Utilization of AODV in Wireless Ad Hoc Networks

Problem statement: Wireless networks are characterized by a dynamic topology triggered by the nodes mobility. Thus, the wireless multi-hops connection and the channel do not have determinist behaviour such as: Interference or multiple paths. Moreover, the nodes invisibility makes the wireless channel difficult to detect. This wireless networks behaviour should be scrutinized. Approach: In our study, we mainly focus on radio propagation models by observing the evolution of the routing layers performances in terms of the characteristics of the physical layer. Results: For this purpose, we first examine and then display the simulation findings of the impact of different radio propagation models on the performance of ad hoc networks. To fully understand how these various radio models influence the networks performance, we have compared the performances of several routing protocols (DSR, AODV and DSDV) for each propagation model. In order to reach credible results, we focused on the notion of nodes speed and the number of connections by using the well known network simulator NS-2. Conclusion: To conclude, the simulation findings are to be taken as a strong reference on the three routing protocols behaviour; however, it shouldnt be considered as an exact representation of its behaviour and real environment because of several simulation constraints such as: the dimension of movement field of mobile nodes, the traffic type and the simulation timing

Section: Dynamic Source Routing (Dsr)mentioning

confidence: 99%

The Impact of Radio Propagation Models on Ad Hoc Networks Performances

Rhattoy¹,

Zatni²

2012

“…Ondemand routing protocols are efficient for routing in large ad hoc networks (Hanapi et al, 2009) because they maintain the routes that are currently needed, initiating a path discovery process whenever a route is needed for message transfer. AODV (Pirzada et al, 2006;Alfawaer et al, 2007b) and DSR (Pirzada et al, 2006;Koul et al, 2008) are two prominent ad hoc routing protocols that have used this approach. In DSR, the routing table at the nodes caches the next hop router information for a destination and use it as long as the next hop router remains active (originates or relays at least one packet for that destination within a specified time-out period).…”

Section: Double Hash Algorithmmentioning

confidence: 99%

Authentication Based and Optimized Routing Technique in Mobile Ad hoc Networks

Varadhaganapathy¹

2011

Problem statement: An Ad hoc network has been defined as a self-organizing, dynamic topology network formed by a group of wireless mobile nodes. Minimal configuration, absence of infrastructure and quick deployment, would make ad hoc networks convenient for emergency situations other than military applications. In recent years, security in Ad hoc Networks as a research topic had started to receive attention from a growing number of researchers. Approach: Several ad hoc network routing protocols have been proposed; only some of them consider the security problems. To secure an ad hoc network, the attributes like availability, confidentiality, integrity, authentication and non-repudiation may be considered. In this study, authentication is taken into consideration. Here, Double Hash Authentication Technique (DHT) has been incorporated for ad hoc networks. The security associations between nodes were established, when they were in the vicinity of each other, by exchanging appropriate cryptographic information. This security mechanism has been simulated on Dynamic Source Routing (DSR) protocol in addition to Self-Healing and Optimized Routing Technique (SHORT) made the routing secure for ad hoc networks. Result: The results have shown that in a moderately changing network, the Double Hash Technique has provided secure routing even in the presence of malicious nodes. Conclusion: The Double Hash Technique in association with SHORT has improved the performance of the DSR protocol

“…This may occur in deployments in which sensors in one area of interest are requested to gather and transmit data at a higher rate than In this case, routing dynamics can lead to congestion on specific paths. These paths are usually close to each other, which lead to an entire zone in the network facing congestion (Alfawaer et al, 2007;Hull et al, 2004;Sharieh et al, 2008). We refer to this zone, essentially an extended hotspot, as the congestion zone.…”

Section: Introductionmentioning

confidence: 99%

Performance Analysis of Congestion Reduction Routing in Wireless Sensor Networks

Sundararajan¹

2011

Problem statement: Data generated in wireless sensor networks may not all be alike: some data may be more important than others and hence may have different delivery requirements, To solve this problem addressed a differentiated data delivery in the presence of congestion in wireless sensor networks and proposed a class of algorithms that enforce differentiated routing based on the congested areas of a network and data priority. Approach: The basic protocol, called Congestion-Reduction Routing (CRR), discovers the congested zone of the network that exists between high-priority data sources and the data sink and using simple forwarding rules, dedicates this portion of the network to forwarding primarily high-priority traffic. Since CRR requires some overhead for establishing the high-priority routing zone, it is unsuitable for highly mobile data sources. To accommodate all these things defined MAC-Enhanced CRR (MCRR), which includes MAC-layer enhancements and a protocol for forming high-priority paths on the fly for each burst of data. MCRR effectively handles the mobility of high-priority data sources, at the expense of degrading the performance of low-priority traffic and presented an extensive simulation results for CRR and MCRR and an implementation of MCRR on a 48-node testbed. Results: Proposed CRR and MCRR algorithms were implemented by using NS2 simulator and the QOS parameters on throughput, packet delivery ratio, delay and energy. All parameters were analyzed and compared with basic AODV mechanism. Conclusion/Recommendations: CRR is better suited for static networks with long-duration HP floods. For bursty HP traffic and/or mobile HP sources, MCRR is a better fit. Because of the lower delay, CRR and its variants appear suitable to real-time data delivery.