19,505 research outputs found
Survey of Spectrum Sharing for Inter-Technology Coexistence
Increasing capacity demands in emerging wireless technologies are expected to
be met by network densification and spectrum bands open to multiple
technologies. These will, in turn, increase the level of interference and also
result in more complex inter-technology interactions, which will need to be
managed through spectrum sharing mechanisms. Consequently, novel spectrum
sharing mechanisms should be designed to allow spectrum access for multiple
technologies, while efficiently utilizing the spectrum resources overall.
Importantly, it is not trivial to design such efficient mechanisms, not only
due to technical aspects, but also due to regulatory and business model
constraints. In this survey we address spectrum sharing mechanisms for wireless
inter-technology coexistence by means of a technology circle that incorporates
in a unified, system-level view the technical and non-technical aspects. We
thus systematically explore the spectrum sharing design space consisting of
parameters at different layers. Using this framework, we present a literature
review on inter-technology coexistence with a focus on wireless technologies
with equal spectrum access rights, i.e. (i) primary/primary, (ii)
secondary/secondary, and (iii) technologies operating in a spectrum commons.
Moreover, we reflect on our literature review to identify possible spectrum
sharing design solutions and performance evaluation approaches useful for
future coexistence cases. Finally, we discuss spectrum sharing design
challenges and suggest future research directions
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
Integration of Carrier Aggregation and Dual Connectivity for the ns-3 mmWave Module
Thanks to the wide availability of bandwidth, the millimeter wave (mmWave)
frequencies will provide very high data rates to mobile users in next
generation 5G cellular networks. However, mmWave links suffer from high
isotropic pathloss and blockage from common materials, and are subject to an
intermittent channel quality. Therefore, protocols and solutions at different
layers in the cellular network and the TCP/IP protocol stack have been proposed
and studied. A valuable tool for the end-to-end performance analysis of mmWave
cellular networks is the ns-3 mmWave module, which already models in detail the
channel, Physical (PHY) and Medium Access Control (MAC) layers, and extends the
Long Term Evolution (LTE) stack for the higher layers. In this paper we present
an implementation for the ns-3 mmWave module of multi connectivity techniques
for 3GPP New Radio (NR) at mmWave frequencies, namely Carrier Aggregation (CA)
and Dual Connectivity (DC), and discuss how they can be integrated to increase
the functionalities offered by the ns-3 mmWave module.Comment: 9 pages, 7 figures, submitted to the Workshop on ns-3 (WNS3) 201
- …