A survey on 5G: The next generation of mobile communication
Added on 2022-10-18
30 Pages26153 Words370 Views
Accepted Manuscript
A survey on 5G: The next generation of mobile communication
Nisha Panwar, Shantanu Sharma, Awadhesh Kumar Singh
PII: S1874-4907(15)00053-1
DOI: http://dx.doi.org/10.1016/j.phycom.2015.10.006
Reference: PHYCOM 302
To appear in: Physical Communication
Received date: 30 June 2015
Revised date: 11 October 2015
Accepted date: 30 October 2015
Please cite this article as: N. Panwar, S. Sharma, A.K. Singh, A survey on 5G: The next
generation of mobile communication, Physical Communication (2015),
http://dx.doi.org/10.1016/j.phycom.2015.10.006
This is a PDF file of an unedited manuscript that has been accepted for publication. As a
service to our customers we are providing this early version of the manuscript. The manuscript
will undergo copyediting, typesetting, and review of the resulting proof before it is published in
its final form. Please note that during the production process errors may be discovered which
could affect the content, and all legal disclaimers that apply to the journal pertain.
A survey on 5G: The next generation of mobile communication
Nisha Panwar, Shantanu Sharma, Awadhesh Kumar Singh
PII: S1874-4907(15)00053-1
DOI: http://dx.doi.org/10.1016/j.phycom.2015.10.006
Reference: PHYCOM 302
To appear in: Physical Communication
Received date: 30 June 2015
Revised date: 11 October 2015
Accepted date: 30 October 2015
Please cite this article as: N. Panwar, S. Sharma, A.K. Singh, A survey on 5G: The next
generation of mobile communication, Physical Communication (2015),
http://dx.doi.org/10.1016/j.phycom.2015.10.006
This is a PDF file of an unedited manuscript that has been accepted for publication. As a
service to our customers we are providing this early version of the manuscript. The manuscript
will undergo copyediting, typesetting, and review of the resulting proof before it is published in
its final form. Please note that during the production process errors may be discovered which
could affect the content, and all legal disclaimers that apply to the journal pertain.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65A Survey on 5G: The Next Generation of Mobile Communication1
Nisha Panwar1, Shantanu Sharma1, and Awadhesh Kumar Singh2
2
1Department of Computer Science, Ben-Gurion University of the Negev, Israel.3
{panwar, sharmas}@cs.bgu.ac.il.4
2Department of Computer Engineering, National Institute of Technology, Kurukshetra, India.5
aksinreck@nitkkr.ac.in6
Abstract7
A rapidly increasing number of mobile devices, voluminous data, and higher data rate are pushing to rethink8
the current generation of the cellular mobile communication. The next or fifth generation (5G) cellular networks9
are expected to meet these requirements. The 5G networks are broadly characterized by three unique features:10
ubiquitous connectivity, very low latency, and very high-speed data transfer. The 5G networks will provide novel11
architectures and technologies beyond state-of-the-art architectures and technologies. In this paper, we will find12
an answer to the question: “what will be done by 5G and how?” We investigate and discuss serious limitations13
of the fourth generation (4G) cellular networks and corresponding new features of 5G networks. We identify14
challenges in 5G networks, new technologies for 5G networks, and a comparative discussion of the proposed15
architectures that can be categorized on the basis of energy-efficiency, network hierarchy, and network types.16
Interestingly, implementation issues, e.g., interference, QoS, handoff, security-privacy, channel access, and load17
balancing, hugely effect the realization of 5G networks. Furthermore, our discussion highlights the feasibility18
of these models through an evaluation of existing real-experiments and testbeds.19
Keywords: Cloud radio access networks; cognitive radio networks; D2D communication; dense deployment; multi-tier20
heterogeneous network; privacy; security; tactile Internet.21
1 Introduction22
The evolution of the cellular network generations is primarily influenced by a continuous growth in wireless user23
devices, data usage, and the need for a better quality of experience (QoE). It is expected that more than 50 billion24
connected devices will utilize the cellular network services by the end of the year 2020 [1], and it will result in a25
tremendous increase in data traffic, as compared to the year 2014 [2]. However, state-of-the-art solutions are not26
sufficient for the challenges mentioned above. In short, the increase of 3D (‘D’evice, ‘D’ata, and ‘D’ata transfer27
rate) encourages the development of 5G networks.28
Specifically, the fifth generation (5G) of the cellular networks will highlight and address three broad29
views, as: (i) user-centric (by providing 24×7 device connectivity, uninterrupted communication services,30
and a smooth consumer experience), (ii) service-provider-centric (by providing a connected intelligent31
transportation systems, road-side service units, sensors, and mission critical monitoring/tracking services),32
and (iii) network-operator-centric (by providing an energy-efficient, scalable, low-cost, uniformly-monitored,33
programmable, and secure communication infrastructure). Therefore, 5G networks are perceived to materialize34
the three main features as below:35
• Ubiquitous connectivity: In the future, many types of devices will connect ubiquitously and provide an36
uninterrupted user experience. In fact, the user-centric view will be realized by ubiquitous connectivity.37
• Zero latency: 5G networks will support life-critical systems and real-time applications and services with zero38
delay tolerance. Hence, it is envisioned that 5G networks will realize zero latency, i.e, very low latency of the39
order of 1 millisecond [3, 47]. In fact, the service-provider-centric view will be realized by the zero latency.40
