POZNAN UNIVERSITY OF TECHNOLOGY ACADEMIC JOURNALS No 53 Electrical Engineering 2007 __________________________________________ * Poznan University of Technology. Maciej PIECHOWIAK* Piotr ZWIERZYKOWSKI* Artur ĩODħ* A NEW HEURISTIC ALGORITHM FOR MULTICAST CONNECTIONS IN PACKET NETWORKS There have been many heuristic algorithms determining multicast connection trees proposed over the past few years. However, the proposed methods are only approximations of the most favourable solutions and thus, a necessity of finding a better and more suitable algorithm is still topical and up-to-date. The present article aims at presenting the attempts of finding a constrain algorithm that would be more effective than those presented in relevant literature so far. Keywords: multicast, algorithm, packet networks, heuristics 1. INTRODUCTION The multicast technology is based on the simultaneous transmission of data, from the source node to a group of destinations, i.e. concurrently to multiple destinations. Over the last few years, multicast algorithms have become more important due to the specificity of data transmitted in transport networks [1]. The increase in traffic capacity of present-day networks has offered great advantages in distributed applications such as multimedia data transmission in real time, video- on-demand, teleconferencing, etc. To ensure reliable transmission, multimedia applications demand high requirements for the processing of audio and video data to be met by Quality of Service parameters. Quality requirements concerning, for example, steady guaranteed delay value accompanying a hop of a packet between the transmitting and receiving node down a specified route of the network still pose a challenge for designers of real time applications. The simplest example of an application of this kind is voice transmission. With the transmission of voice data in packets, numerous delays occur such as queuing delay, propagation delays, delays induced by codecs or serialization of delays. Queuing delays mostly depend on the applied planning algorithms, which can define the delay value by determining the maximum value (the worst case) or mean value. The relevant literature includes many solutions ensuring the bandwidth and delay for single streams which are based on the worst case (such streams are