This paper describes an overview of demands on wireless communications from the point of view of robotics, oceanics and aviation technologies. These technologies are mostly applied to extreme environments, where humans cannot easily approach and directly operate equipment. In such environments, reliable and robust wireless communications are highly required to perform missions perfectly. However, there are many issues for wireless technologies to meet those requirements due to poor propagation and large delay conditions. This paper discusses wireless communication technologies required in land-sea-and-air environments based on the recent development challenges of unmanned ground and marine robots and next-generation air-transportation systems. This paper will contribute future wireless communication techniques for unmanned robots and next-generation aviations.