Maciej Piechowiak

Efficiency Analysis of Multicast Routing Algorithms in Large Networks

The paper presents the research results of multicast heuristic algorithms. The paper is an extension of previous publications presented in [14, 15] that discussed small network structures reflecting real Internet topology. It approaches basic methods of generating the Internet topology - Waxman method and the Barabasi-Albert method. A performance study of multicast trees constructed by the algorithms is carried out and analysed, also with the heuristic network generator - Inet.

Performance of Fast Multicast Algorithms in Real Networks

Multicast heuristic algorithms are currently the field of interest for networks researchers. The optimization analysis of fast algorithms is performed using random and heuristic networks (graphs). This theoretical work approaches problem of constructing trees between the sender and group of receivers in real computer networks. The paper presents basic methods of generating the Internet topology on graph level -Waxman method and the Barabasi-Albert method. A performance study of multicast trees constructed by the algorithms is carried out and analysed, also with the heuristic network generator -Inet.

Multicast Routing Algorithm for packet networks with the application of the Lagrange Relaxation

The paper presents a proposal of a new multicast routing algorithm for finding a multicast tree in packet-switched networks. The objective of the MLRA (Multicast Routing Algorithm with Lagrange Relaxation) is to minimize the cost of paths between the source and each destination node using Lagrange relaxation, and eventually, minimize the total cost of multicast tree. A wide range of simulation experiments carried out by the authors for many network topologies and parameters confirmed the effectiveness of the proposed algorithm.

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 most favourable solutions and thus, a necessity for 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 two-criteria algorithm that would be more effective than those presented in relevant literature so far.

The evaluation of multicast routing algorithms with delay constraints in mesh networks

Wireless mesh networks are playing an important role in extending the implementation of traditional wireless infrastructure (cellular networks, wireless LAN, etc). Routing design in mesh networks is a challenge because of limited node resources. Thus efficient data transmission techniques like multicasting regarding quality of service requirements are under scrutiny. The article analyzes and explores the performance of multicast heuristic algorithms and quality of multicast trees in mesh networks.

Analysis of the Influence of Group Members Arrangement on the Multicast Tree Cost

In the paper we introduce a group members arrangement as a new parameter for analyzing multicast routing algorithms finding multicast trees. We also propose a new multicast routing algorithm without constraints. The objective of STA (Switched Trees Algorithm) is to minimize the total cost of the multicast tree using a modification of the classical Prims algorithm (Pruned Prims Heuristic) and the SPT (Shortest Path Tree) algorithm that constructs a shortest path tree between a source and each multicast node.

The Evaluation of Unconstrained Multicast Routing Algorithms in Ad-Hoc Networks

Wireless ad-hoc networks are playing an important role in extending the implementation of traditional wireless infrastructure (cellular networks, wireless LAN, etc). Routing design in ad-hoc networks is a challenge because of limited node resources. Thus efficient data transmission techniques like multicasting are under scrutiny. The article analyzes and explores the performance of multicast heuristic algorithms without constraints and quality of multicast trees in ad-hoc networks and proves the thesis that well-known multicast heuristic algorithms designed for packet networks have a good performance in ad-hoc networks with grid structure.

A new delay-constrained multicast routing algorithm for packet networks

There have been many heuristic algorithms finding multicast trees proposed in the literature. The necessity for finding a better and more suitable algorithm is still topical and relevant. The paper presents a new multicast routing algorithm for finding a multicast tree in packet-switched networks. The objective of the proposed KSPMA algorithm is to minimize cost of constrained paths between the source and destination nodes using the generalized Dijkstras algorithm regarding maximum delay bound along each path. A wide range of simulation research carried out by the authors, for many network topologies and parameters, has confirmed the effectiveness of the proposed algorithm.

The Linguistic Modeling of Fuzzy System as Multicriteria Evaluator for the Multicast Routing Algorithms

The paper presents the use of fuzzy system in multicriteria evaluation of algorithms that generate multicast trees and optimize realtime data transmission in computer networks. These algorithms take into account a number of factors such as: cost, bandwidth or delay, and their efficiency can be represented by total cost of multicast tree or average path’s cost in multicast tree [18]. However, there is a lack of accurate methods for comparing and evaluating these algorithms. In addition, it is difficult to identify with precision the weight of the criteria. The paper describes various proposals models underlying linguistic system that performs two-criteria assessment. These proposals show how to implement linguistic changes and their impact on the results of the fuzzy system.

Application of IP multicast in embedded systems with OpenWRT

The effectiveness of multicast technology can significantly reduce network load, especially in networks that support multimedia transmission. This technique has reported number of implementations due to increasing interest in audiovisual technology. However, multicast is still a mystery for many programmers, network administrators and ordinary users who could make it more popular, and utilize this promising technique of transmission. This paper presents the configuration of IP multicasting on end-user network device (embedded system) with an application of OpenWRT Linux distribution. Some efficiency aspects were also discussed in this paper.