Boosting Coverage and Capacity: The Future of mmWave Fixed Wireless Access
In our increasingly connected world, where 5G is the norm and 6G is on the horizon, Fixed Wireless Access (FWA) has emerged as a key technology for alleviating spectrum congestion. By leveraging high-band mmWave frequencies, FWA delivers the high-speed, low-latency broadband connectivity essential for internet delivery to the home over a wireless connection. At the heart of this capability are phased array antennas, which enable FWA systems to transmit strong, focused signals in mmWave bands, effectively addressing the challenges of limited range and signal penetration commonly associated with high-frequency communications.
Although mmWave networks have made inroads into the FWA market, they have faced headwinds. Limitations associated with mmWave FWA technology include short-range signal coverage and high sensitivity to obstacles and environmental conditions, such as rain and vegetation, which make deployment challenging in certain areas. These challenges sometimes require engineers to make trade-offs in application deployments to ensure cost-effectiveness and efficiency.
In this article, we will address these FWA deployment challenges and provide some innovative solutions. We will also discuss the enablement of CPE using the same AESA antenna systems. Additionally, we will explore examples of low-cost, scalable designs tailored explicitly for mass deployments in both FWA Access Points (APs) and Customer Premises Equipment (CPEs). Additionally, we will discuss how Qorvo designs offer specific advantages, such as high signal strengths and reduced signal noise, to enhance the existing FWA infrastructure further.
Market Relevance of Fixed Wireless Access
The profitability of FWA is heavily influenced by household density and the landscape area in which it is deployed. In highly dense environments, such as downtown urban areas where household density exceeds 1,600 households per square kilometer, FWA installations are generally not prioritized. This is because many wireless alternatives, including fiber-optic networks and other broadband solutions, are already widely available, making FWA less competitive.
In dense urban and urban areas, with household densities ranging from 400 to 1,600 households per square kilometer, FWA finds an opportunity to perform well. These regions often feature a mix of wireless and fixed broadband solutions. Still, FWA can stand out by providing high-speed, low-latency connectivity, particularly in areas where traditional wired broadband infrastructure is limited or prohibitively expensive to deploy.
Suburban areas, with household densities ranging from 120 to 400 households per square kilometer, represent a prime target for FWA profitability. Here, the balance between population density and infrastructure cost makes FWA a highly attractive option. Suburban deployments benefit from the scalability and cost-effectiveness of FWA, enabling providers to deliver reliable internet access without the need for extensive physical cabling.
In rural and very rural areas, where household densities drop to less than 120 households per square kilometer, FWA faces challenges. Long-haul RF links are often necessary to reach these sparsely populated regions. While FWA can provide connectivity in these areas, its profitability is limited compared to urban and suburban settings, and it is often used as a supplementary solution rather than the primary mode of internet access. In Table 1 below, we provide a summary of where FWA usage excels.
A Layered Deployment Approach
The integration of mmWave and mid-band C-band frequencies creates a robust, layered approach to addressing the diverse coverage and capacity demands in various environments, such as dense urban, urban, suburban, and rural areas. Mid-band frequencies (i.e., 1-6 GHz) enable larger cell sites, providing broad coverage across wide areas, which is particularly effective in suburban and rural settings where population density is lower. On the other hand, mmWave frequencies excel in delivering high-capacity, low-latency connectivity, making them ideal for dense urban and urban areas where households demand higher data rates.
This layered approach optimizes spectrum utilization by leveraging the strengths of each frequency band. Mid-band frequencies ensure foundational coverage in both cellular and consumer premise equipment, while mmWave supplements this by focusing on high-density regions or areas close to base stations, where it can maintain Quality of Service (QoS) levels above 1 Gbps. This strategy, shown in Figure 2, supports both high-performing households, which can fully utilize cell capacity with the highest modulation and coding rates Modulation and Coding Scheme (MCS), and low-performing households, which benefit from the robust baseline coverage provided by the mid-band. (Modulation and Coding Scheme is a metric that measures the parameters of a Wi-Fi connection between a client device and a wireless access point)
The inclusion of mmWave cells significantly enhances network capacity within mid-band coverage areas, ensuring that minimum QoS requirements are maintained even during periods of high traffic. As illustrated in Figure 2, the layered deployment of mmWave and mid-band frequencies enables gigabit-level speeds for households within range while also maintaining a reliable QoS for all users. This strategy creates a balanced and efficient network infrastructure, delivering both high performance and reliability to meet the diverse needs of users across various coverage areas.
