Fixed Wireless Access Research Articles

Identifying QOS impacts on the 4G LTE and 5G FWA integration using 2300 to 2400 MHz band reallocation for high-speed internet alternative to traditional fiber

Although 5G technology has been in development for a considerable time, significant challenges regarding its effective implementation still need to be addressed. A key issue lies in using frequency and ensuring coexistence with previous technologies that continue to serve existing users because users in many countries' late adoption of new technologies does not always progress smoothly. This research paper aims to evaluate 5G Fixed Wireless Access (FWA) utilizing the 2300 to 2400 MHz spectrum that is usually used in 4G LTE previous technology, positioned as a viable alternative to traditional fiber optic networks, and its impact on technology valuation in spectrum usage to solve high-speed alternative traditional fiber in rural and urban areas. The study focuses on Quality of Service (QoS) related to user experience with a standard wireless access service parameter while analyzing payload growth and revenue generation improvements compared to LTE technologies. Through rigorous trials, our results demonstrate that 5G FWA not only preserves the QoS experienced but significantly enhances it as a feasibility analysis of network productivity by combining 4G and 5G technology in one service area. The implementation trial of 5G FWA resulted in notable increases of 50 % in more than 20 Mbps data throughput, contributing to 27 % substantial growth in payload and revenue in an area using only 4G LTE before 5G FWA was implemented. By providing detailed performance metrics, the trials highlighted the potential for 5G FWA to deliver broadband services more efficiently and cost-effectively, particularly in regions where geographical or economic factors constrain the expansion of fiber optics.

Renewable Energy Powered and Open RAN-Based Architecture for 5G Fixed Wireless Access Provisioning in Rural Areas

Renewable Energy Powered and Open RAN-Based Architecture for 5G Fixed Wireless Access Provisioning in Rural Areas

Towards a connected nation: Exploring telecommunication technology ecosystems for effective, efficient, and economical deployment strategies

This article investigates the telecommunication technology ecosystem to formulate strategies for building a connected nation using effective, efficient, and economical combination of technologies. It examines both wireless systems (e.g., Microwave Transport Radio, Cellular Access Radio Systems, WiFi, Fixed Wireless Access, Satellite Systems) and wireline systems (e.g., Fiber Optics). The analysis evaluates each technology's inherent characteristics, benefits, challenges, cost, deployment ease, capabilities, scalability, and applications in urban and rural settings. Emphasis is placed on leveraging these technologies for various services, including voice, data, video, AI, emergency services, telemedicine, and robotic health operations in underserved and urban regions. A Scenario-Need-Technology Mix Matrix (SNTMM) is developed to assist service providers, governments, policymakers, program managers, and communities in selecting the appropriate technologies to meet their needs effectively and economically.

Ensemble prediction of RRC session duration in real-world NR/LTE networks

In the rapidly evolving realm of telecommunications, Machine Learning (ML) stands as a key driver for intelligent 6 G networks, leveraging diverse datasets to optimize real-time network parameters. This transition seamlessly extends from 4 G LTE and 5 G NR to 6 G, with ML insights from existing networks, specifically in predicting RRC session durations. This work introduces a novel use of weighted ensemble approach using AutoGluon library, employing multiple base models for accurate prediction of user session durations in real-world LTE and NR networks. Comparative analysis reveals superior accuracy in LTE, with 'Data Volume' as a crucial feature due to its direct impact on network load and user experience. Notably, NR sessions, marked by extended durations, reflect unique patterns attributed to Fixed Wireless Access (FWA) devices. An ablation study underscores the weighted ensemble's superior performance. This study highlights the need for techniques like data categorization to enhance prediction accuracies for evolving technologies, providing insights for enhanced adaptability in ML-based prediction models for the next network generation.

Vegetation Loss Measurements for Single Alley Trees in Millimeter-Wave Bands.

As fixed wireless access (FWA) is still envisioned as a reasonable way to achieve communications links, foliage attenuation becomes an important wireless channel impairment in the millimeter-wave bandwidth. Foliage is modeled in the radiative transfer equation as a medium of random scatterers. However, other phenomena in the wireless channel may also occur. In this work, vegetation attenuation measurements are presented for a single tree alley for 26-32 GHz. The results show that vegetation loss increases significantly after the second tree in the alley. Measurement-based foliage losses are compared with model-based, and new tuning parameters are proposed for models.

