Information system model applications to global mobile personal communication systems

Information system models provide direction, goal clarification and organization, and aid in the selection of a technology during the concept and development stages of projects. Information system models introduced include a Top-Down Model, an Open Systems Interconnect (OSI) model, an Input-Process-Output (IPO) Model, a Hardware-Software-Media (HSM), and a technology analysis grid. The evolution of information system service is discussed to demonstrate the usefulness of the information system models. Investigations in worldwide communications systems revealed a demand for services such as voice, fax, data communication, and paging in remote locations and on a global scale. Several Global Mobile Personal Communication System (GMPCS) satellites are in early development stages, and financed by multinational consortiums.