scholarly journals Towards Intelligent Caching and Retrieval Mechanisms for Upcoming Proposals on Vehicular Delay-Tolerant Networks

2011 ◽  
Vol 7 (1) ◽  
pp. 1 ◽  
Author(s):  
Bruno M. C. Silva ◽  
Vasco N. G. J. Soares ◽  
Joel J. P. C. Rodrigues
Keyword(s):  
Network Performance ◽  
Ad Hoc ◽  
Storage Capacity ◽  
State Of The Art ◽  
Delay Tolerant Networks ◽  
Opportunistic Networks ◽  
Network Nodes ◽  
Intermittent Connectivity ◽  
Delay Tolerant ◽  
Carry And Forward

Vehicular delay-tolerant networks (VDTNs) are opportunistic networks that enable connectivity in challenged scenarios with unstable links where end-to-end communications may not exist. VDTN architecture handles non-real timeapplications using vehicles to relay messages between network nodes. To address the problem of intermittent connectivity, network nodes store messages on their buffers, carrying them through the network while waiting for transfer opportunities. The storage capacity of the nodes affects directly the network performance. Therefore, it is important to incorporate suitable network protocols using self-contained messages to improve communication that supports store-carry-and-forward operation procedures. Clearly, such procedures motivate content cachingand retrieval. This paper surveys the state-of-the art on intelligent caching and retrieval mechanisms focusing on ad-hoc and delay tolerant networks (DTN). These approaches can offer important insights for upcoming proposals on intelligent caching and retrieval mechanisms for VDTNs.

scholarly journals Distributed Misbehavior Detection Scheme for Delay Tolerant Networks

2019 ◽  
Vol 8 (9S3) ◽  
pp. 1288-1292
Keyword(s):  
Network Performance ◽  
Detection System ◽  
Delay Tolerant Networks ◽  
Secure Routing ◽  
Security Model ◽  
Detection Scheme ◽  
Misbehavior Detection ◽  
Distributed Approach ◽  
Intermittent Connectivity ◽  
Delay Tolerant

Opportunistic forwarding mechanism in Delay Tolerant Networks (DTN), are prone to get disconnected from the nodes in the network. These types of networks deal with intermittent connectivity, large delays.Existing routing protocols of DTNs fights with these issues, but fail to integrate the security available for delay tolerant networks,it is necessary to design a secure routing protocol to overcome these issues. There are centralized Trust Authority (TA) based security systems but the disconnection or failure of TA, affects the security model and network performance. It becomes crucial to have the distributed approach for security system and have multiple TAs working on security model. This reduces the possibility of poor network performance. The paper presents a distributed misbehavior detection system, and implements multiple TAs for implementing the security model for DTN.

scholarly journals Malicious Node Detection in Delay Tolerance Network

2021 ◽  
pp. 294-297
Author(s):  
Er. Ashu Garg ◽  
Sourav
Keyword(s):  
Network Performance ◽  
Ad Hoc ◽  
Malicious Node ◽  
Malicious Nodes ◽  
Switched Networks ◽  
Intermittent Connectivity ◽  
Partitioned Networks ◽  
Delay Tolerant ◽  
In Transit ◽  
Route Request

Delay tolerant networks (DTNs), such as sensor networks with scheduled intermittent connectivity, vehicular DTNs that disseminate location-dependent information, and pocket-switched networks that allow humans to communicate without network infrastructure, are highly partitioned networks that may suffer from frequent disconnectivity. In DTNs, the in-transit messages, also named bundles, can be sent over an existing link and buffered at the next hop until the next link in the path appears. This message propagation process is usually referred to as the “store-carry-and-forward” strategy, and the routing is decided in an “opportunistic” fashion. We aim to evaluate the added effect of the presence of malicious nodes on ad hoc network performance, and determine appropriate measures to detect malicious nodes. A malicious node advertising itself as having a valid route to the destination. With this intension the attacker consumes or intercepts the packet without any forwarding. An attacker can completely modify the packet and generate fake information, this cause the network traffic diverted or dropped. Let H be a malicious node. When H receives a Route Request, it sends back a Route Reply immediately, which constructs the data and can be transmitted by itself with the shortest path. So S receives Route Reply and it is replaced by H->S. then H receives all the data from S. In this research we propose a new assesment based scheme for detection of Malicious Nodes in DTN. And examine different strategies for prevention to malicious nodes as well as Compare out come proposed scheme with the earliest established schemes.

scholarly journals Non-dominated Sorting Genetic Algorithm-II for Throwbox Deployment in Delay Tolerant Networks

