How do you create a new ‘G’? Like 5G

Have you ever thought about how a new ‘G’ is created?

Principal Researcher

Principal Researcher

5G is the next generation in mobile communications, addressing a wide range of use cases. An integral part of 5G is today’s 4G, and, therefore, those at the forefront of 4G technologies are also more likely to lead the introduction of 5G. This is certainly true of Ericsson – we’ve taken the lead in creating previous generations of technology, and our patent portfolio covers 2G, 3G and 4G. Now, through a continuation of our pioneering research and technology development, we’re ready to advance business and society in more innovative ways than ever before, with the introduction of 5G.

All-new interface

The 5G air interface is an evolution of LTE and New Radio (NR). NR will exploit frequencies up to almost 100 GHz and improve performance, enabling uses cases not covered by LTE. Tight interworking between the two technologies is supported which is crucial – not only at initial roll-out when NR coverage may not be uniform, but also as a way to exploit the wider bandwidths available at the very high carrier frequencies addressed by NR. Providing coverage at higher frequencies is more challenging than lower frequencies, simply due to the laws of physics. LTE at lower frequencies can, therefore, be used to provide reliable coverage; this is complemented by NR at high frequencies for capacity and extreme data rates, when radio conditions allow.

NR features new technologies that are not part of the current 4G framework. Since NR addresses a wide range of use cases, many of which are yet unknown, forward-compatibility is a key requirement to allow new functionality to be added in the future. Ultra-lean design is one of the tools to guarantee this.

In essence, an ultra-lean design minimizes the amount of always-on signals in order to maximize the possibility of introducing new transmission schemes in the future. An ultra-lean design also brings the benefit of reduced interference levels, enabling higher capacity and data rates, as well as reduced power consumption on the network side. With always-on signals kept to a minimum, several of the fundamental functionalities need to be designed differently. For example, unlike LTE, the lack of an omni-present, cell-specific reference signals cannot be used as an indication of a lost connection.

Beam-centric design

Advanced multi-antenna technologies will play even more of an important role in 5G than LTE, to ensure high capacity and good coverage. Propagation conditions at the higher carrier frequencies are different and so using beamforming to ‘focus’ energy where the user is located becomes crucial. This includes tracking the user’s movement to guarantee a good connection. Such a ‘beam-centric design’ also means that mechanisms for cell search, random access, mobility, and system-information distribution need to be designed with beamforming in mind from the start, unlike LTE.

The basic transmission scheme in NR will, similarly to LTE, be based on OFDM (orthogonal frequency-division multiplexing) but with the possibility for a scalable numerology. For very large cells, or for coexistence with LTE and NB-IoT on the same carrier, 15 kHz subcarrier spacing is used. Higher subcarrier spacing of 30 kHz up to 480 kHz, are also supported. For example, 30 kHz or 60 kHz can be useful for smaller cells, and 120 kHz is beneficial in the mm-wave range to mitigate phase noise. Transmissions are organized in slots of 14 symbols, each with the possibility for very fast hybrid-ARQ feedback to minimize latency.

Ultra-high reliability and low latency (URLLC) refers to a set of use cases where data needs to be delivered at a very low latency while maintaining a high reliability. In NR this can be done through so-called mini-slots, which are significantly shorter than the slots typically used for ‘normal’ data transmission. A mini-slot based transmission can pre-empt an ongoing slot-based transmission, in case very urgent data arrives at the base station. Mini-slots are also useful when supporting unlicensed spectrum, as they provide the ability to start a transmission immediately after a successful listen-before-talk, without having to wait for a slot boundary.

Toward standardization

Like the generations that have come before, 5G standardization is spearheaded by the 3rd Generation Partnership Project (or 3GPP, as it’s more commonly known). This collaborative project brings together telecommunications companies from all over the world in order to establish an international standard for 5G, and Ericsson is one of the major players in this organization.

The next step in 5G development is taking place right now: the standardization of the new technology. 3GPP Release 15 starts in March this year and ends in mid-2018. However, to meet the need for initial commercial deployments, 3GPP will deliver a first version of the specifications by the end of 2017. This will be a non-standalone version of NR, which relies on LTE for some of the basic functionality – while the mid-2018 version will cover standalone operation as well. In the next version, Release 16, the NR specifications will support all the IMT-2020 requirements and form the basis for 3GPP’s submission to the ITU (International Telecommunication Union).

The standardization process is a highly innovative and complex one – the amount of documents sent in to just one of these working groups, during one meeting, is around two and a half times what Shakespeare wrote in his entire life. By the time we reach wide-scale deployment in 2020, a lot of intensive work will have gone into deciding the standard – and Ericsson will have been there every step of the way, determining the future of 5G, for the benefit of all.

Watch this video where I explain how Ericsson is involved in setting the standard for 5G.

Find out more about about patents and licensing for 5G.

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