DOORAE(Distance Object Oriented collaboRAtion Environment) is a framework for supporting development on multimedia collaborative environment. It provides functions well capable of developing multimedia distance education system for students as well as teachers. It includes session management, access control, concurrency control and handling late comers. There are two approaches to software architecture on which applications for multimedia distance education environment in situation-aware middleware are based. This paper proposes a new model of fault tolerance agent based on situation-aware ubiquitous computing for a multimedia home study system which is based on CARV.