|Issue:||North America I 2014|
|Topic:||Tomorrow’s telecom: Preparing for a 5G World|
|Title:||VP, Research & Technology|
|Organisation:||Nokia Siemens Networks|
Lauri Oksanen is the Vice President of Research and Technology in Nokia Solutions and Networks. With over 25 years of extensive experience in the telecommunications industry, he is responsible for the development of new technologies at NSN. Lauri started his telecoms career at Nokia Cables in 1988, where he developed the quality system for the unit and managed research and development in the area of fiber optics. In 1995, Lauri moved to Nokia Networks, where he first worked in GSM and OFDM research, and in the company’s 3G WCDMA program with responsibility for the development of planning, optimization and performance of the system, including the creation of the world’s first 3G Radio Planning Tool. Later, Lauri led Network Systems Research covering radio access, core and services. Since 2006 he headed technology in Nokia Networks, covering also software and hardware research. His group developed the Nokia Networks’ LTE radio and architecture proposal. This included the power efficient uplink concept and flat architecture, which formed the core of the final standard.
Lauri has a Diploma (MSc) in Engineering from the Helsinki University of Technology, and a Licentiate of Technology from the Helsinki University of Technology.
The new era of bigger and faster data drives in not only 4G technology, which is now in progress, but also the era of 5G, which is yet to be specified. It is clear that three areas in particular need to evolve: cell size, spectrum utilization and performance. Reduced cell size must overcome interference and installation costs. More spectrum will be licensed in the millimeter band ranges, but higher ranges of 70–85 GHz will need costly changes to equipment. Performance must also be improved significantly. Higher density of cells will require automated management, and new precision applications, such as autonomous vehicles, will require ever decreasing latency. In fact, SDN and virtualization are already paving the way for 5G.
Looking into the future of technology is something like looking at a new baby and trying to predict what her life will be like. There are few certainties, but some patterns are likely to emerge over the coming years. While it’s impossible to prepare for everything that will take place, making plans will make it easier to adapt to what will come.
One of the most dynamic areas of technical development over the past two decades is that of wireless mobility. We have seen mobile networks grow from the most basic voice functionality to full-scale providers of multimedia and cutting-edge entertainment.
The first generation of large-scale mobile technology was referred to as 2G. This was the initial radio access technology (RAT) which made it possible for the masses to enjoy the benefits of cell phones and global roaming. Over time a new RAT was developed, with 3G first providing functionality beyond voice communication. But 3G was a compromise that combined different technical solutions, with IT and telecom solutions competing and creating challenges for the network provider.
As it became clear that the ideal use case for the immediate future was Internet access, a clear vision of what 4G needed to be has emerged. As a result, the creation of large-scale 4G networks has been quick and massively successful, with many carriers providing excellent network performance and high speeds for most subscribers. This is particularly true in North America, where the major operators, including AT&T, Bell Canada, Sprint, TELUS, T-Mobile, U.S. Cellular and Verizon, have 4G/LTE network deployments.
As user needs continue to evolve, mobile operators are beginning to look forward to the next generation of network technology. However, there are more questions than answers as to what 5G will become, and what applications will need to be supported. Yet, while the specific use case remains uncertain, there are three key pillars that will characterize successful 5G telecommunications, which network developers will have to address to make 5G a reality: cell size, spectrum and performance.
The reduction in cell size
One of the most certain trends to continue in the coming years is that of increasing traffic. But how much will it truly increase? Experts are uncertain, but some estimates place this growth on the order of 1,000 times during this decade, at least in terms of traffic volume. The other side of the coin is data speed, which will require high network performance.
While it’s unlikely that the average network will need to support this much traffic on a daily basis, it also seems certain that some will. As a result, telecom providers should prepare for this kind of growth in order to be certain they are fielding sufficiently robust networks.
Key to this growth in traffic support will be an increase in cell densification. While today’s most traffic-intense networks require base stations or towers every few hundred meters, 5G will require ultra-dense deployments. The limitations of 4G are already becoming apparent in the most crowded 4G environments, such as a crowded stadium or railway station. It is also becoming increasingly clear that 5G will require cells that can operate every few tens of meters in order to maximize network performance.
