 com Workshop. Du, J., Chizhik, D., Feick, R. et al. (2018). Suburban residential building penetration loss at 28 GHz for fixed wireless access. IEEE Wireless Communication Letters 7 (6): 890-893. References 3 3GPP TSG RAN WG1 (2018). Evaluation Results for NR-U, R1-1812659. 4 Electronic Code of Federal Regulations (2017). Title 47: Telecommunication, PART 96-CITIZENS BROADBAND RADIO SERVICE. 5 3GPP Technical Specifications 38.101-1 (2019). User Equipment radio transmission and reception; Range 1, V. 15.5.0. March 2019. 6 3GPP Technical Specifications 38.101-2 (2019). User Equipment radio transmission and reception; Range 2, V. 15.5.0. March 2019. 5G Architecture Antti Toskala and Miikka Poikselkä Nokia Bell Labs, Finland CHAPTER MENU Introduction, 67 5G Architecture Options, 67 5G Core Network Architecture, 70 5G RAN Architecture, 75 Network Slicing, 81 Summary, 85 References, 86 Introduction The 5G network architecture was influenced by different factors. There was the prepara- tion for cloud-based implementations, readiness to deal with larger data rates and lower latencies than previous generations, enabling new services, as well as the need to inter- work with Long-Term Evolution (LTE), especially in the first phase. All these factors have impacted the 5G architecture. Besides the radio technology development, a new 5G core network has also been defined which allows new service elements in terms of local and global services as well as the new concept of flow-based quality of ser- vice and support for network slicing and many other features enabling a more efficient cloud-based implementation when compared to the LTE core (EPC, Evolved Packet Core). This chapter presents an overview of the different 5G architectures and then COV- ers in more details the radio access network (RAN) architecture and interfaces as well as the 5G Core (5GC) network with key elements and functionalities. This chapter con- cludes with the introduction of network slicing support in Release 15. 5G Architecture Options Originally there