The Effect Of Using XCAST Based Routing Protocol in Wireless Ad Hoc Networks.

Wireless ad hoc networks are a type of wireless network that can be easily created without the need of network infrastructure or central administration

Routing and Security in Mobile Ad Hoc Networks

A Mobile Ad hoc Network (MANET) consists of a set of nodes which can form a network among themselves. MANETs have applications in areas such as military, disaster rescue operations, monitoring animal habitats, etc. where establishing fixed communication infrastructure is not feasible. Routing protocols designed for MANETs can be broadly classified as position-based (geographic), topology-based and hybrid. Geographic routing uses location information of nodes to route messages. Topology-based routing uses network state information for route discovery and maintenance. Hybrid routing protocols use features in both position-based and topology-based approaches. Position-based routing protocols route packets towards the destination using greedy forwarding (i.e., an intermediate node forwards packets to a neighbor that is closer to the destination than itself). If a node has no neighbor that is closer to the destination than itself, greedy forwarding fails. In this case, we say there is void. Different position-based routing protocols use different methods for dealing with voids. Topology-based routing protocols can be classified into on-demand (reactive) routing protocols and proactive routing protocols. Generally, on-demand routing protocols establish routes when needed by flooding route requests throughout the entire network, which is not a scalable approach. Reactive routing protocols try to maintain routes between every pair of nodes by periodically exchanging messages with each other which is not a scalable approach also. This thesis addresses some of these issues and makes the following contribution. First, we present a position-based routing protocol called Greedy Routing Protocol with Backtracking (GRB) which uses a simple backtracking technique to route around voids, unlike existing position-based routing protocols which construct planarized graph of the local network to route around voids. We compare the performance of our protocol with the well known Greedy Perimeter Stateless Routing (GPSR) protocol and the Ad-Hoc On-demand Distance Vector (AODV) routing protocol as well as the Dynamic Source Routing (DSR) protocol. Performance evaluation shows that our protocol has less control overhead than those of DSR, AODV, and GPSR. Performance evaluation also shows that our protocol has a higher packet-delivery ratio, lower end-to-end delay, and less hop count, on average, compared to AODV, DSR and GPSR. We then present an on-demand routing protocol called ``Hybrid On-demand Greedy Routing Protocol with Backtracking for Mobile Ad-Hoc Networks which uses greedy approach for route discovery. This prevents flooding route requests, unlike the existing on-demand routing protocols. This approach also helps in finding routes that have lower hop counts than AODV and DSR. Our performance evaluation confirms that our protocol performs better than AODV and DSR, on average, with respect to hop count, packet-delivery ratio and control overhead. In MANETs, all nodes need to cooperate to establish routes. Establishing secure and valid routes in the presence of adversaries is a challenge in MANETs. Some of the well-known source routing protocols presented in the literature (e.g., Ariadne and endairA) which claim to establish secure routes are susceptible to hidden channel attacks. We address this issue and present a secure routing protocol called SAriadne, based on sanitizable signatures. We show that our protocol detects and prevents hidden channel attacks

FILE SHARING IN AD HOC NETWORKS

mobile ad-hoc network (MANET) is a self-configuring network of mobile routers and associated hosts connected by wireless links, the union of which form an arbitrary topology. The routers are free to move randomly and organise themselves arbitrarily; thus, the network's wireless topology may change rapidly and unpredictably. The network is currently applied in many areas suchas for military purposes, in hospitals, campuses and offices. First of all, the scope of study of this projectwas to understand current wireless standards, the nature of mobile ad hoc networks, the advantages and disadvantages to it. The next step was to understand the requirements of file sharing application in such networks. One of the challenges in MANET is the routing protocol. The Ad Hoc On Demand Distance Vector (AODV) routing protocol was chosen and simulated in a hospital scenario whereby patients' records are constantly uploaded and downloaded by doctors and nurses using mobile devices. The scenario was simulated usingOMNeT++ which is an open source software

