Smart Industry 2/2018

Smart Communications Quo vadis 5G?
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photo ©: Professor Robert W. Heath Jr.
Looking ahead
5G will provide a
combination of evolution
and revolution,
with small and wide
networks allowing
users to benefit from
fast connection
and real-time communications
never
experienced before.
New model
The era of operating
wireless systems at
the millimeter wave
spectrum, ranging
from 30 GHz to 300
GHz, is coming. They
will operate in a very
different manner from
conventional cellular
systems below 6 GHz,
requiring new mathematical
models to
analyze performance.
photo ©: Nokia
be reprogrammed almost at will and
in far less time than its predecessors.
Some providers are already testing
5G technology over 4G frequencies,
albeit at much slower data rates. They
are virtually sure to make this a major
point in their advertising campaigns
leading up to the actual start of true
5G services. In fact, many countries
still need to allot the necessary frequency
bands, which in the past was
usually done by auctioning off entire
blocks of frequencies. In 2015, the
three big German players Deutsche
Telekom, Vodafone, and O2 (Telefonica)
shelled out more than €5 bn for
the choicest bits of online real estate,
which went directly into the state coffers
and was commonly referred to
then as the “digital dividend.” Plans to
auction off G5 territories in late 2018
by the network authority Bundesnetzagentur
had to be postponed
and are now scheduled for early in
2019. Worldwide, the final decision is
expected for ITU’s next World Radiocommunication
Conference (WRC) in
October of next year.
While governments usually assume
that all frequencies are created equal,
there are significant differences
among them. The range between
700 and 800 megahertz (MHz) is
ideal for long-distance transmission,
for instance in lightly populated, rural
areas. The higher the frequency, the
more powerful the signal, so operators
can service more users through
a given radio cell; but this comes at
the cost of less distance – hence the
need for more relay stations, especially
in heavily built-up urban areas
or where there are skyscrapers as obstacles
to the radio waves. Frequencies
of between 3.3 and 4.2 GHz will
be the most important for G5 since
they represent the best compromise
between reach and data throughput.
Manufacturers and telco operators
are pushing for uniform regulation
on an international scale, but if the
past is any guide, this will hardly happen.
5G is slated to surpass its predecessors
in almost every respect. The 600-
odd delegates at the 3rd Generation
Partnership Project (3GPP) recently
announced the first version of a universal
5G standard; called New Radio
(NR), it defines the so-called air interface,
or access mode, which forms
the communication link between
the two stations in mobile or wireless
communications. However, 5G,
by its nature, can do very well without
a core or backbone because it
relies on multi-hop relaying – a type
of communication in radio networks
in which network coverage area is
larger than the radio range of single
nodes. Therefore, to reach some destination,
a node can use other nodes
as relays. 5G also allows for device-todevice
(D2D) or peer-to-peer (P2P)
networking, which creates a direct
link between sensors and actuators
without the help (and cost) of using
a telco operator. Telcos, understandably,
take a dim view of this practice,
and it remains to be seen whether
multi-hop will be a viable alternative
in the market.
Want a slice?
RG hardly relies on fixed connections;
instead customers are allotted
slices of the mighty, but flexible, core
network, depending on their needs
and budget restrictions. Previously,
mobile networks did not operate
this way. In the future, a customer in
need of very high transmission rates
might be assigned a relatively high
frequency band or maybe even more
than one band at a time. Slicing also
enables operators to guarantee certain
degrees of latency or the maximum
number of TCP/IP packets lost
over a specified time frame. This will
be important for new business models
that rely on “always-on” connections.
Virtual and augmented reality
applications are especially sensitive
to latency problems. 5G will be able
to operate with latencies of less than
a millisecond, whereas UTMS and LTE
only manage about 400 and 40 milliseconds
respectively.
Failure in autonomous systems such
as self-driving cars and trucks or pilotless
passenger jets would result in
catastrophic loss of life, so 5G adds
plenty of redundancy to avoid any
chance of something going wrong.
The systems will transmit every signal
multiple times and, if necessary,
through separate radio bands. This
trick also means that packet loss is
kept to a bare minimum, even over
long distances and under unfavorable
conditions. This, however, is still