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5G New Radio (5G NR)

The_Golden_Gate_Bridge_7775.jpg
(The Golden Gate Bridge, San Francisco, California - Jeff M. Wang)
 
 
 

-  5G NR: A New Radio Interface and Radio Access Technology

5G is the fifth generation of wireless technology and NR stands for a new radio interface and radio access technology for cellular networks - a physical connection method for radio based communication. Other kinds of radio access technologies include Bluetooth, Wi-Fi and 4G LTE.

All cell phones use radio waves to facilitate communication as they convert your voice into digital signals. Internet data is sent and received via these radio waves, too. 

5G NR uses two frequency ranges: frequency range 1 (FR1) includes 6 Ghz frequency bands and below. Frequency band 2 (FR2) includes bands in the millimeter wavelength (or mmWave) range, which includes 20-60 Ghz. That mmWave range is particularly helpful to enable 5G Ultra Wideband (UWB).

5G has three main focuses - mobile networking, IoT, and very high-performance industrial control - of which mobile networking will be the most important for most people over the next few years, and which is best thought of as a continuation of 4G's Long Term Evolution (LTE) under a new flag. 

5G is not an incremental improvement over 4G, it’s a revolutionary new technology that requires a new approach in designing and deploying networks. Driving this technology is a new radio interface, which will enable mobile network operators (MNOs) to achieve higher efficiencies with similar allocated spectrum. New network hierarchies will facilitate 5G-sliced networks, allowing multiple traffic types to be allocated dynamically according to specific traffic needs.

 

- 5G’s Modulation, OFDM (Orthogonal Frequency Division Multiplexing)

One of the defining elements of any mobile communications system is the waveform used for the radio link in the radio access network. Like other cellular networks, 5G networks use a system of cell sites that divide their territory into sectors and send encoded data through radio waves. 

Each cell site must be connected to a network backbone, whether through a wired or wireless backhaul connection. 5G networks use a type of encoding called OFDM (Orthogonal Frequency Division Multiplexing), which is similar to the encoding that 4G LTE uses. OFDM gives good spectral efficiency whilst providing resilience to selective fading and it also enables multiple access capability to be implemented using OFDMA.

Orthogonal Frequency-Division Multiplexing (OFDM) has become the standard modulation format for 5G New Radio. OFDM is an efficient modulation format used in modern wireless communication systems including 5G. OFDM combines the benefits of Quadrature Amplitude Modulation (QAM) and Frequency Division Multiplexing (FDM) to produce a high-data-rate communication system. QAM refers to a variety of specific modulation types: BPSK (Binary Phase Shift Keying), QPSK (Quadrature Phase Shift Keying), 16QAM (16-state QAM), 64QAM (64-state QAM), etc. 

The basic concept of OFDM was first proposed by R. W. Chang, recognizing that bandlimited orthogonal signals can be combined with significant overlap while avoiding interchannel interference.  Using OFDM, we can create an array of subcarriers that all work together to transmit information over a range of frequencies. These subcarriers must be orthogonal functions.

 

- Radio Air Interface

An air interface is the radio frequency portion of the circuit between the mobile device and the active base station. The active base station can change as the user is on the move, with each changeover known as a handoff. 5G NR stands for a new radio interface and radio access technology for cellular networks - a physical connection method for radio based communication. Other kinds of radio access technologies include Bluetooth, Wi-Fi and 4G LTE. All cell phones use radio waves to facilitate communication as they convert your voice into digital signals. Internet data is sent and received via these radio waves, too. 

With the demanding requirements being placed upon the new 5G standard, a totally new radio interface and radio access network has been developed. Called 5G New Radio (or 5G NR), the new radio interface provides for the growing needs for mobile connectivity. 

5G NR (New Radio) is a new radio access technology (RAT) developed by 3GPP for the 5G (fifth generation) mobile network. It was designed to be the global standard for the air interface of 5G networks. The 3GPP specification 38 series[3] provides the technical details behind NR, the RAT beyond LTE.

 

- 5G NR: The New Radio Interface for 5G

A new generation of wireless needs a new generation of radio. 5G New Radio (5G NR) is a completely new air interface being developed for 5G. It is being developed from the ground up in order to support the wide variety of services, devices and deployments 5G will encompass, and across diverse spectrum, but 5G NR will build on established technologies to ensure backwards and forwards compatibility. 5G NR follows 2G, 3G and 4G and their respective associated technologies (such as GSM, UMTS, LTE, LTE Advanced Pro and others). 5G NR is equivalent to how the mobile communications industry has used LTE to describe 4G technology or UMTS to describe 3G technology. 

The development of the 5G NR is key to enabling the 5G system to work and it provides a number of significant advantages when compared to 4G. 5G NR utilises modulation, waveforms and access technologies that will enable the system to meet the needs of high data rate services, those needing low latency and those needing small data rates and long battery lifetimes amongst others.

 

- A New Spectrum Comes Into Play

The key to understanding 5G NR is that service providers employ a combination of radio frequencies to deliver high-speed data services to their end customers. For their part, 5G low, mid, and high bands each possess different capabilities with regards to speed and range. 

