5G Backhaul Research Articles

Performance Analysis of Subcarrier Index Modulation OFDM in a DWDM-FSO link

Free Space Optics (FSO) is a wireless optical communication system using light to establish high-capacity links between points without the need for physical cables. However, its susceptibility to atmospheric conditions such as fog, rain, and turbulence presents challenges to signal quality maintenance. To address this, Dense Wavelength Division Multiplexing (DWDM), traditionally employed in fiber optics, is leveraged to optimize bandwidth utilization and scalability in high-capacity communications. The integration of DWDM into FSO systems offers redundancy and resilience against signal degradation induced by atmospheric conditions. To the best of our knowledge, this is the first time a paper explores the performance of the Subcarrier Index Modulation Orthogonal Frequency Division Multiplexing (SIM-OFDM) technique within a DWDM-FSO system. The objective is to reinforce FSO link robustness and improve transmission rates. Through a comparative analysis with conventional OFDM in an Additive White Gaussian Noise (AWGN) channel, the study reveals a notable Signal-to-Noise Ratio (SNR) gain of at least 3dB with enhanced SIM-OFDM (ESIM-OFDM). Simulations, conducted with realistic parameters within the DWDM-FSO architecture, demonstrate that ESIM-OFDM modulation enables a transmission range of 2 km with an aggregated rate of 10.1 Gb/s. These results underscore the potential of SIM-OFDM in enhancing FSO system performance through the integration of DWDM technology. The proposed ESIM-OFDM DWDM-FSO scenario could represent a highly interesting solution for establishing 5G Backhaul links.

Hybrid FSO/mmWave wireless system: A plausible solution for 5G backhaul applications

Hybrid FSO/mmWave wireless system: A plausible solution for 5G backhaul applications

Parallel Deployment and Performance Analysis of a Multi-Hop Routing Protocol for 5G Backhaul Networks Using Cloud and HPC Platforms

Parallel Deployment and Performance Analysis of a Multi-Hop Routing Protocol for 5G Backhaul Networks Using Cloud and HPC Platforms

Microwave Link License Fee for 5G Backhaul Connectivity (Study Case: Indonesia)

Frequency is a limited resource that cannot be made by humans. Therefore, its usage needs to be regulated so new technology like 5G still get frequency allocation. The 28 GHz frequency is an option that can be used in Indonesia for 5G technology, because it gets a large bandwidth allocation, namely 112 MHz. For the frequency to be used efficiently, one of the efforts is using the frequency license fee. In Indonesia, the frequency license fee is regulated in the regulation regarding BHP ISR for microwave link services. However, prices applied in Indonesia for 5G backhaul frequencies are too low compared to other countries such as India and Australia. With the same conditions, India applies Rp. 771,207,014, Australia Rp. 142,318,583, while Indonesia applies Rp. 32,949,287 for the frequency license fee. Based on the results of calculations, simulations, and changes to the components of the BHP ISR formula, it increases the frequency license fee to Rp. 81,320,400 which experienced an increase of 146%. The new price obtained is still below the price of other countries, because other countries have a larger GDP than Indonesia. This new price expected to make frequency usage more efficient and provide an increase in state income.

Secure RoF based 5G backhaul communication using semiconductor laser generated optical chaos

Abstract The fifth generation is considered as the revolutionary technology around the world, but this revolution brings many challenges along with it, especially when employ the advance properties such as massive multiple-input–multiple-output (MIMO) antennae, network densification and new spectrum exploration etc. One more challenge which we consider working on is the cost effective, secure backhaul communication system. The connection of massive and large traffic cells with the core network by using backhaul demands extraordinary requirements concerning availability, latency, capacity, cost efficiency and most importantly security. In the present work, we demonstrated the security implementation in 5G backhaul network by securing RoF signal through optical chaos generated by semiconductor laser. RoF signal of 60 GHz is generated in unlicensed band and after chaos masking with chaos, signal is transmitted over optical fiber to analyze the results. Simulations are carried out by using licensed software (Optisystem version 14.0) and results are analyzed by using multiple data rates and fiber lengths. Moreover, analysis of our scheme is carried out by using RZ and NRZ formats and by varying the power of the laser.

120 GHz microstrip power amplifier MMICs in a commercial GaAs process

Abstract Single-ended and balanced 90–120 GHz microstrip power amplifier MMICs have been designed for cost-sensitive 5G and 6G backhaul in a commercial 6-inch, 0.1-µm GaAs process. At 108 GHz, measured output power is 20.4 and 22.5 dBm, respectively. At 120 GHz, measured output is 12.6 and 17.4 dBm, respectively. This is the highest reported for GaAs, among the highest reported to date for microstrip MMIC amplifiers at these frequencies and competitive with more expensive InP and GaN processes. Measurement is compared with simulation.

