Abstract

In this paper, we discuss some aspects where fusion frames and g-frames behave differently from frames. Several counterexamples to make clear their different behaviour are given. We also improve some results on g-frames. Moreover, we extend the notion of redundancy to g-frames and show that most of the desirable properties of lower and upper redundancies on frames and fusion frames can carry over g-frames. We also study the relationship between redundancy of g-frames and their dual g-frames, redundancy for infinite g-frames and the excess of g-frames.