Abstract
We propose new strategies in core selection methods and core-based tree (CBT) construction based on new methods of computing delay variation. As a result, we propose an algorithm, which guarantees that the delay from the source to any destination does not exceed a real-time constraint. Furthermore, we address the problem of satisfying the delay variation constraint under cost minimization. We present a new core and path selection methods that take both cost and delay simultaneously into consideration. Thus, we achieve a balance of optimizing cost and delay of the multicast tree. The problem is known to be as NP-complete. A solution to this problem is required to provide decent real-time communication services such as on-line gaming, shopping, and teleconferencing.