E-band backhaul antenna for fine beam alignment

Abstract An E-band Cassegrain switched beam high-gain antenna concept for 5G backhauling systems is proposed in this article. The antenna requirements target the compensation of small misalignments (within ±1 degrees in both azimuth and elevation planes) in E-band backhauling links due to adverse weather conditions or thermal deformations. The intended antenna is able to realize beam-switching operations by using a feed-array architecture based on a 7 × 7 array of cavity-backed magnetoelectric (ME) dipoles, where every element is capable of providing a steering of ±0.33 degrees in both the elevation and the azimuth planes. The ME dipole illuminators combined with a Cassegrain reflector provide a gain of 52 dBi within the whole scanning range. Besides, they can be easily integrable with the front-end modules, thus being an easily implementable and low-cost alternative to other more complex solutions based on horns or lens antennas.

Book Reviews: 5G Backhaul and Fronthaul

Book Reviews: 5G Backhaul and Fronthaul

Efficient Network Slicing with SDN and Heuristic Algorithm for Low Latency Services in 5G/B5G Networks.

This paper presents a novel approach for network slicing in 5G backhaul networks, targeting services with low or very low latency requirements. We propose a modified A* algorithm that incorporates network quality of service parameters into a composite metric. The algorithm's efficiency outperforms that of Dijkstra's algorithm using a precalculated heuristic function and a real-time monitoring strategy for congestion management. We integrate the algorithm into an SDN module called a path computation element, which computes the optimal path for the network slices. Experimental results show that the proposed algorithm significantly reduces processing time compared to Dijkstra's algorithm, particularly in complex topologies, with an order of magnitude improvement. The algorithm successfully adjusts paths in real-time to meet low latency requirements, preventing packet delay from exceeding the established threshold. The end-to-end measurements using the Speedtest client validate the algorithm's performance in differentiating traffic with and without delay requirements. These results demonstrate the efficacy of our approach in achieving ultra-reliable low-latency communication (URLLC) in 5G backhaul networks.

A W-Band SPDT Photoconductive Evanescent-Mode Waveguide Switch

This letter presents the design, fabrication, and measurement of a silicon micromachined photoconductive evanescent (EVA)-mode waveguide switch operating in a single-pole double-throw (SPDT) configuration. Two EVA-mode waveguides loaded with silicon posts are placed in a Y configuration with a common feeding waveguide. In the absence of photoexcitation, the dielectric posts and EVA channel exhibit a bandpass filter response that allows low-loss propagation of signals on the order of 2.0 dB at 96.7 GHz. When photoexcited, the low conductive posts and EVA channel yield a very high isolation of 36.5 dB up to 102.4 GHz within <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$W$ </tex-math></inline-formula> -band. The proposed design shows promise for 5G and 6G communication backhaul devices.

Millimeter-Wave Feasibility in 5G Backhaul: A Cross-Layer Analysis of Blockage Impact

The wireless backhaul has become a key enabler for 5G technology by presenting a cost-effective and scalable alternative to the typical fiber backhaul. WiGig protocols, such as IEEE 802.11ad and later IEEE 802.11ay, have been considered for backhaul connectivity of 5G mobile networks, thanks to the availability of high bandwidths capable of achieving fiber-like data rates. However, this band suffers from high propagation loss that can only be compensated using highly directional antennas, making mmWave links more susceptible to blockage and errors. Thus, to effectively evaluate the viability of WiGig-based technologies in wireless backhaul scenarios, it is crucial to characterize the impact of obstruction across the different network layers. This article presents an extensive measurement campaign and cross-layer analysis of physical (PHY), medium access control (MAC), and transport layers metrics measured for outdoor WiGig-based hardware submitted to short-term and long-term blockage. This study found that maintaining constant and higher modulation and coding schemes (MCSs) in long-term blocked channels may induce packet errors as high as 100%, round-trip-time (RTTs) that can be in the order of a few seconds, and packet losses as high as 90%. Even dynamically adjusting the MCS, the performance can be highly degraded. This effect was exacerbated in short-term links, as they suffered from more extreme MCS changes upon sudden obstructions. Temporary line of sight (LOS) obstruction was shown to cause maximum delays of half a second and a PER of around 20%; in more extreme cases, it has even led to temporary link failures.

