In the Race to 5G, New Standard Is Being Set Now

August 22, 2016

August 23, 2016

Antenna design and measurement are at the heart of this challenge

By Nicolas Gross

In a world where mobile devices have outnumbered people, it is easy to forget we lived without smartphones 15 years ago. From 1G to 4G cellular technology, each new generation of mobile networks has brought higher speeds and new uses, which have had huge impacts on our personal and professional lives. Today, the industry is buzzing about the arrival of 5G, which is expected between 2017 and 2020. With speeds up to 10 Gbps and ultra-low latency around 1 millisecond (50 times faster than 4G), this next-generation network holds enormous promises, including smart cities, driverless cars, critical health care and the Internet of Things revolution, to name just a few.

It is no surprise that, similarly to the Olympic Games, a technological worldwide race is on to be the first and to set the standard. The challenges ahead are manifold. They mostly revolve around the harmonization of the radio spectrum, antenna design and measurement.

The Challenges Ahead

5G will instigate a drastic harmonization of the radio spectrum.

First, remember that data is transmitted via radio waves. Radio waves are split into bands of different frequencies, with each band reserved for a different type of communication: aeronautical and maritime navigation signals, television broadcasting, mobile data, military use, etc. As new protocols are developed, radio frequencies (RF) for them are limited to what’s left over. Finding new space and coordinating the use of that space will demand complex negotiations.

Second, new applications such as driverless transportation or remote surgery mean that a sudden data connection dropout is not an option. 5G will have to provide an uninterrupted user experience every time, as if capacity were limitless. Several networks are currently providing connectivity for end-user wireless devices: cellular, Wi-Fi, millimeter-wave, and M2M (machine-to-machine or, more clearly, device-to-device) are a few examples. 5G is most likely to integrate the coordination of the various protocols and dispersed frequency bands in order to offer the end user the expected seamless connection.

5G aims to accommodate increases in data throughput. Many technologies are being evaluated. And, similar to the coordination of protocols, 5G networks will not be based on one single technology, but instead on a combination of several. These technologies will have to work alongside each other, if not together, in an optimum way to support a wide range of upcoming exciting applications.

Millimeter-wave technologies and massive multiple-input, multiple-output (MIMO) communications are two such technologies. Millimeter waves allow for high-speed and high-capacity data transmission, yet they can only be used for short-range, point-to-point, line-of-sight connections. Massive MIMO could be a valid alternative. Massive MIMO refers to a technique where the base station employs a high number of antennas that point

localized beams of radio signals toward each device, allowing significant gains in capacity and traffic density. The basic physics principles for massive MIMO are already proven, and experimental systems are being deployed.

Measurement Industry

The necessary mix of technologies required for 5G to hit the airwaves means the antenna measurement industry is being put to the test. Innovation in this industry will have to rapidly follow suit with flexible solutions to measure the variety of new devices that will need evaluation. On top of testing each new implemented technology, it will also have to test the many various combinations of technologies, network elements and protocols to ensure correct interoperability.

Among the many to take shape, both millimeter-wave and massive MIMO technologies bring challenges. For those aiming to benefit from the high speed and high capacity of the millimeter-wave spectrum, the players will require systems capable of providing measurements in the millimeter-wave bands. Only a small handful exists today. Because most available wider bandwidths of the RF spectrum are in the higher frequency bands (as high as 100 GHz), a key part of the challenge resides in designing the right antennas as well. Once they have the two that coincide, they’ll gain considerable traction in the race.

The MIMO system works by having the baseband algorithm respond to the RF channel characteristics. Because the baseband is split between the transmitter and the receiver, and because these two elements are most likely to come from different suppliers (the infrastructure vendor and the device vendor), then the full detailed list of the parameters required for the algorithm must be specified in the technology standards documents. For massive MIMO, this is likely to be a highly complex and detailed specification to ensure full interoperability.

Another challenge related to this area is the issue of connector-less devices, because large antenna arrays required for massive MIMO will be designed to be compact to achieve cost and deployment efficiency. This means that there is unlikely to be space for RF connectors or test ports to attach test equipment. The miniature size of millimeter-wave antennas has already led to this dilemma. The expected logical next step is therefore over-the-air testing.

Generally speaking, the future of RF device testing is challenging and will need highly precise instrumentation and flexible testing solutions in order to deal with millimeter-wave transceivers or better intelligence for massive MIMO. More complex shielded chambers will be required, even tunable to a variety of frequency bands. Alongside this, the simulation of multipath signals using fading simulators will grow further in importance, as will the technical demands and capabilities required in such equipment.

Finally, did we mention the pressure of time? This complex testing needs to take place in the minimum amount of time because the race is on.

Olympic Games of 5G Development

World sporting events are a key factor contributing to the growth in technology deployment and trials on a grand scale.

In 2018, the Winter Olympics in South Korea and the World Cup in Moscow both offer the perfect opportunity to launch 5G trials in real-life scenarios.

In 2020, the Japan Summer Olympics look set to become a starting point for a live demonstration of 5G, which could be the base of a commercial deployment.

At this stage, it’s not possible to know which country or which company, or consortium of companies, will win the 5G race, but what is certain is that the win will depend not only on the speed of innovation, but also on the speed at which testing capabilities for those devices will follow. This is a complex challenge that the industry excitedly faces, and I bet the first one to pass the tests with flying colors will hit the market running and set the standard for the rest to follow.

Since 2009, Nicolas Gross has been applications director at Microwave Vision Group (MVG) in Paris, where he leads the company’s software systems and product development for antenna measurement. He began work at MVG in 2005 as an antenna engineer. In 2007, he headed multiple-probe antenna systems measurement development.