Blockchain for 5G: Opportunities and Challenges

5G is a revolutionary technology in mobile telecommunications that promises to be 20x faster than today's 4G technology. The novel characteristics of 5G can be exploited to support new business models and services that require seamless interactions among multiple parties that may include mobile operators, enterprises, telecom providers, government regulators, and infrastructure providers. Meanwhile, blockchain technology has evolved as an enabling, disruptive, and transformational technology that has started to be adopted across many industry vertical domains. Blockchain has been increasingly used to register, authenticate and validate assets and transactions, govern interactions, record data and manage the identification among multiple parties, in a trusted, decentralized, and secure manner. In this paper, we discuss and highlight how blockchain can be leveraged for 5G networks. First, an overview of blockchain capabilities as well as smart contracts, decentralized storage and trusted oracles are presented. Second, potential opportunities in which blockchain features are used to enable 5G services are outlined. Third, examples of system integration architecture and sequence flow diagrams to illustrate how blockchain along with other supporting decentralized technologies can support and facilitate such opportunities are discussed. Finally, key challenges and open research problems are identified and discussed.