FSMA SI 2021 1 Principal 2

Abstract

2  Abstract-Mobile communication has been one of the prime disruptors of the modern times. Since the 1980s, the world has witnessed new generation of mobile communication technologies every decade. Each new incoming generation is better than the previous one in several ways. The recently arrived fifth generation (5G) has several advanced features when compared with its predecessor. However, it is clear that there will be several shortcomings in this generation when compared with the other advanced contemporary information and communication technologies (ICTs). These shortcomings of 5G are going to be the main motivation for the next new mobile generation. According to the existing trends in ICTs, the new incoming version will be known as the Sixth Generation of Mobile Communication (6G). In this article, we show the main driving forces behind 6G, its expected features and key enabling technologies. The market potentials and disrupting features have also been discussed. Index Terms-6G, 6G features, motivation for 6G, deployment timeline of 6G, the Grace

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Revista de Sistemas de Informação da FSMA
n. 27 (2021) pp. 2-9
http://www.fsma.edu.br/si/sistemas.html
2

Abstract—Mobile communication has been one of the prime
disruptors of the modern times. Since the 1980s, the world has
witnessed new generation of mobile communication technologies
every decade. Each new incoming generation is better than the
previous one in several ways. The recently arrived fifth
generation (5G) has several advanced features when compared
with its predecessor. However, it is clear that there will be several
shortcomings in this generation when compared with the other
advanced contemporary information and communication
technologies (ICTs). These shortcomings of 5G are going to be
the main motivation for the next new mobile generation.
According to the existing trends in ICTs, the new incoming
version will be known as the Sixth Generation of Mobile
Communication (6G). In this article, we show the main driving
forces behind 6G, its expected features and key enabling
technologies. The market potentials and disrupting features have
also been discussed.
Index Terms—6G, 6G features, motivation for 6G, deployment
timeline of 6G, the G-race
I. INTRODUCTION
N the recent decades, we have come across several
disrupting technologies which have changed the course and
trends of the societies. Cellular mobile communication is
one of them. Mobile cellular communications were started in
the early 1980s, but the popularity was achieved in the early
1990s. Since then, every decade the world has witnessed new
generations of mobile communication technologies with much
improved features and performances. According to the
observed trends, a new generation arrives each ten years with
their incremental versions found in between. For instance, 2G
came to the markets in the early 1990s, 3G in the early 2000s,
4G in early 2010s, and now the initial versions of 5G came to
Manuscript received on October 13, 2020, revised on March 31, 2021.
Final version was created on June 12, 2021. This work was supported in part
by Bule Hora University Internal Grant on Next Generation Wireless
Networks (BHU/RPD/132/13).
S. K. Routray is with the Department of Electrical and Computer
Engineering, Bule Hora University, Bule Hora, Ethiopia. (Corresponding
author: sudhir.routray@bhu.edu.et).
S. Mohanty is with the Department of Economics, Management, Industrial
Engineering and Tourism, University of Aveiro, Aveiro, Portugal. (Email:
sasmita@ua.pt).
the markets in 2020. In between these generations, we observe
several incremental versions. These intermediate incremental
versions are observed in the forms of A.bG which are
normally better than AG and inferior than (A+1)G [1]. In this
notation, A is a positive integer which ranges from 1 and 6
(currently, this is the case, as we have 5G already available in
some countries and its next generation is in plan for 2030 roll
out), and b is an integer smaller than 10 [1]. For instance, we
have already seen 2.5G and 2.9G in the past. In the recent
past, we have also witnessed 4.5G, which is commonly known
as Long Term Evolution (LTE) Advanced Pro in the Third
Generation Partnership Project (3GPP) terminologies.
The Sixth Generation (6G) is a recent subject and its research
is very much at its infancy. Some literatures are available on
this topic. The common patterns of new mobile generations
are discussed in [1]. The technical specifications and
performance metrics of 4.5G (LTE Advanced Pro) have been
presented and compared with the 5G specifications of ITU [1].
