Future 5G use cases will disrupt the RF component industry

Yole Développement’s work on telecom infrastructure can be found in two distinct market reports: 5G’s Impact on Telecom Infrastructure 2019 and Active and Passive Antenna Systems for Telecom Infrastructure 2019. From them, here we highlight a few insights into 5G technologies and markets.

Despite what marketing talks say, fifth generation (5G) wireless technology is NOT about incredibly high throughput, for prospective fantasist use cases like in-the-street enhanced reality. 5G is about opening new markets to operators while offering a potential synergy between industries, people and technology.

5G is the standardization by the telecom industry of technologies that were already appearing due to actual technological demand. The PC5 protocol used for automotive communication is nothing more than telecom’s response to Dedicated Short Range Communication (DSRC)/Intelligent Transport System (ITS) G5, which are automotive communication protocols based on WiFi. Narrowband Internet of Things (NB-IoT) and Long Term Evolution for Machines (LTE-M) are telecom’s response to Low Power Wide Area Network (LPWAN) specifications like SigFox or Long Range WAN (LoRaWAN). 5G is an offering from the telecom industry in order to provide a complete, coherent, reliable and convenient solution to multiple industries for efficiency improvement and value creation while opening to new revenue sources.

This being said, the potential of high throughput and low latency for user equipment is what is put forward today, especially for marketing reasons. This is because the consumer will be the first revenue source for a return on investment regarding 5G deployments. It is understood in the industry that no actual concrete use case exists yet for consumer 5G, but that potential – yet unknown – killer applications may come out of it and create value for consumers. As an example, in the early 2010s, at 4G’s debut, no one would have had Uber in mind.

A simplistic mapping of the potential markets for the telecom industry is featured in figure 1. The nascent interest today lays in the consumer market, while future interests are mostly in the industry and in enterprises.

Nevertheless, whether the use case of 5G is actual or not, its completion and use will create a need for higher rate data exchanges. These exchanges may not necessarily come from consumer user equipment though, instead they will potentially be from industrial use, or the automotive industry. In any case, data throughput will have to be improved. Only a few options exist for the telecom industry to do so. Two of them are of interest today: increasing spectrum using new Sub6/mmWave radios or increasing efficiency using beamforming and sector multiplicity.

This dual approach to enhanced throughput translates into very specific improvements technology-wise and a drastic evolution of the technology that can shuffle the cards at the component manufacturer level.

Beamforming

If we look at increased efficiency, beamforming is the main evolution. Beamforming is the capability offered to an antenna system to create a directive beam of signal that can be sent toward a specific user. It allows a potentially great throughput improvement, especially by giving the opportunity to communicate with different users in the same area using the same frequency without interference, and improving signal reception thus improving performance. Beamforming nevertheless requires a very specific modification of the architecture of the antenna system. In standard systems, two to four streams of data were amplified in what is called a remote radio head (RRH), bringing the signal up to 240W power levels before being radiated by a sixteen element antenna array. But for beamforming purposes, instead of two streams of high-power signal being radiated, up to sixty-four individual flows of signal are amplified at low power levels and radiated by one antenna element each. The reason for that is the nature of beamforming itself. Beamforming is the use of electromagnetic wave interference in order to create a signal that is amplified in a very specific direction, but destroyed in all others. To interfere with itself, an identical signal has to be sent from different antenna elements, but with a precisely calculated phase-shifting and amplitude modification. In order to do so, the same high power signal cannot be used for all antenna elements like in RRH, the signal has to be independently modified at each antenna element level. This is what is called active antenna systems (AAS). These systems therefore differ from standard RRH systems. The two main modifications are a multiplicity of low power components instead of a few high power ones, and the addition of beamforming for each antenna element. This results in the addition of what are called gain blocks, which are wideband, linear power amplifiers, Radio Frequency (RF) switches, phase shifters and attenuators. This creates a direct increase in the system’s bill of materials, and therefore a potential revenue opportunity for RF component makers. On the other hand, the reduction of power level translates in the switching from high-power power amplifiers manufactured on specifically adapted technology platforms to multiple low-power power amplifiers, which can use an alternate technology platform, thus threatening current RF component providers’ revenues.

In general, even though the past decades have seen a steady investment from operators in their network improvement, a diversion of value is expected from cost of operation toward antenna systems’ RF front-ends in order to respond to this increased bill of materials from additional RF components. From Yole Développement’s perspective, for example, the general RF component market for antenna systems is expected to see 8% annual growth between 2018 and 2025, as shown in figure 1. Strong growth comes from components dedicated to, or which have been multiplied in, active antenna systems such as RF switches and gain blocks.

