12,935 research outputs found
V2X Meets NOMA: Non-Orthogonal Multiple Access for 5G Enabled Vehicular Networks
Benefited from the widely deployed infrastructure, the LTE network has
recently been considered as a promising candidate to support the
vehicle-to-everything (V2X) services. However, with a massive number of devices
accessing the V2X network in the future, the conventional OFDM-based LTE
network faces the congestion issues due to its low efficiency of orthogonal
access, resulting in significant access delay and posing a great challenge
especially to safety-critical applications. The non-orthogonal multiple access
(NOMA) technique has been well recognized as an effective solution for the
future 5G cellular networks to provide broadband communications and massive
connectivity. In this article, we investigate the applicability of NOMA in
supporting cellular V2X services to achieve low latency and high reliability.
Starting with a basic V2X unicast system, a novel NOMA-based scheme is proposed
to tackle the technical hurdles in designing high spectral efficient scheduling
and resource allocation schemes in the ultra dense topology. We then extend it
to a more general V2X broadcasting system. Other NOMA-based extended V2X
applications and some open issues are also discussed.Comment: Accepted by IEEE Wireless Communications Magazin
DFCV: A Novel Approach for Message Dissemination in Connected Vehicles using Dynamic Fog
Vehicular Ad-hoc Network (VANET) has emerged as a promising solution for
enhancing road safety. Routing of messages in VANET is challenging due to
packet delays arising from high mobility of vehicles, frequently changing
topology, and high density of vehicles, leading to frequent route breakages and
packet losses. Previous researchers have used either mobility in vehicular fog
computing or cloud computing to solve the routing issue, but they suffer from
large packet delays and frequent packet losses. We propose Dynamic Fog for
Connected Vehicles (DFCV), a fog computing based scheme which dynamically
creates, increments and destroys fog nodes depending on the communication
needs. The novelty of DFCV lies in providing lower delays and guaranteed
message delivery at high vehicular densities. Simulations were conducted using
hybrid simulation consisting of ns-2, SUMO, and Cloudsim. Results show that
DFCV ensures efficient resource utilization, lower packet delays and losses at
high vehicle densities
How to Choose the Relevant MAC Protocol for Wireless Smart Parking Urban Networks?
Parking sensor network is rapidly deploying around the world and is regarded
as one of the first implemented urban services in smart cities. To provide the
best network performance, the MAC protocol shall be adaptive enough in order to
satisfy the traffic intensity and variation of parking sensors. In this paper,
we study the heavy-tailed parking and vacant time models from SmartSantander,
and then we apply the traffic model in the simulation with four different kinds
of MAC protocols, that is, contention-based, schedule-based and two hybrid
versions of them. The result shows that the packet interarrival time is no
longer heavy-tailed while collecting a group of parking sensors, and then
choosing an appropriate MAC protocol highly depends on the network
configuration. Also, the information delay is bounded by traffic and MAC
parameters which are important criteria while the timely message is required.Comment: The 11th ACM International Symposium on Performance Evaluation of
Wireless Ad Hoc, Sensor, and Ubiquitous Networks (2014
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