Several intermediate versions of different mobile generations
and the observed trends have been presented in this article. It
shows the intensity of current competition for better mobile
access in the recent years. David and Berndt (2018) discussed
beyond 5G networks [2]. In this paper, the main vision and
requirements for 6G have been presented in brief. There are
several possibilities beyond 5G in terms of new networks and
services. Several flexible radio access technologies beyond 5G
have been analyzed in [3]. Specifically, the waveforms, frame
design strategies and numerology of the beyond 5G radio
technologies have been emphasized in this paper. It shows
several improvements are possible in beyond 5G networks [3].
High throughput satellites have generated a lot of interest in
the recent years. A flexibility analysis model for high
throughput satellites has been presented in [4] which promise
a lot of utilities for the future generation applications.
Appropriate satellite mobile integration can improve the
availability and reliability of the wireless networks. Consumer
electronics driven global trends of communications have been
presented in [5]. It shows the scale and pace of changes
happening in information and communication technologies
(ICT) these days. It shows that the developing countries have
already overcome the developed countries in terms of number
of subscribers in mobile communication. The net revenue of
ICT sectors of developing countries has also exceeded that of
Why Do We Need 6G?: Main Motivation and
Driving Forces of Sixth Generation Mobile
Communication Networks
Sudhir K. Routray, Senior Member, IEEE, and Sasmita Mohanty
I

Routray, S. K.; Mohanty, S. / Revista de Sistemas de Informação da FSMA n. 27 (2021) pp. 2-9
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the developed countries. The future ICT networks and their
potentials have been predicted from the Bell lab’s visions in
[6]. It shows that the networks of the future will be very
advanced and efficient. Many features of those networks will
be much beyond the current predictions. Some visions and the
potential techniques of 6G are presented in [7]. In this work, it
is predicted that 6G will use new spectrum and its energy
efficiency will be better than that of 5G. It will have better
security and flexibility.
Optical communication is the trend setter in the high speed
regime since the 1970s [8]. The trends of highest available
speeds through optical fiber are explained using Keck’s law.
The ways to maintain the high speed trends of Keck’s law
have been presented in this work. This indicates that there is
no real competitors for optical fibers as far as the data rates are
concerned. 6G will borrow several aspects of optical
communications.
Key aspects of device to device communication (D2DC) in 6G
have been studied in [9]. Several bottlenecks of 5G based
D2DC will be overcome in 6G. Each device in 6G will remain
interconnected with several other devices in its surroundings.
Energy efficiency is a prime goal in the new mobile
communication networks [10]. 5G has much better
improvements over the previous 4G mobile communication
systems when it comes to energy efficiency. In fact, 5G is
much more advanced than the previous generations/versions
of mobile communications in terms of the energy spent per bit
[10]. Several advanced networks are envisioned for the future
Internet. Light can be used for fast communications in the
access area which is now known as Light Fidelity (LiFi). It
has the potential to communicate at speeds of 100 Gb/s and
beyond [11].
There are several access technologies available which are
faster than 5G, such as terabit passive optical network (PON),
and wireless optical communication networks. Terabit PON is
among the fastest access technologies currently known [12].
Recently, terabit digital subscriber lines (DSLs) have been
proposed for cheap and fast local area connections [13]. These
are better service providers in the static conditions than the
5G.
Several changing trends of optical communications are
presented with examples in [14]. It shows that both the
wireless and optical communications improve very fast.
Optical communication is readily adapting to the advanced
techniques of wireless communication [14]. In 6G, these
advanced networks will be used for faster data rates. New
initiatives for 6G research in USA are presented in [15]. It
shows the market prospects of 5G in the coming years. Several
new features and applications of 5G are presented with future
outlook by Qualcomm 5G in [16]. It also shows that there will
be several shortcomings in 5G which are going to open the
roads for 6G.
In 6G, many advanced features will be added which will make
it ready for the future tasks. Several papers describe a myriad
of recent developments in 4.5G and 5G [17] – [19]. These
trends show that the scientists and engineers involved with 5G
progress steadily towards the IMT 2020 specifications of ITU.
