Thematic-Based Group Communication
Raymond Pardede (Budapest University of Technology and Economics, Hungary), Gábor Hosszú (Budapest University of Technology and Economics, Hungary) and Ferenc Kovács (Budapest University of Technology and Economics, Hungary)
Copyright: © 2008
This article reviews the most important fact of the ALM and introduces to the emerging area of the multicasting, namely the multicast over ad hoc networks, including geocast. After these a novel concept of modeling relative density of members called bunched mode and a proposed ALM multicast transport protocol called shortest tunnel first (STF) are described. The bunched mode is based on the thematic multicast concept (TMC), which means that it is a typical multicast scenario where there are many interested hosts in certain institutes and these institutes are relatively far from each other. This situation is called bunched mode, in which the members of a multicast group are locally in the dense mode, and globally their situation similar to the sparse mode because these spots are far from each other. This article also presents a simple chatting program called PardedeCAST as the tools of STF and TMC research.
Key Terms in this Chapter
Multicast Routing Protocol: In order to forward the multicast packets, the routers have to create multicast routing tables using multicast routing protocols.
IP-Multicast: Network-level multicast technology, which uses the special class-D IP-address range. It requires multicast routing protocols in the network routers.
ALM Routing Protocol: The members of the hosts construct delivery tree using similar algorithms than the IP-multicast routing protocols do.
Application-Level Multicast (ALM): A novel multicast technology, which does not require any additional protocol in the network routers, since it uses the traditional unicast IP transmission.
Multicast Island: Multicast capable network, where all routers have multicast routing protocols and the IP-multicast is available. One of the main problems of the IP-multicast is to connect the multicast islands into an Internet-wide network.
Peer-to-Peer (P2P): It is a communication way where each node has the same authority and communication capability. They create a virtual network, overlaid on the Internet. Its members organize themselves into a topology for data transmission.
Application-Level Network (ALN): The applications, which are running in the hosts, can create a virtual network from their logical connections. This is also called overlay network. The operations of such software entities are not able to understand without knowing their logical relations.
Ad Hoc Network: It is a network which does not need any infrastructure. An example of such a network is the Bluetooth.
Thematic Multicast Concept (TMC): It means a multicast scenario that is typical in practice, where there are many interested hosts in certain institutes and these institutes are relatively far from each other. The appropriate distribution model takes into account this special topology that is manifested in the name of bunched mode, which is between the sparse- and the dense mode multicast dissemination models.