2019 ◽  
Vol 8 (4) ◽  
pp. 7475-7479
Keyword(s):  
Genetic Algorithm ◽  
Delay Tolerant Networks ◽  
Opportunistic Networks ◽  
Transmission Range ◽  
Message Delivery ◽  
Average Delay ◽  
Optimal Deployment ◽  
Simulation Results ◽  
Delay Tolerant ◽  
Carry And Forward

Delay-tolerant networks (DTNs) are basically opportunistic networks and uses store-carry-and-forward switching for message forwarding. Performance of DTNs can be improved by placing stationary nodes, called throwboxes which increases the contact opportunities among nodes. Throwbox is viewed as relaying node and the message delivery is enhanced by spreading as many messages as possible. Increasing the contact opportunities in throwbox based DTN model depends on the deployment of throwboxes in suitable places. The objective of this paper is to identify optimal deployment locations of the throwboxes with a pre-specified transmission range, and to maximize the coverage of all the throwboxes in order to increase average delivery and to reduce the average delay among all the nodes in the network. We use Non-Dominated Sorting Genetic Algorithm–II for optimizing the deployment of throwboxes in DTN. The simulation results are analyzed for better strategy in deploying throwboxes and to improve the performance of throwbox-augmented DTNs.

scholarly journals Performance Evaluation of Social Routing Protocols Based on the Effect of Delivery Ratio and Average Hop Count in Delay-tolerant Networks (DTN)

2019 ◽  
Vol 4 (12) ◽  
pp. 155-158
Author(s):  
Sujan Chandra Roy ◽  
Farhana Enam ◽  
Md. Ashraful Islam
Keyword(s):  
Routing Protocol ◽  
Routing Protocols ◽  
Ad Hoc ◽  
Delay Tolerant Networks ◽  
Opportunistic Networks ◽  
Destination Node ◽  
Delivery Ratio ◽  
Hop Count ◽  
Message Transmission ◽  
Delay Tolerant

Delay-Tolerant Networks (DTNs) are part of Opportunistic networks. In the case of opportunistic networks, the joined node of a network can have zero or partial knowledge about other nodes in a network. For this reason, the evident information towards the nodes in the existing network is most difficult to collect for forwarding the message. The application of Opportunistic networks is where have a high tolerance for long delays, high error rate, etc. DTNs are also sparse dynamic Ad-hoc networks were source to destination path does not present all-time for successfully message transmission. As DTN has no end-to-end path for message transmission source to destination node so, the routing design is so sophisticated. The social-based routing protocol is developed to improve the routing mechanism by focusing on social behavior and the interaction with the nodes of a network. Consequently, the performance analysis of existing several DTN routing protocols represents a significant role in designing or developing a new routing protocol for a specific scenario. This article investigates the execution of ordinary routing protocols of DTNs such as Epidemic, Binary Spray and Wait (BSNW), including two social-based routing protocols such as Scorp and dLife using Opportunistic Network Environment (ONE) simulator. The performance of these routing protocols is measured based on delivery ratio and average hop count with inevitable simulation settings. From the simulation result, it is condensed that for higher delivery ratio, BSNW is best, and for average hop count, dLife is the best routing protocol.  

Trust-Threshold Based Routing in Mobile Ad Hoc Delay Tolerant Networks

2011 ◽  
Author(s):  
MoonJeong Chang ◽  
Ing-Ray Chen ◽  
Fenye Bao ◽  
Jin-Hee Cho
Keyword(s):  
Ad Hoc ◽  
Delay Tolerant Networks ◽  
Mobile Ad Hoc ◽  
Delay Tolerant

scholarly journals Genetic Improvement of Routing Protocols for Delay Tolerant Networks

2021 ◽  
Vol 1 (1) ◽  
pp. 1-37
Author(s):  
Michela Lorandi ◽  
Leonardo Lucio Custode ◽  
Giovanni Iacca
Keyword(s):  
Routing Protocols ◽  
Genetic Improvement ◽  
Ad Hoc ◽  
Delay Tolerant Networks ◽  
Unmanned Vehicles ◽  
Test Cases ◽  
Urban Networks ◽  
Delivery Probability ◽  
Apply Genetic ◽  
Delay Tolerant

