Existing radio access networks (RANs) allow only for very limited sharing of the communication and computation resources among wireless operators and heterogeneous wireless technologies. We introduce ...the LayBack architecture to facilitate communication and computation resource sharing among different wireless operators and technologies. LayBack organizes the RAN communication and multi-access edge computing (MEC) resources into layers, including a devices layer, a radio node (enhanced Node B and access point) layer, and a gateway layer. LayBack positions the coordination point between the different operators and technologies just behind the gateways and thus consistently decouples the fronthaul from the backhaul. The coordination point is implemented through a software defined networking (SDN) switching layer that connects the gateways to the backhaul (core) network layer. A unifying SDN orchestrator implements an SDN-based management framework that centrally manages the fronthaul and backhaul communication and computation resources and coordinates the cooperation between different wireless operators and technologies. We illustrate the capabilities of the introduced LayBack architecture and SDN-based management framework through a case study on a novel fluid cloud RAN (CRAN) function split. The fluid CRAN function split partitions the RAN functions into function blocks that are flexibly assigned to MEC nodes, effectively implementing the RAN functions through network function virtualization. We find that for non-uniform call arrivals, the computation of the function blocks with resource sharing among operators increases a revenue rate measure by more than 25% compared to the conventional CRAN where each operator utilizes only its own resources.
Open radio access network (ORAN)-based vehicular networks play a pivotal role in future traffic data sharing. Due to the openness of the ORAN framework, it is necessary to encrypt the sharing data to ...prevent unauthorized access or misuse by malicious participants. However, current efforts struggle to address some emerging security requirements, such as the bilateral control of sending and access rights in cellular vehicle-to-everything (C-V2X) communications, as well as evolving replay attack on encrypted data. With these challenges, this paper presents a fine-grained access control encryption (FGACE) scheme for secure communication in ORAN-based vehicular networks. Our FGACE enables fine-grained and bilateral control over senders and receivers. We design a novel sanitization algorithm against dishonest sanitizer and replay attack. Furthermore, we deeply explore security models for replay attack on encrypted data to support secure sanitization, i.e., attribute-based replayable CCA security and related definitions. We prove that our FGACE satisfies the proposed security definitions. Feature comparison demonstrates that our scheme does better in security and privacy. Experimental results show that our scheme outperforms compared schemes. When the number of attributes increases to 50, our total computational overhead is lowest, and the total storage overhead is approximately less than 1/3 of other schemes. The impressive performance indicates that our FGACE is practical in ORAN-based vehicular networks.
Mobile edge computing (MEC) has been deemed as one of the key technologies for pushing powerful computing ability to the radio access network. Different scenarios require different services, and ...tasks usually require computing in a specific runtime environment. However, few studies have taken this into consideration. To this end, the authors propose a novel model of service-dependent task offloading for the multiuser MEC system with resource constraints. Through determining which services should be deployed at the network edge and how many tasks should be offloaded, a revenue maximisation problem is constructed. Accordingly, they propose an iterative optimisation algorithm with high performance for the service deploying and task offloading problem. Finally, numerical simulations reveal that their proposed algorithm outperforms other schemes.
The deployment of new 5G wireless interfaces based on massive multiantenna transmission and beamforming is expected to have a significant impact on the complexity and power consumption of the ...transport network. This paper analyzes the energy performance of four radio access network (RAN) architectures, each one utilizing a different option for splitting the baseband processing functions. The radio segment is based on Long-Term Evolution (LTE) and 5G radio access technologies. The transport segment is based on optical wavelength division multiplexing, where coherent and direct detection transmissions are considered. The energy consumption of each RAN architecture is weighted against i) the benefits for the radio segment as a function of the level of centralization of the baseband processing functions and ii) the power consumption levels needed to accommodate the capacity generated at each base station. Results show that, with LTE radio interfaces, the energy consumption of the transport network amounts to only a few percent of the overall network power consumption. As a result, fully centralized LTE radio architectures are a viable option, with energy savings of at least 27% compared with conventional distributed architectures. On the other hand, with advanced 5G radio interfaces, centralized architectures, if not carefully designed, might become impractical due to the excessive energy consumption of the transport network (i.e., as a result of the huge capacity to be accommodated). This aspect can be mitigated via a careful joint design of the radio and the transport network (i.e., leveraging on appropriate optical transmission techniques and compromising where needed on the radio network performance).
We propose using power-over-fiber (PoF) in some part of future 5G cellular solutions based on radio access networks considering currently installed front-haul solutions with single mode fiber to ...optically power communication systems for 5G new radio (NR) data transmission. Simulations addressing design parameters are presented. Radio-over-fiber (RoF) transmission over single mode fiber (SMF) is experimentally implemented and tested for link lengths ranging from 100 m up to 10 km with injected PoF signals up to 2 W. 64QAM, 16QAM and QPSK data traffic of 100 MHz bandwidth are transmitted simultaneously with the PoF signal showing an EVM compliant with 5G NR standard, and up to 0.5 W for 256QAM. EVM of 4.3% is achieved with RF signal of 20 GHz and QPSK modulation format in coexistence with delivering 870 mW of optical power to a photovoltaic cell (PV) after 10 km-long SMF link. Using PoF technology to optically powering remote units and Internet-of-Things (IoT) solutions based on RoF links is also discussed.
Cloud radio access network (C-RAN) is a novel architecture for future mobile networks to sustain the exponential traffic growth thanks to the exploitation of centralized processing. In C-RAN, one ...data processing center or baseband unit (BBU) communicates with users via distributed remote radio heads (RRHs), which are connected to the BBU via high capacity, low latency fronthaul links. In this letter, we study C-RAN with wireless fronthauls due to their flexibility in deployment and management. First, a tight upper bound of the system block error rate (BLER) is derived in closed-form expression via union bound analysis. Based on the derived bound, adaptive transmission schemes are proposed. Particularly, two practical power optimizations based on the BLER and pair-wise error probability (PEP) are proposed to minimize the consumed energy at the RRHs while satisfying the predefined quality of service (QoS) constraint. The premise of the proposed schemes originates from practical scenarios where most applications tolerate a certain QoS, e.g., a nonzero BLER. The effectiveness of the proposed schemes is demonstrated via intensive simulations.
The exponential traffic growth, demand for high speed wireless data communications, as well as incessant deployment of innovative wireless technologies, services, and applications, have put ...considerable pressure on the mobile network operators (MNOs). Consequently, cellular access network performance in terms of capacity, quality of service, and network coverage needs further considerations. In order to address the challenges, MNOs, as well as equipment vendors, have given significant attention to the small-cell schemes based on cloud radio access network (C-RAN). This is due to its beneficial features in terms of performance optimization, cost-effectiveness, easier infrastructure deployment, and network management. Nevertheless, the C-RAN architecture imposes stringent requirements on the fronthaul link for seamless connectivity. Digital radio over fiber-based common public radio interface (CPRI) is the fundamental means of distributing baseband samples in the C-RAN fronthaul. However, optical links which are based on CPRI have bandwidth and flexibility limitations. Therefore, these limitations might constrain or make them impractical for the next generation mobile systems which are envisaged not only to support carrier aggregation and multi-band but also envisioned to integrate technologies like millimeter-wave (mm-wave) and massive multiple-input multiple-output antennas into the base stations. In this paper, we present comprehensive tutorial on technologies, requirements, architectures, challenges, and proffer potential solutions on means of achieving an efficient C-RAN optical fronthaul for the next-generation network such as the fifth generation network and beyond. A number of viable fronthauling technologies such as mm-wave and wireless fidelity are considered and this paper mainly focuses on optical technologies such as optical fiber and free-space optical. We also present feasible means of reducing the system complexity, cost, bandwidth requirement, and latency in the fronthaul. Furthermore, means of achieving the goal of green communication networks through reduction in the power consumption by the system are considered.
Mobile fronthaul is an important network segment that bridges wireless baseband units and remote radio units to support cloud radio access network. We review recent progresses on the use of ...frequency-division multiplexing to achieve highly bandwidth-efficient mobile fronthaul with low latency. We present digital signal processing (DSP) techniques for channel aggregation and deaggregation, frequency-domain windowing, adjacent channel leak age ratio reduction, and synchronous transmission of both the I/Q waveforms of wireless signals and the control words (CWs) used for control and management purposes. In a proof-of-concept experiment, we demonstrate the transmission of 48 20-MHz LTE signals with a common public radio interface (CPRI) equivalent data rate of 59 Gb/s, achieving a low round-trip DSP latency of <;2 μs and a low mean error-vector magnitude (EVM) of ~2.5% after fiber transmission. In a follow-up experiment, we further demonstrate the transmission of 32 20-MHz LTE signals together with CPRI-compliant CWs, corresponding to a CPRI-equivalent data rate of 39.32 Gb/s, in single optical wavelength channel that requires an RF bandwidth of only ~1.6 GHz. After transmission over 5-km standard single-mode fiber, the CWs are recovered without error, while the LTE signals are recovered with an EVM of lower than 3%. Applying this technique to future 5G wireless networks with massive multiple-input multiple-output is also discussed. This efficient mobile fronthaul technique may find promising applications in future integrated fiber/wireless access networks to provide ultrabroadband access services.
The 5G and Beyond (B5G) networks aim to support diverse use cases - extremely low latency, high data rates, and dense user connectivity. However, meeting these use cases results in an increase in ...energy consumption due to the use of computing resources in the B5G networks. While several studies focus on 5G Core Network (5G CN) energy consumption, it's essential to acknowledge that a substantial 75% of the network's overall energy usage occurs within the Radio Access Network (RAN). Hence, it's crucial to focus on RAN energy performance improvements. This paper exploits various open-source software tools that measure and monitor RAN energy, which helps design energy-efficient RAN. Different RAN architectures such as Monolithic, Disaggregated, and Control Plane and User Plane Separation (CUPS) are considered to measure and monitor energy consumption using open-source software tools - S-tui and Scaphandre. We study energy consumption as a function of the number of connected User Equipments (UEs) and the impact of connecting multiple Distributed Units (DUs) on the energy consumption of both the Control Plane (CP) and User Plane (UP) of gNB Central Unit (CU). We also study the energy consumption of various open source 5G CN. Finally, this study examines the influence of various RAN parameters on energy consumption by using a real-time dataset of the monolithic RAN scenario.
Network slicing (NS) has been well discussed in the transport network (TN) and core network (CN) domains. This paper extends it to the radio access network (RAN) domain, and the NS in RAN, TN and CN ...domains is defined as end-to-end (E2E) NS system. The advantages of using NS in the RAN domain with two-level resource allocation scheme are studied and shown by numerical simulations. Then the E2E NS system architecture and components are proposed and demonstrated with hardware and software. The demonstration shows the capability with very fine spectral granularity, and the slice creation, delete and adjustment schemes in sub-minute time, which could be used in the operator's network.
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