CTN Issue: May 2014

The Mobile Communications Industry is on the move again, innovating and inventing its way to pervasive always-on, always-connected broadband 5G services. Realizing these services is not trivial; challenges include the interoperability and/or evolution of seven billion 2G-3G-4G existing mobile connections worldwide.  It also must consider overcoming a mature environment that is already approaching theoretical speed, bandwidth and performance limits. This issue of CTN presents a selection of the most-read trending IEEE ComSoc articles from academia, R&D leaders, and industry insiders; they reveal and define for us:

1. What is 5G?
2. What disruptive technologies are shaping 5G?
3. How fast is 5G?
4. What will be different in 5G networks, devices and connections?

Keywords

#5G #M2M #D2D #IEEE80211ad #mmWave #MIMO #communications #smartphone #3GPP #LTE #WigGi #4G #GSMA #ITU #IEEE #WiFi #Wireless #Mobile #trends #P2P #technology #innovation #broadband #spectrum #IoT

1. Five Disruptive Technology Directions for 5G

The authors present the five technologies for 5G that could lead to both architectural and component disruptions: (1) device-centric architectures, (2) millimeter wave; (3) massive MIMO; (4) smarter devices; and (5) native support for machine-to-machine communications. The key ideas for each technology are described, along with their potential impact on 5G and the research challenges that remain.

1. Device-centric architectures: The base-station-centric architecture of cellular systems may change in 5G. It may be time to reconsider such concepts as uplink and downlink, as well as control and data channels. 5G systems will use nodes on an ad hoc basis.
2. Millimeter wave (mmWave): While spectrum has become scarce at microwave frequencies, it is plentiful in the mmWave realm. Such a spectrum “el Dorado” has led to an mmWave “gold rush”.  Although far from being fully understood, mmWave technologies have already been standardized for short-range services (IEEE 802.11ad) and deployed for niche applications such as small-cell backhaul.
3. Massive MIMO: Massive multiple-input multiple-output (MIMO) proposes using a very large number of antennas to spatially multiplex data.  Massive MIMO may require major architectural changes, particularly in the design of macro base stations, and it may also lead to new types of deployments.
4. Smarter devices: 2G-3G-4G cellular networks were built under the design premise of having complete control at the infrastructure side. The proposal is for 5G systems to drop this design assumption and exploit intelligence at the device side within different layers of the software protocol stack.  For example, one could allow device-to-device (D2D) connectivity or exploit smart caching at the mobile smartphone side. While this design philosophy mainly requires a change at the node level (component change), it also has implications at the architectural level.
5. Native support for machine-to-machine (M2M) communication: A native inclusion of M2M communication in 5G has three main requirements: support of a massive number of low-data-rate devices, sustaining a minimal data rate in virtually all circumstances, and very-low-latency data transfer. Addressing these requirements in 5G requires new methods and ideas at both the component and architectural levels.

Title and author(s) of the original paper in IEEE Xplore:

Title: Five Disruptive Technology Directions for 5G
Author(s): F. Boccardi, R.W. Heath, A. Lozano, T.L. Marzetta, and P. Popovski
This paper appears in: IEEE Communications Magazine
Issue Date: February 2014

2. Cellular Architecture and Key Technologies for 5G Wireless Communication Networks

The fourth generation wireless communication systems have been deployed or are soon to be deployed in many countries. However, with an explosion of wireless mobile devices and services, even 4G systems cannot adequately address issues such as the spectrum crisis and high energy consumption. Wireless system designers have been facing demand for increasingly higher data rates. 5Th generation (5G) wireless systems will address these needs and more and are expected to be deployed by 2020. This article proposes cellular architectures that separate indoor and outdoor scenarios. In addition, it discusses various promising technologies for 5G wireless communication systems, such as massive MIMO, energy-efficient communications, cognitive radio networks, and visible light communications.

There are several challenges for 5G designers. One of the most crucial challenges is the physical scarcity of radio frequency (RF) spectra allocated for cellular communications.  These frequency spectra have been used heavily, and there is no more to spare in the existing cellular bands. Another challenge is the deployment of advanced wireless technologies comes at the cost of high energy consumption. In addition to environmental concerns, it has been reported by cellular operators that the energy consumption of base stations contributes to over 70% of their electricity bill.  Other challenges include but are not limited to: increasing spectral efficiency, high data rate coupled with high mobility requirements,  seamless coverage, diverse quality-of-service (QoS) requirements, and fragmented user experience (incompatibility of different wireless devices/interfaces and heterogeneous networks).

