The 5G NR numerology for the carrier is similar to LTE includes subcarrier spacing (SCS) and CP.
15 kHz Subcarrier Spacing (SCS) is not enough and multiple larger SCS values with 2^μ × 15 kHz, where μ = 0, 1, 2, 3, 4 were introduced for the mobility requirement supporting up to 500 km/h.
The CP length is defined to well mitigate the impact of the delay spread, and have a reasonable overhead.
In the case 15 kHz SCS of LTE, the ratio of CP length over the duration of one OFDM symbol is 7.03%, Which is reused for 5G NR in the case of 15 kHz SCS and normal CP.
As the duration of one OFDM symbol is equal to the reciprocal of SCS, the CP length for other SCS will be proportionally reduced by 2μ, μ = 0, 1, 2, 3, 4 which keeps the same ratio of CP overhead as 15 kHz.
Supported transmission numerologies
NR supports multiple numerologies on the same carrier and, consequently, there are multiple resource sets of resource grids, one for each numerology Since a resource block is 12 subcarriers.
Resource grids for two different subcarrier spacing.
The resource block boundaries are aligned across numerologies such that two resource blocks at a subcarrier spacing of Δf occupy the same frequency range as one resource block at a subcarrier spacing of 2Δf.
Frequency bands within the scope of Release 15 in 3GPP are divided into two frequency ranges:
5G NR Frequency Band and corresponding subcarrier spacing
frequency bands where NR will operate are in both paired and unpaired spectra, NR supports
both FDD and TDD operation
5G NR Spectrum and duplex schemes
The Carrier bandwidth available in frequency ranges FR1 and FR2 are given in the table:
Carrier bandwidth supported in 5G NR
Release 15 of the 3GPP specifications for NR includes 26 operating bands in frequency range 1 and three in frequency range 2.
Bands Defined by 3GPP for NR in
Frequency Range 1:
Bands Defined by 3GPP for NR in Frequency Range 2
Although 5G relies on existing network
infrastructure and concepts, there are several new features to 5G. Such
features-new radio (NR) and new core 5GC, operation in high spectrum bands mmWave with
massive MIMO antenna systems.
The air interface between the gNodeB and user equipment (UE) has been named the new radio (NR).
However, the interface between the ng-eNodeB and UE remains the same as in LTE, evolved universal terrestrial radio access (E-UTRA). The gNodeBs and ng-eNodeBs are connected to one another via the new Xn interface.
The NR interface is designed to support multiple frequency ranges and bandwidths, low latency with flexible slots configuration, multi-gigabits-per-second data rates and increased spectral efficiency.
The new core 5GC is a service-based architecture in which different network functions (providers) offer services to other NFs (consumers) through interfaces. The NFs can be placed at specific locations to fulfil certain latency requirements. This allows operators to deploy and adapt the network according to their needs.
This network structure is a cloud-native, programmable, modular architecture designed to create multiple logical networks (or slices) running over the same physical or virtual resources.
This design responds to the different network requirements of the different use cases. The technology behind this architecture is network functions virtualization and software defined networking.
A new spectrum needs to be introduced to ensure 5G meets the defined requirements. New frequencies will range from 450 MHz to approximately 50 GHz. High frequency bands will deliver faster data rates and extended capacity, especially at millimeter wave bands (above 24 GHz).
The Release 15 NSA specification defines the E-UTRA - NR dual connectivity operation, whereby a UE is connected to one eNodeB acting as a master node and one en-gNodeB acting as a secondary node.
The en-gNodeB is a node providing NR user plane connectivity to the UE and might be connected to the evolved packet core (EPC) through the S1-U interface.
The eNodeB is connected to the EPC via the S1 interface and to the en-gNodeB via the X2 interface.
In 5G, not all traffic is equal. Mobile operators must be able to match different services with different levels of access, a concept known as network slicing.
Many critical applications, such as autonomous vehicles and remote surgery, will demand prioritized 5G “slices” to guarantee a secured continuous service.
