597 research outputs found
Data Offloading in Load Coupled Networks: A Utility Maximization Framework
We provide a general framework for the problem of data offloading in a
heterogeneous wireless network, where some demand of cellular users is served
by a complementary network. The complementary network is either a small-cell
network that shares the same resources as the cellular network, or a WiFi
network that uses orthogonal resources. For a given demand served in a cellular
network, the load, or the level of resource usage, of each cell depends in a
non-linear manner on the load of other cells due to the mutual coupling of
interference seen by one another. With load coupling, we optimize the demand to
be served in the cellular or the complementary networks, so as to maximize a
utility function. We consider three representative utility functions that
balance, to varying degrees, the revenue from serving the users vs the user
fairness. We establish conditions for which the optimization problem has a
feasible solution and is convex, and hence tractable to numerical computations.
Finally, we propose a strategy with theoretical justification to constrain the
load to some maximum value, as required for practical implementation. Numerical
studies are conducted for both under-loaded and over-loaded networks.Comment: 12 pages, accepted for publication in IEEE Transactions on Wireless
Communication
Surrogate modeling based cognitive decision engine for optimization of WLAN performance
Due to the rapid growth of wireless networks and the dearth of the electromagnetic spectrum, more interference is imposed to the wireless terminals which constrains their performance. In order to mitigate such performance degradation, this paper proposes a novel experimentally verified surrogate model based cognitive decision engine which aims at performance optimization of IEEE 802.11 links. The surrogate model takes the current state and configuration of the network as input and makes a prediction of the QoS parameter that would assist the decision engine to steer the network towards the optimal configuration. The decision engine was applied in two realistic interference scenarios where in both cases, utilization of the cognitive decision engine significantly outperformed the case where the decision engine was not deployed
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
D21.3 Analysis of initial results at EuWIN@CTTC
Deliverable D21.3 del projecte europeu NEWCOM#The nature of this Deliverable of WP2.1 (“Radio interfaces for next-generation wireless systems”) is mainly descriptive and its purpose is to provide a report on the status of the different Joint Research Activities (JRAs) currently ongoing, some of them being performed on the facilities that are available at EuWInPeer ReviewedPreprin
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