Image: 5G Building on the LTE Revolution

5G Building on the LTE Revolution

Our future 5G world will be one of high connectivity and extreme communications as never before seen. 5G NR is the global standard for providing a unified, more capable 5G wireless air interface. It will deliver significantly faster and more responsive mobile broadband experiences, and it will extend mobile technology to connect and redefine a multitude of new industries.

Unlike previous mobile network technology turns, 5G will not be a “rip-and-replace” of existing 4G/LTE networks, but instead symbiotically coexist and serve as the cornerstone from which many of the 5G use cases and applications will be delivered around ultra-broadband, low latency and massive machine type communications. Much of the technology that our future 5G world will require has already been introduced and implemented from 3GPP releases 12, 13 and 14. 5G will take these technologies and concepts and expand upon them, taking them to new heights, especially for those applications utilizing millimeter wave frequencies. With theoretical data rates of 10Gbps and 1ms end-to-end latencies, 5G will break many boundaries, but not without LTE paving the way.

Market Growth Potential

From a financial perspective, 5G revenue potential will greatly impact the industry, bolstered by wider bandwidths and faster networks. By 2025, worldwide revenues from 5G services expect to top nearly $250 billion annually, according to industry forecasts. Expectations are high for 5G. 5G technology will build on existing investments and infrastructure from today’s advanced LTE networks, in addition to introducing some entirely new technologies never before used on such a massive, commercial scale. Soon mobile operators will have to make the decision as to whether or not they will continue to squeeze out more bandwidth and performance out of their existing LTE technology with higher levels of carrier aggregation, modulation, and unlicensed spectrum, or make the leap to 5G NR, with its 10-20X improvement in bandwidth but requirement for new equipment and infrastructure.

But perhaps the most impressive expectation is that 5G will allow cellular technology to expand into markets and use cases that have not been imagined yet. First, this new technology will create endless opportunities as it enters the world of machines, with applications such as autonomous vehicles, wearable consumer devices and the ability to connect millions of remote industrial sensors.

LTE Sets the Foundation for 5G

It’s undeniable that 5G has plenty of moving parts—from sophisticated beam-forming antennas to the use of very high frequencies at millimeter wave. None of this would be possible without the foundation already built by LTE. Continuing advancements in LTE are establishing the foundation for 5G. Gigabit LTE, for example, has the ability to deliver much higher data rates than standard LTE by leveraging some key capabilities that were previously introduced by 3GPP, such as MIMO, Carrier Aggregation and 256 QAM. As both a precursor and foundation for 5G, the continuing evolution of LTE will accelerate the expansion of mobile into new vertical markets such C-V2X, the Internet of Things (IoT) and much more.

5G Numerologies and Frame Structures

5G NR Differences from LTE

LTE radio access (or, in 3GPP terms, eUTRAN) is an OFMD based technology with a fixed subcarrier spacing of 15 kHz that supports carrier bandwidths from 1.4 MHz up to 20 MHz. LTE has a packet-switched architecture that supports a wide range of data applications. Voice is also supported as voice over LTE (VoLTE) or using fallback mechanisms to 3G and circuit-switched technologies.

The 5G NR specification embraces a flexible air interface. It aims to include different use case families—from enhanced mobile broadband (eMBB) and massive machine type communications (MIoT) to ultra-reliable, low latency communications (URLLC)—that span across industries. These different use cases require a wide variety of air interface characteristics in terms of frequency range, subcarrier spacing, carrier bandwidths, symbol durations, etc.; the network architecture needs to offer many options. Table 1 shows the flexibility of frequency-specific parameters.

To cope with the different 5G NR use cases and demands per service, 3GPP defines the concept of bandwidth parts (BWP). Each BWP has a fixed numerology (fixed subcarrier spacing, number and location of the resource block, symbol duration, etc.).

User equipment (UE) can be configured with up to four carrier bandwidth parts in downlink/uplink, but at any given time only a single downlink/uplink carrier bandwidth part can be active. The downlink control information (DCI), radio resource control (RRC) or a timer can trigger the switch of the active BWP.

Parameter Frequency range 1 (<24 GHz, mostly <6 GHz) Frequency Range 2 (>24 GHz)
Carrier aggregation Up to 16 carriers Up to 16 carriers
Bandwidth per carrier 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100 MHz 50, 100, 200, 400 MHz
Subcarrier spacing 15, 30, 60 kHz 60, 120, 240 (not for data) kHz
Table 1: 5G NR flexibility in frequency domain parameters

Another significant difference between LTE and 5G NR is the position of the synchronization signals, namely the primary (PSS) and secondary synchronization signals (SSS) within the carrier. Synchronization signals are very important. They are the first information that mobile devices need to identify in order to access the network.

In LTE, the sync signals are always located in the center of the carrier bandwidth; this makes them easy to find. In 5G NR, the sync signals are part of the SS/PBCH block (also called synchronization signal block, SSB) containing the physical broadcast channel (PBCH) information. These SS/PBCH blocks can be located at multiple positions all over the carrier bandwidth and are broadcast periodically as defined symbols in the radio frames and different beams versus time.

5G NR Rollout

Another significant difference between LTE and 5G NR is the position of the synchronization signals, namely the primary (PSS) and secondary synchronization signals (SSS) within the carrier. Synchronization signals are very important. They are the first information that mobile devices need to identify in order to access the network.

In LTE, the sync signals are always located in the center of the carrier bandwidth; this makes them easy to find. In 5G NR, the sync signals are part of the SS/PBCH block (also called synchronization signal block, SSB) containing the physical broadcast channel (PBCH) information. These SS/PBCH blocks can be located at multiple positions all over the carrier bandwidth and are broadcast periodically as defined symbols in the radio frames and different beams versus time.

Conclusion

With the 5G NR network rollout clearly on the horizon, network operators worldwide are planning pre-commercial network trials or even starting commercial network rollouts. The aim is to overcome the challenge of a more demanding and complex air interface and deliver the commercial and technical benefits offered by 5G. A 5G NR measurement solution should provide accurate and reliable data collection with coverage measurements, application QoE measurements, and verification of the device interaction with a real 5G NR network. Rohde & Schwarz fulfills all these requirements from a single source with its end-to-end 5G NR network measurement solution in line with the company’s slogan, “Be ahead in 5G. Turn visions into reality.”

5G Resources

Free 5G NR Wall Poster

See 5G NR use cases and how LTE-Advanced Pro paves the way for 5G, explore carrier bandwidth and how it relates to 5G NR numerology, and compare standalone and non-standalone 5G NR deployment scenarios.

Get My Poster

Image: 5G evolution to 6G

5G Evolution: The Path to 6G

In this white paper, we explore the evolution from 5G to 6G from a service, air interface and network perspective, as well as take a crystal ball perspective on how the future with 6G may look.