B-ROS re-balanced learning method for PS-A-RoF FWA communication

The enhanced remote area communication (eRAC) scenario is an important growth point in the communication market. In some remote areas where optical fiber access cannot be realized or the laying cost is too high, fixed wireless access (FWA) is an appropriate supplementary solution for eRAC. Adopting analog radio over fiber (A-RoF) technology to implement FWA can overcome the bandwidth limitation of electronic devices and realize high-frequency carrier communication economically to achieve high-capacity wireless communication. Also, probabilistic shaping (PS) technology can be combined with A-RoF to further improve the flexibility of the network and coverage of service provision. However, in the PS-A-RoF network, the high RF power introduces more undesired nonlinear effects into the network, and it is often necessary to deploy supervised machine learning (ML) compensation modules in wireless receivers (WRs). But the module performances are affected by the uneven probability distribution of PS-QAM constellation points. In this paper, we employ the PS-A-RoF nonlinear model to theoretically investigate the correlation between the distribution of training symbols and the wireless A-RoF system’s performance. Our analysis reveals that reducing the variance of training symbol power contributes to a lower BER in the A-RoF network. We introduce a borderline random over-sampling (B-ROS) that matches with the PS-A-RoF nonlinear model, instead of the mainstream ROS, which is only at the data level. Based on the B-ROS scheme, only the minority examples below the borderline are over-sampled to reach a better variance performance. Introducing the B-ROS method into the supervised complex value nonlinear compensation module can further improve the decision accuracy of WRs with the restoration of phase information, without increasing additional computational resource consumption. The vector noise power, training symbol power variance, and noise factor metrics have been calculated to optimize the borderline value of our ML-based approach. We also present experimental data on the proof-of-concept A-RoF experiment for PS-64QAM. The results demonstrate a promising nonlinear compensation performance of the B-ROS WR, and the optimal borderline agrees well with the one deduced from the theoretical model under certain transmission conditions. Our proposed B-ROS scheme lessens the training size demand and can improve the receiver sensitivity by 0.51 dB compared to the common ML-based WR and by 0.7 dB compared to the conventional ROS scheme.

Digital Twin Backed Closed-Loops for Energy-Aware and Open RAN-based Fixed Wireless Access Serving Rural Areas

Digital Twin Backed Closed-Loops for Energy-Aware and Open RAN-based Fixed Wireless Access Serving Rural Areas

Competitive Effects of Fixed Wireless Access on Wireline Broadband Technologies

Abstract In this paper, we investigate the potential consumer savings to U.S. home broadband consumers in cable modem monopoly markets, should fixed wireless access technologies become available as a competitive alternative. We use a Choice-Based Conjoint survey and Hierarchical Bayes estimation to calculate the proportion of home broadband consumers that would switch to a fixed wireless access option if it was made available in a cable modem monopoly market. We then utilize a monopoly pricing model to estimate the downward pricing pressure this competition would place on incumbent cable modem monopoly prices. We find that fixed wireless entry at current prices would convert 18 percent of cable-only households and lead to a 37 percent reduction in the price of cable modem service. We also find entry into non-monopoly markets where a fiber-optic broadband alternative already exists, and find muted conversion rates and price reductions. Our results indicate that the deployment of fixed-wireless access would generate substantial consumer savings in cable modem monopoly markets, which constitute 30 precent all cable modem subscribers in the United States.

Self-triplexing HMSIW antenna with enhanced isolation and extremely low frequency ratio

A self-triplexing antenna based on half-mode substrate integrated waveguide (HMSIW) cavity is proposed in this paper. The HMSIW cavity is designed as a combination of two eighth-mode substrate integrated waveguide (EMSIW) cavities and a single quarter-mode substrate integrated waveguide (QMSIW) cavity. The self-triplexing property is achieved by placing a narrow longitudinal slot on one of the EMSIW cavities and an annular cut on the QMSIW cavity. The proposed triplexer antenna operates at three distinct yet closely spaced frequencies 3.85 GHz, 4.12 GHz and 4.54 GHz with an extremely low frequency ratio (FR) of 1.18. The three operating bands are 3.82 - 3.88 GHz, 4.08 – 4.14 GHz and 4.51 – 4.57 GHz. The operating frequencies can be tuned independently by varying the dimensions of the slots. A minimum port isolation of 29 dB is achieved between the three cavities that contributes for self-triplexing property. The measured gain at three resonant frequencies is 6.02, 5.74 and 6.35 dBi, respectively. The proposed HMSIW self-triplexing antenna occupies a very small area of 0.14 λ02 (λ0 is the free space wavelength at the lowest operating frequency) and it is extremely useful for fixed wireless access and point-to-point commercial microwave applications.

