QoS-based ordered delivery for multimedia objects in a group

In distributed applications, a group of multiple processes are cooperating by exchanging multimedia objects. The objects am decomposed into a sequence of messages which are units of transmission in a network. Following the causality relation among multimedia objects, we define novel types of causally precedent relations among messages decomposed from objects transmitted in a group of multiple processes. Only messages required to be causally ordered are ordered in each process. This means the overhead to causally deliver multimedia objects in a group can be reduced.