• High-speed Gigabit connection: The zero latency property could be achieved using a high-speed connection for41
fast data transmission and reception, which will be of the order of Gigabits per second to users and machines [3].42
1
Manuscript
Click here to view linked References
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65A Survey on 5G: The Next Generation of Mobile Communication1
Nisha Panwar1, Shantanu Sharma1, and Awadhesh Kumar Singh2
2
1Department of Computer Science, Ben-Gurion University of the Negev, Israel.3
{panwar, sharmas}@cs.bgu.ac.il.4
2Department of Computer Engineering, National Institute of Technology, Kurukshetra, India.5
aksinreck@nitkkr.ac.in6
Abstract7
A rapidly increasing number of mobile devices, voluminous data, and higher data rate are pushing to rethink8
the current generation of the cellular mobile communication. The next or fifth generation (5G) cellular networks9
are expected to meet these requirements. The 5G networks are broadly characterized by three unique features:10
ubiquitous connectivity, very low latency, and very high-speed data transfer. The 5G networks will provide novel11
architectures and technologies beyond state-of-the-art architectures and technologies. In this paper, we will find12
an answer to the question: “what will be done by 5G and how?” We investigate and discuss serious limitations13
of the fourth generation (4G) cellular networks and corresponding new features of 5G networks. We identify14
challenges in 5G networks, new technologies for 5G networks, and a comparative discussion of the proposed15
architectures that can be categorized on the basis of energy-efficiency, network hierarchy, and network types.16
Interestingly, implementation issues, e.g., interference, QoS, handoff, security-privacy, channel access, and load17
balancing, hugely effect the realization of 5G networks. Furthermore, our discussion highlights the feasibility18
of these models through an evaluation of existing real-experiments and testbeds.19
Keywords: Cloud radio access networks; cognitive radio networks; D2D communication; dense deployment; multi-tier20
heterogeneous network; privacy; security; tactile Internet.21
1 Introduction22
The evolution of the cellular network generations is primarily influenced by a continuous growth in wireless user23
devices, data usage, and the need for a better quality of experience (QoE). It is expected that more than 50 billion24
connected devices will utilize the cellular network services by the end of the year 2020 [1], and it will result in a25
tremendous increase in data traffic, as compared to the year 2014 [2]. However, state-of-the-art solutions are not26
sufficient for the challenges mentioned above. In short, the increase of 3D (‘D’evice, ‘D’ata, and ‘D’ata transfer27
rate) encourages the development of 5G networks.28
Specifically, the fifth generation (5G) of the cellular networks will highlight and address three broad29
views, as: (i) user-centric (by providing 24×7 device connectivity, uninterrupted communication services,30
and a smooth consumer experience), (ii) service-provider-centric (by providing a connected intelligent31
transportation systems, road-side service units, sensors, and mission critical monitoring/tracking services),32
and (iii) network-operator-centric (by providing an energy-efficient, scalable, low-cost, uniformly-monitored,33
programmable, and secure communication infrastructure). Therefore, 5G networks are perceived to materialize34
the three main features as below:35
• Ubiquitous connectivity: In the future, many types of devices will connect ubiquitously and provide an36
uninterrupted user experience. In fact, the user-centric view will be realized by ubiquitous connectivity.37
• Zero latency: 5G networks will support life-critical systems and real-time applications and services with zero38
delay tolerance. Hence, it is envisioned that 5G networks will realize zero latency, i.e, very low latency of the39
order of 1 millisecond [3, 47]. In fact, the service-provider-centric view will be realized by the zero latency.40
• High-speed Gigabit connection: The zero latency property could be achieved using a high-speed connection for41
fast data transmission and reception, which will be of the order of Gigabits per second to users and machines [3].42
1
Manuscript
Click here to view linked References
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65A few more key features of 5G networks are enlisted and compared to the fourth generation (4G) of the cellular43
networks, as below [4, 5, 6]: (i) 10-100x number of connected devices, (ii) 1000x higher mobile data volume per44
area, (iii) 10-100x higher data rate, (iv) 1 millisecond latency, (v) 99.99% availability, (vi) 100% coverage, (vii) x
1045
energy consumption as compared to the year 2010, (viii) real-time information processing and transmission, (ix) x
546
network management operation expenses, and (x) seamless integration of the current wireless technologies.475G
Networks
Increased
data rate
&
network
capacity
Densification, FDD,
CRN, mMIMO, D2D
communication, full
duplex radio
Multi-RAT, self-heal,
densification, CRN,
NFV, SDN, C-RAN,
RANaaS, CONCERT,
Low latency
Cache, fast
handoff, D2D
communication,
mobile small-
cells, self-heal Scalability
Environmental
friendly & less
money
QoSSecurity &
privacy
Interference &
handoff
management
NFV, SDN,
C-RAN,
RANaaS,
CONCERT
Delay-bound QoS,
Quality management
equipment, multi-links
with multi-flow and
multi-QoS
C-RAN, VLC,
mmWave,
mMIMO, small-
cells, D2D
communication,
user separation
Monitoring and
encryption-decryption
SIC, CRN,
advance receiver,
joint
detection/decodi
ng
Inter-tier, intra-
tier, and
multi-RAT
handoff,
Figure 1: Requirements and proposed solutions for the
development of 5G networks. The inner, middle, and
outermost layers present requirements, solutions, and
applications of 5G networks, respectively. Two colored
wedges highlight primary features of 5G networks.