The network will be sliced into multiple virtual networks running on a common network infrastructure, each with its own set of characteristics.
A network slice is composed of a RAN and a core network with either physical or virtualized functions.
Multiple-input multiple-output aims to increase the number of transmitting and receiving antennas (TX RX) to have more signal paths and achieve gains in spectral efficiency.
This would make it possible to provide higher capacity within the same spectrum.
While conventional MIMO, as defined in LTE, uses few TX RX antennas, 5G goes further with massive MIMO by using dozens or even hundreds of antennas at the same time.
Massive MIMO is expected to be used in the new millimeter-wave frequencies, with rectangular antenna arrays in both the base station and the UE.
MEC: Multi-access edge computing.
The 5G network architecture will support multi-access edge computing technology.
MEC provides cloud-computing capabilities running at the edge of the network, taking advantage of the low latency and high bandwidth provided by 5G.
It is expected that MEC will foster the creation of innovative services and use cases such as video analytics, location services, augmented reality, data caching and optimized content distribution.
The evolution from 4G to 5G in the transport network:
The introduction of 5G promises to deliver new capabilities and new technologies that include the use of higher radio frequency bands to support additional bandwidth mmWave, faster and more efficient fronthaul connections, more reliable and cost effective timing, and more granularity in the distribution of network functions .
Network functions virtualization (NFV): refers to the replacement of network functions on dedicated appliances - such as routers, load balancers, and firewalls - with virtualized instances running as software.
NFV’s purpose is to transform the way networks are built and services are delivered. With NFV, any enterprise can simplify a wide array of network functions, as well as maximize efficiencies and introduce new revenue-generating services faster and easier than ever before.
5G NFV and Network Slicing.
In 5G, NFV will enable network slicing - a virtual network architecture aspect that allows multiple virtual networks to be created atop a shared physical infrastructure.
Virtual networks can then be customized to meet the needs of applications, services, devices, customers, or operators. In 5G, NFV will also enable the distributed cloud, helping to create flexible and programmable networks for the needs of tomorrow.
Mobile Broadband addresses the human-centric use cases for access to multi-media content, services and data.
The demand for mobile broadband will continue to increase, leading to enhanced Mobile Broadband.
The enhanced Mobile Broadband usage scenario will come with new application areas and requirements in addition to existing Mobile Broadband applications for improved performance and an increasingly seamless user experience. This usage scenario covers a range of cases, including wide-area coverage and hotspot, which have different requirements.
For the hotspot case, i.e. for an area with high user density, very high traffic capacity is needed, while the requirement for mobility is low and user data rate is higher than that of wide area coverage.
For the wide area coverage case, seamless coverage and medium to high mobility are desired, with much improved user data rate compared to existing data rates. However the data rate requirement may be relaxed compared to hotspot.
The peak data rate of IMT-2020, for enhanced Mobile Broadband is expected to reach 10 Gbit/s.
However under certain conditions and scenarios IMT-2020 would support up to 20 Gbit/s peak data rate,
IMT-2020 would support different user experienced data rates covering a variety of environments for enhanced Mobile Broadband.
For wide area coverage cases, e.g. in urban and sub-urban areas, a user experienced data rate of 100 Mbit/s is expected to be enabled.
In hotspot cases, the user experienced data rate is expected to reach higher values (e.g. 1 Gbit/s indoor).
The minimum requirements for peak data rate are as follows:
- Downlink peak data rate is 20 Gbit/s.
- Uplink peak data rate is 10 Gbit/s.
Peak data rate is the maximum achievable data rate under ideal conditions (in bit/s),
which is the received data bits assuming error-free conditions assignable to a single mobile station, when all assignable radio resources for the corresponding link direction are utilized (i.e. excluding radio resources that are used for physical layer synchronization, reference signals or pilots, guard bands and guard times).
Peak data rate is defined for a single mobile station. In a single band, it is related to the peak spectral efficiency in that band.
User experienced data rate is the 5% point of the cumulative distribution function (CDF) of the user throughput.
