Onel L. A. López is a Researcher at the University of Oulu, Finland. His research focuses on wireless communications, including energy harvesting setups, and efficient access techniques for massive, machine-type communications. Hirley Alves, D.Sc., is Assistant Professor on Machine-type Wireless Communications at the University of Oulu, Finland. His research focuses on massive connectivity and ultra-reliable low latency communications for future wireless networks.