Advancements in Beamforming ICs
Recent advancements in Beamforming ICs (BFICs) have significantly accelerated the deployment of FWA in households, addressing the growing demand for high-speed connectivity. However, mmWave radios present unique challenges compared to mid-band and sub-6 GHz systems. Signals transmitted at mmWave frequencies attenuate much faster over distance than those at sub-6 GHz or mid-band frequencies. Furthermore, critical performance metrics such as high amplifier output power, good power-added efficiency (PAE), low noise figure, high receiver sensitivity linearity and low DC power consumption are more challenging to achieve at mmWave frequencies due to the inherent physics of semiconductors. Unlike the mature and cost-effective sub-6 GHz ecosystem, which has been refined over decades for commercial wireless applications, mmWave technologies face higher costs and complexities, making widespread deployment a more significant challenge for wireless providers and communication service providers (CSPs). However, there is a solution.
To overcome these challenges, mmWave systems use phased array antennas, which employ multiple elements to steer or collect energy. See Figure 3. By adjusting the amplitude and phase of signals at each antenna element, phased arrays can steer energy in desired directions while minimizing energy loss in unwanted directions. While phased array antennas have been used in government markets for over five decades, these systems often relied on high-cost technologies. However, today’s commercial array antennas remove these high-cost barriers. Commercializing a mmWave communications ecosystem demands a focus on reducing capital expenditures (CAPEX) and operational expenditures (OPEX) while ensuring scalability and delivering high-quality service. New technological advancements in BFICs and antenna array designs have addressed these expense and deployment challenges.
Performance Improvements with New Beamforming ICs
New Beamforming ICs address FWA deployment challenges by introducing significant improvements in key metrics, such as Effective Isotropic Radiated Power (EIRP), which enhances uplink and downlink performance by improving signal strength and reducing link budgets. EIRP, a measure of the radiated power in the direction of peak antenna gain, directly contributes to better signal reliability and improved bits-per-cell-site metrics. With today’s BFIC metric upgrades, uplink link budgets show an 18 dB improvement, and downlink budgets have improved by 10 dB. These advancements enable greater coverage and capacity, supporting up to three times more users per cell site than previous systems. This translates to enhanced QoS with fewer interruptions and higher data rates for end-users.
Moreover, improved signal-to-noise ratio (SNR) and data rate efficiency further enhance network performance. The newer BFIC technologies of today offer higher linear output power and improved noise figure performance, resulting in a substantial improvement in signal levels between the gNodeB and Customer Premise Equipment (CPE). These improvements increase user capacity, expand coverage areas, and reduce the number of radios required for deployment. By lowering the CAPEX for CSPs while simultaneously improving network performance, new BFICs represent a transformative step toward building a commercially viable mmWave ecosystem that meets the demands of modern connectivity.
FWA Key Performance Metrics
Performance metrics are crucial in evaluating the efficiency and reliability of Active Electronically Scanned Array (AESA). Parameters such as EIRP, range, and EIS play essential roles in determining the Signal-to-Noise Ratio (SNR), which directly impacts the quality and speed of data transmission. A higher SNR enables more robust communication, supporting higher Modulation and Coding Scheme levels and faster data rates. Below is a breakdown of these performance metrics and their influence on wireless communication systems:
- EIRP represents the total power radiated by an antenna, factoring in both the transmitter power and antenna gain. A higher EIRP indicates a stronger signal being transmitted, which improves the SNR at the receiver end. A high EIRP also directly enhances the system's ability to transmit data over longer distances or in environments with potential interference. In mmWave systems, maximizing EIRP is crucial for maintaining high performance and ensuring reliable communication links.