Therefore, the revolutionary scope and the48
consequent advantages of the envisioned 5G49
networks demand new architectures, methodologies,50
and technologies (see Figure 1), e.g., energy-efficient51
heterogeneous frameworks, cloud-based52
communication (software-defined networks (SDN)53
and network function virtualization (NFV)),54
full duplex radio, self-interference cancellation55
(SIC), device-to-device (D2D) communications,56
machine-to-machine (M2M) communications, access57
protocols, cheap devices, cognitive networks (for58
accessing licensed, unlicensed, and shared frequency59
bands), dense-deployment, security-privacy60
protocols for communication and data transfer,61
backhaul connections, massive multiple-input and62
multiple-output (mMIMO), multi-radio access63
technology (RAT) architectures, and technologies64
for working on millimeter wave (mmWave) 30–30065
GHz. Interestingly, 5G networks will not be a mere66
enhancement of 4G networks in terms of additional67
capacity; they will encompass a system architecture68
visualization, conceptualization, and redesigning at69
every communication layer [51].70
Several industries, Alcatel-Lucent [7],71
DOCOMO [8], GSMA Intelligence [5], Huawei [9],72
Nokia Siemens Networks [3], Qualcomm [10], Samsung [11], Vodafone,1 the European Commission supported73
5G Infrastructure Public Private Partnership (5GPPP) [4], and Mobile and Wireless Communications Enablers for74
the Twenty-Twenty Information Society (METIS) [6], are brainstorming with the development of 5G networks.75
Currently, the industry standards are yet to be explored about the expected designs and architectures for 5G76
networks.77
Scope of the paper. In this paper, we will review the vision of the 5G networks, advantages, applications, proposed78
architectures, implementation issues, real demonstrations, and testbeds. The outline of the paper is provided in79
Figure 2. In Section 2, we will discuss the vision of 5G networks. Section 3 presents challenges in the development80
of 5G networks. Section 4 address the current proposed architectures for 5G networks, e.g., multi-tier, cognitive81
radio based, cloud-based, device proximity based, and energy-efficient architectures. Section 5 presents issues82
regarding interference, handoff, quality of services, load balancing, channel access, and security-privacy of the83
network. Sections 6, 7, and 8 present several methodologies and technologies involved in 5G networks, applications84
of 5G networks, and real demonstrations and testbeds of 5G networks, respectively.85
We would like to emphasize that there are some review works on 5G networks by Andrews et al. [20],86
Chávez-Santiago et al. [35], and Gavrilovska et al. [50], to the best of our knowledge. However, our perspective87
about 5G networks is different, as we deal with a variety of architectures and discuss several implementation affairs,88
technologies in 5G networks along with applications and real-testbed demonstrations. In addition, we intentionally89
avoid an mmWave oriented discussion in this paper, unlike the current work [20, 35, 50].90
We encourage our readers to see an overview about the generations of the cellular networks (see Table 1) and91
crucial limitations of the current cellular networks in the next section.92
1http://www.surrey.ac.uk/5gic/research
2
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65A few more key features of 5G networks are enlisted and compared to the fourth generation (4G) of the cellular43
networks, as below [4, 5, 6]: (i) 10-100x number of connected devices, (ii) 1000x higher mobile data volume per44
area, (iii) 10-100x higher data rate, (iv) 1 millisecond latency, (v) 99.99% availability, (vi) 100% coverage, (vii) x
1045
energy consumption as compared to the year 2010, (viii) real-time information processing and transmission, (ix) x
546
network management operation expenses, and (x) seamless integration of the current wireless technologies.475G
Networks
Increased
data rate
&
network
capacity
Densification, FDD,
CRN, mMIMO, D2D
communication, full
duplex radio
Multi-RAT, self-heal,
densification, CRN,
NFV, SDN, C-RAN,
RANaaS, CONCERT,
Low latency
Cache, fast
handoff, D2D
communication,
mobile small-
cells, self-heal Scalability
Environmental
friendly & less
money
QoSSecurity &
privacy
Interference &
handoff
management
NFV, SDN,
C-RAN,
RANaaS,
CONCERT
Delay-bound QoS,
Quality management
equipment, multi-links
with multi-flow and
multi-QoS
C-RAN, VLC,
mmWave,
mMIMO, small-
cells, D2D
communication,
user separation
Monitoring and
encryption-decryption
SIC, CRN,
advance receiver,
joint
detection/decodi
ng
Inter-tier, intra-
tier, and
multi-RAT
handoff,
Figure 1: Requirements and proposed solutions for the
development of 5G networks. The inner, middle, and
outermost layers present requirements, solutions, and
applications of 5G networks, respectively. Two colored
wedges highlight primary features of 5G networks.