Machine Learning-based Inverse Model for Few-Mode Fiber Designs

The medium for next-generation communication is considered as fiber for fast, secure communication and switching capability. Mode division and space division multiplexing provide an excellent switching capability with high data transmission rate. In this work, the authors have approached an inverse modeling technique using regression-based machine learning to design a weakly coupled few-mode fiber for facilitating mode division multiplexing. The technique is adapted to predict the accurate profile parameters for the proposed few-mode fiber to obtain the maximum number of modes. It is for a three-ring-core few-mode fiber for guiding five, ten, fifteen, and twenty modes. Three types of regression models namely ordinary least-square linear multi-output regression, k-nearest neighbors of multi-output regression, and ID3 algorithm-based decision trees for multi-output regression are used for predicting the multiple profile parameters. It is observed that the ID3-based decision tree for multioutput regression is the robust, highly-accurate machine learning model for fast modeling of FMFs. The proposed fiber claims to be an efficient candidate for the next-generation 5G and 6G backhaul networks using mode division multiplexing.

A Flexible Web Traffic Generator for the dimensioning of a 5G backhaul in NPN

Web-based services have nowadays aggregated the majority of applications, ranging from multimedia delivery to instant messaging, embracing requirements from different classes of users (i.e., gamers, streamers, professionals, etc.). The common factor is the need for connectivity everywhere and every time at high performance and quality, while the services traffic profiles and the users’ behaviour can be drastically different. This need is fully satisfied by the recent 5G mobile networks, where the coexistence of heterogeneous applications with different Quality of Service (QoS) levels is possible, defining new vertical markets and cutting-edge applications. In this context, we propose a Flexible Web Traffic Generator (FWTG) tool to model the dynamics of recent applications and user interactions in a realistic way, allowing the generation of real-time HTTP traffic and the possibility to inject it into real networks. FTWG represents a valid in-laboratory solution for the rapid configuration and applications performance evaluation of network slices in the context of 5G Non-Public Networks (NPN), pursuing an effective emulation approach. The advantage of this approach is that it allows the evaluation of real traffic response to different network configurations (and vice-versa), using components, equipment and network functions of the target network under test. After the description of the rationale and the methodology for defining FWTG models and their implementation, we defined a set of Key Performance Indicators (KPI) generated by the tool (e.g., number of requested objects and size, request rate, throughput, etc.). Then, we present initial validation tests on a Linux-based testbed representing the 5G-based scenarios of interest, emulating also a satellite backhaul as representative of a use-case requiring cost-effective dimensioning. Numerical outcomes of running FWTG in different configurations are then provided, considering a variation of the number of users sharing the same resources, their composition and traffic type, showing with concrete examples the usefulness and flexibility of FWTG in supporting 5G network configuration optimizations. Definitively, the tool is released as Open Source software on Gitlab.

A New RF Satellite Link Analyzing and Antenna Effect on Satellite Communication

Satellite communications (SatComs) recently, have admitted as a new technological advances that attracted and raised special investment and ventures. Space communication technology has found many application areas from costly, one-of-a-sort structures, to utilize again of technology on sequential tasks, to the progress of canonical protocols accepted by space agencies of lots of countries. Satellite communication has accepted as one of the important technologies for 5G backhauling, particularly on bandwidth request increased in 5G mobile broad band (eMBB) applications. This paper presents the efficiency of the satellite communication system using 16 QAM digital modulation technique for the X band. This digital modulation method presents high data rate in transmission without raising the bandwidth compared with other digital modulation methods. Applications are realized in Matlab environment and obtained conclusions are discussed such as power spectrum diagrams, constellation schemas and BER ratio for several bands such as 4, 8, 12, 16 GHz.

Modified PSO Based Channel Allocation Scheme for Interference Management in 5G Wireless Mesh Networks

Efficient channel management is a challenge that next-generation wireless networks need to meet in order to satisfy increasing bandwidth demand and transmission rate requirements. Non-orthogonal multiple access (NOMA) is one of such efficient channel allocation methods used in 5G backhaul wireless mesh networks. In this paper, we propose a power demand-based channel allocation method for 5G backhaul wireless mesh networks by employing NOMA and considering traffic demands in small cells, thereby improving channel utility. In this scheme, we work with physical layer transmission. The foremost aim is to mutually optimize the uplink/downlink NOMA channel assignment in order to increase user fairness. The approach concerned may be divided into two steps. First, initial channel allocation is performed by employing the traveling salesman problem (TSP), due to its similarity to many-to-many double-side user-channel allocation. Second, the modified particle swarm optimization (PSO) method is applied for allocation updates, by introducing a decreasing coefficient which may have the form of a standard stochastic estimate algorithm. To enhance exploration capacity of modified the PSO, a random velocity is included to optimize the convergence rate and exploration behavior. The performance of the designed scheme is estimated through simulation, taking into account such parameters as through put, spectral efficiency, sum-rate, outage probability, signal to-interference plus noise ratio (SINR), and fairness. The proposed scheme maximizes network capacity and improves fairness between the individual stations. Experimental results show that the proposed technique performs better than existing solutions.

