Many compensative measures have been proposed recently the make the cell loss in ATM (asynchronous transfer mode) networks subjectively imperceptible. These schemes include the simple automatic repeat quest (ARQ) scheme, error concealment by command refreshment, appropriate queueing disciple and priority switching design and layered source coding schemes. The authors summarize these efforts and, in particular, elaborate on different layered source coding schemes. Four types of signal priority classification schemes are identified: bit-plane separation (FDS) combined with bit-plane-frequency separation (CBFS), and feature plane separation (FPS). Different layered coding techniques are discussed and compared. Some open questions and recommendations are also presented for further research and study.>