This approach is already seen in certain Wi-Fi applications, such as homes with more than one router. There are problems, however, with interference from other devices such as neighbors’ routers. The 5G environment will have to successfully overcome the challenges inherent in the use of such small cell deployments. This includes coordination between heterogeneous connecting technologies and connections between local nodes and access points higher in the network hierarchy.
The use of more spectrum
Another integral part of realizing 5G will be the use of larger parts of the communications spectrum. Without this increase, communities that have no wired broadband will be unable to take advantage of new services.
As the amount of traffic everywhere increases, current systems operating on centimeter-band frequencies will need to be used more efficiently. This is already happening in today’s 4G environment with carrier aggregation. Today’s networks operate primarily in the range of 700 MHz range to 3.5 GHz and require good area spectral efficiency.
The difference in a 5G network, however, will be the licensing and use of much wider bands of millimeter-band frequencies, which will change system requirements. In the 70–85 GHz range, there is potentially a lot of new spectrum available, but these areas will require significant adaptation to current equipment for feasibility of use.
Today’s radios are not generally sensitive enough to make effective use of these higher frequencies. This means that the hardware will need to continue evolving to support 5G systems and frequency bands. In addition, these frequencies are also not well suited to providing wide area coverage, and may be used for dense local cells instead. Telecom providers will be working in the coming years to address these challenges in anticipation of increasing traffic.
The need for improved network performance
The third significant area that must be addressed in a successful 5G telecom network is that of performance. Not only will the amount of traffic be increasing, but so will the demand for speed and flexibility in the face of continued application development. We are already seeing this in today’s 4G deployments, with users now streaming high-definition videos and games to tablets and smartphones. This trend is likely to continue throughout the coming decade.
While telecom providers often advertise their maximum network speeds, the reality is that the most significant need in terms of bitrates is an improvement in the minimum average data rate that is provided. While users in areas with densely spaced access points will in the future be able to see speed in the order of several hundreds of megabits per second, those in other areas that are further from the base station or tower will not reach such high speeds. All users are still competing for bandwidth against other users in the same radio cell. Providers must support a consistently higher base rate for all users, that is sufficient to support their growing needs.
Another consequence of smaller cells will be a vast increase in the number of access points that must be maintained cost-effectively. Even in current multisystem 2G+3G+4G networks, this is becoming difficult to do in an optimally manual way, and will be much more challenging in 5G. In order to prevent skyrocketing operational costs, network providers will have to implement effective automation systems to maintain an optimal network environment for the user. Another challenge in installing numerous new access points is to connect them to the core network. Many access points will be connecting wirelessly to core networks simply because a dedicated fiber network will be unfeasible in their cases.
More and more devices are connecting to the Internet, from home thermostats to Internet-enabled refrigerators. Many of these devices require only a small amount of bandwidth, sending and receiving information only occasionally. While their individual requirements are low, there will be many more such devices connecting to the networks. .
Tomorrow’s high-performance networks will demand greatly reduced latency for certain applications to create a satisfactory experience. The first goal will be to reduce latency to the point below the human tactile ability to perceive, i.e. ~ ten milliseconds. This is a good start, but there will be the need for even lower latency for certain highly sensitive control applications. If, for example, autonomous vehicle systems begin to see widespread deployment, this will require extremely low latency as vehicles detect each other’s position at high speeds, and send and receive information about their location and road conditions.
Latency can only progress so far, which is where other technology such as the distributed processing cloud comes in. When network delays are squeezed down to the millisecond level, the speed of light itself becomes the limiting factor. Telecom providers may find it necessary to distribute data centers to maximize proximity to large groups of users, rather than just maintaining a smaller number of large centers.
We are already beginning to see certain networking technologies that are paving the way for 5G communications. Software-Defined Networking (SDN), for example, is enabling the development of new networks that are simpler to control. This will greatly enhance the flexibility of tomorrow’s networks and improve providers’ ability to respond to changing user demands.
While there is no single answer as yet to what 5G will be, it will most likely make use of both current and emerging radio access technologies. Blending the use of different spectrum bands; dealing with small, ultra-dense cells; and ensuring consistent, high-performance networks will ensure that mobile carriers in the next few years will be able to keep up with the ever-growing need for mobility. Carriers should begin preparing now to make certain that the transition to 5G after 2020 will involve as few growing pains as possible.