5G Radio Access
Driven by the rapidly growing demand for fast and responsive connectivity, Samsung Electronics is pushing hard to define and introduce the next generation of mobile standards. These efforts are already shaping architectures and technologies that will transform networks and services, encouraging a shift in the way we think about connectivity.
Building the 5G Foundation
As an active contributor to the ITU-R, Samsung is a strong proponent of the organization's International Mobile Telecommunications vision for 2020 (IMT-2020), which establishes a set of future benchmarks for network technologies that will meet the growing connectivity demand.
The radio access component of future networks will play a critical role in reaching the goals of IMT-2020, through the evolution of data transmission principles and the addition of key techniques that improve throughput, capacity, spectral efficiency, power consumption, and device density among others.
More than Numbers
While the IMT-2020 goals play a pivotal role in directing research and development, 5G networks will need to go far beyond numerical improvements in order to meet the requirements of evolving network usage that we are seeing today. Indeed, while 5G networks will enable the delivery of some very impressive services to the traditional mobile subscriber, dozens of previously unconnected industries are now incubating ideas that will completely transform the role of mobile telecommunications in today's society.
In order to support these services, 5G radio access networks (5G RAN) will need to be flexible. They will need to be able to adapt to a wide range of different service requirements so that network and third party service providers alike can deploy new applications, services and devices seamlessly and sustainably. Through the evolution of the radio air interface, the implementation of 'software-defined' principles and more, the 5G RAN will enable transparent connectivity for a new generation of information-driven users and industries.
Next-Generation RAN Architecture
5G radio access deployments will be characterized by their highly dense, throughput focused and software-driven nature. Foremost among the differences between 5G and LTE will be the logical separation of each component of the 5G fNB (future NodeB). In particular, we will see the baseband split, with the lower layers of the 5G protocol stack merging with the radio unit to form a new element called the Access Unit (AU). Meanwhile, leveraging software virtualization, some limited core network functionality will be decentralized and co-located with the upper layers of the
A Wealth of Available Spectrums
Perhaps the most apparent transformation taking place with 5G is the move towards an entirely new region of the radio spectrum. While existing frequency bands below 6 GHz will still play an important role in next-generation networks, the adoption of centimeter and millimeter wave bands (3-30 GHz and 30-300 GHz, respectively) will be critical to the delivery of consistent, multi-Gbps throughputs. In fact, one of the most exciting aspects of this part of the radio spectrum is the abundance of available, or lightly used spectrum. In many countries, there is a potential minimum of 7GHz of total bandwidth, spread across the 28 GHz, 37 GHz, 39 GHz and 60 GHz frequencies alone -- far more than is available in the overly crowded spectrum commonly used for 3G and LTE today (between 400 MHz and 2.6 GHz).
Some of this spectrum, such as the 60 GHz band, is expected to remain unlicensed in many jurisdictions, and is only very lightly used by other radio access technologies such as 802.11ad (commonly known as WiGig), and may provide a nearly global baseline for 5G access. Meanwhile, the 28 and 39 GHz bands, will likely be available through regulatory licensing. This potential capacity will be a key enabler for use cases ranging from dense IoT deployments to ubiquitous mobile 4K and 8K video-on-demand.
Advanced Signal Enhancement Techniques
In order to overcome the natural range and propagation challenges of millimeter waves, 5G radio access will implement a series of techniques designed to improve a signal's ability to reach each local user device without generating undue interference or consuming unnecessary energy resources. Two such techniques include:
Beamforming involves the shaping of radio signals into tightly focused beams in order to maximize the signal quality within the target while avoiding noisy interference in surrounding areas. This is analogous to a spotlight, which confines light in such a way as to provide intensely bright illumination on a target, without flooding the entire area with unnecessary or unwanted light.
MIMO (Multiple Input, Multiple Output) uses advanced signal processing to allow generate multiple radiowaves that are calculated to support, rather than interfere with, each other. The signals generated can serve a single user (Single User MIMO) or multiple users (Multi-User MIMO). This improves the capacity and signal quality of a cell, particularly in dense scenarios.
The Importance of Interworking
It's important to understand that the 5G radio access network will not be designed to replace or supplant the existing LTE networks. In fact, a core design principle of 5G networks is the assurance of seamless interworking between the two radio access technologies (RATs), and a step beyond that: leveraging the synergy between the individual strengths of both LTE and 5G radio access.
In this way, it is likely that LTE will provide a foundational general connectivity layer, in much the same way that 2G and 3G networks did as LTE was first being deployed. This underlying LTE layer will also generally take responsibility for some of the important traditional functions of mobile networks: voice service (VoLTE) and messaging. Combined with evolution towards a 5G-based multi-RAT core network, LTE will also play a critical role in providing connectivity for certain classes of IoT traffic that are less dependent upon capacity, low latency or ultra-reliability.
5G Deployment Characteristics
Early concerns regarding millimeter waves (mmWaves) centred around two limiting characteristics of the frequency itself, namely its apparently high rate of atmospheric absorption and its decreased object penetration capabilities.
However, while this means that overall range of mmWave is limited compared to the frequencies commonly used for 3G and LTE today, this actually provides some very significant benefits in terms of network deployment and signal quality. In particular, the short range and abrupt drop-off in signal strength means that 5G base stations and small cells can be deployed in very high density scenarios with greatly reduced concern for interference between adjacent cells. Interference has been one of the biggest challenges for cellular networks, and many of Samsung's most advanced solutions have tackled interference in particular in order to improve network quality. The nature of mmWave radio will further increase the potency of Samsung’s interference mitigation technologies, providing significant benefit to operators and users alike.