Design and evaluation of UDLR satellite network model

For satellite communication links to be used comprehensively and in a manner consistent with their features as a basis for Internet communications, it has become necessary to add a framework based on the features of satellite communications to the protocol architecture of the Internet. For this purpose, the authors' group has been engaged in the development of the new UDLR (unidirectional link routing) protocol mechanism. This paper discusses UDLR from the following viewpoints. (1) The method of actual network construction should be established effectively so as to make use of the features and advantages of satellite communications. (2) Conditions other than protocol definitions should be stated clearly for the purpose. (3) A feasibility network should be constructed to explore the optimal application area. The principles in their current form are summarized for each of the above points. UDLR has been implemented on the feasibility testbed over the whole Asian area. The transparent coexistence of a multi-cast video distribution system utilizing the concurrency feature of satellite communications and other Internet application systems has been achieved. It is demonstrated that UDLR functions effectively in the use of satellite communications in the Internet. The possibility of using satellite communications to support new modes of Internet application, such as broadcast stream distribution, is shown.