Optimal Meshing Degree Performance Analysis in a mmWave FWA 5G Network Deployment

Fifth-generation technologies have reached a stage where it is now feasible to consider deployments that extend beyond traditional public networks. Central to this process is the application of Fixed Wireless Access (FWA) in 5G Non-public Networks (NPNs) that can utilise a novel combination of radio technologies to deploy an infrastructure on top of 5G NR or entirely from scratch. However, the use of FWA backhaul faces many challenges in relation to the trade-offs for reduced costs and a relatively simple deployment. Specifically, the use of meshed deployments is critical as it provides resilience against a temporary loss of connectivity due to link errors. In this paper, we examine the use of meshing in a FWA backhaul to determine if an optimal trade-off exists between the deployment of more nodes/links to provide multiple paths to the nearest Point of Presence (POP) and the performance of the network. Using a real 5G NPN deployment as a basis, we have conducted a simulated analysis of increasing network densities to determine the optimal configuration. Our results show a clear advantage for meshing in general, but there is also a performance trade-off to consider between overall network throughput and stability.

Design and planning of a 5G fixed wireless network

This research explains how to design and plan fixed wireless access connections in an urban setting using 5th generation (5G) technology in a multi-user urban scenario. Although the antennas used had a high gain, the 28 GHz carrier frequency proved incompatible with the connections due to path loss. The additional loss due to foliage led to a drop in the receiver sensitivity to -84 dBm. The loss due to weather conditions resulted in lower received signal strength. The lower frequency of 3.5 GHz performed better and is recommended to establish successful communication over multi-kilometer distances. As a result, this study demonstrates how vulnerable high 5G carrier frequencies are to typical path loss impairments.

Sustainable fixed wireless access with blockchain secured software defined network

Recently, there has been a tremendous increase in the number of service providers offering Fixed Wireless Access (FWA). The main goal of service providers is to offer guaranteed service (GB/month) for all contents by meeting sustainability Key Performance Indicators (KPIs): cost-efficiency and security. To minimize the risk of physical deployment and handle partial recovery, network slicing between service providers is considered by using the same FWA as a service by joint consideration of Infrastructure as a Service (IaaS) and Software as a Service (SaaS). This can only be handled by Software-Defined Network (SDN) controlled OpenFlow-based FWA. However, current OpenFlow switches in the market are used only as IaaS which does not meet cost-efficiency requirement alone. The software-defined OpenFlow tables can be increased by network administrator, which is not recommended because of having no authorization limitation and poses configuration risks on the device. Here, the research question is how can the service providers keep their own network sustainable by using infrastructure in a secure, cost-efficient, and conforming to the standard in a fair way? Therefore, Sustainable Fixed Wireless Access (SFWA) is newly proposed by OpenFlow-based blockchain in this paper. To handle low computational work and fair scheduling, Proof of Stake (PoS) consensus mechanism and Weighted Fair Content Scheduling algorithms are proposed for the validation process of the blocks that stores dynamic configuration details of service providers. At the end of the whole procedure, the valid blockchain is stored in the Secure Policy Database in OpenFlow-based FWA switches. According to performance evaluation, eMBB and URLLC contents can be served by 40% and 53% discount on cost per user with guaranteed service in FWA. The service provider offers a more sustainable network by blockchain-based secured SFWA than the conventional centralized authority-based FWA.

Downlink Cell-Free Fixed Wireless Access: Architectures, Physical Realities, and Research Opportunities

