1,687 research outputs found
Fine-Grained vs. Average Reliability for V2V Communications around Intersections
Intersections are critical areas of the transportation infrastructure
associated with 47% of all road accidents. Vehicle-to-vehicle (V2V)
communication has the potential of preventing up to 35% of such serious road
collisions. In fact, under the 5G/LTE Rel.15+ standardization, V2V is a
critical use-case not only for the purpose of enhancing road safety, but also
for enabling traffic efficiency in modern smart cities. Under this anticipated
5G definition, high reliability of 0.99999 is expected for semi-autonomous
vehicles (i.e., driver-in-the-loop). As a consequence, there is a need to
assess the reliability, especially for accident-prone areas, such as
intersections. We unpack traditional average V2V reliability in order to
quantify its related fine-grained V2V reliability. Contrary to existing work on
infinitely large roads, when we consider finite road segments of significance
to practical real-world deployment, fine-grained reliability exhibits bimodal
behavior. Performance for a certain vehicular traffic scenario is either very
reliable or extremely unreliable, but nowhere in relative proximity to the
average performance.Comment: 5 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:1706.1001
Fine-Grained Reliability for V2V Communications around Suburban and Urban Intersections
Safe transportation is a key use-case of the 5G/LTE Rel.15+ communications,
where an end-to-end reliability of 0.99999 is expected for a vehicle-to-vehicle
(V2V) transmission distance of 100-200 m. Since communications reliability is
related to road-safety, it is crucial to verify the fulfillment of the
performance, especially for accident-prone areas such as intersections. We
derive closed-form expressions for the V2V transmission reliability near
suburban corners and urban intersections over finite interference regions. The
analysis is based on plausible street configurations, traffic scenarios, and
empirically-supported channel propagation. We show the means by which the
performance metric can serve as a preliminary design tool to meet a target
reliability. We then apply meta distribution concepts to provide a careful
dissection of V2V communications reliability. Contrary to existing work on
infinite roads, when we consider finite road segments for practical deployment,
fine-grained reliability per realization exhibits bimodal behavior. Either
performance for a certain vehicular traffic scenario is very reliable or
extremely unreliable, but nowhere in relatively proximity to the average
performance. In other words, standard SINR-based average performance metrics
are analytically accurate but can be insufficient from a practical viewpoint.
Investigating other safety-critical point process networks at the meta
distribution-level may reveal similar discrepancies.Comment: 27 pages, 6 figures, submitted to IEEE Transactions on Wireless
Communication
Vehicle-to-Vehicle Communications with Urban Intersection Path Loss Models
Vehicle-to-vehicle (V2V) communication can improve road safety and traffic efficiency, particularly around critical areas such as intersections. We analytically derive V2V success probability near an urban intersection, based on empirically supported line-of-sight (LOS), weak-line-of-sight (WLOS), and nonline-of-sight (NLOS) channel models. The analysis can serve as a preliminary design tool for performance assessment over different system parameters and target performance requirements
Two-Hop Connectivity to the Roadside in a VANET Under the Random Connection Model
We compute the expected number of cars that have at least one two-hop path to
a fixed roadside unit in a one-dimensional vehicular ad hoc network in which
other cars can be used as relays to reach a roadside unit when they do not have
a reliable direct link. The pairwise channels between cars experience Rayleigh
fading in the random connection model, and so exist, with probability function
of the mutual distance between the cars, or between the cars and the roadside
unit. We derive exact equivalents for this expected number of cars when the car
density tends to zero and to infinity, and determine its behaviour using
an infinite oscillating power series in , which is accurate for all
regimes. We also corroborate those findings to a realistic situation, using
snapshots of actual traffic data. Finally, a normal approximation is discussed
for the probability mass function of the number of cars with a two-hop
connection to the origin. The probability mass function appears to be well
fitted by a Gaussian approximation with mean equal to the expected number of
cars with two hops to the origin.Comment: 21 pages, 7 figure
Performance Evaluation of Adaptive Cooperative NOMA Protocol at Road Junctions
Vehicular communications (VCs) protocols offer useful contributions in the
context of accident prevention thanks to the transmission of alert messages.
This is even truer at road intersections since these areas exhibit higher
collision risks and accidents rate. On the other hand, non-orthogonal multiple
access (NOMA) has been show to be a suitable candidate for five generation (5G)
of wireless systems. In this paper, we propose and evaluate the performance of
VCs protocol at road intersections, named adaptive cooperative NOMA (ACN)
protocol. The transmission occurs between a source and two destinations. The
transmission is subject to interference originated from vehicles located on the
roads. The positions of the interfering vehicles follow a Poison point process
(PPP). First, we calculate the outage probability related to ACN protocol, and
closed form expressions are obtained. Then we compare it with other existing
protocols in the literature. We show that ACN protocol offers a significant
improvement over the existing protocols in terms of outage probability,
especially at the intersection. We show that the performance of ACN protocol
increases compared to other existing protocols for high data rates. The
theoretical results are verified with Monte-Carlo simulations
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