Therefore, the revolutionary scope and the48
consequent advantages of the envisioned 5G49
networks demand new architectures, methodologies,50
and technologies (see Figure 1), e.g., energy-efficient51
heterogeneous frameworks, cloud-based52
communication (software-defined networks (SDN)53
and network function virtualization (NFV)),54
full duplex radio, self-interference cancellation55
(SIC), device-to-device (D2D) communications,56
machine-to-machine (M2M) communications, access57
protocols, cheap devices, cognitive networks (for58
accessing licensed, unlicensed, and shared frequency59
bands), dense-deployment, security-privacy60
protocols for communication and data transfer,61
backhaul connections, massive multiple-input and62
multiple-output (mMIMO), multi-radio access63
technology (RAT) architectures, and technologies64
for working on millimeter wave (mmWave) 30–30065
GHz. Interestingly, 5G networks will not be a mere66
enhancement of 4G networks in terms of additional67
capacity; they will encompass a system architecture68
visualization, conceptualization, and redesigning at69
every communication layer [51].70
Several industries, Alcatel-Lucent [7],71
DOCOMO [8], GSMA Intelligence [5], Huawei [9],72
Nokia Siemens Networks [3], Qualcomm [10], Samsung [11], Vodafone,1 the European Commission supported73
5G Infrastructure Public Private Partnership (5GPPP) [4], and Mobile and Wireless Communications Enablers for74
the Twenty-Twenty Information Society (METIS) [6], are brainstorming with the development of 5G networks.75
Currently, the industry standards are yet to be explored about the expected designs and architectures for 5G76
networks.77
Scope of the paper. In this paper, we will review the vision of the 5G networks, advantages, applications, proposed78
architectures, implementation issues, real demonstrations, and testbeds. The outline of the paper is provided in79
Figure 2. In Section 2, we will discuss the vision of 5G networks. Section 3 presents challenges in the development80
of 5G networks. Section 4 address the current proposed architectures for 5G networks, e.g., multi-tier, cognitive81
radio based, cloud-based, device proximity based, and energy-efficient architectures. Section 5 presents issues82
regarding interference, handoff, quality of services, load balancing, channel access, and security-privacy of the83
network. Sections 6, 7, and 8 present several methodologies and technologies involved in 5G networks, applications84
of 5G networks, and real demonstrations and testbeds of 5G networks, respectively.85
We would like to emphasize that there are some review works on 5G networks by Andrews et al. [20],86
Chávez-Santiago et al. [35], and Gavrilovska et al. [50], to the best of our knowledge. However, our perspective87
about 5G networks is different, as we deal with a variety of architectures and discuss several implementation affairs,88
technologies in 5G networks along with applications and real-testbed demonstrations. In addition, we intentionally89
avoid an mmWave oriented discussion in this paper, unlike the current work [20, 35, 50].90
We encourage our readers to see an overview about the generations of the cellular networks (see Table 1) and91
crucial limitations of the current cellular networks in the next section.92
1http://www.surrey.ac.uk/5gic/research
2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65Generations Year Features Limitations
1G 1980s Analog signals for voice only communications Very less security
2G 1990s Digital signals, voice communications, and text
messaging
Very less support for the Internet
3G 1998-99 Voice communications, wireless mobile and fixed
Internet access, video calls, and mobile television (TV)
Less support for high-speed
Internet
4G 2008-09 Higher data rate (hundreds of megabits per second) No support for 50 billion ubiquitous
connected devices
5G 2020 Mentioned in Section 1
Table 1: The generations of the cellular networks.1. Introduction
An introduction
of the paper and
scope of the paper
2. Desideratum
of 5G Networks
Dramatic upsurge in
device scalability,
massive data
streaming and high
data rate, spectrum
utilization,
ubiquitous
connectivity, and
zero latency
1.1 Limitations of
the current cellular
networks
No support for
bursty data
traffic, inefficient
utilization of
processing
capabilities of a
base-station, co-
channel
interference, no
support for
heterogeneous
wireless
networks, and no
separation of
indoor and
outdoor users
4. Architectures of the
Future/5G Mobile
Cellular Networks
4.1 Two-tier Architectures
How small-cells are
deployed under macrocells?
A Survey on 5G: The Next Generation of Mobile Communication 3. Challenges in
the Development
of 5G Networks
Increase data rate
and network
capacity with low
power consumption,
scalability and
flexibility, handling
interference,
environmental
friendly, low latency
and high reliability,
price, high mobility,
self-healing
infrastructures, QoS,
and security and
privacy of the
network and UEs
5.Implementation
Issues in 5G
Networks
6. Methodologies
and Technologies
for 5G Networks
Remaining
methodologies and
technologies are
discussed, e.g., SIC,
DUD, NFV, SDN,
mmWave, M2M
communication,
mMIMO, VLC
7. Applications
of 5G Networks
Personal usages,
virtualized homes,
smart societies,
smart grids, the
tactile Internet,
automation, health-
care systems,
logistics and
tracking, and
industrial usages
8. Real
Demonstrations
of 5G Networks
How industries and
academia are
looking towards
5G? What kind of
real
implementations
and testbeds they
are doing?
5.1 Interference
Management
4.2 CRN-based
Architectures
How CRNs are deployed
under a macrocell?
4.3 D2D Communication
Architectures
How devices communicate
to their close devices
without involving a MBS?
4.4 Cloud-based
Architectures
How the cloud facilitate
communication in 5G
networks?
4.5 Energy-efficient
Architectures
How to save energy in 5G
networks?
5.2 Handoff
Management
5.3 QoS
Management
5.4 Load
balancing
5.5 Channel
Access Control
Management
5.6 Security and
Privacy
Management in
5G Networks
Figure 2: Schematic map of the paper.