In [20], the natural evolution of 5G to 6G has been presented
while highlighting the shortcomings of 5G. The authors
provided and industry focused 5G scenario to justify the 6G
requirements and the future steps.
Global restructuring of the telecommunications sector due to
the recent developments are highlighted in [21]. It also shows
the overall impact of the recent disruptions on the economy
and the society as a whole. Energy efficiency in the cellular
communications has been improved significantly. In [22], the
continuous improvement in the energy efficiency in 4G and
5G shows that 6G will be more energy efficient than the
previous mobile generations. The 6G vision and its potential
technological impacts have been discussed in [23]. The
authors have also predicted the potential techniques for 6G
which are based on the recent research trends [23]. In [24], a
similar kind of predictive study has been conducted on the
vision, requirements, enabling technologies, and the
architectural issues of 6G. In [25], uses of artificial
intelligence (AI) and machine learning (ML) for common and
advanced applications in 6G have been studied. It shows that
6G will have extensive AI and ML applications for wide range
of tasks and services. In [26], main attractive features of 6G
networks and how the AI is going to affect its performances
have been analyzed. In [27], potential new initiatives in 6G
have been predicted based on the recent observations. Several
challenges in the development of 6G have been predicted
considering the technological roadmap.
The nature and scale of IoT in 6G have been presented in [28]
using the projected technology trends in massive machine type
communications (mMTC). In this context, the authors have
highlighted six main features of mMTC in 6G.
In this article, we study the main motivations for 6G. We
analyze the main driving forces behind 6G and how it will
affect the mobile communication markets. We study the
development of the past mobile generations and correlate them
with the 6G driving forces. We also compare the 6G wireless
communication developments with the different computing
generations driven by the microprocessors.
The remainder of this article is organized in four sections. In
section II, we present the main motivation for 6G. In the
section III, we show the general trends of mobile generations
which explain the genesis of new generations in the past. In
the section IV, we predict the nature, timeline and the social
significance of 6G. In section V, we conclude this article with
the main points.
II. MAIN MOTIVATION FOR 6G
Analyzing the past generations and their motivation factors,
we find a lot of common factors which push generation AG
into generation (A+1)G. Typically, motivation for every new
mobile generation comes from the shortcomings of the
previous generation [1]. In case of 6G too, this is going to be
the major reason. 5G has been specified with several advanced
features which are shown in Table I. All these features are not

Routray, S. K.; Mohanty, S. / Revista de Sistemas de Informação da FSMA n. 27 (2021) pp. 2-9
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available yet. The current testing achievements in the
laboratory are also shown in Table I. Those features will be
improved over time in the coming years. It shows that despite
having all those advanced features, 5G will not be the perfect
technology to meet all the user demands in terms of quality
and quantity. Those shortcomings will be addressed in 6G.
Over the years, ICT restructuring has been observed to be an
endless process. It is very much clear that ICT restructuring is
a continuous process [21]. It happens at every company and
country level. As a part of restructuring, technology and
management related changes are always added to the service
provisioning [17]. It provides strategic edges to an operator
over its rivals. Therefore, irrespective of the state of the
technologies, ICT restructuring will keep on adding advanced
features to their services.
Recently, 5G has been deployed in the non-standalone mode
at several places. Once the 5G is rolled out in the major cities
around the world its performances can be measured directly.
Then the user experiences and 5G utilities in the real world
can be measured directly. This is expected to happen around
2025. It is true that all the ITU specifications of 5G will not be
available to the users in the near future. Only the incremental
advances will be observed. The full potential of 5G can only
be achieved after several years of its initial deployment.
5G developments have several drawbacks in achieving the
ITU specifications. For instance, software defined networking
(SDN) is an integral part of 5G [18]. It would work through
network function virtualization (NFV). SDN would slice or
segregate different types of service allocations in to different
slices. These slicing mechanisms would slowdown the speed
or in other words the data rates will be affected by SDN.
Similarly, clouds and fogs will have enhanced roles in 5G.
Too many transactions or computing in clouds would
inherently increase the latency. So, the latency reduction will
be affected through the intense cloudification of 5G. All these
drawbacks of 5G will take time to be solved. That is how a
new generation would be brought in to improve the
performances of 5G mobile communication and computing.
