**Intact Gift Giving Condition book**

Direct-to-Device (D2D) satellite communications are transforming the future of mobile connectivity. How can an ordinary smartphone communicate directly with a satellite hundreds of kilometers above the Earth? Advances in Low Earth Orbit (LEO) constellations, 3GPP Non-Terrestrial Networks (NTN), and modern cellular technologies are making it possible for standard smartphones to communicate directly with satellites, extending coverage far beyond the reach of terrestrial networks. Direct-to-Device Satellite Communications Fundamentals provides a practical, engineering-focused introduction to this rapidly evolving field.