Omnet++ Research Papers

Most modern metropolitan cities have suffered from increasing traffic accidents and jams. Vehicular adhoc network (VANET), consisting of information collecting, processing and transmitting units embedded in vehicles assisted by roadside infrastructures, has been proposed as one the most promising solution to problems introduced by the increasing number of vehicles in modern cities. To achieve the goal, it is crucial to allow the transportation administration center to collect information about the traffic and road status through VANET. A major obstacle in this scenario is the privacy concern on the vehicles.

To address this issue, this paper proposes a generic privacy-preserving traffic monitoring framework which allows individual vehicle driving status and the road usage information are collected while the privacy of the vehicles is well preserved. This goal is achieved by the novel technology of distinguishing individual vehicles with their spatio-temporal occupations. The continual change of spatio-temporal identities provides privacy for vehicles in a natural way, which remains nonetheless traceable by a trusted authority to prevent misbehaving vehicles from abuse the privacy-preserving mechanism provided by the system.

Ad-hoc network can be defined as a collection of number of mobile nodes which makes a temporary network. Black hole can be defined as a malicious node which on any request of route replies in an incorrect manner as if it has new route to the goal and then it drops all incoming packets. Loss will be very high if malicious nodes work collectively. This attack can be defined as cooperative black hole attack.

This paper gives the analysis of Black Hole ADOV performance by frequently changing number of mobile nodes and by also changing black hole nodes. To analyze this various performance metrics are used which includes average end to end delay, loss of packet and packet delivery ratio and It has been seen that effect on end to end delay is higher that on loss of packet.

In an ad hoc network, selfish nodes do not cooperate in packet forwarding of other nodes to maximise their own welfare. Such nodes will have a negative effect on the performance of the network. In this study, an enhanced node cooperation technique (ENCT) is proposed which is a hybrid technique of reputation-based mechanism and incentive-based mechanism. It evaluates relaying nodes’ behaviour, calculates its reputation and outwitting selfish nodes by utilising receipts submitted by each relaying node in the path to a centralised authority rather than using promiscuous mode.

A mathematical analysis is provided which demonstrates that the expected gain of reputation for a particular node is maximum if it adopts cooperative behaviour. To motivate nodes for cooperation, variable incentives are provided proportionate to their reputation and current behaviour. Simulation results demonstrate modification of reputation and incentive with varying number of selfish nodes, traffic connections, and topology with static and dynamic behaviour of selfish nodes. The result shows that the ENCT is robust, fair and efficient technique.

Public key management scheme in mobile ad hoc networks (MANETs) is an inevitable solution to achieve different security services such as integrity, confidentiality, authentication and non reputation. Probabilistic asymmetric key pre-distribution (PAKP) is a self-organized and fully distributed approach. It resolves most of MANET’s challenging concerns such as storage constraint, limited physical security and dynamic topology. In such a model, secure path between two nodes is composed of one or more random successive direct secure links where intermediate nodes can read, drop or modify packets. This way, intelligent selection of intermediate nodes on a secure path is vital to ensure security and lower traffic volume.

In this paper, subjective logic is used to improve PAKP method with the aim to select the most trusted and robust path. Consequently, our approach results in a better data traffic and also improve the security. Proposed algorithm chooses the least number of nodes among the most trustworthy nodes which are able to act as intermediate stations. We exploit two subjective logic based models: one exploits the subjective nature of trust between nodes and the other considers path conditions. We then evaluate our approach using network simulator NS-3. Simulation results confirm the effectiveness and superiority of the proposed protocol compared to the basic PAKP scheme.

Although some scaling law-based studies have been conducted for describing the asymptotic capacity of Vehicular Ad Hoc Networks (VANETs), the obtained results are not easy to directly use for estimating the actual capacity of a communication link or the entire network. To overcome this drawback, an interference-based capacity analysis is carried out in this letter for the abstracted 1-dimensional VANETs scenario.

For a reasonable and tractable modeling, the classic Car-Following model is applied to represent the dynamic change of the inter-vehicle distance, which strongly affects the power decay of both the signal and interference in the network. Based on that, a series of probability characteristics is derived for the worst-case interfering scenario, which finally leads to the stochastic characteristics for both the link and network capacity.

We consider the problem of neighbor discovery in ad hoc network which is full duplex and uses directional antennas. Directional transmission is prerequisite for some ad hoc networking applications and makes the neighbor discovery less efficient than omni-directional broadcast. Full duplex enables simultaneous transmission and reception and facilitates the directional neighbor discovery.

We present a simple one way handshaking algorithm and feasible decision rules for terminating the neighbor discovery procedure. The effect of transmission error and the collision on the algorithm is also considered. At the same time, the performance of the algorithm is analyzed. Lastly, simulations are given to show the effectiveness and efficiency of the algorithm.

We propose employing receiver cooperation in centralized topology control to improve energy efficiency as well as network connectivity. The idea of transmitter cooperation has been widely considered in topology control to improve network connectivity or energy efficiency. However, receiver cooperation has not previously been considered in topology control. In particular, we show that we can improve both connectivity and energy efficiency if we employ receiver cooperation in addition to transmitter cooperation.

Consequently, we conclude that a system based both on transmitter and receiver cooperation is generally superior to one based only on transmitter cooperation. We also show that the increase in network connectivity caused by employing transmitter cooperation in addition to receiver cooperation is at the expense of significantly increased energy consumption. Consequently, system designers may opt for receiver-only cooperation in cases for which energy efficiency is of the highest priority or when connectivity increase is no longer a serious concern.

In a mobile ad-hoc network, to establish a stable routing path is one of the important technical issues to transmit data from source to destination by multi-hop transmission. Mobile ad-hoc network has time varying channels, and traffic congestion or unstable link condition can be severe problems. To solve those problems, multi-path routing protocols were proposed.

Conventional multi-path routing, however, requires much more nodes and power consumption. In this paper, we propose partial multi-path routing with interference avoidance. The proposed routing does not establish another full routing path but establish a partial multi-path to complement some poor links, and the routing paths have enough distance from each other to reduce path interference.

Route establishment between source and destination is a difficult process in mobile ad hoc network. Many approaches have been developed to find a route from source to destination without considering the stability of the nodes and its link life time. It affects the QoS parameters such as throughput, packet loss, delay, packet delivery ratio. So, in this proposed work a link breakage prediction algorithm is added to the AODV protocol.

By using signal strengths from the received packets the link breakage time is predicted and sends a warning message to the source node of active route if the link is soon to be broken. Also the next optimal route to the destination node will be elected before the breakage of any actual route’s link.

Dynamic topology and limited resources are major limitations that make intrusion detection in mobile adhoc network (MANET) a difficult task. In recent years, several anomaly detection techniques were proposed to detect malicious nodes using static and dynamic baseline profiles, which depict normal MANET behaviors.

In this research, we investigated different baseline profile methods and conducted a set of experiments to evaluate their effectiveness and efficiency for anomaly detection in MANETs using C-means clustering technique. The results indicated that a static baseline profile delivers similar results to other baseline profile methods. However, it requires the least resource usage while a dynamic baseline profile method requires the most resource usage of all the baseline models.