S-ROGUE: Routing protocol for Unmanned Systems on the Surface

International audienceThe cooperation of heterogeneous unmanned systems , for instance, between aerial engines and terrestrial engines, relies on reliable communication. Data delivery is ensured by routing protocols, but traditional routing approaches, MANET and DTN, are not efficient in such networks. In this paper, we propose the S-ROGUE routing protocol combining the paradigms MANET and DTN and switching between them according to the network connectivity. On the one hand, the S-ROGUE MANET algorithm relies on a proactive approach and a novel metric to anticipate link disruptions and detect unidirectional links. On the other hand, the S-ROGUE DTN algorithm uses on a reinforcement learning technique to select the best routing action. It implements also a replication control and packet prioritization to improve routing performances. We lead a performance evaluation of S-ROGUE with similar routing protocols in realistic simulated environments and conclude that S-ROGUE has the best routing performance regardless the scenarios

An Enhanced AODV Protocol for VANETs with Realistic Radio Propagation Model Validation

International audienceIn this paper we evaluate V-AODV a version of AODV (Ad-hoc On-demand Distance Vector) especially created for Vehicular Ad-hoc NETworks (VANETs). V-AODV is designed to run with a complex cross layered metric based on both delay from node to node and Bit Error Rate (BER) coming from the physical layer. We conducted simulations with the NS2 simulator taking in account a realistic environment tool called Communication Ray Tracer (CRT). Our results show that the basic propagation models usually in use with NS2 are not suitable for VANETs simulations. We also show that when using a routing metric based on delay and BER, the first parameter is more relevant in terms of QoS than the second one

Realistic wireless communication simulations for VANETS

International audienceVehicular Ad­hoc NETworks (VANETs) are mainly evaluated through simulations in which the choice of a realistic wireless channel model is a central point. Deterministic channel models bring good realism but need huge simulation time, whereas with statistical models the computational effort is reduced, but sadly so is the realism of the model. In this paper, we present a semi­deterministic channel model, called UM­CRT, based on a deterministic channel simulator, CRT (Communication Ray Tracer) and a statistical channel model, SCME-UM (Spatial Channel Model Extended - Urban Microcell). To integrate it into the NS­2 network simulator, we couple it to self­developed fully compliant 802.11p and 802.11n physical layers. Simulations in urban environment show both a good realism and a reduced computation time indicating that UM­CRT is adapted for VANETs simulations

UM-CRT : Un modèle de canal semi-déterministe pour les VANETs

National audienceLe choix d'un modèle de canal efficace pour la simulation des VANETs (Vehicular Ad-hoc NETworks) est difficile. Avec un modèle de canal purement déterministe les simulations sont réalistes mais prennent un temps très long, voire prohibitif. Dans le cas d'un modèle purement statistique, les simulations sont rapides mais le réalisme obtenu est limité. Dans ce papier nous proposons UM-CRT, un modèle de canal semi- déterministe basé sur un simulateur 3D déterministe de canal et sur le modèle statistique géométrique de canal SCME-UM (Spatial Channel Model Extended - Urban Micro). Nous avons intégré ce modèle dans le simulateur de réseaux NS-2 et montré qu'il fournit des résultats proches de ceux du modèle déterministe en un temps très nettement réduit

A semi-deterministic channel model for VANETs simulations

International audienceIn this paper we propose a semi-deterministic channel propagation model for VANETs (Vehicular Ad-hoc NETworks) called UM-CRT. It is based on CRT (Communication Ray Tracer) and SCME-UM (Spatial Channel Model Extended - Urban Micro) which are respectively a deterministic channel simulator and a statistical channel model. It uses a process which adjusts the SCME-UM model using relevant parameters extracted from CRT. In order to evaluate this new model, we incorporate it into the NS-2 network simulator. Our results show that UM-CRT is adapted to VANETs simulations as it approximates in a realistic manner channel propagation mechanisms while improving simulation time

A survey of V2V channel modeling for VANET simulations

International audienceMost Vehicle to Vehicle (V2V) network protocols are evaluated by simulation. However in most network simulators, the physical layer suffers from a lack of realism. Therefore, realistic V2V channel modeling has become a crucial issue in Intelligent Transportation Systems (ITS) networks. V2V channels are known to exhibit specific features which imply the design of new simulation models. In this survey paper, we first recall the main physical features of such wireless time and frequency dispersive channels. Next, three "simulation-ready" V2V channel models found in the literature are reviewed. Finally, two complete VANET simulation frameworks are presented. They illustrate the importance of a realistic channel and physical layer modeling in vehicular networking

An investigation of the bits corruption in the IEEE 802.11p

Data rate management algorithms aim to perform a proper selection of the signal modulation and the coding rate to avoid the corruption of data bits. This paper describes a preliminary investigation on the bit corruption pattern related to the IEEE 802.11p standard. Measurements have been acquired with an experimental test-bed made up with a couple of software radios to perform white-box tests. Software radios are stationary and operate on the same channel without disturbances coming from concurrent communication. The aim of this experimental test-bed is to represent a static scenario where vehicles are stationary such as a crossroad situation. The data analysis shows that a data length reduction as an impact as much as a decrease of the data rate. A deeper analysis of the data bit corruption distribution highlights that some bits are more corrupted than others, rejecting the independent and identically distributed assumption for some situations. This opens a perspective to design algorithms dealing with multiple constraints, even if they are NP-complete

Low Latency V2X Applications and Network Requirements: Performance Evaluation

Vehicle-to-Everything (V2X) communication promises improvements in road safety and efficiency by enabling low-latency and reliable communication services for vehicles. Besides using Mobile Broadband (MBB), there is a need to develop Ultra Reliable Low Latency Communications (URLLC) applications with cellular networks especially when safety-related driving applications are concerned. Future cellular networks are expected to support novel latencysensitive use cases. Many applications of V2X communication, like collaborative autonomous driving requires very low latency and high reliability in order to support real-time communication between vehicles and other network elements. In this paper, we classify V2X use-cases and their requirements in order to identify cellular network technologies able to support them. The bottleneck problem of the medium access in 4G Long Term Evolution(LTE) networks is random access procedure. It is evaluated through simulations to further detail the future limitations and requirements. Limitations and improvement possibilities for next generation of cellular networks are finally detailed. Moreover, the results presented in this paper provide the limits of different parameter sets with regard to the requirements of V2X-based applications. In doing this, a starting point to migrate to Narrowband IoT (NB-IoT) or 5G - solutions is given

Latency Reduction for Narrowband LTE with Semi-Persistent Scheduling

The excessive control signaling in Long Term Evolution networks required for dynamic scheduling impedes the deployment of ultra-reliable low latency applications. Semi-persistent scheduling was originally designed for constant bit-rate voice applications, however, very low control overhead makes it a potential latency reduction technique in Long Term Evolution. In this paper, we investigate resource scheduling in narrowband fourth generation Long Term Evolution networks through Network Simulator (NS3) simulations. The current release of NS3 does not include a semi-persistent scheduler for Long Term Evolution module. Therefore, we developed the semi-persistent scheduling feature in NS3 to evaluate and compare the performance in terms of uplink latency. We evaluate dynamic scheduling and semi-persistent scheduling in order to analyze the impact of resource scheduling methods on up-link latency

Impact d'un modèle de propagation réaliste sur un protocole de routage pour les VANETs

Dans ce travail, nous présentons le protocole de routage V­AODV, une amélioration du protocole AODV (Ad­hoc On­demand Distance Vector) pour les VANETs (Vehicular Ad hoc NETworks)