254 research outputs found
A Survey on Multi-AP Coordination Approaches over Emerging WLANs: Future Directions and Open Challenges
Recent advancements in wireless local area network (WLAN) technology include
IEEE 802.11be and 802.11ay, often known as Wi-Fi 7 and WiGig, respectively. The
goal of these developments is to provide Extremely High Throughput (EHT) and
low latency to meet the demands of future applications like as 8K videos,
augmented and virtual reality, the Internet of Things, telesurgery, and other
developing technologies. IEEE 802.11be includes new features such as 320 MHz
bandwidth, multi-link operation, Multi-user Multi-Input Multi-Output,
orthogonal frequency-division multiple access, and Multiple-Access Point
(multi-AP) coordination (MAP-Co) to achieve EHT. With the increase in the
number of overlapping APs and inter-AP interference, researchers have focused
on studying MAP-Co approaches for coordinated transmission in IEEE 802.11be,
making MAP-Co a key feature of future WLANs. Moreover, similar issues may arise
in EHF bands WLAN, particularly for standards beyond IEEE 802.11ay. This has
prompted researchers to investigate the implementation of MAP-Co over future
802.11ay WLANs. Thus, in this article, we provide a comprehensive review of the
state-of-the-art MAP-Co features and their shortcomings concerning emerging
WLAN. Finally, we discuss several novel future directions and open challenges
for MAP-Co.Comment: The reason for the replacement of the previous version of the paper
is due to a change in the author's list. As a result, a new version has been
created, which serves as the final draft version before acceptance. This
updated version contains all the latest changes and improvements made to the
pape
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
On the Relay-Fallback Tradeoff in Millimeter Wave Wireless System
Millimeter wave (mmWave) communications systems are promising candidate to
support extremely high data rate services in future wireless networks. MmWave
communications exhibit high penetration loss (blockage) and require directional
transmissions to compensate for severe channel attenuations and for high noise
powers. When blockage occurs, there are at least two simple prominent options:
1) switching to the conventional microwave frequencies (fallback option) and 2)
using an alternative non-blocked path (relay option). However, currently it is
not clear under which conditions and network parameters one option is better
than the other. To investigate the performance of the two options, this paper
proposes a novel blockage model that allows deriving maximum achievable
throughput and delay performance of both options. A simple criterion to decide
which option should be taken under which network condition is provided. By a
comprehensive performance analysis, it is shown that the right option depends
on the payload size, beam training overhead, and blockage probability. For a
network with light traffic and low probability of blockage in the direct link,
the fallback option is throughput- and delay-optimal. For a network with heavy
traffic demands and semi-static topology (low beam-training overhead), the
relay option is preferable.Comment: 6 pages, 5 figures, accepted in IEEE INFOCOM mmNet Worksho
Spectrum Sharing in mmWave Cellular Networks via Cell Association, Coordination, and Beamforming
This paper investigates the extent to which spectrum sharing in mmWave
networks with multiple cellular operators is a viable alternative to
traditional dedicated spectrum allocation. Specifically, we develop a general
mathematical framework by which to characterize the performance gain that can
be obtained when spectrum sharing is used, as a function of the underlying
beamforming, operator coordination, bandwidth, and infrastructure sharing
scenarios. The framework is based on joint beamforming and cell association
optimization, with the objective of maximizing the long-term throughput of the
users. Our asymptotic and non-asymptotic performance analyses reveal five key
points: (1) spectrum sharing with light on-demand intra- and inter-operator
coordination is feasible, especially at higher mmWave frequencies (for example,
73 GHz), (2) directional communications at the user equipment substantially
alleviate the potential disadvantages of spectrum sharing (such as higher
multiuser interference), (3) large numbers of antenna elements can reduce the
need for coordination and simplify the implementation of spectrum sharing, (4)
while inter-operator coordination can be neglected in the large-antenna regime,
intra-operator coordination can still bring gains by balancing the network
load, and (5) critical control signals among base stations, operators, and user
equipment should be protected from the adverse effects of spectrum sharing, for
example by means of exclusive resource allocation. The results of this paper,
and their extensions obtained by relaxing some ideal assumptions, can provide
important insights for future standardization and spectrum policy.Comment: 15 pages. To appear in IEEE JSAC Special Issue on Spectrum Sharing
and Aggregation for Future Wireless Network
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