15-02-2013, 12:01 PM
Mobile Ad-Hoc Networks Extensions to Zone Routing Protocol
Mobile Ad-Hoc Networks.doc (Size: 257.5 KB / Downloads: 28)
ABSTRACT:
Secure communication, an important aspect of any networking environment, is an especially signicant challenge in ad hoc networks. The MANET paradism seeks to enable communication across networks whose topology and membership can change frequently. Its distinctive feature is that network nodes need to collaborate with their peers in supporting the network functionality. In such an environment, malicious or selfish nodes can disrupt or even deny the communications of potentially any node within the ad hoc networking domain. This is so, exactly because every node in the network is not only entitled, but is in fact required, to assist in the network establishment, the network maintenance, and the network operation.
Ad-Hoc Networks consist of peer-to-peer communicating nodes that are highly mobile. As such, an ad-hoc network lacks infrastructure and topology of the network changes dynamically. The task of routing data from a source to a destination in such a network is challenging. Several routing protocols have been proposed for wireless ad-hoc networks. Most of these protocols, however, presuppose the presence of bi-directional links between the nodes in the network. In reality the ad-hoc network may consist of heterogeneous nodes with different power capabilities and hence, different transmission ranges. When this is the case, a given node might be able to receive the transmission of another given node but might not be able to successfully transmit to the latter. Thus, unidirectional links are formed. Most of the current routing protocols are unsuitable for deployment when such unidirectional links are present. We consider a routing protocol called the zone routing protocol (ZRP) that has been proposed for wireless ad-hoc networks with bi-directional links. The zone routing protocol employs a hybrid proactive (table driven) and reactive (on- demand) methodology to provide scalable routing in the ad-hoc network. However, in the presence of unidirectional links some routes remain undiscovered if ZRP is used.
ADVANTAGES:
There are a number of implementations of the Ad-hoc On-demand Distance Vector (AODV) routing protocol available for the Linux platform.
The AODV protocol consists of a number of messages which it uses for route discovery, route maintenance and repair, and neighbor detection.
DISADVANTAGES:
Development of ad-hoc routing protocols has been slow because current operating systems do not provide adequate direct system-services for their implementation.
ZONE ROUTING PROTOCOL:
The Zone Routing Protocol (ZRP) was introduced in 1997 by Haas and Pearlman. It is either a proactive or reactive protocol. It is a hybrid routing protocol. It combines the advantages from proactive (for example AODV) and reactive routing (OLSR). It takes the advantage of pro-active discovery within a node's local neighborhood (Interzone Routing Protocol (IARP)), and using a reactive protocol for communication between these neighborhoods (Interzone Routing Protocol (IERP)). The Broadcast Resolution Protocol (BRP) is responsible for the forwarding of a route request. ZRP divides its network in different zones. That's the nodes local neighborhood. Each node may be within multiple overlapping zones, and each zone may be of a different size. The size of a zone is not determined by geographical measurement. It is given by a radius of length, where the number of hops is the perimeter of the zone. Each node has its own zone.
ADVANTAGES OF ZRP:
one consisting of devices equipped with wireless interface cards, which come together to form multi-hop wireless networks dynamically and automatically .
It tries to maintain the most up-to-date map of the network.
Time required sending messages is less.
Easy to use by every one.
Easy to understand the mechanism.
It requires less band width.