Routing plays a fundamental role in network applications, but it is especially challenging in Delay Tolerant Networks (DTNs). These are a kind of mobile ad hoc networks made of, e.g., (possibly, unmanned) vehicles and humans where, despite a lack of continuous connectivity, data must be transmitted while the network conditions change due to the nodes’ mobility. In these contexts, routing is NP-hard and is usually solved by heuristic “store and forward” replication-based approaches, where multiple copies of the same message are moved and stored across nodes in the hope that at least one will reach its destination. Still, the existing routing protocols produce relatively low delivery probabilities. Here, we genetically improve two routing protocols widely adopted in DTNs, namely, Epidemic and PRoPHET, in the attempt to optimize their delivery probability. First, we dissect them into their fundamental components, i.e., functionalities such as checking if a node can transfer data, or sending messages to all connections. Then, we apply Genetic Improvement (GI) to manipulate these components as terminal nodes of evolving trees. We apply this methodology, in silico, to six test cases of urban networks made of hundreds of nodes and find that GI produces consistent gains in delivery probability in four cases. We then verify if this improvement entails a worsening of other relevant network metrics, such as latency and buffer time. Finally, we compare the logics of the best evolved protocols with those of the baseline protocols, and we discuss the generalizability of the results across test cases.

scholarly journals A Hop Count Based Heuristic Routing Protocol for Mobile Delay Tolerant Networks

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Lei You ◽  
Jianbo Li ◽  
Changjiang Wei ◽  
Chenqu Dai ◽  
Jixing Xu ◽  
...  
Keyword(s):  
Routing Protocol ◽  
Ad Hoc ◽  
Delay Tolerant Networks ◽  
Network Partitioning ◽  
Heuristic Function ◽  
Hop Count ◽  
Dynamic Topology ◽  
Mobile Ad Hoc ◽  
Hoc Networks ◽  
Delay Tolerant

Routing in delay tolerant networks (DTNs) is a challenge since it must handle network partitioning, long delays, and dynamic topology. Meanwhile, routing protocols of the traditional mobile ad hoc networks (MANETs) cannot work well due to the failure of its assumption that most network connections are available. In this paper, we propose a hop count based heuristic routing protocol by utilizing the information carried by the peripatetic packets in the network. A heuristic function is defined to help in making the routing decision. We formally define a custom operation for square matrices so as to transform the heuristic value calculation into matrix manipulation. Finally, the performance of our proposed algorithm is evaluated by the simulation results, which show the advantage of such self-adaptive routing protocol in the diverse circumstance of DTNs.

Delay Tolerant Networks

2019 ◽  
pp. 448-480 ◽  
Author(s):  
Vandana Kushwaha ◽  
Ratneshwer Gupta
Keyword(s):  
Vehicular Networks ◽  
Low Cost ◽  
Delay Tolerant Networks ◽  
Opportunistic Networks ◽  
Delay Tolerant Network ◽  
Data Packets ◽  
Security Issues ◽  
Terrestrial Environments ◽  
Routing Congestion ◽  
Delay Tolerant

Opportunistic networks are one of the emerging evolutions of the network system. In opportunistic networks, nodes are able to communicate with each other even if the route between source to destination does not already exist. Opportunistic networks have to be delay tolerant in nature (i.e., able to tolerate larger delays). Delay tolerant network (DTNs) uses the concept of “store-carry-forward” of data packets. DTNs are able to transfer data or establish communication in remote area or crisis environment where there is no network established. DTNs have many applications like to provide low-cost internet provision in remote areas, in vehicular networks, noise monitoring, extreme terrestrial environments, etc. It is therefore very promising to identify aspects for integration and inculcation of opportunistic network methodologies and technologies into delay tolerant networking. In this chapter, the authors emphasize delay tolerant networks by considering its architectural, routing, congestion, and security issues.

Analysis of Existing Trust Based Routing Schemes Used in Wireless Network

2016 ◽  
Vol 10 (2) ◽  
pp. 26-40 ◽  
Author(s):  
Kajal S. Patel ◽  
Jagdish S. Shah
Keyword(s):  
Wireless Network ◽  
Network Performance ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Battery Life ◽  
Delayed Response ◽  
Error Message ◽  
Trust Value ◽  
Network Nodes ◽  
Routing Schemes

Wireless networks are vulnerable to many security attacks as they use wireless media and a node has to depend on unknown intermediate nodes for data transmission. Cryptographic algorithms used for wired network cannot work efficiently in wireless network, as in wireless network nodes are mobile and battery operated. Nodes may also have limited resources available. So, to detect malicious activities on node and improve stability of route while routing in mobile ad hoc network, trust-based routing is used. Communication parameters used in calculating trust value in most of existing trust based protocol (wireless network) are number of successful session or packet forwarded between two nodes, number of packet dropped or delayed, response time, battery life, mobility of node etc. This paper provides analysis of existing trust based routing by surveying current “sate of the art” work in this area. This paper also proposed a new parameter (number of route error message sent by a node) of a wireless node which can affect the network performance and can be used to calculate trust value.

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