76,347 research outputs found
Reducing the Environmental Impact of Wireless Communication via Probabilistic Machine Learning
Machine learning methods are increasingly adopted in communications problems,
particularly those arising in next generation wireless settings. Though seen as
a key climate mitigation and societal adaptation enabler, communications
related energy consumption is high and is expected to grow in future networks
in spite of anticipated efficiency gains in 6G due to exponential
communications traffic growth. To make meaningful climate mitigation impact in
the communications sector, a mindset shift away from maximizing throughput at
all cost and towards prioritizing energy efficiency is needed. Moreover, this
must be adopted in both existing (without incurring further embodied carbon
costs through equipment replacement) and future network infrastructure, given
the long development time of mobile generations. To that end, we present
summaries of two such problems, from both current and next generation network
specifications, where probabilistic inference methods were used to great
effect: using Bayesian parameter tuning we are able to safely reduce the energy
consumption of existing hardware on a live communications network by
whilst maintaining operator specified performance envelopes; through
spatiotemporal Gaussian process surrogate modeling we reduce the overhead in a
next generation hybrid beamforming system by over , greatly improving the
networks' ability to target highly mobile users such as autonomous vehicles.
The Bayesian paradigm is itself helpful in terms of energy usage, since
training a Bayesian optimization model can require much less computation than,
say, training a deep neural network
SINVAD: Search-based Image Space Navigation for DNN Image Classifier Test Input Generation
The testing of Deep Neural Networks (DNNs) has become increasingly important
as DNNs are widely adopted by safety critical systems. While many test adequacy
criteria have been suggested, automated test input generation for many types of
DNNs remains a challenge because the raw input space is too large to randomly
sample or to navigate and search for plausible inputs. Consequently, current
testing techniques for DNNs depend on small local perturbations to existing
inputs, based on the metamorphic testing principle. We propose new ways to
search not over the entire image space, but rather over a plausible input space
that resembles the true training distribution. This space is constructed using
Variational Autoencoders (VAEs), and navigated through their latent vector
space. We show that this space helps efficiently produce test inputs that can
reveal information about the robustness of DNNs when dealing with realistic
tests, opening the field to meaningful exploration through the space of highly
structured images
On the interaction between Autonomous Mobility-on-Demand systems and the power network: models and coordination algorithms
We study the interaction between a fleet of electric, self-driving vehicles
servicing on-demand transportation requests (referred to as Autonomous
Mobility-on-Demand, or AMoD, system) and the electric power network. We propose
a model that captures the coupling between the two systems stemming from the
vehicles' charging requirements and captures time-varying customer demand and
power generation costs, road congestion, battery depreciation, and power
transmission and distribution constraints. We then leverage the model to
jointly optimize the operation of both systems. We devise an algorithmic
procedure to losslessly reduce the problem size by bundling customer requests,
allowing it to be efficiently solved by off-the-shelf linear programming
solvers. Next, we show that the socially optimal solution to the joint problem
can be enforced as a general equilibrium, and we provide a dual decomposition
algorithm that allows self-interested agents to compute the market clearing
prices without sharing private information. We assess the performance of the
mode by studying a hypothetical AMoD system in Dallas-Fort Worth and its impact
on the Texas power network. Lack of coordination between the AMoD system and
the power network can cause a 4.4% increase in the price of electricity in
Dallas-Fort Worth; conversely, coordination between the AMoD system and the
power network could reduce electricity expenditure compared to the case where
no cars are present (despite the increased demand for electricity) and yield
savings of up $147M/year. Finally, we provide a receding-horizon implementation
and assess its performance with agent-based simulations. Collectively, the
results of this paper provide a first-of-a-kind characterization of the
interaction between electric-powered AMoD systems and the power network, and
shed additional light on the economic and societal value of AMoD.Comment: Extended version of the paper presented at Robotics: Science and
Systems XIV, in prep. for journal submission. In V3, we add a proof that the
socially-optimal solution can be enforced as a general equilibrium, a
privacy-preserving distributed optimization algorithm, a description of the
receding-horizon implementation and additional numerical results, and proofs
of all theorem
On the interaction between Autonomous Mobility-on-Demand systems and the power network: models and coordination algorithms
We study the interaction between a fleet of electric, self-driving vehicles
servicing on-demand transportation requests (referred to as Autonomous
Mobility-on-Demand, or AMoD, system) and the electric power network. We propose
a model that captures the coupling between the two systems stemming from the
vehicles' charging requirements and captures time-varying customer demand and
power generation costs, road congestion, battery depreciation, and power
transmission and distribution constraints. We then leverage the model to
jointly optimize the operation of both systems. We devise an algorithmic
procedure to losslessly reduce the problem size by bundling customer requests,
allowing it to be efficiently solved by off-the-shelf linear programming
solvers. Next, we show that the socially optimal solution to the joint problem
can be enforced as a general equilibrium, and we provide a dual decomposition
algorithm that allows self-interested agents to compute the market clearing
prices without sharing private information. We assess the performance of the
mode by studying a hypothetical AMoD system in Dallas-Fort Worth and its impact
on the Texas power network. Lack of coordination between the AMoD system and
the power network can cause a 4.4% increase in the price of electricity in
Dallas-Fort Worth; conversely, coordination between the AMoD system and the
power network could reduce electricity expenditure compared to the case where
no cars are present (despite the increased demand for electricity) and yield
savings of up $147M/year. Finally, we provide a receding-horizon implementation
and assess its performance with agent-based simulations. Collectively, the
results of this paper provide a first-of-a-kind characterization of the
interaction between electric-powered AMoD systems and the power network, and
shed additional light on the economic and societal value of AMoD.Comment: Extended version of the paper presented at Robotics: Science and
Systems XIV and accepted by TCNS. In Version 4, the body of the paper is
largely rewritten for clarity and consistency, and new numerical simulations
are presented. All source code is available (MIT) at
https://dx.doi.org/10.5281/zenodo.324165
A survey of self organisation in future cellular networks
This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks
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