1.1 Limitations of the Conventional Cellular Systems93
4G networks are not substantial enough to support massively connected devices with low latency and significant94
spectral efficiency, which will be crucial in the future. In this section, we discuss a few crucial aspects in which95
conventional cellular networks lag behind, thereby motivating the evolution of 5G networks.96
No support for bursty data traffic. There are several mobile applications that send heartbeat messages to their97
servers and occasionally ask for a very high data transfer speed for a very short duration. Such types of data98
transmission may consume more battery life of (mobile) user equipments (UEs) with increasing bursty data in the99
network, and hence, may crash the core network [123]. However, only one type of signaling/control mechanism is100
designed for all types of the traffic in the current networks, creating high overhead for bursty traffic [64, 25].101
Inefficient utilization of processing capabilities of a base-station. In the current cellular networks, the processing102
power of a base-station (BS) can only be used by its associated UEs, and they are designed to support peak time103
traffic. However, a BS’s processing power can be shared across a large geographical area when it is lightly loaded.104
For example: (i) during the day, BSs in business areas are over-subscribed, while BSs in residential areas are105
almost idle, and vice versa [115], and (ii) BSs in residential areas are overloaded in weekends or holidays while106
BSs in business areas are almost idle [92]. However, the almost idle BSs consume an identical amount of power as107
over-subscribed BSs, hence, the overall cost of the network increases.108
Co-channel interference. A typical cellular network uses two separate channels, one as a transmission path from a109
UE to a BS, called uplink (UL), and the reverse path, called downlink (DL). The allocation of two different channels110
for a UE is not an efficient utilization of the frequency band. However, if both the channels operate at an identical111
frequency, i.e., a full duplex wireless radio [27], then a high level of co-channel interference (the interference112
between the signals using an identical frequency) in UL and DL channels is a major issue in 4G networks [86]. It113
3
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65Generations Year Features Limitations
1G 1980s Analog signals for voice only communications Very less security
2G 1990s Digital signals, voice communications, and text
messaging
Very less support for the Internet
3G 1998-99 Voice communications, wireless mobile and fixed
Internet access, video calls, and mobile television (TV)
Less support for high-speed
Internet
4G 2008-09 Higher data rate (hundreds of megabits per second) No support for 50 billion ubiquitous
connected devices
5G 2020 Mentioned in Section 1
Table 1: The generations of the cellular networks.1. Introduction
An introduction
of the paper and
scope of the paper
2. Desideratum
of 5G Networks
Dramatic upsurge in
device scalability,
massive data
streaming and high
data rate, spectrum
utilization,
ubiquitous
connectivity, and
zero latency
1.1 Limitations of
the current cellular
networks
No support for
bursty data
traffic, inefficient
utilization of
processing
capabilities of a
base-station, co-
channel
interference, no
support for
heterogeneous
wireless
networks, and no
separation of
indoor and
outdoor users
4. Architectures of the
Future/5G Mobile
Cellular Networks
4.1 Two-tier Architectures
How small-cells are
deployed under macrocells?
A Survey on 5G: The Next Generation of Mobile Communication 3. Challenges in
the Development
of 5G Networks
Increase data rate
and network
capacity with low
power consumption,
scalability and
flexibility, handling
interference,
environmental
friendly, low latency
and high reliability,
price, high mobility,
self-healing
infrastructures, QoS,
and security and
privacy of the
network and UEs
5.Implementation
Issues in 5G
Networks
6. Methodologies
and Technologies
for 5G Networks
Remaining
methodologies and
technologies are
discussed, e.g., SIC,
DUD, NFV, SDN,
mmWave, M2M
communication,
mMIMO, VLC
7. Applications
of 5G Networks
Personal usages,
virtualized homes,
smart societies,
smart grids, the
tactile Internet,
automation, health-
care systems,
logistics and
tracking, and
industrial usages
8. Real
Demonstrations
of 5G Networks
How industries and
academia are
looking towards
5G? What kind of
real
implementations
and testbeds they
are doing?
5.1 Interference
Management
4.2 CRN-based
Architectures
How CRNs are deployed
under a macrocell?
4.3 D2D Communication
Architectures
How devices communicate
to their close devices
without involving a MBS?
4.4 Cloud-based
Architectures
How the cloud facilitate
communication in 5G
networks?
4.5 Energy-efficient
Architectures
How to save energy in 5G
networks?
5.2 Handoff
Management
5.3 QoS
Management
5.4 Load
balancing
5.5 Channel
Access Control
Management
5.6 Security and
Privacy
Management in
5G Networks
Figure 2: Schematic map of the paper.
1.1 Limitations of the Conventional Cellular Systems93
4G networks are not substantial enough to support massively connected devices with low latency and significant94
spectral efficiency, which will be crucial in the future. In this section, we discuss a few crucial aspects in which95
conventional cellular networks lag behind, thereby motivating the evolution of 5G networks.96
No support for bursty data traffic. There are several mobile applications that send heartbeat messages to their97
servers and occasionally ask for a very high data transfer speed for a very short duration. Such types of data98
transmission may consume more battery life of (mobile) user equipments (UEs) with increasing bursty data in the99
network, and hence, may crash the core network [123]. However, only one type of signaling/control mechanism is100
designed for all types of the traffic in the current networks, creating high overhead for bursty traffic [64, 25].101
Inefficient utilization of processing capabilities of a base-station. In the current cellular networks, the processing102
power of a base-station (BS) can only be used by its associated UEs, and they are designed to support peak time103
traffic. However, a BS’s processing power can be shared across a large geographical area when it is lightly loaded.104
For example: (i) during the day, BSs in business areas are over-subscribed, while BSs in residential areas are105
almost idle, and vice versa [115], and (ii) BSs in residential areas are overloaded in weekends or holidays while106
BSs in business areas are almost idle [92]. However, the almost idle BSs consume an identical amount of power as107
over-subscribed BSs, hence, the overall cost of the network increases.108
Co-channel interference. A typical cellular network uses two separate channels, one as a transmission path from a109
