This thesis discusses the design issues and fundamental techniques of a Local Area Network (LAN), designs and chooses a LAN for the military. The three HQs and DoD of Korea operate their own computer center with no connection among them. All the exchange of data is performed manually and slowly. But, they want to rapidly and accurately exchange information among the fields of logistics, intelligence and operations. The purpose of this thesis is multifold. The first purpose is to research the user's function through the system analysis. Second, this study highlights the user's requirements for the ROKM concept to evolve from its present state. The third purpose is to describe the selection process to determine the optional fundamental technical ingredients of LANs for specific operating environments. The last purpose is to evaluate the above results for the selection of a vendor and construct a model LAN for the ROKM.