36,817 research outputs found
Hybrid Spectrum Sharing in mmWave Cellular Networks
While spectrum at millimeter wave (mmWave) frequencies is less scarce than at
traditional frequencies below 6 GHz, still it is not unlimited, in particular
if we consider the requirements from other services using the same band and the
need to license mmWave bands to multiple mobile operators. Therefore, an
efficient spectrum access scheme is critical to harvest the maximum benefit
from emerging mmWave technologies. In this paper, we introduce a new hybrid
spectrum access scheme for mmWave networks, where data is aggregated through
two mmWave carriers with different characteristics. In particular, we consider
the case of a hybrid spectrum scheme between a mmWave band with exclusive
access and a mmWave band where spectrum is pooled between multiple operators.
To the best of our knowledge, this is the first study proposing hybrid spectrum
access for mmWave networks and providing a quantitative assessment of its
benefits. Our results show that this approach provides major advantages with
respect to traditional fully licensed or fully unlicensed spectrum access
schemes, though further work is needed to achieve a more complete understanding
of both technical and non technical implications
Optimal Virtualized Inter-Tenant Resource Sharing for Device-to-Device Communications in 5G Networks
Device-to-Device (D2D) communication is expected to enable a number of new
services and applications in future mobile networks and has attracted
significant research interest over the last few years. Remarkably, little
attention has been placed on the issue of D2D communication for users belonging
to different operators. In this paper, we focus on this aspect for D2D users
that belong to different tenants (virtual network operators), assuming
virtualized and programmable future 5G wireless networks. Under the assumption
of a cross-tenant orchestrator, we show that significant gains can be achieved
in terms of network performance by optimizing resource sharing from the
different tenants, i.e., slices of the substrate physical network topology. To
this end, a sum-rate optimization framework is proposed for optimal sharing of
the virtualized resources. Via a wide site of numerical investigations, we
prove the efficacy of the proposed solution and the achievable gains compared
to legacy approaches.Comment: 10 pages, 7 figure
Distributed Channel Assignment in Cognitive Radio Networks: Stable Matching and Walrasian Equilibrium
We consider a set of secondary transmitter-receiver pairs in a cognitive
radio setting. Based on channel sensing and access performances, we consider
the problem of assigning channels orthogonally to secondary users through
distributed coordination and cooperation algorithms. Two economic models are
applied for this purpose: matching markets and competitive markets. In the
matching market model, secondary users and channels build two agent sets. We
implement a stable matching algorithm in which each secondary user, based on
his achievable rate, proposes to the coordinator to be matched with desirable
channels. The coordinator accepts or rejects the proposals based on the channel
preferences which depend on interference from the secondary user. The
coordination algorithm is of low complexity and can adapt to network dynamics.
In the competitive market model, channels are associated with prices and
secondary users are endowed with monetary budget. Each secondary user, based on
his utility function and current channel prices, demands a set of channels. A
Walrasian equilibrium maximizes the sum utility and equates the channel demand
to their supply. We prove the existence of Walrasian equilibrium and propose a
cooperative mechanism to reach it. The performance and complexity of the
proposed solutions are illustrated by numerical simulations.Comment: submitted to IEEE Transactions on Wireless Communicaitons, 13 pages,
10 figures, 4 table
A Review of Interference Reduction in Wireless Networks Using Graph Coloring Methods
The interference imposes a significant negative impact on the performance of
wireless networks. With the continuous deployment of larger and more
sophisticated wireless networks, reducing interference in such networks is
quickly being focused upon as a problem in today's world. In this paper we
analyze the interference reduction problem from a graph theoretical viewpoint.
A graph coloring methods are exploited to model the interference reduction
problem. However, additional constraints to graph coloring scenarios that
account for various networking conditions result in additional complexity to
standard graph coloring. This paper reviews a variety of algorithmic solutions
for specific network topologies.Comment: 10 pages, 5 figure
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