1. Bundesnetzagentur. (2019). 5G spectrum fees for local usages. Retrieved July 1, 2021, from https://www.bundesnetzagentur.de/SharedDocs/Pressemitteilungen/EN/2019/20191031_LokalesBreitband.html
2. Industrie 4.0: Hit or Hype?;R.Drath;IEEE Industrial Electronics Magazine,2014
3. Erol, S., Schuhmacher, A., & Sihn, W. (2016). Resource Efficiency for Global Competitiveness. In International Conference on Competitive Manufacturing (COMA) (pp. 495–500). Retrieved from http://publica.fraunhofer.de/documents/N-382579.html
4. ETSI. (2011). TR 102 889-2 - V1.1.1 - Electromagnetic compatibility and Radio spectrum Matters (ERM); System Reference Document; Short Range Devices (SRD); Part 2: Technical characteristics for SRD equipment for wireless industrial applications using technologies different from Ultra-Wide Band (UWB). Sophia Antipolis Cedex. Retrieved from https://www.etsi.org/deliver/etsi_tr/102800_102899/10288902/01.01.01_60/tr_10288902v010101p.pdf
5. ETSI. (2015). TS 103 235 - V1.1.1 - Reconfigurable Radio Systems (RRS); System architecture and high level procedures for operation of Licensed Shared Access (LSA) in the 2 300 MHz - 2 400 MHz band. Sophia Antipolis Cedex.