The exponential growth in mobile data traffic – typical estimates give an approximately 1000x increase over the next decade – requires a proportional response from the world’s wireless communication researchers. Based on the Internet Protocol architecture of 4G communication systems, unprecedented numbers of smart and heterogeneous wireless devices will be accessing future 5G mobile and wireless communication systems with a continuing growth of Internet traffic. Therefore, compared with 4G communication systems, significantly higher wireless transmission rates are expected in 5G communication systems. Moreover, energy efficiency concepts will be fully integrated into future wireless communication systems to protect the environment.The goal of this special issue is to publish a collection of non-incremental research papers that collectively provide insight into what a 5G wireless communication system might look like. In particular, this journal solicits high-quality original research papers on aspects of the air interface for future wireless communication systems.