Chapter 1 is an introduction of this book which explains the basic idea about the advantages of satellites over the internet, why satellites will play a key role in the NGI and applications of satellite for NGI. The rest of the chapters are organized as follows. Chapter 2 gives basic information regarding to satellite network. The satellite network topology is explained in detail with the concepts of satellite network configuration, related issues in the satellite networks and types of satellite networks. Chapter 3 mainly focuses on the LEO satellite constellation. First we describe about LEO satellite network with the types of LEO satellite constellation. Chapter 4 explains about routing classification and basic routing algorithm in the LEO satellite networks. It also discussed drawback of routing algorithm. In Chapter 5, explain modification in the routing algorithm for satellite network. We also explain the modified code of implantation of the routing algorithm. Chapter 6 mainly focuses on simulation results with the detailed explanations. Chapter 7, Conclusions are provided, which summarize the major results obtained in this book and future scope of work.