5G gets chameleon-like thanks to novel air-interface Whereas 4G was mostly a milestone for mobile Internet speed, its successor will have to cope with a multitude of devices with different needs and capabilities, all connected to the Internet of Things. FANTASTIC-5G has developed an air interface capable of configuring connections based on individual device and service requirements. Digital Economy © chombosan, Shutterstock The world of the all-connect is upon us – a time where watches, fridges, ovens, cars, sensors and all kind of devices will benefit from connectivity to the Internet and between each other. Making this work, however, could easily become a real headache: ‘Different devices and use cases impose different requirements to the system,’ explains Dr. Frank Schaich, research engineer at Nokia Bell Labs and coordinator of the FANTASTIC-5G project. ‘Some will require ultra-low response times, some will require extreme high data rates, and others will need to be served in an extremely energy-efficient manner to ensure very high battery lifetimes.’ To do that, 5G networks will have to be smart, which means implementing adaptive features and configurations into the specifications of the network, and doing it from the earliest stages of development. Unless this requirement is met, some devices and use cases will inevitably be left behind. The FANSTASTIC-5G consortium wanted to avoid such a scenario at all cost: Unlike the LTE standard, which was based on a cell-centric design and lacked flexibility, its FANSTASTIC-5G-powered successor had to be user-centric. The project team started by listing and analysing the service categories being foreseen for 5G, before identifying the key technologies required to efficiently serve them. Then, they proceeded to design and thorough testing. ‘Our proposal consisted in developing and experimenting with specific technologies and configurations to allow the system to meet all foreseeable requirements. We have analyzed interdependencies and have identified the required means to efficiently incorporate those into the overall system. This means that our product, the multi-service air interface (AI), is able to concurrently support different device categories and their associated use cases, in a tailored manner, without leading to inefficient use of resources,’ Dr Schaich says. Concretely, the AI is able to automatically configure the different connections between device and network according to the former’s requirements, for example access procedure to be used, the RLC-states to camp on, etc. The project also proposes management procedures and fundamental design decisions, thereby enabling the system to efficiently multiplex the various use cases. In total, seven simulation campaigns were run to evaluate the AI developed under the project, to ensure that it enabled high capacity; ultra-low-latency and high reliability; support for low-cost and low-energy devices; massive access; ubiquitous coverage and high mobility; and, last but not least, in-band coexistence of services. Dr Schaich points out that both link level and system level simulations were run to numerically evaluate the benefits of the project’s AI, and that some technologies were even implemented in hardware. Mathematical tools have also been used, notably to assess theoretical limits, he says. All in all, the project resulted in over 80 publications in major ICT conferences as well as important contributions to 3GPP standardization. A total of 13 patents, related to the various parts of the interface such as waveform design, superposition coding and enhanced receivers, were filed. A follow-up project including original FANTASTIC-5G and other members, named ONE5G, is already on track. Keywords FANTASTIC-5G, 5G, 4G, Internet of Things, air interface, ONE5G