Recently a new paradigm of wireless access, termed as cell-free massive multiple-input multiple-output (MIMO), has drawn significant research interest. Its primary distinction from conventional massive MIMO aided cellular networks is the ability to eliminate the detrimental inter-cell interference (ICI), or to convert ICI into extra power for the intended signal via a multi-cell cooperation approach originated from network MIMO. However, the information-theoretical limit of cell-free access is achieved at the expense of large network configuration overhead and high MIMO processing complexity. Because of the dynamic nature of wireless channels, the global channel state information (CSI) invoked for network MIMO quickly becomes outdated, leading to performance degradation. This paper focuses on the cell-free implementation of fixed wireless access (FWA), a complementary solution to fibre-to-the-premise (FTTP) where the latter is prohibitively expensive. In particular, we discuss the centralisation architectures and channel characteristics of cellfree FWA, as well as their joint implications on imperfect CSI performance. Moreover, measurement-based offline simulations show that the long coherence time ('quasi-static') assumption of real-world FWA channels is only valid against a completely motionless background, and thus it should not be used in FWA system design or performance analysis. Finally, we present new research opportunities for cell-free FWA in terms of physical infrastructure, data processing as well as machine learning.

Characterization of Vegetation Loss and Impact on Network Performance at $V$-Band Frequencies

Wireless communication systems using millimeter-wave (mmWave) frequencies can be used for high-throughput applications such as fixed wireless access, where static line-of-sight links are used to provide internet connectivity. The directive antennas are typically mounted on building facades above street level. Therefore, the wireless links are mainly subject to attenuation due to atmospheric absorption, rain, and vegetation. In this letter, we present vegetation loss measurements at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V$</tex-math></inline-formula> -band frequencies ranging from 50 to 75 GHz, using a spectrum analyzer-based channel sounder. Existing vegetation models, including the vegetation-dependent exponential decay (VED) model, are validated based on the measured vegetation loss. Furthermore, IEEE 802.11ad transceivers are used for the validation of the vegetation models, and to evaluate the influence of vegetation on the network performance via packet error rate (PER) and throughput measurements.

Planning 5G Networks for Rural Fixed Wireless Access

We study the planning of a rural 5G multi-user massive MIMO fixed wireless access system to offer fixed broadband service to homes. Specifically, we aim to determine the user limit, i.e., the maximum number of homes that can simultaneously receive target minimum bit rates (MBRs) on the downlink (DL) and on the uplink (UL) given a set of network resources and a cell radius. To compute that limit, we must understand how resources should be shared between the DL and UL and how user and stream selection, precoding and combining, and power distribution should be performed. We use block diagonalization and propose a static grouping strategy that organizes homes into fixed groups (of possibly different sizes) in the DL and UL; then we develop a simple approach to compute the user limit that we validate numerically. We study the impact of group size and show that smaller groups yield larger user limits in a 3.5 GHz band. We show how the user limit at different cell radii is impacted by the system bandwidth, the number of antennas at the base station and homes, the transmit power, and the DL and UL MBRs. Lastly, we offer insights into how the network could be operated.

MmWave Physical Layer Network Modeling and Planning for Fixed Wireless Access Applications.

The large bandwidths that are available at millimeter-wave frequencies enable fixed wireless access (FWA) applications, in which fixed point-to-point wireless links are used to provide internet connectivity. In FWA networks, a wireless mesh is created and data are routed from the customer premises equipment (CPE) towards the point of presence (POP), which is the interface with the wired internet infrastructure. The performance of the wireless links depends on the radio propagation characteristics, as well as the wireless technology that is used. The radio propagation characteristics depend on the environment and on the considered frequency. In this work, we analyzed the network characteristics of FWA networks using radio propagation models for different wireless technologies using millimeter-wave (mmWave) frequencies of 28 GHz, 60 GHz, and 140 GHz. Different scenarios and environments were considered, and the influence of rain, vegetation, and the number of subscribers was investigated. A network planning algorithm is presented that defines a route for each CPE towards the POP based on a predefined location of customer devices and considering the available capacity of the wireless links. Rain does not have a considerable effect on the system capacity. Even though the higher frequencies exhibit a larger path loss, resulting in a lower power of the received signal, the larger bandwidths enable a higher channel capacity.

Evaluating 60 GHz FWA Deployments for Urban and Rural Environments in Belgium.

Fixed wireless access (FWA) provides a solution to compete with fiber deployment while offering reduced costs by using the mmWave bands, including the unlicensed 60 GHz one. This paper evaluates the deployment of FWA networks in the 60 GHz band in realistic urban and rural environment in Belgium. We developed a network planning tool that includes novel backhaul based on the IEEE 802.11ay standard with multi-objective capabilities to maximise the user coverage, providing at least 1 Gbps of bit rate while minimising the required network infrastructure. We evaluate diverse serving node locations, called edge nodes (EN), and the impact of environmental factors such as rain and vegetation on the network design. Extensive simulation results show that defining a proper EN's location is essential to achieve viable user coverage higher than 95%, particularly in urban scenarios where street canyons affect propagation. Rural scenarios require nearly 75 ENs per km2 while urban scenarios require four times (300 ENs per km2) this infrastructure. Finally, vegetation can reduce the coverage by 3% or increment infrastructure up to 7%, while heavy rain can reduce coverage by 5% or increment infrastructure by 15%, depending on the node deployment strategy implemented.