A Survey of Applying Ad Hoc Wireless Sensor Actuator Networks to Enhance Context-Awareness in Environmental Management Systems

Sensor mesh networking is set to be one of the key tools for the future of Ambient Intelligence (AmI) due to new emerging technologies in Ad hoc Wireless Sensor Networks (AWSNs). AWSNs symbolize the new generation of sensor networks with many promising advantages applicable to most networked environments. Unfortunately, however, these practical technologies have some technical problems and, as a consequence, this fascinating field has created novel and interesting challenges, which in turn, have inspired many ongoing research projects and more are likely to follow. Almost certainly, there will be notable improvements in the management of control/actuator networks as a consequence of enhancing the sensitivity capabilities of systems. With an emphasis on Ad hoc Wireless Sensor Actuator Networks (AWSANs) this study presents a systematic analysis of the different existing techniques to improve such systems. It also discusses, analyzes and summarizes the advantages these technologies offer in certain applications and presents a generic solution, in the form of a case study, for an AmI system to enhance the overall environmental management of a campus based on a hierarchical network using an AWSAN

Energy-Efficient Reliable Sensor-to-Sink Data Transfer for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are generally energy and resource constrained. As the traffic pattern in most WSN applications is from sensor-to-sink, in-network data aggregation methods are employed for effective utilization of available resources. As aggregated data packets contain correlated information, a significant amount of information is lost if a data packet is lost. In order to reliably transfer the aggregated data packets, there arises a need for data transport protocols that provide reliability at the packet level. Existing protocols that provide reliable data transfer for sensor-to-sink traffic either provide reliability at the event level or are not energy efficient. By employing duty cycles, energy-efficiency can be improved but it degrades the network performance in terms of latency. To provide energy-efficiency while enhancing the packet level reliability, we propose an energy-efficient reliable data transfer protocol. This protocol provides packet level reliability by extending the concept of monitors and improves the energy-efficiency by employing duty cycles. To further reduce the energy consumption and congestion in the network, only a subset of nodes is chosen as active nodes to transfer the data. We implemented our protocol using the NS2 simulator for evaluating its performance. Results show that our protocol has significant improvement in packet delivery ratio and energy savings

FILE SHARING IN AD HOC NETWORKS

mobile ad-hoc network (MANET) is a self-configuring network of mobile routers and associated hosts connected by wireless links, the union of which form an arbitrary topology. The routers are free to move randomly and organise themselves arbitrarily; thus, the network's wireless topology may change rapidly and unpredictably. The network is currently applied in many areas suchas for military purposes, in hospitals, campuses and offices. First of all, the scope of study of this projectwas to understand current wireless standards, the nature of mobile ad hoc networks, the advantages and disadvantages to it. The next step was to understand the requirements of file sharing application in such networks. One of the challenges in MANET is the routing protocol. The Ad Hoc On Demand Distance Vector (AODV) routing protocol was chosen and simulated in a hospital scenario whereby patients' records are constantly uploaded and downloaded by doctors and nurses using mobile devices. The scenario was simulated usingOMNeT++ which is an open source software

Improving Data Freshness to Enhance the Quality of Observations in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are used to achieve either continuous monitoring or event-detection in the area of interest. In continuous monitoring applications, each sensor node transmits its sensed data to the sink node (base station) periodically; while in event-detection driven applications, nodes report to the sink node once an event occurs. Continuous monitoring applications require periodic refreshed data at the sink node. Data reaching the sink node after a certain threshold is not useful for processing or analysis because it is stale. Data freshness along with reliable data delivery is critical in such applications. Current protocols in this area measure freshness only in terms of latency or delay of packets received at the sink node. However, improving overall delay alone does not necessarily improve data freshness. To address the needs of continuous monitoring applications, we adapt an existing protocol that provides packet-level reliability and augment it with prioritization and rate control mechanisms to improve data freshness. We implemented our protocol using the ns-2 simulator for evaluating its performance and identified metrics for measuring data freshness. Results show that prioritization and rate control improves data freshness significantly