- The distance between the transmitter and receiver is a critical determinant of SNR because of path loss. As the range increases, signal strength decreases, which negatively impacts the SNR. For mmWave frequencies, where attenuation is higher than in lower frequency bands, range considerations are even more significant. Effective system design minimizes these losses to maintain adequate SNR levels for signal optimal performance.
- EIS measures the minimum signal strength a receiver can detect, essentially quantifying the receiver's sensitivity. A better EIS allows the system to detect weaker signals, which is especially valuable in low-signal environments or at the edge of a cell's coverage area. Combined with a high EIRP, good EIS ensures that even faint signals are processed effectively, maintaining high SNR and system reliability.
- The SNR is a fundamental metric in communication systems as it directly determines the available MCS level, which affects the achievable data rate. A high SNR enables the system to utilize higher-order modulation schemes in conjunction with a lower code rate, allowing for faster data transmission. Conversely, a lower SNR forces the system to use lower-order modulation schemes with more robust error correction, leading to slower data rates to ensure signal integrity.
- MCS and Data Rate: MCS levels represent different combinations of modulation and coding rates. Higher MCS levels correspond to higher data rates but require a stronger signal (better SNR) to operate effectively. See Figure 9 for MCS and SNR measurement results.
- SNR Impact: A high SNR enables the decoding of complex modulation schemes with a low probability of errors, resulting in higher data throughput. Conversely, low SNR results in a shift to lower MCS levels, sacrificing speed for reliability.
- EVM is a key metric used to measure the quality of a digital signal in wireless communication systems. It represents the difference between the expected voltage value of a transmitted symbol and the actual received symbol, providing insight into amplitude and phase distortion in digitally modulated signals. EVM is calculated as the length of a vector connecting the ideal and measured symbol points, with larger EVM values indicating more significant distortion and a higher probability of bit errors. It can be expressed relative to either the max/peak power or the root mean square (RMS) power of the constellation. As a critical performance indicator, EVM is widely used to evaluate over-the-air links between antennas and phased arrays, helping engineers identify sources of signal impairment and optimize transmitter and receiver designs for improved signal fidelity.
- The image in Figure 5 illustrates the concept of EVM and how noise affects digital signal transmission. On the left, an ideal constellation diagram is shown, where transmitted symbols align perfectly with their intended positions. In the middle, noise impairment is introduced, causing the constellation points to spread out from their reference locations, an effect caused by a lower SNR. As SNR decreases, these points deviate further from the ideal positions, increasing the likelihood of symbol misinterpretation. On the right, a visualization of EVM is presented, depicting the vector difference between an ideal reference point and a received symbol. The diagram also highlights how EVM can be measured relative to the peak power (green) or the root mean square (RMS) power (blue) of the constellation, both of which are used to assess signal quality in wireless communication systems.
EIRP (Effective Isotropic Radiated Power)
Range
EIS (Equivalent Isotropic Sensitivity)
SNR (Signal-to-Noise Ratio)
EVM (Error Vector Magnitude)
SNR and Its Impact
By carefully balancing EIRP, range and EIS, mmWave systems can optimize SNR to support higher MCS levels and maximize data rates. These improvements are critical for delivering high-quality service and meeting the growing demands of modern wireless communication networks.
Another critical factor for FWA and other wireless standard implementations is reducing system power consumption. Optimizing key performance metrics, such as those listed above (i.e., EIRP, EIS and SNR), helps make lower power consumption requirements more achievable. Additionally, advanced design techniques, such as power amplifier (PA) digital pre-distortion (DPD), can enhance overall transmitter efficiency and reduce power consumption. In turn, this can enable a lower-grade Power over Ethernet (PoE) solution to reduce the total bill of materials cost. By leveraging these methods and optimizing performance criteria, system providers can reduce FWA power consumption by up to 40% to 50%.