UE to a BS, called uplink (UL), and the reverse path, called downlink (DL). The allocation of two different channels110
for a UE is not an efficient utilization of the frequency band. However, if both the channels operate at an identical111
frequency, i.e., a full duplex wireless radio [27], then a high level of co-channel interference (the interference112
between the signals using an identical frequency) in UL and DL channels is a major issue in 4G networks [86]. It113
3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65also prevents the network densification, i.e., the deployment of many BSs in a geographical area.114
No support for heterogeneous wireless networks. Heterogeneous wireless networks (HetNets) are composed of115
wireless networks of diverse access technologies, e.g., the third generation (3G), 4G, wireless local area networks116
(WLAN), WiFi, and Bluetooth. HetNets are already standardized in 4G; however, the basic architecture was not117
intended to support them. Furthermore, the current cellular networks allow a UE to have a DL channel and a UL118
channel must be associated with a single BS that prevents the maximum utilization of HetNets. In HetNets, a UE119
can select a UL channel and a DL channel from two different BSs belonging to two different wireless networks for120
performance improvement [29, 42].121
No separation of indoor and outdoor users. The current cellular networks have a single BS installed near the122
center of the cell and interacts with all the UEs irrespective of the indoor or outdoor location of the UEs; while123
UEs stay indoors and outdoors for about 80% and 20% of the time, respectively. Furthermore, the communication124
between an indoor UE and an outside BS is not efficient in terms of data transfer rate, spectral efficiency, and125
energy-efficiency, due to the attenuation of signals passing through walls [107].126
Latency. When a UE receives an access to the best candidate BS, it takes several hundreds of milliseconds in the127
current cellular networks [121], and hence, they cannot support the zero latency property.128
2 Desideratum of 5G Networks129
A growing number of UEs and the corresponding surge in the bandwidth requirement for the huge amount of data130
transmission certainly necessitate the novel enhancement to the current technology. In this section, we highlight131
requirements of the future 5G networks.132
Dramatic upsurge in device scalability. A rapid growth of smart phones, gaming consoles, high-resolution TVs,133
cameras, home appliances, laptops, connected transportation systems, video surveillance systems, robots, sensors,134
and wearable devices (watches and glasses) is expected to continue exponentially in the near future. Therefore, 5G135
networks are perceived to support massively connected devices [107, 1, 15].136
Massive data streaming and high data rate. A vast growth in a number of wireless devices will of course137
result in a higher amount of data trading (e.g., videos, audio, Web browsing, social-media data, gaming, real-time138
signals, photos, bursty data, and multimedia) that will be 100-times more as compared to the year 2014 and would139
overburden the current network. Thus, it is mandatory to have matching data transfer capabilities in terms of new140
architectures, methods, technologies, and data distribution of indoor and outdoor users [61, 15, 60].141
Spectrum utilization. The two different channels (one for a UL and another for a DL) seem redundant from142
the point of view of the spectrum utilization [59]. In addition, the currently allocated spectrums have their143
significant portions under-utilized [12]. Hence, it is necessary to develop an access control method that can144
enhance the spectrum utilization. Furthermore, the spectrum utilization and efficiency have already been stretched145
to the maximum. It definitely requires spectrum broadening (above 3 GHz) along with novel spectrum utilization146
techniques [34].147
Ubiquitous connectivity. Ubiquitous connectivity requires UEs to support a variety of radios, RATs, and bands148
due to the global non-identical operating bands. In addition, the major market split between time division duplex149
(e.g., India and China) versus frequency division duplex (e.g., US and Europe) so that UEs are required to support150
different duplex options. Hence, 5G networks are envisioned for seamless connectivity of UEs over HetNets [13].151
Zero latency. The future mobile cellular networks are expected to assist numerous real-time applications, the tactile152
Internet [47, 46], and services with varying levels of quality of service (QoS) (in terms of bandwidth, latency, jitter,153
packet loss, and packet delay) and QoE (in terms of users’ and network-providers’ service satisfaction versus154
feedback). Hence, 5G networks are envisioned to realize real-time and delay-bound services with the optimal QoS155
and QoE experiences [15, 86].156
3 Challenges in the Development of 5G Networks157
The vision of 5G networks is not trivial to achieve. There are several challenges (some of the following challenges158
are shown in Figure 1 with their proposed solutions) to be handled in that context, as mentioned below:159
4
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65also prevents the network densification, i.e., the deployment of many BSs in a geographical area.114
No support for heterogeneous wireless networks. Heterogeneous wireless networks (HetNets) are composed of115
wireless networks of diverse access technologies, e.g., the third generation (3G), 4G, wireless local area networks116
(WLAN), WiFi, and Bluetooth. HetNets are already standardized in 4G; however, the basic architecture was not117
intended to support them. Furthermore, the current cellular networks allow a UE to have a DL channel and a UL118
channel must be associated with a single BS that prevents the maximum utilization of HetNets. In HetNets, a UE119
can select a UL channel and a DL channel from two different BSs belonging to two different wireless networks for120
performance improvement [29, 42].121
No separation of indoor and outdoor users. The current cellular networks have a single BS installed near the122
center of the cell and interacts with all the UEs irrespective of the indoor or outdoor location of the UEs; while123
UEs stay indoors and outdoors for about 80% and 20% of the time, respectively. Furthermore, the communication124
between an indoor UE and an outside BS is not efficient in terms of data transfer rate, spectral efficiency, and125
energy-efficiency, due to the attenuation of signals passing through walls [107].126
Latency. When a UE receives an access to the best candidate BS, it takes several hundreds of milliseconds in the127
current cellular networks [121], and hence, they cannot support the zero latency property.128
2 Desideratum of 5G Networks129
A growing number of UEs and the corresponding surge in the bandwidth requirement for the huge amount of data130
