Performance evaluation of a cooperative reputation system for vehicular delay-tolerant networks

João Aff Dias,Lei Shu,Joel Jpc Rodrigues,Sana Ullah

doi:10.1186/1687-1499-2014-88

Abstract

Abstract In the last decade, both scientific community and automotive industry enabled communications among vehicles in different kinds of scenarios proposing different vehicular architectures. Vehicular delay-tolerant networks (VDTNs) were proposed as a solution to overcome some of the issues found in other vehicular architectures, namely, in dispersed regions and emergency scenarios. Most of these issues arise from the unique characteristics of vehicular networks. Contrary to delay-tolerant networks (DTNs), VDTNs place the bundle layer under the network layer in order to simplify the layered architecture and enable communications in sparse regions characterized by long propagation delays, high error rates, and short contact durations. However, such characteristics turn contacts very important in order to exchange as much information as possible between nodes at every contact opportunity. One way to accomplish this goal is to enforce cooperation between network nodes. To promote cooperation among nodes, it is important that nodes share their own resources to deliver messages from others. This can be a very difficult task, if selfish nodes affect the performance of cooperative nodes. This paper studies the performance of a cooperative reputation system that detects, identify, and avoid communications with selfish nodes. Two scenarios were considered across all the experiments enforcing three different routing protocols (First Contact, Spray and Wait, and GeoSpray). For both scenarios, it was shown that reputation mechanisms that punish aggressively selfish nodes contribute to increase the overall network performance.

Highlights

Vehicular networks have been emerging as a suitable solution to enable communications in different kind of scenarios using vehicles
7 Conclusions In the last years, vehicular architectures have been the focus of research by the scientific community and by the automotive industry
Vehicular delay-tolerant networks (VDTNs) have been proposed as a possible solution to overcome the most challenging issues of vehicular communications

Summary

Introduction

Vehicular networks have been emerging as a suitable solution to enable communications in different kind of scenarios using vehicles (i.e., cars, buses, trams, etc.). To evaluate nodes’ reputation scores this scheme considers cooperativeness and accuracy of peer-provided data To calculate these tokens, the proposed scheme uses persistent identifiers, frequency of encounters, and a known set of anchored trustworthy sources to serve as nucleating points for building trust relationships with previously unknown devices. The data plane exchanges data bundles among nodes, according to the contact time scheduled for the data plane Based on this architectural behavior, a reputation system for VDTNs is proposed to provide a sophisticated tool that allows network nodes to detect, identify, and avoid contacts with selfish or misbehavior nodes. Each time a contact opportunity is available, the encountered node is added to the reputation table (if it does not already exist) and the reputation score is updated using the VDTN out-of-band-signaling at the control plane phase At this phase, nodes exchange control information (setup messages), such as node type, geographical location, route, speed, supported link technologies properties, energy status, and buffer status. All the network nodes are equipped with the standard IEEE 802.11b interface to allow communications with other nodes and a data rate of 6 Mbps

Findings

Performance metrics and routing protocols

Conclusions