Inherently, there are several drawbacks in the 5G development
process in achieving the ITU specifications. In Fig. 1, we
illustrate the ITU specifications of 5G and the current 5G non-
standalone performance parameters. It shows that the gaps are
significant and it would take several years to achieve the full
ITU specifications. Security aspects in 5G are still not very
strong and this is currently a big problem for 5G which is
expected to be significantly improved in 6G.
From the performances of the previous instances, it has been
observed that the mobile generations are not the overall best
access technologies of their times. Some of their contemporary
technologies outperform them. It is also true in case of 5G. By
2025, the standalone version of 5G is expected to be deployed
widely. At that time there would be several better access
technologies. From the current technology trends, we can
easily predict a few technologies in the access area which are
better than the 5G. In section IV, we show some of these
advanced technologies. These technologies would motivate for
a better next generation cellular communication networks.
This is the direct indication of a better technology that could
move beyond 5G.
III. GENERAL TRENDS OF MOBILE COMMUNICATIONS
The general trends of mobile technologies development follow
a specific pattern. In order to understand any new generation,
we should go through the genesis of the past generations. It
provides logical reasons behind the development of any new
version or generation.
Initial wireless mobile communications were tried in the early
eighties as analog communication. However, it was not
successful. The real mobile communications started as a
digital technology in the mid-1980s and its commercial
popularity around the world came in the early 1990s. This was
the second generation (2G) mobile communication. The 2G
services were basically voice based services. Gradually, new
features were added to it such as the SMS service through
global packet radio services (GPRS) which is also known as
2.5G. Basically, GPRS was a value addition to the 2G
services. Gradually, the data rate demands were on the rise. It
was not possible in the typical 2G framework of that time.
Therefore, there was a demand for faster communication of
voice, data and videos. Thus a new version/generation was
required. Mobile companies around the world joined hands for
this. They formed a new group which is well known as 3GPP
LTE for the future long term evolution of mobile technologies.
This 3GPP initiative streamlined the development of future
TABLE I
ITU TE CHNIC AL SPE CIFICA TION F OR 5G (PERFORMANCE IN DICAT ORS, THEIR RANGES , AND THEIR PROPOSED TECH NOLOG IES) A LONG W ITH TH EIR
PROPO SED PR ACTIC AL VALU ES AN D THE PROPOSE D TECH NOLOG IES FOR DEPLOYMENT
#
5G Attributes
Range
Current Achievement in Test
Special Conditions
1
Data rate
0.1 – 20 Gbps [10]
10 Gbps [16]
Maximum download speed under favourable conditions
2
Spectral Efficiency
4.5 [10]
4 [17]
Using Massive MIMO and large QAM constellations
3
Data Processing
10 Mb/s/m2 [10]
3 Mb/s/m2 [10]
This is based on the recent estimated cases in 2020
4
Device Density
1 million/km2 [10]
5000 /km2 [18]
This is based on the recent estimated cases in urban areas in 2020
5
Mobility
Up to 500 km/h [10]
350 km/h [19]
Speed fluctuates, and it degrades performances
6
Transmission Delay
1 ms [10]
10 ms [19]
Several constraints are there at multiple stages
7
Energy Consumption
1 μJ per 100 bits [10]
10 μJ per 100 bits [10]
This is the estimated value based on several instances

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mobile generations.
The 2G difficulties for faster (i.e., higher data rates)
communication resulted in the planning for the 3G. However,
the 3G planning and specifications were not achieved in a
short time which resulted in several sub-3G versions such as
2.8G and 2.9G. Gradually, these intermediate versions led
toward the 3G specifications. Finally, 3G emerged as the
technology for data communication over the mobile platforms.
Initial 3G data rates were very low. However, the 3G
initiatives for data transfer became very popular as there was
no other alternative available in the early 2000s. Mainly, the
Internet access over the mobile phones was a very attractive
feature for the users. Internet penetration after the arrival of
3G increased significantly.
