Innovation and change are major drivers for technology-based industries. The evolution of mobile networks is constant, adjusting and innovating in cyclical patterns. An old technology will disappear when a new one emerges. Less effective networks are taken out of commission to allow their more powerful successor to flourish. 5G is the fifth and latest generation of mobile technology, following through on its predecessors: 1G (~1980), 2G (~1990), 3G (~2000) and 4G (~2010).
What is 5G?
What is 5G/IMT-2020?
40 years of mobile generations
5G objectives, requirements and scenarios
There is a broad consensus on what kind of performance 5G technology will have to support.
5G will not just be about improved throughputs but also about providing the right throughput for the right user, on average and not just in theory. Although 4G has improved throughputs considerably compared to 3G, there is a sizeable difference between peak and average throughputs. As an example, with 5G, the target is to provide 50 Mbps connectivity everywhere, thus addressing both coverage and capacity issues.
- 5G will need to suit a whole raft of services, ranging from consumer services to any of the industry’s vertical markets, by way of public safety organisations. Whereas 4G was conceived purely as a mobile broadband technology, 5G will have to be flexible enough to allow new services or business models to emerge.
- 5G will thus have to function on any kind of spectrum, be it low or very high frequency bands, shared, licensed or unlicensed. It will need to work more easily with other technologies (terrestrial or not), perform perfectly in both densely populated and rural areas, and operate as effectively in traditional cellular mode as in new configurations – such as mesh/relay mode – when necessary.
- Of course, 5G will also need to be more spectrum efficient and more energy efficient to enable new use cases, new devices and connected objects to emerge and communicate with the resources available. Together with energy efficiency, cost effectiveness will be a vital factor for 5G.
In terms of concrete specifications the EU-funded project, METIS, defined 5G as a technology that can support mobile data volumes that are 1,000 times higher per area; 10 to 100 times more connected devices; typical user data rates that are 10 to 100 times higher; 10 times longer battery life for low power MMC; and five times lower end-to-end latency.
ITU-R describes three usage scenarios for IMT-2020 systems. FWA (Fixed Wireless Access) or WTTH (Wireless To The Home) is an additional usage scenario.
- eMBB (enhanced Mobile Broadband)
- mMTC (Massive machine Type Communications)
- uRLLC (ultra Reliable Low Latency Communications)
- FWA or WTTH is about providing connectivity to homes thanks to wireless networks rather than fixed ones.
5G technology enablers
Key technologies for 5G include the use of mmWaves, massive MIMO, additional new waveforms, spectrum sharing, multi Radio Access Technologies (RAT) integration, Ultra-Wide Band (UWB) radio modules, Cloud or Centralised RAN, Device to Device (D2D), Network Function Virtualisation (NFV), Software Defined Network (SDN), Mobile Edge Computing (MEC) and Network Slicing.
SDN-NFV (Network virtualisation)
- Network virtualisation is the uncoupling of network hardware and software. It enables network functions to be run on traditional IT servers instead of dedicated hardware. Beyond the direct benefits of running network functions on hardware produced in volume, the virtualisation of a network brings greater flexibility in terms of network architecture.
- SDN (Software Defined Network) is a concept based on the separation of the control plane and data plane of the network architecture.
An SDN architecture is built around a centralised control layer, using control software.
- NFV (Network Functions Virtualisation) refers to the process of virtualising i.e. implementing network services in software form using standardised servers (which currently run on proprietary hardware).
Heterogeneous networks, also known as HetNets, refer to the provision of mobile services using a combination of different technologies and sites (2G, 3G, 4G, Wi-Fi). Heterogeneous Networks are wireless networks comprised of different types of base stations and wireless technologies. HetNets manage macro and small cells, Distributed Antenna Systems (DAS) and Wi-Fi hotspots, when present.
- Multiple Input Multiple Output (MIMO) technology is key to improving spatial efficiency. Massive MIMO uses a very large number of service antennas (hundreds or thousands) that are operated in a fully consistent and adaptive fashion. Multiple User (MU-MIMO) form offers a dual advantage: a base station that can communicate simultaneously with multiple user equipment on the same frequencies and the ability to send multiple data streams.
- Beamforming is about controlling and reducing interference. It requires MIMO antennae and is able to broadcast the same signal using multiple antennae. Beamforming uses signal reflection and diffusion to perform communications in non-line-of-sight (NLOS) situations.
The combination of massive MIMO and beamforming techniques creates the ability to pack more elements and concentrate the transmission’s path towards a receiver, and thus increase coverage with a single antenna at a time when antenna elements are becoming significantly smaller.
Network slicing is a concept that derives from the virtualisation of network functions, and aims to make services RAT-agnostic. The core idea is to use the same hardware to meet different needs (use cases or users with specific needs). It also acts as a support for multiple air interfaces, which can include the LTE air interface as well as any newly developed ones.
There is a relatively broad consensus within the industry that network slicing should focus chiefly on fully integrating LTE-A with 5G, but provide only limited interworking with 2G and 3G, which are native circuit-switched radio access technologies whose full support would be complicated to achieve and counter-productive.
Network Slicing has become a fundamental element of 5G technology, enabling a wide range of use cases and providing customised connectivity. It is thus possible to provide very low latencies in some network slices and very high bandwidth in other slices.
