Critical and Massive Machine Type Communication Towards 6G

Abstract

The society as a whole – including vertical sectors such as industries, intelligent transport systems, smart cities, etc. – is becoming increasingly digitalized. Machine Type Communication (MTC), encompassing its massive and critical aspects, and ubiquitous wireless connectivity are among the main enablers of such digitization at large. The recently introduced 5G New Radio is natively designed to support both aspects of MTC to promote the digital transformation of the society and particularly improve the overall efficiency of different vertical sectors. However, it is evident that some of the more demanding requirements cannot be fully supported by 5G networks. Alongside, further development of the society towards 2030 will give rise to new and more stringent requirements on wireless connectivity in general, and MTC in particular. Driven by the societal trends towards 2030, the next generation (6G) will be an agile and efficient convergent network serving a set of diverse service classes and a wide range of key performance indicators (KPI). This white paper explores the main drivers and requirements of an MTC-optimized 6G network, and presents a set of research directions for different aspects of MTC that can be synthesized in the following six key research questions: Will the main KPIs of 5G, namely reliability-latency-scalability, continue to be the dominant KPIs in 6G; or will emerging metrics like energy-efficiency, end-to-end (E2E) performance measures and sensing become more important? How to deliver different E2E service mandates with different KPI requirements through a multi-disciplinary approach jointly considering optimization at the physical up to the application layer? What are the key enablers towards designing ultra-low power receivers and highly efficient sleep modes to support ultra-low-cost ultra-low-power or even passive MTC devices? How to tackle a disruptive rather than incremental joint design of a massively scalable waveform and medium access policy to efficiently support global connectivity for MTC? How to support new service classes characterizing mission-critical and dependable MTC in 6G through multifaceted connectivity and non-cellular centric wireless solutions? What are the potential enablers of long term secure schemes considering the heterogeneous requirements and capabilities of MTC devices? How to design lightweight and flexible usable ways of handling privacy in MTC by combining the user perspective with the technical perspective?