Two to three years post-launching, the major demerits of 3G
came to light. The users and the operators realized that the
communication speed over 3G are not realistic as the other
contemporary technologies such as WiFi and WiMAX were
much better than 3G when it comes to the data rates. WiFi was
easily accessible in the static environment and was also
cheaper when compared with the cellular services. It was
widely adopted in offices, universities, and residential areas.
WiMAX was much better than 3G in both static and mobile
conditions. This was the main motivation for the 3GPP to look
beyond 3G. Therefore, 4G was proposed whose performances
were several times better than the 3G.
The proposed performance specifications of 4G were several
times better than 3G. Nevertheless, all those specifications
were not achievable in a short span of time such as six months
or one year. Thus incremental versions of 3G appeared in the
market. They were better than 3G and inferior to 4G.
Finally, 4G rolling out was started in 2009, but only in a few
cities. The widespread 4G deployment was achieved only in
the second half of 2010s. The performances of 4G were way
better than the 3G services. However, drawbacks of 4G came
to light very fast. Again, WiFi and several other access
technologies used to outperform 4G. Thus the next advanced
version of 4G was planned by 3GPP. However, this time the
plan was much more different. It was a giant leap over the
previous versions. The fifth generation was proposed to be
much superior to 4G in several aspects.
The 5G specifications were mainly imitating the performances
of optical access technologies. PONs can provide hundreds of
Gbps data rates. Even as early as 2011, terabit PONs were
tested in the laboratories. When compared with the PONs,
wireless communications were far behind. One of the main
aims of 5G development group was to provide fiber-like
experience in the wireless domain.
IV. WHAT 6G WILL BE?
It is really very difficult to predict what exactly 6G will be.
For instance, the research on 5G started around 2009 [1].
However, the exact features of 5G were defined by the ITU in
collaboration with other standardization bodies much later in
2015 [10]. Similar uncertainties were also observed for the
predictions over 3G and 4G at the time of their inception.
Unless the complete standards are agreed by the expert
participating groups around the world, it is not possible to
know its exact features. However, from the past experiences of
the previous mobile generations, we predict the following
features of 6G.
Fig. 1. ITU Specifications of the main parameters of 5G vs. the best practically possible specifications of 5G in 2021. The initial 5G non-standalone
specifications in 2020 are much inferior to the ITU specifications of 5G.

Routray, S. K.; Mohanty, S. / Revista de Sistemas de Informação da FSMA n. 27 (2021) pp. 2-9
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1. 6G will be better than 5G in all performance related
aspects [1]. This is the trend observed in all the previous
generations in the past [1]. Therefore, it is very much
clear from the past instances that 6G has to be better than
5G in all the main performance related aspects.
2. The peak data rate proposed for 5G is 20 Gbps and the
peak data rate of 6G will be around 100 Gbps [20].
However, it is noteworthy that the peak data rates are not
the operational data rates. The average data rates are
those that are used in day to day operations. These
average data rates are much lower than the peak data
rates.
3. The 5G latency of 1 ms would be further reduced in
some select applications [20] in 6G. There are several
emerging applications in the recent years which demand
very low latency. By 2030, these applications will be
high in number and the device densities will also be
proportionately high. Thus ultra low latency in 6G will
be provided using several new technologies [29].
4. In 6G, device densities and IoT connectivity will be
denser than the 5G [20]. In recent years, IoT and other
mMTC technologies have become very popular in almost
all the technology sectors. Even in the homes and offices
we have seen the widespread presence of IoT devices. In
2030, it will be more widespread. An enhanced IoT
application in 6G is presented in [29] which indicate the
extent and scale of IoT in 6G.
5. Energy efficiency in 6G will be certainly better than 5G
and new energy saving mechanisms will be added to 6G
[10]. Energy efficiency is essential for high speed
wireless communication technologies. In 5G, the energy
efficiency has been improved significantly in comparison
to 4G. In 6G, it will be further improved and the energy
per bit will be much less than what we see in 5G.
6. Spectral efficiency in 6G will be better than that of 5G
[17]. MIMO provides wonderful ways to improve the
spectral efficiency in 5G using beamforming. In 6G,
spectral efficiency will be improved using advanced
signal processing and large modulation constellations.