Catch the Pitch of 5G FWA: EMF and Throughput Measurements of 3.5-GHz Standalone Deployment in a Baseball Stadium

The provisioning of 5G technology does not only involve mobile terminals, but also new services such as Fixed Wireless Access (FWA). The aim of this study is to examine the ElectroMagnetic Field (EMF) and throughput performance of a FWA deployment utilizing Standalone technology operating at 3.5 GHz. To address the unique characteristics of 5G FWA signals, an innovative framework has been designed based on the measurement of 5G FWA spectrum using four independent chains and an additional traffic generation chain to saturate the radio link capacity at the measurement location. Methodologies for evaluating 5G FWA exposure under conservative conditions, such as measurements of exposure during active traffic generation and maximum power extrapolations, are also introduced. Results from real measurements taken at a baseball stadium show that 5G FWA exposure is consistently low, typically below 0.4 V/m, with an upper bound of 0.59 V/m, while the achieved throughput is up to 250 Mbps. Additionally, the measured 5G exposure levels are a small fraction compared to those emitted by other technologies such as 4G. Furthermore, the values estimated by simulation from the output power counters of the base station are found to be in close agreement with the measured exposure levels.

Maximum-Likelihood-Based Location, Orientation, Transmitted Power, and Antenna Beamwidth Estimator Utilizing the Angle-of-Arrival and Received Power for Spectrum Sharing at Millimeter Wave Bands

The fifth-generation (5G) system utilizing millimeter wave is available in Japan, but more bandwidth is demanded by the mobile phone operators to accommodate the demand for high data rate. Allocation of the vacant spectrum is impossible due to the past spectrum allocation to other radio systems. For example, 24.25-27.5 GHz has been allocated for the fixed wireless access (FWA) and license exempt small power data communication system in Japan. Although Japanese government is considering to license a part of the band for 5G under the spectrum sharing scheme, the coexistence design is quite challenging due to unavailable operation data of such systems in a form of database for the coexistence study. For this purpose, this paper introduces a maximum-likelihood estimator (MLE), which utilizes the angle-of-arrival (AoA) and received power of the line-of-sight (LOS)/diffraction paths as well as the map database to simultaneously estimate these unknown parameters via the spectrum sensing. It was applied to the measurement data obtained from a sub-urban environment where a commercial fixed wireless access system with similar operational parameters is under operation. Its performance was evaluated for a different number of receiver (Rx) points. The results showed that the parameter estimation accuracy is proportional to the number of receiver points. The distance and orientation errors of 45 m and 5 deg were achieved at 90th percentile with 40 Rx points. Furthermore, the prediction performance of the effective isotropic radiated power (EIRP) was decent, albeit a slight underestimation of the beamwidth.

Outdoor mmWave Channel Modeling for Fixed Wireless Access at 60 GHz

AbstractThe large bandwidths that are available at millimeter wave (mmWave) frequency bands allow high‐throughput wireless communication systems that enable fixed wireless access (FWA) applications. In FWA networks, a stationary link is created between antennas installed at building facades or street furniture, such as lampposts. A Line‐of‐Sight (LOS) scenario is preferred, but to guarantee the quality of service to the user, communication should remain possible when the LOS path is obstructed. In this paper, outdoor channel models at 60 GHz are presented that can be used for the design and optimization of FWA networks, based on measurements with the Terragraph wireless system using IEEE Std. 802.11ad radios. LOS path loss measurement data is analyzed and building reflection loss, diffraction loss, and vegetation loss are measured. There is limited diffuse scattering, but reflections on the wall frame structure result in reflected paths with low losses. Existing vegetation models that are based on measurement campaigns at lower frequencies underestimate vegetation loss at mmWave frequencies, as measured excess attenuation values range from 15 to 25 dB for distances lower than 14 m. The presented channel models are used for link budget calculations for FWA networks.