Master Thesis - 2001

Recently, there are various broadcasting services. Meanwhile, broadband subscriber lines of IP network are rapidly spread. These will increase requirements for on-demand contents delivery services. Thus, it is very important to provide efficient and guaranteed services for contents delivery over IP network.

We defined two delivery unit, ``Group of GoPs'' and ``Type of Frame(I or P or B),'' on the basis of the MPEG characteristics with periodical NACK from clients. The former is tolerant to the burst packet loss. The latter is useful for giving priority to important frames. Multicast by block delivery has two phases, ``Transmission Phase'' and ``Retransmission Phase.'' In the former phase, a server multicasts a block. In the latter phase, a server retransmits lost packets with multicast according to proper delivery unit. And we assumed that intermediate nodes suppress the traversed NACKs to avoid NACK implosion.