transmission certainly necessitate the novel enhancement to the current technology. In this section, we highlight131
requirements of the future 5G networks.132
Dramatic upsurge in device scalability. A rapid growth of smart phones, gaming consoles, high-resolution TVs,133
cameras, home appliances, laptops, connected transportation systems, video surveillance systems, robots, sensors,134
and wearable devices (watches and glasses) is expected to continue exponentially in the near future. Therefore, 5G135
networks are perceived to support massively connected devices [107, 1, 15].136
Massive data streaming and high data rate. A vast growth in a number of wireless devices will of course137
result in a higher amount of data trading (e.g., videos, audio, Web browsing, social-media data, gaming, real-time138
signals, photos, bursty data, and multimedia) that will be 100-times more as compared to the year 2014 and would139
overburden the current network. Thus, it is mandatory to have matching data transfer capabilities in terms of new140
architectures, methods, technologies, and data distribution of indoor and outdoor users [61, 15, 60].141
Spectrum utilization. The two different channels (one for a UL and another for a DL) seem redundant from142
the point of view of the spectrum utilization [59]. In addition, the currently allocated spectrums have their143
significant portions under-utilized [12]. Hence, it is necessary to develop an access control method that can144
enhance the spectrum utilization. Furthermore, the spectrum utilization and efficiency have already been stretched145
to the maximum. It definitely requires spectrum broadening (above 3 GHz) along with novel spectrum utilization146
techniques [34].147
Ubiquitous connectivity. Ubiquitous connectivity requires UEs to support a variety of radios, RATs, and bands148
due to the global non-identical operating bands. In addition, the major market split between time division duplex149
(e.g., India and China) versus frequency division duplex (e.g., US and Europe) so that UEs are required to support150
different duplex options. Hence, 5G networks are envisioned for seamless connectivity of UEs over HetNets [13].151
Zero latency. The future mobile cellular networks are expected to assist numerous real-time applications, the tactile152
Internet [47, 46], and services with varying levels of quality of service (QoS) (in terms of bandwidth, latency, jitter,153
packet loss, and packet delay) and QoE (in terms of users’ and network-providers’ service satisfaction versus154
feedback). Hence, 5G networks are envisioned to realize real-time and delay-bound services with the optimal QoS155
and QoE experiences [15, 86].156
3 Challenges in the Development of 5G Networks157
The vision of 5G networks is not trivial to achieve. There are several challenges (some of the following challenges158
are shown in Figure 1 with their proposed solutions) to be handled in that context, as mentioned below:159
4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65Data rate and network capacity expansion with energy optimization. The deployment of more BSs in a160
geographical area, use of the higher frequency bands, and link improvement might support the network capacity161
expansion, billions of UEs, high data rate, high volume of data, and efficient backhaul data transfer to the core162
network. However, the implementation of these solutions is a cumbersome task in terms of economy and energy163
intake. Hence, the network capacity is required to be significantly increased, keeping the energy consumption and164
cost under strict control.165
Proposed solutions: Network densification or small-cell deployment [15, 28, 107] (Section 4.1), cognitive166
radio networks (CRNs) [16] (Section 4.2), mMIMO [71, 81, 87] (Section 6), network offload using D2D167
communication [33, 104, 113] (Section 4.3), efficient backhaul networks [51, 88] (Section 4.1.1), energy-efficient168
architectures [62, 83] (Section 4.5), full duplex radios [27] (Section 6), NFV, and SDN based architectures [14, 78,169
97, 119] (Section 6).170
Scalability and flexibility. These are the most prominent features of the future mobile communication. The171
future cellular infrastructures and methodologies must be designed to work in HetNets. Moreover, a vast number172
of potential users might request simultaneously for a set of services. Therefore, 5G networks must be powerful173
enough to support a scalable user demand across the coverage area [78, 94].174
Proposed solutions: NFV- and SDN-based architectures [14, 78, 97, 119] (Section 6).175
Single channel for both UL and DL. A full duplex wireless radio [27] uses only a single channel for transmitting176
and receiving signals at identical time and frequency. Thus, a full duplex system achieves an identical performance177
as having different UL and DL channels, and hence, increases link capacity, saves the spectrum, and cost. However,178
the implementation of full duplex systems is not trivial, because now a radio has to use sophisticated protocols179
for the physical and the data link layers [122], and mechanisms to remove the effects of interference [59]. The180
advantages of a full duplex radio in 5G networks are given in [56, 59, 64].181
Handling interference. Handling interference among communicating devices is a well-known challenge in the182
wireless communication. Due to a growing number of UEs, technologies (e.g., HetNets, CRNs, full duplex, and183
D2D communication) and applications, the interference will also increase in 5G networks, and the state-of-the-art184
technique may not perform well in the future cellular networks [61]. In 5G networks, a UE may receive interference185
from multiple macrocell base-stations (MBSs), various UEs, and small-cell base-stations (SBSs). Hence, it is186
required to develop an efficient (in terms of avoiding network overload) and reliable (in terms of perfect interference187
detection and decoding) interference management technique for channel allocation, power control, cell association,188
and load balancing.189
Proposed solutions: Self-interference cancellation [64, 59], an advance receiver with interference joint190
detection/decoding, and network-side interference management [86]. We will discuss these solutions in Section 5.1.191
Environmentally friendly. The current radio access network (RAN) consumes 70%-80% of the total power [64,192
114]. The wireless technologies consume lots of energy that lead to huge CO2 emission and inflate the cost. It is193
a serious threat to the environment [107]. Thus, it is required to develop energy-efficient communication systems,194
hardware, and technologies, thereby the ratio between the network throughput and energy consumption is equitable.195
Proposed solutions: Cloud-RAN (C-RAN) [114, 62], visual light communication (VLC) [114], mmWave [114],196
