1,078 research outputs found
Sub-6GHz Assisted MAC for Millimeter Wave Vehicular Communications
Sub-6GHz vehicular communications (using DSRC, ITS-G5 or C-V2X) have been
developed to support active safety applications. Future connected and automated
driving applications can require larger bandwidth and higher data rates than
currently supported by sub-6GHz V2X technologies. This has triggered the
interest in developing mmWave vehicular communications. However, solutions are
necessary to solve the challenges resulting from the use of high-frequency
bands and the high mobility of vehicles. This paper contributes to this active
research area by proposing a sub-6GHz assisted mmWave MAC that decouples the
mmWave data and control planes. The proposal offloads mmWave MAC control
functions (beam alignment, neighbor identification and scheduling) to a
sub-6GHz V2X technology, and reserves the mmWave channel for the data plane.
This approach improves the operation of the MAC as the control functions
benefit from the longer range, and the broadcast and omnidirectional
transmissions of sub-6GHz V2X technologies. This simulation study demonstrates
that the proposed sub-6GHz assisted mmWave MAC reduces the control overhead and
delay, and increases the spatial sharing compared to a mmWave-only
configuration (IEEE 802.11ad tailored to vehicular networks). The proposed MAC
is here evaluated for V2V communications using 802.11p for the control plane
and 802.11ad for the data plane. However, the proposal is not restricted to
these technologies, and can be adapted to other technologies such as C-V2X and
5G NR.Comment: 8 pages, 5 figure
Heterogeneous V2V Communications in Multi-Link and Multi-RAT Vehicular Networks
Connected and automated vehicles will enable advanced traffic safety and
efficiency applications thanks to the dynamic exchange of information between
vehicles, and between vehicles and infrastructure nodes. Connected vehicles can
utilize IEEE 802.11p for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure
(V2I) communications. However, a widespread deployment of connected vehicles
and the introduction of connected automated driving applications will notably
increase the bandwidth and scalability requirements of vehicular networks. This
paper proposes to address these challenges through the adoption of
heterogeneous V2V communications in multi-link and multi-RAT vehicular
networks. In particular, the paper proposes the first distributed (and
decentralized) context-aware heterogeneous V2V communications algorithm that is
technology and application agnostic, and that allows each vehicle to
autonomously and dynamically select its communications technology taking into
account its application requirements and the communication context conditions.
This study demonstrates the potential of heterogeneous V2V communications, and
the capability of the proposed algorithm to satisfy the vehicles' application
requirements while approaching the estimated upper bound network capacity
IMPLEMENTATION OF A PHOTOVOLTAIC FLOATING COVER FOR IRRIGATION RESERVOIRS
[EN] The article presents the main features of a floating photovoltaic cover system (FPCS) for water irrigation reservoirs whose purpose is to reduce the evaporation of water while generating electrical power. The system consists of polyethylene floating modules which are able to adapt to varying reservoir water levels by means of tension bars and elastic fasteners. (C) 2013 Elsevier Ltd. All rights reserved.Redón-Santafé, M.; Ferrer-Gisbert, P.; Sánchez-Romero, F.; Torregrosa Soler, JB.; Ferran Gozalvez, JJ.; Ferrer Gisbert, CM. (2014). IMPLEMENTATION OF A PHOTOVOLTAIC FLOATING COVER FOR IRRIGATION RESERVOIRS. Journal of Cleaner Production. 66:568-570. doi:10.1016/j.jclepro.2013.11.006S5685706
Analytical Models of the Performance of C-V2X Mode 4 Vehicular Communications
The C-V2X or LTE-V standard has been designed to support V2X (Vehicle to
Everything) communications. The standard is an evolution of LTE, and it has
been published by the 3GPP in Release 14. This new standard introduces the
C-V2X or LTE-V Mode 4 that is specifically designed for V2V communications
using the PC5 sidelink interface without any cellular infrastructure support.
In Mode 4, vehicles autonomously select and manage their radio resources. Mode
4 is highly relevant since V2V safety applications cannot depend on the
availability of infrastructure-based cellular coverage. This paper presents the
first analytical models of the communication performance of C-V2X or LTE-V Mode
4. In particular, the paper presents analytical models for the average PDR
(Packet Delivery Ratio) as a function of the distance between transmitter and
receiver, and for the four different types of transmission errors that can be
encountered in C-V2X Mode 4. The models are validated for a wide range of
transmission parameters and traffic densities. To this aim, this study compares
the results obtained with the analytical models to those obtained with a C-V2X
Mode 4 simulator implemented over Veins
Mode Selection for 5G Heterogeneous and Opportunistic Networks
5G and beyond networks will offer multiple communication modes including device-to-device
and multi-hop cellular (or UE-to-network relay) communications. Several studies have shown that these
modes can signi_cantly improve the Quality of Service (QoS), the spectrum and energy ef_ciency, and the
network capacity. Recent studies have demonstrated that further gains can be achieved when integrating
demand-driven opportunistic networking into Multi-Hop Cellular Networks (MCN). In opportunistic MCN
connections, devices can exploit the delay tolerance of many mobile data services to search for the most
ef_cient connections between nodes. The availability of multiple communication modes requires mode
selection schemes capable to decide the optimum mode for each transmission. Mode selection schemes
have been previously proposed to account for the introduction of D2D and MCN. However, existing mode
selection schemes cannot integrate opportunistic MCN connections into the selection process. This paper
advances the state of the art by proposing the _rst mode selection scheme capable to integrate opportunistic
MCN communications within 5G and beyond networks. The conducted analysis demonstrates the potential
of opportunistic MCN communications, and the capability of the proposed mode selection scheme to select
the most adequate communication mode.This work was supported in part by the Spanish Ministry of Economy, Industry, and Competitiveness, AEI, and FEDER funds under Grant
TEC2017-88612-RGrant TEC2014-57146-Rand in part by the Generalitat Valenciana under Grant GV/2016/049
- …