05-07-2010, 07:10 PM
A Self-Repairing Tree Topology Enabling Content-Based Routing in Mobile Ad Hoc Networks
Aim:
The mainstay of this project is to achieve the repair strategies to tolerate the frequent topological reconfigurations in Mobile AdHoc Networks by Content Based Routing (CBR) using a protocol namely COMAN.
CONTENT BASED ROUTING (CBR) differs from classical routing in that messages are addressed based on their content instead of their destination. In conventional systems, the sender explicitly specifies the intended message recipients using a unicast or multicast address. Instead, in CBR, the sender simply injects the message in the network, which determines how to route it according to the nodesâ„¢ interests. Therefore, in CBR, it is the receiver that determines message delivery, not the sender. Although it enables multipoint communication, CBR is not simply multicast. In multicast, the address of the multicast groups (or topics) must be defined a priori and made globally known or available. In CBR, message consumers define their own message classes. These select only the desired messages, need not be known to other components, and can be arbitrarily overlapping. The difference between multicast and CBR is reflected also in the routing mechanisms enabling them. Multicast approaches typically propagate messages along a tree defined on a per-group basis, spanning all the receivers for that group. Therefore, a message addressed to multiple groups is typically duplicated at the sender, and each copy is routed independently. In CBR, the absence of an explicit and a priori definition of groups, along with the fact that every message can be addressed to a different set of components, discourages the use of separate per-group trees. Instead, most systems connect all the brokers (the CBR application level routers) in a single tree-shaped network. This broker tree is exploited to forward messages. Usually, these are not flooded to the entire tree but routed toward the interested components according to the message content and the subscriptions stored at tree nodes.
Motivation: CBR fosters a form of implicit communication that breaks the coupling between senders and receivers. Senders no longer need to determine the address of communication parties. Similarly, receivers do not know who is the sender of a message, unless this information is somehow encoded in the message itself. The sharp decoupling induced by this form of communication enables one to easily add, remove, or change components at runtime with little impact on the overall architecture.
Contribution: This paper overcomes the limitation above by achieving the following goal:
Defining a protocol to organize the nodes of a MANET in a single self-repairing tree that efficiently supports CBR
The goal of supporting CBR explains the rationale behind the choice of a tree topology. Therefore, our self-repairing tree enables the reuse of mainstream CBR protocols in the dynamic scenario characterizing MANETs, by leveraging off the consistent body of results related to the tree-based CBR. At the same time, providing a tree able to self-repair upon changes in the physical topology of a MANET is only our minimal (and obvious) target. Our ultimate goal is to design a protocol whose characteristics simplify the operations of the CBR layer operating on it.
Existing System:
In Multicast Ad Hoc On-Demand Distance Vector (MAODV) protocol for multicast over MANETs. Indeed, MAODV organizes the members of each multicast group in a single tree without relying on any underlying multihop unicast solution. Moreover, the page link repair process of MAODV is localized around one of the two end points of the broken link. This limits the impact of reconfiguration to a small portion of the system
Proposed System:
This paper proposes the logic concerned with the maintenance of the tree topology and adapt, extend, and optimize it in a context from MAODV. It was not designed for CBR. The result and main contribution of this paper is COntent-based routing for Mobile Ad hoc Networks (COMAN), a protocol for maintaining a CBR
System Requirements:
Hardware Requirements
¢ SYSTEM : Pentium IV 2.4 GHz
¢ HARD DISK : 40 GB
¢ FLOPPY DRIVE : 1.44 MB
¢ MONITOR : 15 VGA colour
¢ MOUSE : Logitech.
¢ RAM : 256 MB
Software Requirements
¢ Operating system :- Windows XP Professional
¢ Front End :- Microsoft Visual Studio .Net 2005
¢ Coding Language :- Visual C# .Net