7. More artificial intelligence (AI) and machine learning
(ML) applications will find their ways in 6G [25]. In the
recent years, we have witnessed widespread applications
of AI and ML in several applications. Both in industrial
and non-industrial applications these technologies are
popular. In businesses, these technologies are used for
optimal use of resources.
8. Bigger roles are expected for optical networking in 6G
[22]. In every new mobile generation, we have witnessed
increased usage of the optical communications. In 5G,
optical networks are extended till the last mile. In 6G,
high speed optical links will be used more frequently to
handle the demand for data and device connectivity.
9. More complex device to device communications will be
observed in 6G [9]. From the recent projections on the
IoT devices and the emerging applications of mMTC, it
is clear that the device densities will grow many times. In
order to provide better connectivity and ease of
communication several new techniques will be used for
sharing the data.
10. 6G will have the ability to operate over new frequency
bands [26]. New bands are predicted to be used in 6G.
Especially, the terahertz frequency bands are being tested
in the laboratories for cellular applications. Hopefully, by
2030 it will be ready for applications in 6G.
11. Satellite cellular connectivity will get better through the
6G framework [4]. Several new applications such as the
commercial and research communications at the remote
areas where human civilization does not exist are very
poorly served. Currently, used cellular technologies are
not suitable for those applications. Therefore, satellite
integration with the cellular networks is essential to fill
this void.
Application-wise 6G may not be used by individuals to a large
extent in its initial years. Rather it will be suitable for business
applications and mobile computing demands. 6G would be a
very complex system where the hybridization of optical
wireless communications will be very much intertwined.
A. Limitations of 5G
6G will borrow the ideas and techniques which are better than
5G in terms of performance. Currently, there are some
technologies which perform better than the proposed 5G
specifications. We provide a list of commonly identified
access technologies in the following paragraph. It includes
both the wired and wireless access technologies whose
performances have already been tested. They are:
1. PONs which provide higher data rates, lower latency and
better reliability [14]; even terabit PONs are available
which can carry gigantic amounts of data [12];
2. 400 Gigabit Ethernet which has already been used since
last few years [8];
3. 800 Gigabit Ethernet is now available for deployment in
core and access networks [8];
4. High throughput satellites are capable of dealing with
higher data rates than 5G [4];
5. Several private satellite operators are planning to
provide high speed Internet services through satellites
and high altitude platforms [7];
6. LiFi provides very high data rates in the line-of-sight
communication channels [11];
7. Twisted copper wires provide very high data rates (more
than 100 Gbps) in the short range [13].
It is expected that 6G would be associated with all these
technologies. It may incorporate several of these technologies
in the access devices through software applications or similar
tools when deployed. Therefore, both in the static and moving
conditions it would provide the best possible services.
B. Who are Interested in 6G?
Not everyone is a fan of new mobile generations. There are
special interest groups who want the new mobile generations.
There are several types of interest groups. First of all, the
telecommunication vendors are the ones who benefit the most
from the new mobile generations [17]. They are the experts
who design and develop the networks for these new
generations. Without the advances of the mobile generations,

Routray, S. K.; Mohanty, S. / Revista de Sistemas de Informação da FSMA n. 27 (2021) pp. 2-9
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their businesses do not grow very fast. So, it is always a win-
win condition for the telecom vendors to roll out a new
technology. The new technologies come with new techniques
and equipments which are the direct source of revenue for
these vendors. These vendors also play main roles in the
research and development of the new mobile generations.
The next beneficiaries are the telecom operators. Operators
make money from their services. New generations come with
new services and thus new income sources emerge for them.
Of course it is true that some of the old services also become
obsolete or do not produce revenue. However, in the
competitive business arena the operators want to defeat their
rivals through advanced technologies. Governments also want
new technologies to earn new taxes and revenues.
In addition to these stake holders there are also the pure
research and innovation teams and companies who get direct
benefits from the new generations.
