96 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
Cellular Wireless Networks in the Upper Mid-Band
The upper mid-band -- roughly from 7 to 24 GHz -- has attracted considerable
recent interest for new cellular services. This frequency range has vastly more
spectrum than the highly congested bands below 7 GHz while offering more
favorable propagation and coverage than the millimeter wave (mmWave)
frequencies. Realizing the full potential of these bands, however, will require
fundamental changes to the design of cellular systems. Most importantly,
spectrum will likely need to be shared with incumbents including communication
satellites, military RADAR, and radio astronomy. Also, due to the wide
bandwidth, directional nature of transmission, and intermittent occupancy of
incumbents, cellular systems will need to be agile to sense and intelligently
use large spatial and bandwidth degrees of freedom. This paper attempts to
provide an initial assessment of the feasibility and potential gains of
wideband cellular systems operating in the upper mid-band. The study includes:
(1) a system study to assess potential gains of multi-band systems in a
representative dense urban environment; (2) propagation calculations to assess
potential cross interference between satellites and terrestrial cellular
services; and (3) design and evaluation of a compact multi-band antenna array
structure. Leveraging these preliminary results, we identify potential future
research directions to realize next-generation systems in these frequencies.Comment: 11 page
Context-Aware Spectrum Coexistence of Terrestrial Beyond 5G Networks in Satellite Bands
Spectrum sharing between terrestrial 5G and incumbent networks in the
satellite bands presents a promising avenue to satisfy the ever-increasing
bandwidth demand of the next-generation wireless networks. However, protecting
incumbent operations from harmful interference poses a fundamental challenge in
accommodating terrestrial broadband cellular networks in the satellite bands.
State-of-the-art spectrum-sharing policies usually consider several worst-case
assumptions and ignore site-specific contextual factors in making
spectrum-sharing decisions, and thus, often results in under-utilization of the
shared band for the secondary licensees. To address such limitations, this
paper introduces CAT3S (Context-Aware Terrestrial-Satellite Spectrum Sharing)
framework that empowers the coexisting terrestrial 5G network to maximize
utilization of the shared satellite band without creating harmful interference
to the incumbent links by exploiting the contextual factors. CAT3S consists of
the following two components: (i) context-acquisition unit to collect and
process essential contextual information for spectrum sharing and (ii)
context-aware base station (BS) control unit to optimize the set of operational
BSs and their operation parameters (i.e., transmit power and active beams per
sector). To evaluate the performance of the CAT3S, a realistic spectrum
coexistence case study over the 12 GHz band is considered. Experiment results
demonstrate that the proposed CAT3S achieves notably higher spectrum
utilization than state-of-the-art spectrum-sharing policies in different
weather contexts
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