Regarding "mmWave," which uses a higher frequency band among 5G, frequency allocation is progressing, but usage has not increased as expected. Digital beamforming is attracting attention as a technology that can improve the performance of mmWave 5G. This time, we had the opportunity to interview the head of BeammWave, a company based in Europe that is developing digital beamforming solutions. We asked BeammWave how digital beamforming will step up mmWave 5G and what applications it will lead to.

People we spoke to：　BeammWave, AB, CEO / Stefan Svedberg（Picture left）、　VP of Business Development and Sales / Robert Cadman（Picture center）、　Head of Business Development and Sales, Japan / Masanori Sakuuchi（Picture right）

-----Your company is working on developing digital beamforming technology for mmWave 5G. What issues does this technology solve for mmWave 5G? Please explain the background to this development.

So far, mmWave has been a disappointment, failing to provide the much-needed offload for MNOs and not being a platform for innovation. Currently, there is very little traffic in mmWave frequency bands and no new use cases beyond fixed wireless access (FWA).
The propagation characteristics of mmWave are well known and to enable mmWave in mobile networks, beamforming is required. Beamforming is a mandatory part of the mmWave 5G specification.
Beamforming can be performed in two ways: analog or digital, but to date the industry has believed that digital beamforming is too complex to perform on a smartphone, so analog beamforming is implemented in all commercial products. However, analog beamforming has several performance impediments:
First, beamforming on mmWave signals requires a very compact design. As a result, analog beamforming creates thermal issues that limit uplink performance. A compact solution is also limited to inflexible "antenna array" construction.
Second, when beamforming is done in the analog domain, the only information that can be processed is the combined signal from all antennas with a particular beamforming direction applied. Analog beamforming is controlled by applying different pre-configured settings (codebooks) that represent different directions, but it first performs a routine called beam sweeping to find the direction in which to receive or transmit a signal. In other words, a trial and error method is applied to find the direction. Because this is a slow method (up to 0.5 seconds), mobile devices such as smartphones cannot react quickly enough to their movements and are instructed by the network to fall back to sub-6GHz frequency bands. This results in no offload and poor performance.

-----How does digital beamforming help solve these issues?

Digital beamforming digitizes all antenna signals, allowing beamforming directions to be calculated instantly and adjusted in directions in milliseconds. This results in greater beamforming accuracy, greater flexibility in antenna placement, no thermal issues, fewer antennas, and many other benefits.
Simply put, digital beamforming does not use codebooks or beam sweeps, but instead uses an algorithmic approach to use all available antenna information to deliver faster, more reliable, and higher performance connections. In our evaluations, digital beamforming improves network performance by 50% in both throughput and capacity.

-----Please give us an overview of your company's business, including the lineup of products you are developing.

We have a HW portfolio that replaces the RF front-end and beamformer with a digital beamforming concept consisting of digital beamforming accelerator chips (DBFA) and zero-IF, triple-band, CMOS RFFE. This HW solution can be used in mmWave smartphones, base stations and CPE. The algorithms are also part of this concept and are used in the baseband of the host device.

Figure 1 BeammWave's product portfolio

We are currently working on projects with three major companies in the telecommunications industry, and we are also in various discussions with several other customers and have a fairly large pipeline.
Currently, we are working on projects with three business partners: Molex, an Asian market leader with over 70,000 employees, and Alpha Networks, which partners with major MNOs in Asia. Although none of them have commercial products yet, we are working together on pre-commercial development using our Advanced Development Platform (ADP1).

-----Is there anywhere where we can actually see your products and technologies? Are you planning to exhibit at any exhibitions etc?

As for participation in exhibitions, we are considering exhibiting at the Mobile World Conference (MWC Barcelona 2025) in March this year, Wireless Japan x Wireless Technology Park 2025 to be held at Tokyo Big Sight in May, and at another event, borrowing space from NTT Docomo or XGMF. At that time, we are considering exhibiting our development system. In addition, there is another exhibition scheduled to be held in Tokyo around autumn this year, so we are quite energetically promoting business, such as projects with three current customers and expanding our pipeline.
Our headquarters is in Lund, Sweden, where we have an environment for demonstrations, so you can actually see the waveforms while exchanging signals with digital beamforming, and see how digital beamforming works. We have already delivered development kits to Japanese customers last year, and have received positive feedback from them.
As for applications, we are currently talking to various customers for smartphones and base stations.

-----Compared to conventional 5G communications using analog beamforming, in what aspects and to what extent can we expect performance improvements with mmWave 5G communications utilizing your company's technologies and solutions?

Our product is a system that can offload traffic to high bandwidth in a sustainable way, thereby relieving the burden on congested low bandwidth. This increases both communication capacity and throughput by more than 50%.
In terms of latency, the biggest advantage is that the low latency inherited by mmWave can now be used in a reliable manner even in non-stationary scenarios.
The instability of analog beamforming is affected by various factors such as latency, power consumption, and gain. In simple terms, the entire disadvantage of traditional analog beamforming can be covered by digital beamforming.
The current problem is that when analog beamforming is used for millimeter wave communication, problems arise in radio wave capacity, speed, delay, power consumption, etc., but these all come from the analog method. Regarding sweeping, in the case of analog, there is an antenna and it sweeps in order to search for a base station, but this movement takes a very long time. Then, for example, when traveling by car or train, the moving speed and the sweeping speed do not match and it cannot keep up, so it has to keep sweeping all the time, which requires extra power consumption and causes delay problems. And because it is repeated in this way of trial and error, it consumes more bandwidth. With the digital method, there is no sweeping, and the gain of antennas in various places is calculated internally and used in a combined form, so not only is there no sweeping, but the gain can also be made very large. Since it is all digital processing, power consumption is low and there is no unnecessary communication with the base station, so more users can use it comfortably.
   

