As we’ve seen, there is no single “best” digital satellite radio system. Instead, each of these five systems represents a unique engineering solution tailored to a specific set of challenges. Whether the primary goal was to conquer signal interference in dense cities (System A and Dh), to make receivers affordable for a mass market (System B and Ds), or to deliver a rich multimedia experience (System E), each system was developed as a different tool for a different job. Together, they show the diverse and innovative approaches engineers have taken to achieve the complex goal of broadcasting clear, reliable digital radio from space to listeners on Earth.