New Transmission Infrastructure 5G

The Fifth Dimension

Highly automated driving, Industry 4.0, virtual reality: for the ideas of the digital future to become reality, billions of devices must be able to communicate among themselves in milliseconds. The most important prerequisite for this is a new, wireless transmission infrastructure: 5G.

Text Matea Prgomet

In early 2018, South Korea plans to deliver an Olympic Winter Games of superlatives. These Games are promising the ultimate “athletic experience” for audiences from the comfort of their own sofas at home. Using all-around cameras and holographic imaging, viewers will be able to experience live how a ski jumper flies several hundred meters through the air or get a bobsledder’s-eye view of racing through a narrow chute. Viewers who put on a pair of virtual reality headsets will be able to look around from the athlete’s perspective. It could be the test run for a future that may soon be here.

By 2020, first mobile communication networks will be fitted with the next generation mobile communications network standard, called 5G, which is far more than just a simple expansion of the current 4G standards. “This is about creating a universal network for wireless communications for devices with different requirements,” says Johannes Dommel, a researcher working on the 5G standard at the Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute (HHI) in Berlin.

The coming, fifth generation of mobile communications should lay the foundation for technical innovations in the areas of industry, mobility, energy and health. Highly automated driving, for instance, requires cars to securely communicate with each other almost instantaneously. In the area of telemedicine, doctors would be able to treat patients even at very great distances, and highly specialized surgeons could call in from a different location to support surgeries via telepresence. Smart living for people with physical limitations could also be made much easier, as could the energy transition from fossil fuels to renewable resources based on smart grids.

Yet the requirements necessary for this present completely new challenges. As Dommel explains. “If, as in the case of 5G, you want to increase data transmission by a factor of ten thousand and the number of participating devices by a factor of one hundred, it requires completely new concepts. Therefore various technologies are being combined for 5G, including the exploitation of new frequency domains and the deployment of massive multi-antenna systems.”

Specifically this means there must be an attempt to further expand the already very limited and regulated frequency spectrum to fulfill the requirements for 5G. “The electromagnetic spectrum, the bandwidth currently available, is one of the most important resources for mobile communications,” Dommel says. “Normal mobile communications operate at around 0.8 and 2.6 gigahertz. For 5G, frequencies of up to 60 gigahertz are therefore being evaluated. Behind these multi-antenna systems are what are known as multiple-input and multiple-output systems, or MIMOs, which simply increase the capacity for transmissions. Just imagine: instead of just one transmitter antenna you have hundreds.”

While the outlook is promising, in the here and now there are nonetheless a wide variety of problems that such a complex 5G network entails. One, for instance, is increasing reliability. Cell phone customers remain all too familiar with gaps in service, dropped calls and sluggish internet connectivity. But, in the future, if passenger safety or a patient’s life is literally on the line with a data connection, then there must be failsafe performance. To achieve this, 5G will combine the features of traditional mobile communications with WLAN and other technologies. This supranetwork is also supposed to work at very high speeds, meaning in cars, trains and even airplanes.

The wireless Internet of Things should make possible a speed that can match a human reaction time of around a millisecond—what engineers call a tactile internet. The magic formula for the future may well be: downloads of two gigabytes per second with less than three milliseconds of delay. Which would more or less mean: a high-resolution feature film in total HD quality could be downloaded to a smartphone in less than a second.

Photo: Architecture of Radio, Richard Vijgen 2015, photography: Juuke Schoorl

Such unusually rapid download times, at least by today’s standards, require a functioning 5G data network as well as mobile edge clouds: data centers located near transmission towers to store and process the necessary information. The “edge” in the name has nothing to do with the old eponymous mobile communication standard but instead is a new type of decentralized IT system—always right at the edge of the cellular network. These “mini clouds” would be located on practically every street corner in the future and thus always be close to the action, keeping transmission times as short as possible.

Highly automated driving, for instance, is based on vast amounts of sensor data that must continually be evaluated and interpreted. Multiple communications to and from both vehicles and infrastructure must take place in under a millisecond. For this to be possible, the information cannot travel very long distances. Signals can cover three hundred kilometers in a millisecond. But if they are first sent to a far off central location, processed there, and then sent back, the accident has already happened, long before the cars involved could be warned.

For all of this to become possible, security will continue to be indispensable in the future. “Data transmission and data analysis must be robust even back at the air interface,” Dommel says. “And safety-critical applications must be protected from attack.” Only once security has been established can 5G and the increasing links between humans and the digital world be developed further. “One goal of 5G is to have communications running in the background,” he continues. “We shouldn’t even notice that we’re connected when the car contacts the garage, the refrigerator calls the supermarket, or the heart-rate monitor updates the social network.”

Will things be far enough along for the 2018 Olympics? Dommel is looking forward to finding out. Even its use for the Olympic Games in Tokyo in 2020 may be too soon—although the Japanese as well as the South Koreans have proclaimed 5G Games as their goal.