User throughput (during active time) is defined as the number of correctly received bits, i.e. the number of bits contained in the service data units (SDUs) delivered to Layer 3, over a certain period of time.
The target values for the user experienced data rate are as follows in the Dense Urban environment:
- Downlink user experienced data rate is 100 Mbit/s.
- Uplink user experienced data rate is 50 Mbit/s.
Area traffic capacity is the total traffic throughput served per geographic area (in Mbit/s/m2).
The target value for Area traffic capacity in downlink is 10 Mbit/s/m2 in the Indoor Hotspot - eMBB
Connection density is the total number of devices fulfilling a specific quality of service per unit area (per Km2).
The minimum requirement for connection density is 1000000 devices per Km2.
The 5G wireless communications will be driven by three use cases of enhanced mobile broadband, massive machine-type communication, and ultra-reliable low latency communication.
The enhanced mobile broadband is designed for high bandwidth internet access suitable for web browsing, video streaming, and virtual reality.
The massive machine-type communication is responsible for establishing narrow band Internet applications such as narrowband IoT.
The ultra-reliable low latency communication facilitates certain delay-sensitive applications such as factory automation, remote surgery and autonomous driving.
Of all the above technologies, ultra-reliable low latency communication will be the most stringent to achieve based on the 1 ms end-to-end latency, link reliability of 99.99999% and error rates that are lower than 1 packet loss in 100000 packets as recommended by the ITU.
New techniques are required to meet with the stringent latency and reliability requirements for ultra-reliable low latency communication as we migrate into the domain of haptic communications, tactile Internet, intelligent transport system and industry 4.0 era revolution.
Latency specifies the end to end communication delay, measuring the time between the sending of a given piece information and the corresponding response.
To give an example, latency can be identified in the time gap between the moment you click “stop” and the instant in which a remotely driven vehicle actually starts braking.
Reducing the latency experienced by the end users from hundredths of a second to a few of milliseconds can have an unexpected impact, leading to a real digital revolution.
Low delays achieved by the development of 5G-based mobile networks open the way to radically new experiences/opportunities, including multiplayer mobile gaming, virtual reality experiences, factory robots, self-driving cars and other applications for which a quick response is not optional at all, but a strong prerequisite.
Focusing on self-driving vehicles, current cellular networks already provide a wide variety of tools that address some of the technology and business requirements.
For example, LTE Category-M and Narrow Band-Internet of Things are excellent low-power sensor communication technologies.
However, in order to enable complex vehicle maneuvering, determining and recommending individual actions, e.g. acceleration, deceleration, lane changes or route modifications, the vehicles must be able to share and receive information about their driving intentions in almost real time. This low-latency demand certainly requires the development of an overall 5G system architecture to provide optimized end-to-end vehicle to everything (V2X) connectivity.
Several emerging technologies including wearable devices, virtual and augmented reality, and full immersive experience are shaping the demeanour of human end users, and they have special requirements for user satisfaction.
Therefore, these use cases of the next generation network push the specifications of 5G in multiple aspects such as data rate, latency, reliability, device and network energy efficiency, traffic volume density, mobility, and connection density.
Current fourth generation networks are not capable of fulfilling all the technical requirements for these services
Latency is highly critical in some applications such as automated industrial production, control/robotics, transportation, health-care, entertainment, virtual realty, education, and culture.
In some cases, we need latency as low as 1 ms with packet loss rate no larger than 0.01.
Several latency critical services which need to be supported by 5G are described as follows.
Factory automation includes Realtime control of machine and system for quick production lines and limited human involvement. In these cases, the production lines might be numerous and contiguous.
This is highly challenging in terms of latency and reliability.
Therefore, the latency requirement for factory automation applications is between 0.25 ms to 10 ms with a very low packet loss rate.
Intelligent Transportation Systems: Autonomous driving and optimization of road traffic requires ultra reliable low latency communication.
According to intelligent transportation systems (ITS), different cases including autonomous driving, road safety, and traffic efficiency services have different requirements.
