A fault tolerant architecture for transportation information services of e-government

Many governments have been spreading Intelligent Transportation Systems (ITS) nationwide based on the National ITS Architecture. The real time information of transportation is one of the key services of an electronic government (e-government) and the ITS. The ITS consists of advanced communications, electronics, and information technologies to improve the efficiency, safety, and reliability of transportation systems. The core functions of the ITS are collection, management, and provision of real time transport information, and it can be deployed based on the Common Object Request Broker Architecture (CORBA) of the Object Management Group (OMG) efficiently because it consists of interconnected heterogeneous systems across national and local governments. Fault Tolerant CORBA (FT-CORBA) supports real time requirement of transport information stably through redundancy by replication of server objects. However, object replication, management, and related protocols of FT-CORBA require extra system CPU and memory resources, and can degrade the system performance both locally and as a whole. This paper proposes an improved architecture to enhance performance of FT-CORBA based ITS by generating and managing object replicas adaptively during system operation with an agent. The proposed architecture is expected to be applicable to other FT-CORBA based systems for an e-government.