Independence concepts for belief functions

In this paper, we try to study the independence concept for belief functions theory, as applied to one interpretation of this theory called the transferable belief model (TBM). In this context, two new results axe given in this paper : first, the concept of belief function independence has different intuitive meaning which are non-interactivity, irrelevance and doxastic independence, second, the concepts of non-interactivity and independence are identical under a new property called irrelevance preservation under Dempster's rule of combination.