The users that take part in a video multicast session often have different bandwidth capabilities, and also
experience different loss rates in the network. The process of delivering video to these receivers appropriate to
their available bandwidth is called heterogeneous multicast. We present a solution for this problem based on
the combination of multiple description coding and network coding. The receivers feed back information on the
number of linearly independent descriptions that they obtain, and this is used to optimize the rate allocation
of multiple descriptions. Our simulations show significant improvement in performance compared to unirate
multicast that uses network coding. Unlike the case for unirate multicast, users with higher bandwidth receive
higher quality video with MD/PNC.
We investigate the problem of video multicast in lossy networks using network coding and multiple description
codes. The rate allocation for multiple descriptions can be optimized at the source to generate a scalable video
bitstream such that the expected PSNR of the video at the receivers is maximized. We show that using network
coding with multiple description codes can significantly improve the quality of video obtained at the receiver,
in comparison to routing (with or without replication). Simulations show that as the loss rate increases, the
improvement in the performance increases and in certain cases for loss rate of 0.20, the improvement can be as
high as 3 to 3.5 dB when compared to routing with replication. Moreover, network coding obviates the need to
construct multiple multicast trees for transmission, which is necessary in routing with replication.