The next generation of mobile networks (i.e., 6G) is expected to be an open, generic, and multi-party participatory digital platform for both emerged new application services (e.g., XR, V2X and AI/ML) and traditional mobile internet/voice call services. To meet the ambitious target, 6G network itself first needs to be more resilient to failures in an open/zero-trust environment and highly interoperable for interactions from externals. Unfortunately, the existing design approach for 5G, which is still with a monolithic and operator-centric thinking, seems not quite helpful.

For the two key requirements above, blockchain technology is considered a promising tool to reshape telecom network services in 6G, which is similar to how internet applications (known as Web 2.0) are currently evolved to Web 3.0 decentralized applications (DAPP). The motivation is that a network function (NF), which represents a native network service in 6G, can be converted to a smart contract living in blockchain. In this way, the NF will be temper-proof, transparent and decentralized even across different network domains; in addition, the execution of the NF cannot be manipulated thus guaranteed. As a result, a decentralized 6G network architecture will be resilient to single-point-of-failure and even Byzantine attacks. More importantly, interoperating with an NF means submitting a transaction that triggers a smart contract API, thus becomes much more convenient. Ideally, blockchain-based 6G network and services will gain new features such as identity sovereignty, redefined data ownership, and decentralized autonomous organizations (DAO) that are expected for a long time.

Clearly, there are huge interests on studying how 6G network services can be natively built with blockchain. Nevertheless, this ambitious goal is challenging and many open research problems exist. To bridge the gap, this Special Issue (SI) will focus on three main aspects of blockchain for 6G: native blockchain capability enhancement in 6G network, blockchain technology specialization for 6G network, and prototyping for blockchain-based 6G network services. In summary, this SI thus aims to solicit research progress central around the above three aspects. This will provide invaluable insights on guiding research activities on the line of system designs for 6G. Original contributions shall drop in the following topical areas, plus others that are not explicitly listed but are closely related:

-Native decentralized network architecture for 6G.
-Telecom network service smart contract for 6G.
-Security framework with blockchain for 6G.
-Data management of decentralized telecom network services in 6G.
-Optimization of decentralized 6G services for flexibility, sustainability, and resource utilization.
-Web 3.0 applications in 6G.
-Cryptographic algorithms/protocols for blockchain-based 6G network services.
-System prototyping, verification, and performance evaluation for decentralized 6G network services.

Guest Editors
Wen Tong
Huawei, Canada

Diego R. Lopez
Telefonica, Spain

Schahram Dustdar
TU Wien, Austria

Liqun Chen
University of Surrey, UK

Xianhui Lu
University of Chinese Academy of Sciences (UCAS), China

Xun Xiao
Huawei, Germany