separation of indoor and outdoor users [114], joint investigation of spectral efficiency and energy-efficacy [64, 62],197
multi-tier architectures [62], D2D communication [33, 104, 113], mMIMO architectures [62], and full duplex198
radios [64]. Except the above mentioned solutions, we will discuss some special techniques/architectures in the199
context of energy-efficiency in 5G networks in Section 4.5.200
Low latency and high reliability. Low latency and high reliability are critical in several real-time applications,201
e.g., message transmission by robots monitoring patients, life safety systems, cloud-based gaming, nuclear reactors,202
sensors, drones, and connected transportation systems. However, it is very challenging to have very low latency and203
reliable delivery of data over a large scale network without increasing the network infrastructure cost, as it requires204
the development of techniques providing fast connections, quick handovers, and high data transfer rate.205
Proposed solutions: Caching methods [29, 112], VLC, mmWave, mMIMO (Section 6), fast handover206
techniques [40, 93, 102] (Section 5.2), and D2D communication (Section 4.3).207
Network performance optimization. The performance parameters, e.g., peak data rate, geographical area208
coverage, spectral efficiency, QoS, QoE, ease of connectivity, energy-efficiency, latency, reliability, fairness of209
users, and implementation complexity, are crucial for a cellular network [107]. Hence, a general framework for 5G210
5
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65Data rate and network capacity expansion with energy optimization. The deployment of more BSs in a160
geographical area, use of the higher frequency bands, and link improvement might support the network capacity161
expansion, billions of UEs, high data rate, high volume of data, and efficient backhaul data transfer to the core162
network. However, the implementation of these solutions is a cumbersome task in terms of economy and energy163
intake. Hence, the network capacity is required to be significantly increased, keeping the energy consumption and164
cost under strict control.165
Proposed solutions: Network densification or small-cell deployment [15, 28, 107] (Section 4.1), cognitive166
radio networks (CRNs) [16] (Section 4.2), mMIMO [71, 81, 87] (Section 6), network offload using D2D167
communication [33, 104, 113] (Section 4.3), efficient backhaul networks [51, 88] (Section 4.1.1), energy-efficient168
architectures [62, 83] (Section 4.5), full duplex radios [27] (Section 6), NFV, and SDN based architectures [14, 78,169
97, 119] (Section 6).170
Scalability and flexibility. These are the most prominent features of the future mobile communication. The171
future cellular infrastructures and methodologies must be designed to work in HetNets. Moreover, a vast number172
of potential users might request simultaneously for a set of services. Therefore, 5G networks must be powerful173
enough to support a scalable user demand across the coverage area [78, 94].174
Proposed solutions: NFV- and SDN-based architectures [14, 78, 97, 119] (Section 6).175
Single channel for both UL and DL. A full duplex wireless radio [27] uses only a single channel for transmitting176
and receiving signals at identical time and frequency. Thus, a full duplex system achieves an identical performance177
as having different UL and DL channels, and hence, increases link capacity, saves the spectrum, and cost. However,178
the implementation of full duplex systems is not trivial, because now a radio has to use sophisticated protocols179
for the physical and the data link layers [122], and mechanisms to remove the effects of interference [59]. The180
advantages of a full duplex radio in 5G networks are given in [56, 59, 64].181
Handling interference. Handling interference among communicating devices is a well-known challenge in the182
wireless communication. Due to a growing number of UEs, technologies (e.g., HetNets, CRNs, full duplex, and183
D2D communication) and applications, the interference will also increase in 5G networks, and the state-of-the-art184
technique may not perform well in the future cellular networks [61]. In 5G networks, a UE may receive interference185
from multiple macrocell base-stations (MBSs), various UEs, and small-cell base-stations (SBSs). Hence, it is186
required to develop an efficient (in terms of avoiding network overload) and reliable (in terms of perfect interference187
detection and decoding) interference management technique for channel allocation, power control, cell association,188
and load balancing.189
Proposed solutions: Self-interference cancellation [64, 59], an advance receiver with interference joint190
detection/decoding, and network-side interference management [86]. We will discuss these solutions in Section 5.1.191
Environmentally friendly. The current radio access network (RAN) consumes 70%-80% of the total power [64,192
114]. The wireless technologies consume lots of energy that lead to huge CO2 emission and inflate the cost. It is193
a serious threat to the environment [107]. Thus, it is required to develop energy-efficient communication systems,194
hardware, and technologies, thereby the ratio between the network throughput and energy consumption is equitable.195
Proposed solutions: Cloud-RAN (C-RAN) [114, 62], visual light communication (VLC) [114], mmWave [114],196
separation of indoor and outdoor users [114], joint investigation of spectral efficiency and energy-efficacy [64, 62],197
multi-tier architectures [62], D2D communication [33, 104, 113], mMIMO architectures [62], and full duplex198
radios [64]. Except the above mentioned solutions, we will discuss some special techniques/architectures in the199
context of energy-efficiency in 5G networks in Section 4.5.200
Low latency and high reliability. Low latency and high reliability are critical in several real-time applications,201
e.g., message transmission by robots monitoring patients, life safety systems, cloud-based gaming, nuclear reactors,202
sensors, drones, and connected transportation systems. However, it is very challenging to have very low latency and203
reliable delivery of data over a large scale network without increasing the network infrastructure cost, as it requires204
the development of techniques providing fast connections, quick handovers, and high data transfer rate.205
Proposed solutions: Caching methods [29, 112], VLC, mmWave, mMIMO (Section 6), fast handover206
techniques [40, 93, 102] (Section 5.2), and D2D communication (Section 4.3).207
Network performance optimization. The performance parameters, e.g., peak data rate, geographical area208
coverage, spectral efficiency, QoS, QoE, ease of connectivity, energy-efficiency, latency, reliability, fairness of209
users, and implementation complexity, are crucial for a cellular network [107]. Hence, a general framework for 5G210
5
End of preview
Want to access all the pages? Upload your documents or become a member.