage.