The 5G Core networks (5GC) are witnessing a drastic increase in signaling traffic volume due to flat Service Based Architecture (SBA) with “any to any” Network Function (NF) communication. The increased signaling, if not managed properly, may hamper the timely delivery of control messages, degrading the user's quality of experience. The underlying reason for increased 5GC signaling is high inter-dependencies between NFs that result in long, complex, and sequential system procedures. Moreover, system procedures are not optimally designed for cloud-native SBA based 5GC. This paper analyzes the system procedures for the current 5G network in order to decouple the sequential procedures into small and independent transactions. Once decoupled, the control messages can be executed in parallel, significantly reducing the procedure completion time and improving compute resource utilization. Although we decouple a few control messages in 5G registration procedure, we are limited by the design of NFs, which introduces inter- Nfcoupling. Thus, architectural changes are imperative to enable loose coupling between NFs. We present an end-to-end SBA based network for 6G and propose enhanced system procedures that allow parallel execution of control messages. We perform simulations for the modified registration procedures, demonstrating approximately 13 % and 24 % decrease in procedure completion time for 5G and 6G, respectively.

Trustworthiness, privacy and resilience are expected to be essential requirements of 6G on top of various other conventional performance requirements such as data rate and latency. Primary authentication is a key procedure for initiating secure communication between User Equipment (UE) and Home Network (HN) in 3rd Generation Partnership Project (3GPP). However, primary authentication mechanisms used in 5G are vulnerable against quantum machines, replay attacks, and rouge base-station. To protect against these threats, we propose beyond 5G and 6G primary authentication methods to adapt hybrid mechanisms which combines Post Quantum Cryptography (PQC) and existing asymmetric algorithm with Perfect Forward Secrecy (PFS) guarantee. We evaluate proposed methods using our in-house developed Simulator “WirelessPQCSim.” Our proposed Hybrid mechanisms provide enhanced security without additional CPU overhead with respect to exiting 5G system. We also achieved up to 6.7x speed-up for PQC-based methods with respect to 5G system and provide low latency which is one of the KPI for 6G system.

Network virtualization and cloudification are being actively introduced into mobile networks, but the current control-plane (CP) architecture, which distinguishes radio access network (RAN) from core network (CN), is inefficient in fully utilizing the flexibility provided by such technologies. In this paper, we propose a novel CP architecture, which is based on service-based interface (SBI) throughout the network without distinction between RAN and CN, thus reducing the delay and overhead of control signaling. The proposed architecture not only reduces the completion time and amount of signaling of the control procedures by up to 27% and 45%, respectively, but also provides a cloud-friendly environment in which slices and sub-networks with various characteristics can be easily operated by configuring the CP at will.

To provide coverage to the network devices distributed all over the globe, non-terrestrial networks (NTNs) have been recognized to complement and extend the terrestrial network to remote areas. The Low Earth Orbit (LEO) NTNs face several unprecedented challenges over 5G-NR protocol due to high differential delay and Doppler shifts which drastically impacts the performance of NR-NTN users. In this work, we investigate the impact of large differential delay and Doppler shifts within a NTN cell on the 5G-NR resource allocation and medium access control (MAC) protocol. We then propose an uplink zone-based scheduling technique to address the high differential delay and Doppler shifts for LEO satellites for LEO satellite-based NTNs. Finally, we validate the performance of the proposed strategy by comparing it with the conventional 5G-NR protocol through numerical simulations over the recently developed Samsung’s NR-NTN System Level Simulator.

Moving networks is an emerging paradigm for next-generation communication networks that envisage a technology that could support moving vehicular user equipment (VUE) with high data-rates over a reliable connection under varied mobility scenarios such as high-speed trains, buses on the freeway, etc. However, while operating at mmWave frequencies, the direct base station (BS) to the VUE (BS-to-VUE) link is adversely impacted by penetration losses and frequent link outages. Link outages are caused primarily due to extremely poor Non-Line-of-Sight (NLOS) channel conditions at mmWave frequencies. To address this problem, a novel architecture has been proposed in literature where a vehicular moving-relay (MR) is introduced that serves the VUE via access link while the backhaul to the MR is provided by a BS. In this paper, we exhaustively analyze and numerically quantify the link fragility and outage for spatially consistent channel realizations at 28 and 73 GHz for links between the BS-to-VUE, BS-to-MR, and MR-to-VUE. Furthermore, in this study, we also capture the impact of frequent transitions among LOS and NLOS conditions, human blockage events, and penetration losses. The simulation results reveal that i) the direct link between the BS and VUE would be extremely fragile with link-outage probabilities 17% and 59.5% compared to the relay-aided link with link-outage probabilities 1.1 and 2% for 28 GHz and 73 GHz respectively and that ii) the BS-to-VUE link would be impacted severely by human blockages compared to relay aided links where only the last hop MR-to-VUE link is impacted by human blockages but negligibly due to its relatively short range. Lastly, we have determined closed-form analytical expressions to estimate the link-outage probability of the BS-to-MR link.