C. Timeline for 6G Development
The timeline for 6G is expected to follow the previous
timeline patterns of previous generations. We observed a time
gap of almost 10 years between two mobile generations
starting from 2G to 5G. A similar time gap is expected in
order to reach a preliminary version of 6G.
As expected, 5G will not be rolled out all over the world in
2021. Actually, only some cities across the world will have it.
Around 2025, 5G will be used widely across the world. Rural
deployment in the developing countries may take even longer.
Thus, the incremental versions of 5G will be developed after
2025 which are expected to be better than 5G and inferior to
6G. This gradual process of innovation would make 6G ready
for deployment around 2030.
As it happened with the previous generations, large scale
deployment of 6G will not be immediate; rather it is expected
that 6G will be adopted gradually. It is also true that 6G may
not be attractive for many developing countries as 5G itself
would be too advanced for them. The individual
communication demands can be easily met by the 5G
specifications. Thus 6G and its subsequent versions may
remain limited only to the business and high performance
applications.
D. Impact of 6G on Society and Business
It is very difficult to predict how an advanced technology
would affect the society. In the last two decades, we have
witnessed several disruptions through mobile technologies.
Similar disruptions are equally possible through 6G. However,
5G is likely to cause a lot of changes in the society. Therefore
the arrival of 6G may not be a surprise for several social
activities.
AI and ML are going to play some key roles in 5G. However,
that will not be very mature in just one decade. Therefore, 6G
is envisioned as the true AI powered version of mobile
communication. Several new cognitive applications are
expected in 6G.
Coupling between the satellites and mobile cellular networks
is an advanced form of communication which has the
capability to enhance the performances of several
communication systems. Satellite coupling with cellular
infrastructure is not quite feasible at the moment. In 5G
regime too this may not be achieved to its full potential. It is
expected that in 6G satellite and mobile infrastructure will be
very much compatible. Through satellite conjugation the true
ubiquitous communication will be possible. IoT networks too
will get a boost through the satellite connectivity. It will
provide better availability and reliability for the IoT based
services. Similarly, quantum communication and other
advanced techniques are expected to be parts of 6G.
Therefore, 6G is perhaps the right mobile technology to bring
all these new applications and possibilities together.
E. Key Challenges on the Way to 6G
As we have seen in the previous sections, the main goal of 6G
development is to fill the gaps left over in 5G and to enhance
certain performance aspects of 5G. These gaps in 5G are the
main motivations and also the key challenges for the 6G
development groups. In this sub-section, we show some of the
main challenges 6G will come across. There are several
challenges predicted for 6G development and roll out. In the
following paragraph, we present some of the key challenges in
the initial years of 6G deployment.
In 6G, the satellite cellular integration is one of the main
challenges. In 5G and its previous legacy systems it was clear
that network coverage voids are commonly found despite
good cellular coverage planning. In 6G, this problem is
expected to be handled through the satellites and other high
altitude platforms. However, the costs of these services may
not be a positive aspect for the cellular network operators.
Therefore, a cost effective solution is the main challenge for
ubiquitous network availability in 6G.
Generally, it is expected that the latency in 6G has to be
smaller than the latency observed in 5G. The main problem in
6G is that it will be very much softwarized. The SDN based
networking and network slicing like operations increase the
latency. In 6G, perfect compromise between the low latency
technologies and the softwarized options is essential to
provide low latency communications.
Terahertz frequencies are being planned for use in 6G [6].
There are a lot of challenges in this frequency bands. It will be
a big challenge for the 6G developer to use terahertz bands for
practical cellular communications.
Device capacities are projected to increase almost
exponentially every year. This is going to be a big challenge
for the cellular networks to provide proper management,
control and monitoring of the connected devices [26]. Edge
computing facilities are essential for the end communications
among the devices and the data management facilities. The

Routray, S. K.; Mohanty, S. / Revista de Sistemas de Informação da FSMA n. 27 (2021) pp. 2-9
8
IoT and mMTC services heavily rely on the edge computing
infrastructure. The increasing number of end devices is
certainly a big challenge for the edge facilities. Device to
device connectivity in the 6G framework will be very crowded
as the IoT devices and other mMTC applications are projected
to increase manyfold. Increasing number of devices is going to
pose bigger security challenges. In 6G, good security will
remain a challenge for the operators and the end users.
