EmuCD: An Emulator for Content Dissemination Protocols in Vehicular Networks

Ricardo Chaves,Susana Sargento,Ricardo Matos,Carlos Senna,Diogo Recharte,André Moreira,Miguel Luís

doi:10.3390/fi12120234

Abstract

The development of protocols for mobile networks, especially for vehicular ad-hoc networks (VANETs), presents great challenges in terms of testing in real conditions. Using a production network for testing communication protocols may not be feasible, and the use of small networks does not meet the requirements for mobility and scale found in real networks. The alternative is to use simulators and emulators, but vehicular network simulators do not meet all the requirements for effective testing. Aspects closely linked to the behaviour of the network nodes (mobility, radio communication capabilities, etc.) are particularly important in mobile networks, where a delay tolerance capability is desired. This paper proposes a distributed emulator, EmuCD, where each network node is built in a container that consumes a data trace that defines the node’s mobility and connectivity in a real network (but also allowing the use of data from simulated networks). The emulated nodes interact directly with the container’s operating system, updating the network conditions at each step of the emulation. In this way, our emulator allows the development and testing of protocols, without any relation to the emulator, whose code is directly portable to any hardware without requiring changes or customizations. Using the facilities of our emulator, we tested InterPlanetary File System (IPFS), Sprinkler and BitTorrent content dissemination protocols with real mobility and connectivity data from a real vehicular network. The tests with a real VANET and with the emulator have shown that, under similar conditions, EmuCD performs closely to the real VANET, only lacking in the finer details that are extremely hard to emulate, such as varying loads in the hardware.

Highlights

Despite recent technological advances with regard to vehicular networks, it is still very difficult to develop routing and content dissemination protocols in real scenarios [1]
Across every test and scenario presented in this document, EmuCD was running in an Ubuntu 18.04 virtual machine (VM), with seven dedicated CPU cores at 4.6 GHz and 27 GB of RAM
The CPU and RAM graphs are not restricted to the emulator and its processes, they are for the entire VM: idling and without an emulation running, CPU averaged 0% across all cores and 1 GB of RAM was in use, so the CPU graphs can be considered to be representative of the emulator and its processes, and in the RAM graphs 1 GB must be subtracted from the memory in use

Summary

Introduction

Despite recent technological advances with regard to vehicular networks, it is still very difficult to develop routing and content dissemination protocols in real scenarios [1]. Some aspects inherent to vehicular ad-hoc networks (VANETs), such as mobility models, driver behaviour and wireless channel modelling have a considerable effect on performance results. Due to these challenges, the simulation of realistic mobility models becomes essential for research in order to achieve precisely the desired results that reflect the realistic behaviour of vehicular traffic [3]. Developing a content dissemination protocol for a vehicular network (VANET) is not an easy task: the protocol may be good in theory and in simulations, but with low performance in a real environment. In the case of a VANET, since the nodes keep moving and the network’s topology is very dynamic, repeating a test under the same conditions is not an option

Objectives

Results

Conclusion