Autonomous vehicles require coordination among themselves for actions such as platooning and overtaking.
Road safety includes warnings about collisions or dangerous situations.
Traffic efficiency services control traffic flow using the information of the status of traffic lights and local traffic situations.
For these purposes, latency of 10 ms to 100 ms with low packet loss rate is required.
Robotics and Telepresence: In the near future, remote controlled robots will have applications in diverse sectors such as construction and maintenance in dangerous areas.
A prerequisite for the utilization of robots and telepresence applications is remote-control with real-time synchronous visual-haptic feedback.
In this case, system response times should be less than a few milliseconds including network delays.
Communication infrastructure capable of proving this level of real-time capacity, high reliability and availability, and mobility support is to be addressed in 5G networks.
Virtual Reality: Several applications such as micro-assembly and tele-surgery require very high levels of sensitivity and precision for object manipulations.
VR technology accommodates such services where several users interact via physically coupled VR simulations in a shared haptic environment.
Current networked communication does not allow sufficient low latency for stable, seamless coordination of users.
Typical update rates of display for haptic information and physical simulation are in the order of 1000 Hz which allows round trip latency of 1 ms. Consistent local view of VR can be maintained for all users if and only if the latency of around 1 ms is achieved.
Health care: Tele-diagnosis, tele-surgery and tele rehabilitation are a few notable healthcare applications of low latency tactile Internet.
These allow for remote physical examination even by palpation, remote surgery by robots, and checking of patients’ status remotely.
For these purposes, sophisticated control approaches with round trip latency of 1 to 10 ms and high reliability data transmission is mandatory.
Serious Gaming: The purpose of serious gaming is not limited to entertainment. Such games include problem solving challenges, and goal-oriented motivation which can have applications in different areas such as education, training, simulation, and health.
Network latency of more than 30 to 50 ms results in a significant degrade in game quality and game experience ratings. Ideally, a round trip time on the order of 1 ms is recommended for perceivable human’s interaction with the high-quality visualization.
Smart Grid: The smart grid has strict requirements of reliability and latency. The dynamic control allows only 100 ms of end-to-end latency for switching suppliers .
However, in case of a synchronous co-phasing of
power suppliers, an end-to-end delay of not more than 1 ms is
Education and Culture: Low latency tactile Internet will facilitate remote learning and education by haptic overlay of teacher and students. For these identical multi-modal human-machine interfaces, round trip latency of 5 to 10 ms is allowed for perceivable visual, auditory, and haptic interaction.
In such scenarios, supporting network latency lower than few milliseconds becomes crucial.Based on the applications and use case scenarios above, latency critical services in 5G networks demand an End to end delay of 1 ms to 100 ms.
The latency requirements for various 5G services are summarized in the Table:
The latency of LTE is superior to that of 3G, but still inferior to what can be achieved with the wired Internet. LTE has 10 millisecond frame and 1 millisecond TTI, which are hard limit for latency. The new 5G sub-frame will be at sub millisecond level, to set a base for short latency.
The use cases, and vision of the 5G system lead to diverse requirements that the future mobile broadband system will need to meet.
The 5G unified ecosystem will serve both traditional as well as potential new applications like drones, real time video surveillance, mobile augmented and virtual reality, Internet of Things and so on.
5G will have to cope with a high degree of heterogeneity in terms of:
Services: mobile broadband, massive machine and mission critical communications, broader multicast services and vehicular communications.
Device classes: low-end sensors to high-end tablets.
Deployment types: macro and small cells.
Environments: low-density to ultra-dense urban.
Mobility levels: static to high-speed transport.
By accounting for the majority of needs, the following set of 5G requirements is gaining industry acceptance.
One of the key issues with the 5G requirements is that there are many different interested parties involved, each wanting their own needs to be met by the new 5G wireless system.
This leads to the fact that not all the requirements form a coherent list.
No one technology is going to be able to meet all the needs together.
As a result of these widely varying requirements for 5G, many anticipate that the new wireless system will be a umbrella that enables a number of different radio access networks to operate together, each meeting a set of needs.
