Fundamentals of 5G Mobile Networks

Jonathan Rodriguez

• Publisher: Wiley
• Year: 2015
• ISBN:
  9781118867471
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Mobile & Wireless Communications
• Index: Technology & Engineering

Fundamentals of 5G Mobile Networks provides an overview of the key features of the 5th Generation (5G) mobile networks, discussing the motivation for 5G and the main challenges in developing this new technology. This book provides an insight into the key areas of research that will define this new system technology paving the path towards future research and development. The book is multi-disciplinary in nature, and aims to cover a whole host of intertwined subjects that will predominantly influence the 5G landscape, including the future Internet, cloud computing, small cells and self-organizing networks (SONs), cooperative communications, dynamic spectrum management and cognitive radio, Broadcast-Broadband convergence, 5G security challenge, and green RF. This book aims to be the first of its kind towards painting a holistic perspective on 5G Mobile, allowing 5G stakeholders to capture key technology trends on different layering domains and to identify potential inter-disciplinary design aspects that need to be solved in order to deliver a 5G Mobile system that operates seamlessly.

1
Drivers for 5G: The ‘Pervasive Connected World’

Firooz B. Saghezchi,¹ Jonathan Rodriguez,¹ Shahid Mumtaz,¹ Ayman Radwan,¹ William C. Y. Lee,² Bo Ai,³ Mohammad Tauhidul Islam,⁴ Selim Akl⁴ and Abd-Elhamid M. Taha⁵

¹ Instituto de Telecomunicações, Aveiro, Portugal

² School of Advanced Communications, Peking University, China

³ State Key Laboratory of Rail Traffic Control and Safety, Beijing, China

⁴ School of Computing, Queen’s University, Kingston, Ontario, Canada

⁵ College of Engineering, Alfaisal University, Riyadh, KSA

1.1 Introduction

We have been witnessing an exponential growth in the amount of traffic carried through mobile networks. According to the Cisco visual networking index [1], mobile data traffic has doubled during 2010–2011; extrapolating this trend for the rest of the decade shows that global mobile traffic will increase 1000x from 2010 to 2020.

The surge in mobile traffic is primarily driven by the proliferation of mobile devices and the accelerated adoption of data-hungry mobile devices – especially smart phones. Table 1.1 provides a list of these devices along with their relative data consumptions. In addition to the increasing adoption rate of these high-end mobile devices, the other important factor associated with the tremendous mobile traffic growth is the increasing demand for advanced multi-media applications such as Ultra-High Definition (UHD) and 3D video as well as augmented reality and immersive experience. Today, mobile video accounts for more than 50% of global mobile data traffic, which is anticipated to rise to two-thirds by 2018 [1]. Finally, social networking has become important for mobile users, introducing new consumption behaviour and a considerable amount of mobile data traffic.

Table 1.1 Data consumption of different mobile terminals.

Device	Relative data usage
Feature phone	1x
Smart phone	24x
Handheld gaming console	60x
Tablet	122x
Laptop	515x

The growth rate of mobile data traffic is much higher than the voice counterpart. Global mobile voice traffic was overtaken by mobile data traffic in 2009, and it is forecast that Voice over IP (VoIP) traffic will represent only 0.4% of all mobile data traffic by 2015. In 2013, the number of mobile subscriptions reached 6.8 billion, corresponding to a global penetration of 96%. The ever-growing global subscriber rate spurred on by the world population growth will place stringent new demands on potential 5G networks to cater for one billion new customers.

Apart from 1000x traffic growth, the increasing number of connected devices imposes another challenge on the future mobile network. It is envisaged that in the future connected society, everyone and everything will be inter-connected – under the umbrella of Internet of Everything (IoE) – where tens to hundreds of devices will serve every person. This upcoming 5G cellular infrastructure and its support for Big Data will enable cities to be smart. Data will be generated everywhere by both people and machines, and will be analysed in a real-time fashion to infer useful information, from people’s habits and preferences to the traffic condition on the streets, and health monitoring for patients and elderly people. Mobile communications will play a pivotal role in enabling efficient and safe transportation by allowing vehicles to communicate with each other or with a roadside infrastructure to warn or even help the drivers in case of unseen hazards, paving the way towards autonomous self-driving cars. This type of machine-to-machine (M2M) communications requires very stringent latency (less than 1 ms), which imposes further challenges on the future network.

