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

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.

Author(s):  
Anamika Chauhan ◽  
Kapil Sharma ◽  
Alka Aggarwal

With the ever-escalating amount of vehicular traffic activity on the roads, the efficient management of traffic and safety of the drivers and passengers is of paramount gravity. Vehicular ad-hoc networks (VANETs) have emerged as the systems where vehicles would be perceptive of the locality and can supply the driver with required inputs to take necessary actions to alleviate the various issues. The system is designed to detect and identify essential traffic events and inform all concerned entities and take appropriate action. The characteristics of VANET are the topology is highly mobile, depends on city infrastructure, and the high speed of vehicles. These challenges result in frequent disruption of connections, long delays in delivering the messages. The challenges are overcome through the vehicular delay-tolerant network (VDTN) routing protocols are used that can facilitate communication under these network challenges. In this chapter, the authors evaluate the effect of the node density and message sizes on the performance of the various VDTN routing protocols.


2014 ◽  
Vol 10 (4) ◽  
pp. 213 ◽  
Author(s):  
Sweta Jain ◽  
Meenu Chawla

Delay Tolerant Networks (DTN) are mobile ad-hoc networks in which connections are often disruptive or discontinuous. Data forwarding using an appropriate routing strategy is a highly confronting issue in such networks. The traditional ad-hoc routing protocols which require end-to-end connectivity fail to function here due to frequent occurrences of network partitions. Spray and Wait (SaW) routing algorithm is a popular controlled replication based DTN protocol which provides a better delivery performance balancing the average delay and overhead ratio. An empirical analysis of various spray based approaches that have been proposed for DTN has been performed in this paper to compare and evaluate the basic Spray and Wait algorithms (Source Spray and Wait and Binary Sprayand Wait) with some of its major improvements (Spray andFocus, Average Delivery Probability Binary Spray and Wait and Composite methods to improve Spray and Wait). The main aim of this comparative study is to verify the effect of utility metrics in spray based routing protocols over simple spray based approaches. The ONE simulator has been used to provide a simulation environment to evaluate these algorithms and generate results. The performance metrics used are delivery ratio (DR), overhead ratio (OR) and average latency (ALat). The simulation results show that in terms of delivery ratio and average latency, Composite methods to improve Spray and Wait which incorporates delivery predictability metric in the wait phase and also acknowledgements to delete already deliveredmessages from a node’s buffer, outperforms all the other variants compared.


2019 ◽  
Vol 4 (12) ◽  
pp. 155-158
Author(s):  
Sujan Chandra Roy ◽  
Farhana Enam ◽  
Md. Ashraful Islam

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.  


2011 ◽  
Author(s):  
MoonJeong Chang ◽  
Ing-Ray Chen ◽  
Fenye Bao ◽  
Jin-Hee Cho

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Lei You ◽  
Jianbo Li ◽  
Changjiang Wei ◽  
Chenqu Dai ◽  
Jixing Xu ◽  
...  

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.


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