Research on the Application of Microwave Communication in 5G backhaul

Research on the Application of Microwave Communication in 5G backhaul

Light-Trail Design for 5G Backhaul: Architecture, SDN Impact and Coordinated Multipoint

5G promises to be revolutionary from the perspective of offering unprecedented bandwidth to the end user. In this pursuit, the limited spectrum of the wireless overlay, further constricted by distance, requires strong support from a backhaul network. Such a strong backhaul network should provide large bandwidth pipes with near proximity to the end user at low costs and using pragmatic technology. Naturally, an optical solution is best suited to meet the voluminous bandwidth requirements of the backhaul. This optical solution has to cater to dynamic bandwidth needs among base stations and provide rapid and smart provisioning to meet the requirement of new features such as Coordinated Multipoint (CoMP) among base stations, and yet be low cost. To this end, we propose the use of light-trails (LTs), which are a generalization of a lightpath that provides for dynamic bandwidth communication, sub-wavelength optical grooming and optical layer multicasting using contemporary optics. We observe that each feature of a LT, i.e., dynamic provisioning, optical multicast, and sub-wavelength grooming is strongly desired by the 5G backhaul, implying a clear mapping between them. We investigate the usage of light-trails as a 5G backhaul solution. We discuss the proposed architecture of light-trails for micro cells, pico cells, and femto cells. We present the LT design problem for 5G backhaul as a constrained optimization problem. We also present a mechanism to achieve coordinated multipoint using light-trails. A dynamic virtual topology growth algorithm for the backhaul is also presented and extensively evaluated. The light-trails approach is compared to other approaches, the use of an SDN controller is discussed and significant performance benefits are observed.

Compact E-Band I/Q Receiver in SiGe BiCMOS for 5G Backhauling Applications

The implementation of backhauling links poses several challenges to the designers which are requested to limit the hardware costs in the framework of complex millimeter wave radio systems. This work presents a monolithically integrated E-band I/Q receiver covering the whole bandwidth from 71 to 86 GHz. The chip was implemented in a 55 nm SiGe BiCMOS technology which allows reaching a high level of integration. The receiver is based on a Low Noise Amplifier (LNA) stage and a Variable-Gain Amplifier (VGA) which provide a -11 dBm IP1dB. A double balanced mixer provides I/Q baseband outputs through a reduced-size differential phase shifter which allows to contain the chip size to 1.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

Time Sensitive Networking for 5G NR Fronthauls and Massive Iot Traffic

Integration of public fifth generation mobile network (5G) backhaul and non-public networks is key for the private/local 5G network ecosystem. However, such shared networks, namely, x-haul, must satisfy the extremely diverse traffic demands including low latency and massive number of internet of things (IoT) devices. We propose an x-haul platform with autonomous time aware shaper and adaptive mobile fronthaul compression, which simultaneously accommodates two 5G NR-class fronthauls (2*29.5 Gbps CPRI-equivalent rate) and backhaul traffic with 1,000 IoT devices. From an experiment we conducted to evaluate the proposed platform, mobile fronthaul traffic was transferred with 76-μs deterministic latency via 4 switches and 10-km optical fiber by autonomous time aware shaper while improving the achievable transmission rate of IoT traffic owing to the integration of adaptive compression.

QoE-Aware Video Streaming over Integrated Space and Terrestrial 5G Networks

The integration of the space information network (SIN) with terrestrial infrastructures has been attracting significant attention in the context of 5G, where satellite communications can be leveraged as additional capabilities such as backhauling between the core network and remote mobile edge sites. However, simple addition of SIN capabilities to terrestrial 5G does not automatically lead to enhanced service performance without systematic scheduling of coexisting resources. In this article, we focus on the scenario of multi-link video streaming over both parallel geostationary Earth orbit (GEO) satellite and terrestrial 5G backhaul links for enhancing user quality of experience and network efficiency. The distinct challenge is the complex optimization of scheduling video segment delivery via two parallel channels with very different characteristics while striving to enhance the video quality and resource optimality. We carried out systematic experiments based on a real-life 5G testing framework with integrated GEO satellite and terrestrial backhaul links. The experimental results demonstrate the effectiveness of our proposed 5G edge-computing-based solution for holistically achieving assured user experiences and optimized network resource efficiency in terms of video traffic offloading.