The 1000x mobile traffic growth along with trillions of connected devices is pushing the cellular system to a broadband ubiquitous network with extreme capacity and Energy Efficiency (EE) and diverse Quality of Service (QoS) support. Indeed, it is envisaged that the next-generation cellular system will be the first instance of a truly converged wired and wireless network, providing fibre-like experience for mobile users. This ubiquitous, ultra-broadband, and ultra-low latency wireless infrastructure will connect the society and drive the future economy.

1.2 Historical Trend of Wireless Communications

A new generation of cellular system appears every 10 years or so, with the latest generation (4G) being introduced in 2011. Following this trend, the 5G cellular system is expected to be standardised and deployed by the early 2020s. The standardisation of the new air interfaces for 5G is expected to gain momentum after the International Telecommunication Union-Radiocommunication Sector’s (ITU-R) meeting at the next World Radiocommunication Conference (WRC), to be held in 2015. Table 1.2 summarises the rollout year as well as the International Mobile Telecommunications (IMT) requirements for the peak and the average data rates for different generations of the cellular system. Although IMT requirements for 5G are yet to be defined, the common consensus from academic researchers and industry is that in principle it should deliver a fibre-like mobile Internet experience with peak rates of up to 10 Gbps in static/low mobility conditions, and 1 Gbps blanket coverage for highly mobile/cell edge users (with speeds of > 300 km/h). The round-trip time latency of the state-of-the-art 4G system (Long-Term Evolution – Advanced; LTE-A) is around 20 ms, which is expected to diminish to less than 1 ms for 5G.

Table 1.2 Specifications of different generations of cellular systems.

		IMT requirement for data rate
Generation	Rollout year	Mobile users	Stationary users
1G	1981	–	–
2G	1992	–	–
3G	2001	384 Kbps	>2 Mbps
4G	2011	100 Mbps	1 Gbps
5G	2021	1 Gbps	10 Gbps

Global standards are a fundamental cornerstone in reaching ubiquitous connectivity, ensuring worldwide interoperability, enabling multi-vendor harmonisation and economies of scale. ITU-R is responsible for defining IMT specifications for next-generation cellular systems. Having defined two previous specifications (IMT-2000 for 3G and IMT-Advanced for 4G), it has already commenced activities towards defining specifications for 5G, which is aimed for completion around 2015. ITU-R arranges WRCs every three to four years to review and revise radio regulations. Allocation of new spectrum for mobile communications is already on the agenda of the next WRC, to be held in November 2015.

To understand where we want to be in terms of 5G, it is worthwhile to appreciate where it all started and to mark where we are now. The following provides a roadmap of the evolution towards 5G communications:

• Before 1G (<1983): All the wireless communications were voice-centric and used analogue systems with single-side-band (SSB) modulation.
• 1G (1983–): All the wireless communications were voice-centric. In 1966, Bell Labs had made a decision to adopt analogue systems for a high-capacity mobile system, because at that time the digital radio systems were very expensive to manufacture. An analogue system with FM radios was chosen. In 1983, the US cellular system was named AMPS (Advanced Mobile Phone Service). AMPS was called 1G at the time.
• 2G (1990–): During this period, all the wireless communications were voice-centric. European GSM and North America IS-54 were digital systems using TDMA multiplexing. Since AT&T was divested in 1980, no research institute like Bell Labs could develop an outstanding 2G system as it did for the 1G system in North America. IS-54 was not a desirable system and was abandoned. Then, GSM was named 2G at the time when 3G was defined by ITU in 1997. Thus, we could say that moving from 1G to 2G means migrating from the analogue system to the digital system.
• 2.5G (1995–): All the wireless communications are mainly for high-capacity voice with limited data service. The CDMA (code division multiple access) system using 1.25 MHz bandwidth was adopted in the United States. At the same time, European countries enhanced GSM to GPRS and EDGE systems.
• 3G (1999–): In this generation, the wireless communications platform has voice and data capability. 3G is the first international standard system released from ITU, in contrast to previous generation systems. 3G exploits WCDMA (Wideband Code Division Multiple Access) technology using 5 MHz bandwidth. It operates in both frequency division duplex (FDD) and time division duplex (TDD) modes. Thus, we could say that by migrating from ...