-----What new 5G applications will become possible as a result of improved low latency and power saving performance?

We believe that smartphones are a high-demand target area, so we are targeting that area first. After that, we think there will be base stations, etc.
We believe that future 5G mmWave innovation will come from the widespread availability and availability of mmWave systems, and will not come to fruition until practical solutions with excellent beamforming are widespread. Once that happens, the combination of "infinite" capacity, high speed, and low latency will enable all the innovation we want, including XR, remote, and other industrial applications. The important thing is to realize the original promise of mmWave.

-----For example, do you think it will lead to major changes in the performance, control methods, and uses of robots and self-driving cars? Also, is there a relationship with the evolution of devices that are smaller and lighter than smartphones, such as wearable devices such as smart glasses?

IoT has evolved from simple sensors and simple on/off control to much more advanced scenarios requiring uplink video, AI, and low latency control. Now there is a demand for advanced scenarios in drones and cars. mmWave can achieve this, but only if the beamforming is robust and reliable.
Basically, mmWave enables high-speed, low-latency communication, and can be used in various fields such as robotics, agriculture, and other fields, including local 5G environments. We provide the basic technology.
In the field of robotics, I think mmWave technology will be essential when realizing robotization. In addition to the speed, latency, and power consumption that will definitely be an issue, moving robots are equipped with many cameras and sensors, so they will need to be able to handle the exchange of huge amounts of data from these. The only solution to deal with this is mmWave. This cannot be overcome by conventional analog methods, so we would like to see mmWave used effectively in robotics, including local 5G, by providing our digital beamforming technology as a basic technology, and we believe that this is the technology for that purpose.

-----Are your technologies and solutions effective in solving the issues of local 5G? For example, does digital beamforming enable precise local 5G construction without radio wave leakage outside the facility premises?

Basically, by using digital beamforming technology, it is possible to achieve communication in a limited area. Digital beamforming technology is used to control the base station, allowing you to control the direction of the antenna and the strength of the radio waves. Since it can be achieved in this way, the answer is yes, it is possible.
BeammWave provides basic beamforming technology, so I think it would be more realistic to have companies that develop base stations, such as Fujitsu or NEC in Japan, adopt this technology and customize it for actual use cases.

-----What applications do you think technologies such as digital beamforming will lead to in the medium to long term?

As I mentioned before, access to "infinite" capacity, high speeds and low latency combined with AI will drive new levels of use cases and innovation. It will also enable greater sharing of real-time data, potentially revolutionizing gaming, entertainment and industrial applications, no matter where you are. Everything will be at your fingertips, all the time.

-----I believe that the technologies and solutions that your company develops and provides are closely related to beyond 5G (6G). Assuming that digital beamforming technology can be aligned with the 6G standard in a desirable way, what applications do you think it will lead to in the medium to long term?

Our technology is applicable to 6G as well as 5G. We are already active in 3GPP and are preparing for 6G. In our view, the only frequency bands available in the quantities required for 6G are in the higher part of the spectrum, which requires beamforming. It is inconceivable that analog beamforming, which has its drawbacks, will not be entirely replaced by digital beamforming in 6G.
Currently, we are focusing on 5G, which already has a market, but the digital beamforming technology itself can be used in 6G as well. We don't know how much data capacity is actually needed in the field of robotics, but 6G will increase the capacity and the frequency will be higher, so we think faster communication will be possible.
We don't have any problems with 6G, but our engineers are also members of 3GPP and participate in various working groups, so we are constantly watching the status of international standards. We will watch the market while watching international standards and see how to develop it, but for the time being, we will focus on 5G. In any case, analog methods will be difficult when it comes to 6G due to its technical characteristics.
We have a concept for digital beamforming systems and architecture, so we are confident that we can apply that concept to 6G. However, the frequencies of 5G and 6G are different, and 6G will have a higher frequency than current 5G, so everything will need to be customized, including existing RF chips and functional blocks such as DBFA that control digital beamforming.

-----What are your expectations and prospects for the Japanese mobile market and industry? Also, do you have any expectations or requests for XGMF, the organization promoting mmWave 5G and 6G in Japan?

We want to move forward with technology leaders in Japan, exploring commercial opportunities first in 5G mmWave and, in the future, 6G. We also want to work further with MNOs to see what we can do to increase the potential for both offloading and innovation.
As for what we would like to ask of XGMF, we would appreciate it if you could give me the opportunity to explain how digital beamforming can help develop high-frequency spectrum at XGMF.
We are currently talking to various stakeholders in Japan, but we feel that there are not many people who understand the entire system. We do not only provide digital beamforming technology, but also have a wide range of knowledge about the overall system level, so we can talk about the entire system of smartphones, for example. In that sense, We would appreciate it if XGMF could provide a place where we can talk about the system level using digital beamforming, for example, smartphones and base stations, and so on, as a whole. It doesn't have to be just XGMF, but also a place where people from a wider range of industries gather. We are currently doing various things with 3GPP, so we would like to move forward together with them, including that.
Currently, we think that mmWave and 5G are not spreading as expected. The reason for this is that, from a technical standpoint, analog beamforming is a bottleneck, preventing the desired performance from being achieved, but this problem can be largely solved by using digital technology. To achieve this, we believe that cooperation is essential across the board, including smartphone vendors, operators, and base stations, so we would be most grateful if you could give us a talk at a venue where everyone can gather.

*This article was prepared as part of a project contracted by the Ministry of Internal Affairs and Communications.