  • 5G low bands deliver 5G coverage over the longest distances. They are typically Frequency Division Duplex (FDD)-based and are either new (for example, 700 MHz) or are already in use and can be repurposed for 5G via spectrum sharing. The low-band frequency family spans 600 MHz through 2600 MHz. The lower frequency characteristic of the low bands makes this spectrum especially well-suited for providing wide area coverage. 
  • 5G mid bands (Sub-6, also referred to as FR1) provide additional capacity, albeit across a shorter distance. They are typically found between 2300MHz and 6000MHz, where the 3500MHz frequency band is the most common for 5G rollouts. Mid bands are ideal for massive Multiple Input, Multiple Output (MIMO) technology deployments. 
  • 5G high bands (mmWave, also referred to as FR2) are found in the range of 24GHz to 40GHz. They deliver large quantities of spectrum and capacity over the shortest distances. They also use massive MIMO to expand capacity and extend coverage. Moreover, they include wide spectrum segments available for 5G along with lower latencies.


The introduction of new frequency bands for 5G is carried out in combination with existing bands used today by service providers. The combined effects of mixing the low, mid and high band for improved capacity and coverage are significant .

 

5G Frequency Bands, Channels for FR1 & FR2

5G NR uses two frequency ranges: frequency range 1 (FR1) includes 6 Ghz frequency bands and below. Frequency band 2 (FR2) includes bands in the millimeter wavelength (or mmWave) range, which includes 20-60 Ghz. That mmWave range is particularly helpful to enable 5G Ultra Wideband (UWB). Millimeter wave spectrum is the cornerstone in enabling 5G Ultra Wideband network. 5G NR will enable the network to support adaptive bandwidth. Key benefits of 5G NR will include more capacity for wireless users, improved links among users (so less lag time and network loss), and enhanced speed of data rates.

5G NR technologies will reshape residential and commercial broadband Internet services. Especially in under-served areas that have issues with last mile connectivity and legacy cable/fiber Internet operators, 5G technologies will enable wireless gigabit and multi-gigabit Internet services in your home or office, without the need for Wi-Fi, or in-conjunction with WiFi-6, and always-connected. 5G fixed wireless will enable new levels of competition between carriers and ISPs, as well as new services with much lower latency, high speed connections for cloud computing, gaming and more.

 

- Non-standalone (NSA) and Standalone (SA): Two Standards-based Paths to 5G 

The actual 5G radio system, known as 5G-NR, won't be compatible with 4G. But all 5G devices, initially, will need 4G because they'll lean on it to make initial connections before trading up to 5G where it's available. That's technically known as a "non standalone," or NSA, network. Later, 5G networks will become "standalone," or SA, not requiring 4G coverage to work. But that's a few years off. 4G will continue to improve with time, as well. 

5G New Radio (NR) is the global standard for a unified, more capable 5G wireless air interface. The air interface, or access mode, is the communication link between the two stations in mobile or wireless communication. The air interface involves both the physical and data link layers (layer 1 and 2) of the OSI model for a connection. 5G-NR will deliver significantly faster and more responsive mobile broadband experiences, and extend mobile technology to connect and redefine a multitude of new industries. 

 

- Beamforming Is Going To Be A Big Deal

As the number of mobile users and their demand for data rises, 5G must handle far more traffic at much higher speeds than the base stations that make up today’s cellular networks. Beamforming is one of the burgeoning technologies that will help get us there. Beamforming is a traffic-signaling system for cellular base stations that identifies the most efficient data-delivery route to a particular user, and it reduces interference for nearby users in the process. The idea of beamforming is not new to mobile communications, as LTE networks extensively use digital beamforming today. With 5G, however, the challenges of signal propagation and smaller antenna sizes motivate the use of extensive analog beamforming techniques.

A massive Multiple-input Multiple-output (mMIMO) technology enables signal transmission to multiple users at increased bandwidth efficiency, resulting in higher system capacity. In 5G NR, the frequency band extends to the millimeter-wave to accommodate increased traffic over a larger bandwidth. 5G NR provides enhanced transmission capabilities to transceivers by utilizing the mMIMO technology with a significantly increased number of antenna elements. Such transmission requires massive arrays to perform accurate high-gain beamforming over the millimeter-wave frequency band. 

Beamforming and mMIMO are sometimes used interchangeably. One way to put it is that beamforming is used in mMIMO, or beamforming is a subset of mMIMO. In general, beamforming uses multiple antennas to control the direction of a wave-front by appropriately weighting the magnitude and phase of individual antenna signals in an array of multiple antennas. That is, the same signal is sent from multiple antennas that have sufficient space between them (at least ½ wavelength). In any given location, the receiver will thus receive multiple copies of the same signal. Depending on the location of the receiver, the signals may be in opposite phases, destructively averaging each other out, or constructively sum up if the different copies are in the same phase, or anything in between. 

 

 

 

[More to come ...]


 


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