IEEE Power Electronics Magazine - March 2021 - 69

Expert View

by Brian Zahnstecher

Derating the 5G Network

T

he massive resources required
to deploy the 5G network
necessitate a payback period
for those financing it to recover
their investment in a way that will
sufficiently motivate the investment
to be made in the first place. While
this is obvious, how to accurately
calculate this can be anything but.
This is a very high-stakes game of
risk management, which is exceedingly dependent on end-users and
network constituents being able to
fully realize the potential of the marketed prospects (the " promise " )
of the 5G network. The ability to
recoup that investment can depend
on a number of different scenarios,
use cases, and environmental factors. This may be driven by subscriptions and a minimization of
bandwidth costs (in terms of acquisition and utilization).
This complicated web of network
constituents does not facilitate stakeholders working together in order to
articulate, assess, and address their
major challenges and find solutions
to meet so many differing needs and
perspectives. This may be due to the
highly siloed nature of so many independent, technical and business analyses conducted in a constrained way
that is not cognizant of the full environment with which they must live
and operate. Without a common

Digital Object Identifier 10.1109/MPEL.2020.3047288
Date of current version: 19 February 2021

language and series of supporting
metrics, there is a lack of a fundamental, unifying factors to cross all
the boundaries. In the IEEE International Network Generations Roadmap (INGR) 2020 Energy Efficiency
Working Group (EEWG)], we believe
this " universal currency " is energy
[1], [2]. Not only is this the missing
link between every form of analysis
involved, but it is the only one that
this extensive group of industry
experts can identify, transcending so
many markets, areas of coverage, and
stakeholder collaborations.
In the December 2019 article in
IEEE Power Electronics Magazine
[4], I introduced the 5G Energy Gap
(5GEG), which highlighted the disparity between available energy
(sources) and demand (loads) of the
[mostly] " micropower " devices representing the majority of " things " in the
highly-scalable edge space of the network. This work also introduced the
power value chain (PVC), a graphical
representation of the energy flow
across all the distribution/conversion
steps between source and load as
well as the power cost factor (PCF), a
unitless number to assess the overall
cost of energy utilization at any given
point within the PVC. Through our
work, these concepts/metrics have
been ex pa nded to ex plore t he
impacts within the 5G network and
propose framework/methodologies
for optimizing their end-to-end
deploy ment in ter ms of energy

March 2021

efficiency (EE). The 5GEG concept
was expanded with the introduction
of the 5G Econ. Gap (5GEcG), a hypothetical representation of the disparity between available power a system
can deliver and the increasing load
dema nd s on it s out put s, wh ich
implies that a power-limited system
and/or network component will not
be able to utilize all its designed
potential and therefore be inhibited
from delivering on the calculated
economics of the payback period [1].
At first glance, the differences
between the 5GEG and the 5GEcG
may not be obvious as they both
relate to negative network ramifications resulting from there being
more load demanded than sources
can provide. The fundamental difference is that 5GEG represents an
energy-focused limitation assessing
the impact on the grid and the utility
side of the equation, resulting from
too many base stations demanding
too much energy at any given time,
thus causing grid stability issues.
Conversely, the 5GEcG is a powerfocused limitation addressing the
impact of the network hardware
(typically base station radios) that
must scale-back edge functionality
as a result of hitting power/thermal
limitations within the system design
envelope. For instance, edge devices
can be bandwidth-limited if too
many are demanding too much concurrently from the same base station, thus resulting in power-gated
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IEEE Power Electronics Magazine - March 2021

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