If we look at the addition of new frequencies, called “new radios”, two approaches have been used. Sub-6 GHz frequencies (FR1) are the allocation of frequency bands below 6 GHz for telecommunications. “Millimeter waves” (FR2, or “mmWave”) are wide bands in the frequencies past 14 GHz. These two approaches are drastically different. Sub-6 GHz new radios are the incremental evolution of LTE frequency bands and technologies. mmWave new radios are a complete disruption technology-wise and implementation-wise.

Sub-6 GHz frequencies can propagate almost as well as LTE frequencies. This makes possible their implementation in standard macro-sites, the towers filled with antenna systems for example, or sites on top of buildings, and without strong technological evolution for most of the RF components. Indeed, components like gain blocks are already wideband and can work properly with frequencies up to 6 GHz. On the other hand, this induces some changes for the main power amplification stage of the system. For high power amplification levels, the preferred technology platform has been silicon LDMOS for the past decade. However, LDMOS cannot correctly function at frequencies over 3 GHz. This has created the need for the development of a new efficient platform: Gallium Nitride (GaN). This has been a major change in the RF component industry in the past few years, and now the two platforms have become complementary. LDMOS enables lower cost power amplifiers at lower frequencies, and GaN enables power amplification at high frequencies.

mmWaves are a complete disruption for the telecom industry, component-wise as well as implementation-wise. On implementation, these frequencies cannot be addressed by standard systems on macro-sites. Indeed, electromagnetic waves in the tens of GHz range have very poor propagation in the air. They can be attenuated by rain drops, cannot penetrate buildings, and require a direct line of sight to the user equipment to be correctly received. This has led to the development of “small cells”. These are small pieces of equipment that are meant to radiate signals to up to fifty meters, compared to up to 2.5 km for LTE macro-site systems. They are meant to be implemented in high density in the streets, on lamp posts for example, and to be deployed mainly in high density urban areas. From the component standpoint, these devices are using a technology coming from the radar industry, called monolithic microwave integrated circuits (MMICs), within which all stages of the RF chain are performed, beamforming, amplification and so on. This approach, which is still at its early stage, is completely new for the telecom industry. New entrants formerly in the radar business like Anokiwave or Wavice make their appearance in the telecom infrastructure field. The difference between standard antenna system front-ends and mmWave small cell front-ends can be seen in figure 2.

For now, mmWave is mostly used for what is called fixed wireless access (FWA). This is a way for operators to connect fixed receivers to the network, typically to connect residents to the network with high throughput connections without the need for fiber implementation. This application is a way to develop mmWave technology, but is not directly related to 5G.

These three different approaches, active antenna systems, sub-6 GHz new radios and mmWave new radios, are the technological innovations impacting RF components that are meant to offer 5G capability to the world. Nevertheless the general interest in each of them is unequal. Active antenna systems are more expensive than standard remote radio heads, sub-6 frequencies require the development of adapted power amplifiers, and the use case for mmWave is not obvious yet.

From a practical standpoint, the short term future is expected to offer us sub-6 GHz remote radio heads in rural areas and low urban density areas, active antenna systems in highly dense urban areas, and potentially mmWave small cells in town centers, stadiums or malls. Even though the use cases for 5G are just at their beginning, telecom operators will still proceed in their deployments. They continuously market 5G as an unavoidable innovation that will enable the world of the future, while waiting for the concrete non-consumer use cases to happen in order to offer the growth driver the industry is currently waiting for.

Antoine Bonnabel works as a Technology & Market Analyst for the Power & Wireless team of Yole Développement (Yole). He carries out technical, marketing and strategic analyses focused on RF devices, related technologies and markets.
Prior to Yole, Antoine was R&D Program Manager for DelfMEMS (FR), a company specializing in RF switches and supervised Intellectual Property and Business Intelligence activities of this company. In addition, he also has co-authored several market reports and is co-inventor of three patents in RF MEMS design.
Antoine holds a M.Sc. in Microelectronics from Grenoble Institute of Technologies (France) and a M.Sc. in Management from Grenoble Graduate School of Business (France).

5G’s Impact on Telecom Infrastructure 2019
Network evolution and 5G implementation are driving massive structural changes

Active and Passive Antenna Systems for Telecom Infrastructure 2019
The transition to active antenna systems and small cells is changing the technological mix of RF components in telecom infrastructure