Cm & MmWave use
- Studies are ongoing in 24-86 GHz spectrum ranges for 5G use. The 25-27.5 GHz, 31.8-33.4 GHz, 37-43.5 GHz, 45.5-50.2 GHz, 50.4-52.6 GHz, 66-79 GHz and 81-86 GHz frequencies are particular targets.
High frequencies are needed to deliver data rates above 1 Gbps. Spectrum above 20 GHz is highly coveted at the regional and national levels. High frequencies with wide bandwidths are indeed required to address new data needs for ultra-fast user connections (10-20 Gbps) delivered by 5G. Above 20 GHz, available bandwidths are of a magnitude of 1 GHz or more, which is sufficient for almost all eMBB applications, including mission-critical services.
The mobile sector’s use of high frequencies requires several technical adjustments, mainly due to propagation characteristics and wavelengths.
The use of high frequencies will have multiple consequences with regard to deployment:
- Point-to-Point paths are possible even under Non-Line-of-Sight (NLOS) conditions. Point-to-Multipoint links are relatively complicated and strictly limited to a range of around 200 m.
- NLOS schemes are very restrictive but not impossible.
- Below 30 GHz, communication from the outside to the inside, communication in NLOS situations and communication from the inside to the outside are technically feasible with small adjustments.
- Between 30 and 60 GHz, only outdoor to indoor communications are technically feasible. Use of beamforming and multiple high gain antennae is required.
- Above 60 GHz, indoor communications are only feasible if they have access to wideband channels.
Mobile services’ use of frequencies above 6 GHz means:
- The opportunity to find bands with larger channels (around 1 GHz in the considered bands)
- A significant reduction in the ranges at very high frequencies. This eases the burden on resources and enables spectrum reuse and sharing. These frequencies will remain focused chiefly on providing capacity.
- Smaller antennae – which are easier to install – and massive MIMO. Combined with beamforming, massive MIMO will likely improve spatial efficiency. Beamtracking is expected to also be used further down the road.
- The opportunity to use millimetre waves in NLOS situations.
Standardising 5G and identifying/allocating 5G spectrum are key to ensuring timely 5G rollouts.
3GPP is expected to be the core driver of 5G standardisation for mobile technologies e.g. 3GPP RAN, CT and SA groups. In addition, the 5G Infrastructure PPP members will also contribute to the being done by a wide range of other standardisation bodies (IETF, ETSI, ONF, Open Daylight, OPNFV, Open Stack…).
5G marks the first time in the mobile industry that the standardisation process has been sped up, in particular because of intense pressure on the 3GPP from non-European actors. At the MWC’17, a number of leading MNOs (AT&T, NTT DOCOMO, South Korea Telecom (SKT), Vodafone Group, BT Group, Telstra, KT Corp, KDDI, Telia Company, Swisscom, Telecom Italia, Etisalat, Sprint, LG Uplus and Deutsche Telekom) and equipment vendors (Ericsson, Qualcomm Technologies, Intel, Vivo, LG Electronics, Huawei and ZTE) called for an acceleration of the 5G New Radio (5G NR) standardisation process (i.e. Release 15)
The objective was to enable large-scale trials in 2019 instead of 2020. The group also suggested the addition of an intermediate milestone (set for the end of 2017) to complete specification documents. Verizon, Samsung and Nokia opposed that decision. Following an agreement in 3GPP in March 2017, the Non Standalone (NSA) implementation of 5G New Radio (NR) was moved forward to December 2017. This intermediate milestone is key to enabling 3GPP-based large-scale trials and deployments as early as 2019, instead of 2020 as initially planned. The Standalone Release15 was approved in June 2018. The late drop was completed in June 2019.
A complete 5G standard that fully satisfies all of the International Telecommunications Union requirements is expected to be completed in June 2020 (Release 16). Release 16 focuses on the verticals’ needs (Automotive, Industrial IoT and Operation in unlicensed bands). Release 16 will deliver generic system improvements and enhancements, particularly positioning MIMO enhancements and power consumption enhancements.
- 600/700/800 MHz
- 3.4-4.2 GHz
- 24-71 GHz
- the 26 GHz band received a global 5G identification through a time-delay mechanism. Member states agreed on an out-of-band emission limit of -33 dBW/200 MHz for 5G base stations until 2027. After 2027, the limit is more restrictive to -39 dBW/200 MHz.
Table 1: mmWave bands for IMT
|Identification for IMT|
|45.5-47 GHz (some countries)|
|47.2-48.2 GHz (some countries)|
Source: based on ITU WRC-15 final Acts, Resolution 238 and WRC-19 provisional Final Acts
At WRC-23, an IMT identification could be approved for 3.3-3.4 GHz, 3.6-3.8 GHz, 6425-7125 GHz and 10.1-10.5 GHz. After 2023, the status of the 470-694 MHz frequencies could be examined: at WRC-15 it was decided that the frequencies would remain under its global current broadcasting allocation in region 1 along with its co-primary allocation and secondary allocation to fixed and mobile in regions 2 (Asia) and 3 (the Americas).
|Identification for IMT||Additional Allocation|
|24.25-27.5 GHz||24.25-25.25 GHz|