ATM adaption layer for video transmission

The authors study some aspects of transmission of video services in an asynchronous transfer mode (ATM) environment. The sources of transmission errors in such a network are channel noise, causing bit error, and network saturation, causing cell losses. Noise can also cause cell loss or insertion when it affects the cell header, but this is a second order effect. The requirements on the ATM adaptation layer (AAL) are studied for videotelephony and TV distribution services. Simulations show the visible effect of errors in different parts of the bit stream. They analyze the need of countermeasures, its effectiveness, overhead, delay and complexity. They also compare service oriented protection, specific network oriented protection (BCH or RS codes with or without interleaving) and universal network oriented protection (FEC field in each cell)