What will the 5G network, which is expected to be standardized around 2020, look like? It is now too early to define this with any certainty. However, it is widely agreed that compared to the 4G network, the 5G network should achieve 1000 times the system capacity, 10 times the spectral efficiency, energy efficiency and data rate (i.e., peak data rate of 10 Gb/s for low mobility and peak data rate of 1 Gb/s for high mobility), and 25 times the average cell throughput. The aim is to connect the entire world, and achieve seamless and ubiquitous communications between anybody (people to people), anything (people to machine, machine to machine), wherever they are (anywhere), whenever they need (anytime), by whatever electronic devices/services/networks they wish (anyhow). This means that 5G networks should be able to support communications for some special scenarios not supported by 4G networks (e.g., for high-speed train users who can travel up to 500 km/hour).  This articles proposes a potential 5G cellular architecture and discuss some promising technologies that can be deployed to deliver  5G requirements.

Title and author(s) of the original paper in IEEE Xplore:

Title: Cellular Architecture and Key Technologies for 5G Wireless Communication Networks
Author(s): C.-X. Wang, F. Haider, X. Gao, X.-H. You, Y. Yang, D. Yuan, H. Aggoune, H. Haas, S. Fletcher, and E. Hepsaydir
This paper appears in: IEEE Communications Magazine
Issue Date: February 2014

3. 5G: Personal Mobile Internet beyond What Cellular Did to Telephony

Cellular technology has dramatically changed our society and the way we communicate. First it changed voice telephony, then moved into data access, applications, and services. However, the Internet has not yet been fully exploited by cellular systems. With the advent of 5G we will have the opportunity to leapfrog beyond current Internet capabilities.

Our work and play today requires obtaining and sharing information from various sources. Today most of the information and data known to mankind has been digitized in one form or another, and is available for consumption and sharing. Accessing the data which is stored and consumed in various formats reliably and efficiently is a challenge.  We need to provide as much capacity as we can, and ensure that we build an efficient and smart architecture that can accommodate future demands for 5G data communications.

Beyond our need for communication and sharing is the need to steer/control elements of our surroundings and environment such as gadgets, sensors, and machines help us carry out our day-today life more efficiently. Once machines become connected, the next natural leap is to have them controlled remotely. This will generate a complete new paradigm for control communications. Today we enjoy the power of telephony and data communications. Our fourth generation (4G) networks enable real-time access to richer content and enable early application of machine type communication, while control communications is in its infancy.

The mobile industry has a rich history of revolutionary applications and technologies that have shaped the daily lives of their customers. First came the need for untethered telephony,’ made real by the success of cordless phones. Then came cellular phones which allowed further mobility of users. This was followed by the success of cellular text messaging.  With the success of wireless LAN technology (WiFi based on the IEEE 802.11 standard), Internet browsing, and the widespread market adoption of laptop computers, untethered Internet data connectivity became a reality and ultimately a necessity for everyone. This phenomenon opened the market for cellular broadband wireless data connectivity. The next logical step was to combine a subset of laptop functions for mobile use and merge it with the cellular telephone, creating today’s smartphone. We now enjoy access to the world’s information at our fingertips, anytime, anywhere. But, is this the end game? Is everything else going to be evolutionary? As difficult as it is to predict, history has shown that the future is ripe for transformations and inventions, especially since we are far away from an ideally connected world.

In the early days of telephony we could not have predicted the applications and devices we have today. Similarly it is difficult to envision how we will use 5G systems in 2020. We do know that the thirst for data will continue, and we need to provide more and more capacity as time goes by far beyond two to three times the spectral efficiency and an order of magnitude capacity improvement from 4G.

Title and author(s) of the original paper in IEEE Xplore:

Title: 5G: Personal Mobile Internet beyond What Cellular Did to Telephony
Author(s): G. Fettweis and S. Alamouti
This paper appears in: IEEE Communications Magazine
Issue Date: February 2014

Statements and opinions given in a work published by the IEEE or the IEEE Communications Society are the expressions of the author(s). Responsibility for the content of published articles rests upon the authors(s), not IEEE nor the IEEE Communications Society.