Summary: 33IEEE Communications Magazine · January 1999
Traffic Management of
Multimedia over ATM Networks
0163-6804/99/$10.00 © 1999 IEEE
ultimedia consists of voice, video, and data in the
same application. When multimedia is transmitted
over a network, video traffic consumes most of the bandwidth,
and also requires a high level of quality of service (QoS) guaran-
tee from the network. In order to reduce the bandwidth require-
ment, video is therefore compressed before transmission over
the network. Video compression is based on removing the tem-
poral and spatial redundancy of information in a video stream.
An MPEG compressed video consists of different types of
frames (I, B, and P), of varying bit rates. A number of these
frames are grouped together to form a group of pictures
(GoP). A GoP begins with an I-frame, followed by B- and P-
frames. If a GoP includes n frames with (m 1) B-frames
between consecutive P-frames, the GoP is denoted MmNn.
Compression greatly reduces the bit rate of the multimedia
stream. However, compressed video is highly bursty in nature.