As very high data download and ultra low latency requirements do not easily sit with low data rate and long battery life times, it is likely that different radio access networks will be needed for each of these requirements.
Accordingly it is likely that various combinations of a subset of the overall list of requirements will be supported when and where it matters for the 5G wireless system.
ITU-R has defined the following main usage scenarios for IMT for 2020 and beyond in their Recommendation, ITU-R M.2083:
Enhanced Mobile Broadband (eMBB) to deal with hugely increased data rates, high user density, and very high traffic capacity for hotspot scenarios as well as seamless coverage, and high mobility scenarios, with still improved used data rates.
Massive Machine-type Communications (mMTC) for the IoT, requiring low power consumption, and low data rates for very large numbers of connected devices.
Ultra-reliable and Low Latency Communications (URLLC) to cater for safety-critical, and mission critical applications which requires different key capabilities according to ITU-R M.2083.
So 5G should deliver significantly increased operational performance, such as increased spectral efficiency, higher data rates, low latency, as well as superior user experience (near to fixed network but offering full mobility and coverage).
5G needs to cater for massive deployment of Internet of Things, while still offering acceptable levels of energy consumption, equipment cost and network deployment and operation cost. It needs to support a wide variety of applications and services.
In recent years there have been several views about the ultimate form that 5G wireless technology should take.
There have been two views of what 5G should be:
This view of the requirements for 5G wireless systems aims to take the
existing technologies including 2G, 3G, 4G, Wi-Fi and other relevant wireless
systems to provide higher coverage and availability, along with more dense
networks. Apart from having requirements to provide traditional services.
A key differentiator would be to enable new services like Machine to Machine, M2M applications along with additional Internet of Things, IoT applications. This set of 5G requirements could require a new radio technology to enable low power, low throughput field devices with long battery lifetimes of ten years or more.
This view of the 5G requirements
takes the more technology driven view and sets specifications for data rates,
latency and other key parameters.
These requirements for 5G would enable a clear demarcation to be made between 4G or other services and the new 5G wireless system.
In order to meet the industry and user needs, it is necessary to accommodate all requirements within the definition process, ensuring that the final definition meets the majority of users needs.
5G is used across three main types of connected services, including enhanced mobile broadband, mission-critical communications, and the massive machine communications.
A defining capability of 5G is that it is designed for forward compatibility the ability to flexibly support future services that are unknown today.
Enhanced mobile broadband:
In addition to making our smartphones better, 5G mobile technology can provide new experiences as Virtual reality and Augmented reality with faster, more uniform data rates, lower latency, and lower cost-per-bit.
5G can enable new services that can transform industries with ultra-reliable, available, low-latency links like remote control of critical infrastructure, vehicles, and medical procedures.
Massive Machine Communications:
5G is meant to connect a massive number of sensors virtually everything through the ability to scale down in data rates, power, and mobility-providing low-cost connectivity solutions.
There are several reasons that 5G will be better than 4G:
5G is significantly faster than 4G.
delivering up to 20 Gigabits-per-second peak data rates and more than 100 Megabits-per-second average data rates. 5G has more capacity than 4G.
5G is designed to support a multiple of 100 increase in traffic capacity and network efficiency.
5G has significantly lower latency than 4G.
to deliver more instantaneous, real-time access: a multiple of 10 decrease in end-to-end latency down to 1ms.
5G uses spectrum better than 4G.
5G is also designed to get the most out of every bit of spectrum across a wide array of available spectrum regulatory paradigms and bands-from low bands below 1 GHz, to mid bands from 1 GHz to 6 GHz, to high bands known as millimeter wave.
5G is a unified platform that is more capable than 4G.
While 4G focused on delivering much faster mobile broadband services than 3G, 5G is designed to be a unified, more capable platform that not only elevates mobile broadband experiences, but also supports new services such as mission-critical communications and the massive IoT.
