50,227 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
Cooperative Interference Control for Spectrum Sharing in OFDMA Cellular Systems
This paper studies cooperative schemes for the inter-cell interference
control in orthogonal-frequency-divisionmultiple- access (OFDMA) cellular
systems. The downlink transmission in a simplified two-cell system is examined,
where both cells simultaneously access the same frequency band using OFDMA. The
joint power and subcarrier allocation over the two cells is investigated for
maximizing their sum throughput with both centralized and decentralized
implementations. Particularly, the decentralized allocation is achieved via a
new cooperative interference control approach, whereby the two cells
independently implement resource allocation to maximize individual throughput
in an iterative manner, subject to a set of mutual interference power
constraints. Simulation results show that the proposed decentralized resource
allocation schemes achieve the system throughput close to that by the
centralized scheme, and provide substantial throughput gains over existing
schemes.Comment: To appear in ICC201
Census Tract License Areas: Disincentive for Sharing the 3.5GHz band?
Flexible licensing model is a necessary enabler of the technical and
procedural complexities of Spectrum Access System (SAS)-based sharing
framework. The purpose of this study is to explore the effectiveness of 3.5GHz
Licensing Framework - based on census tracts as area units, areas whose main
characteristic is population. As such, the boundary of census tract does not
follow the edge of wireless network coverage. We demonstrate why census tracts
are not suitable for small cell networks licensing, by (1) gathering and
analysing the official census data, (2) exploring the boundaries of census
tracts which are in the shape of nonconvex polygons and (3) giving a measure of
effectiveness of the licensing scheme through metrics of area loss and the
number of people per census tract with access to spectrum. Results show that
census tracts severely impact the effectiveness of the licensing framework
since almost entire strategically important cities in the U.S. will not avail
from spectrum use in 3.5GHz band. Our paper does not seek to challenge the core
notion of geographic licensing concept, but seeks a corrective that addresses
the way the license is issued for a certain area of operation. The effects that
inappropriate size of the license has on spectrum assignments lead to spectrum
being simply wasted in geography, time and frequency or not being assigned in a
fair manner. The corrective is necessary since the main goal of promoting
innovative sharing in 3.5 GHz band is to put spectrum to more efficient use.Comment: 7 pages, 5 figures, conferenc
- …