F. The G-Race
Since the 1980s, we see a race in the digital communication
innovation to bring a new mobile generation every decade. It
is now clear that 5G will be rolled out for several cities around
world by 2022. By 2025, this technology will become mature
and almost half of the world should be using it according to
the Gartner predictions. Based on these observed trends we are
going to witness the arrival of 6G in early 2030s or a little
before 2030 as mentioned in the deployment timeline.
However, the G-race may not be very intense as we have seen
it in the previous cases of 3G, 4G and 5G. That is mainly due
to the advances achieved up to 5G. We can compare this with
the different generations of computer processors.
Initially, when the microprocessors came in the 1970s it was a
revolution altogether. Then the second generation came in the
early 1980s, followed by third generation in the late 1980s.
The fourth generation of Pentium processors brought a lot of
aura in the computing world. Then arrived the fifth generation
of multi-core processors. Since then, processors are being
updated to make them faster and better. However, the craze
and aura is no more observed like it was in the previous
generations. We no longer observe the acute generation races
in the microprocessor innovation. That is mainly due to the
speed of the microprocessors achieved in the fifth generation.
The speed of microprocessors from the fourth generation
onwards is good enough to carry out most of the common
personal and office works. The faster processors are required
only for the special projects or advanced computing
applications. Therefore, the craze for the faster new processors
is no longer like the ones seen in the 1990s. A similar
saturation like effect is going to be seen in the mobile ICTs.
After 5G, the common users will not be looking for any faster
communication systems. However, just like the case of
computer processors, some special purpose communication
tasks may need speeds higher than that of 5G.
Overall, the G-race in mobile communication is expected to be
irrelevant after 5G. Though the new mobile technologies may
be developed under the G-hierarchy, they will not get the big
attention from the public as they got till 5G and its previous
legacy generations. However, it is possible that the ICT may
develop in a whole new direction through the empowerment of
AI and machine learning.
V. CONCLUSION
In this paper, we presented the potential driving forces behind
the development of 6G. The major short comings of 5G will
lead the path to the next generation of mobile ICT. Computing
and communication capabilities of the 6G devices will be
better than those of 5G. AI and ML applications will have a
strong presence in 6G. It is expected that the deployment of
6G would start around 2030. 6G will be very much energy and
bandwidth efficient when compared with 5G. The new
dimensions in ICT such as quantum communication and
cellular satellite integration are likely to find places in the 6G
ambit. The G-race in mobile communications is found to be
saturated with 5G. Only some technological voids and a select
performance related aspects will be improved in the future
mobile generations. Therefore 6G and other future generations
will not create the craze and aura like the previous ones.
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Sudhir K. Routray (S’02–M’04–GS’11–M’16–SM’17) works as associate
professors of Electrical and Computer Engineering at Bule Hora University,
Bule Hora. He received his BE in Electrical Engineering from Utkal
University, India; MSc in Data Communications from The University of
Sheffield, UK; and PhD in Telecommunications Engineering from University
of Aveiro, Portugal. He has more than 80 publications in journals, conferences
and books. His areas of interest are: 5G, 6G, IoT, network science, and optical
networking. He is a senior member of IEEE. He volunteers for IEEE in
different roles such as reviewer, editor, technical programme committee
member, and event organizer. He also serves as the IEEE Branch Councilor of
Bule Hora University.
Sasmita Mohanty is a doctoral student of telecommunications management.
She works in the Department of Economics, Management and Industrial
Engineering, University of Aveiro, Aveiro, Portugal. She has an MSc degree
in Management from University of Aveiro, Portugal. She received her
Master’s and Bachelor’s degrees in Economics from Ravenshaw University,
India in 2008 and 2006 respectively. She is a member of Internet Society and
EAI (European Alliance for Innovation). She is a columnist and reviewer of
some reputed magazines. Her areas of interests are: telecommunication
economics, telecommunication management, strategic management, and
managed services in telecommunications.