5G can also natively support all spectrum types (licensed, shared, unlicensed) and bands (low, mid, high), a wide range of deployment models (from traditional macro-cells to hotspots), and new ways to interconnect (such as device-to-device and multi-hop mesh).
5G is the 5th generation mobile network.
It is a new global wireless standard after first G, 2G, 3G, and 4G networks.
5G enables a new kind of network that is designed to connect virtually everyone and everything together including machines, objects, and devices.
Mobile data traffic is rising rapidly, mostly due to video streaming.
Overall mobile data traffic is expected to grow to 77 exabytes per month by 2022, a seven-fold increase over 2017.
Mobile data traffic will grow at a Compound Annual Growth Rate (CAGR) of 46% from 2017 to 2022
mobile video content has much higher bit rates than other mobile content types, mobile video will generate much of the mobile traffic growth through 2022.
Mobile video will grow at a Compound Annual Growth Rate (CAGR) of 55% between 2017 and 2022, higher than the overall average mobile traffic CAGR of 46%.
Of the 77 exabytes per month crossing the mobile network by 2022, nearly 61 exabytes will be due to video.
Mobile video represented more than half of global mobile data traffic beginning in 2012.
With multiple devices, each user has a growing number of connections.
Another significant trend is the growth of
smartphones (including tablets) from 50% share of total devices and
connections in 2017 to over 54% by 2022.
The most noticeable growth is going to occur in M2M connections, followed by tablets.
M2M mobile connections will reach nearly a third (31%) of total devices and connections by 2022.
The M2M category is going to grow at 32% CAGR from 2017 to 2022, and tablets are going to grow at 14% CAGR during the same period.
Along with the overall growth in the number of mobile devices and connections, there is clearly a visible shift in the device mix.
connections-such as home and office security and automation, smart metering and
utilities, maintenance, building automation, automotive, healthcare and
consumer electronics, and more-are being used across a broad spectrum of
well as in the consumer segment.
As real-time information monitoring helps companies deploy new video based security systems, while also helping hospitals and healthcare professionals remotely monitor the progress of their patients, bandwidth-intensive M2M connections are becoming more prevalent.
connections will grow from just under a billion in 2017 to 3.9 billion by 2022,
a 32% CAGR-a four-fold growth.
Internet of Things will require networks that must handle billions more devices.
The phenomenal growth in smarter end-user devices and M2M connections is a clear indicator of the growth of IoT, which is bringing together people, processes, data, and things to make networked connections more relevant and valuable.
An important factor contributing to the growing adoption of IoT is the emergence of wearable devices, a category with high growth potential.
Wearable devices, as the name suggests, are devices that can be worn on a person and have the capability to connect and communicate to the network either directly through embedded cellular connectivity or through another device (primarily a smartphone) using Wi-Fi, Bluetooth, or another technology.
By 2022, there will be 1.1 billion wearable devices globally, growing over two-fold from 526 million in 2017 at a CAGR of 16%.
With a growing number of mobile and increased data traffic both mobile and networks need to increase energy efficiency.
Network operators are under pressure to reduce operational expenditure, as users get used to flat rate tariffs and don't wish to pay more.
The mobile communication technology can enable new use cases (for ultra-low latency or high reliability cases) and new applications for the industry, opening up new revenue streams also for operators.
So 5G should deliver significantly increased operational performance (e.g. increased spectral efficiency, higher data rates, low latency), as well as superior user experience (near to fixed network but offering full mobility and coverage)
5G needs to cater for massive deployment of Internet of Things, while still offering acceptable levels of energy consumption, equipment cost and network deployment and operation cost.
It needs to support a wide variety of applications and services.
first G, 2G, 3G, and 4G all led to 5G, which is designed to provide more connectivity than was ever available before.
5G is a unified, more capable air interface. It has been designed with an extended capacity to enable next-generation user experiences, empower new deployment models and deliver new services.
With high speeds, superior reliability and negligible latency, 5G will expand the mobile ecosystem into new realms.
5G will impact every industry, making safer transportation, remote healthcare, precision agriculture, digitized logistics - and more.