The Design Advantages of a Qorvo Solution
In today’s competitive market, several solutions are available to address the demands of AESA mmWave FWA. However, meeting the stringent key performance metrics outlined earlier requires a carefully engineered design. This is where the Qorvo solution stands out. One of its key advantages is its applicability: it can serve the gNB cellular market (the base station that connects 5G devices to the core 5G network), the Access Point (AP) and CPE FWA markets. This versatility simplifies deployment for carriers, enabling a unified solution across multiple points in the mmWave communications ecosystem.
In the next section, we delve into actual measured performance data obtained using Qorvo’s latest BFICs. The same test setup was used to compare legacy devices with today’s generation of BFICs, ensuring an accurate comparison across generations.
Measured Performance Advantages
The Qorvo FWA solution (see Figure 6) delivers significant improvements in key parameters such as EIRP and EIS. The enhancements in both the solution and BFIC chip designs are crucial for meeting the critical design parameters for transmitting uplinks and receiving downlinks.
The image shown illustrates how Qorvo’s solution is compact enough to be designed to excel across both 5G NR, FWA and Wi-Fi ac/ax/be applications. We will show in the following paragraphs and images how its performance metrics demonstrate its ability to meet demanding communication requirements while maintaining efficiency and reliability.
Higher EIRP ensures stronger transmitted signals, improving coverage and signal quality, while better EIS enables the receiver to detect weaker signals. This enhances system reliability even in challenging environments. These improvements directly translate into better SNR and higher data rates, enabling the new Qorvo design to meet stringent FWA and CPE deployments.
CPEs are crucial devices that connect homes or offices to an FWA network, enabling ultra-fast, high-speed internet access. Acting as the bridge between the FWA network and local area networks (LAN), the FWA CPE allows seamless connectivity for various devices, including smartphones, laptops and IoT systems. It can be deployed indoors or outdoors: indoor CPEs receive and distribute wireless signals directly within the premises, while outdoor CPEs capture signals from base stations and transmit them to indoor units for distribution. Available in two types, with or without Wi-Fi, these devices can either convert signals from an AP into wireless internet for direct use or into Ethernet for wired distribution via routers or switches. With its flexibility and transformative capabilities, 5G FWA CPE plays a crucial role in delivering high-performance internet to end users.
Figure 7 below highlights the tangible improvements in coverage, user capacity, and data rates that the latest Qorvo BFICs deliver. These advancements make the business case for FWA deployments far more compelling.
Improved Quality of Service (QoS)
Examining key metrics, such as line-of-sight (LOS), SNR and uplink/downlink data rates, further illustrates the advantages of Qorvo’s BFICs. As shown in Figures 9, 10 and 11, today’s devices offer a substantial improvement in both SNR and data rates compared to legacy products. A higher SNR enables better modulation and coding schemes, allowing for faster data transmission and fewer connection issues. These improvements translate into a significantly higher QoS for end-users.
This figure shows how the new generation of BFICs achieves higher SNR, enabling robust communication even in challenging conditions.
With improved downlink data rates and faster end-user download speeds, the overall user experience is enhanced.
Higher uplink data rates ensure smoother and more reliable uploads, which are crucial for applications such as video conferencing and cloud-based services.
Qorvo’s solution exemplifies how thoughtful design and advanced technology can overcome the challenges of mmWave FWA and CPE deployments. By improving performance metrics such as EIRP, EIS and SNR, while reducing deployment costs and enhancing scalability, Qorvo’s BFICs pave the way for more efficient and cost-effective FWA and Wi-Fi solutions. These advantages position Qorvo as a leader in providing cutting-edge, high-quality solutions for both today’s and future mmWave AP and CPE markets.
Conclusion
The deployment of mmWave FWA solutions is critical to meeting the surging demand for high-speed, low-latency connectivity in an increasingly connected world. Qorvo's innovative phased array antenna designs, combined with advancements in Beamforming ICs, address the inherent challenges of mmWave technology, including short range and high signal attenuation. By achieving significant improvements in key performance metrics, such as EIRP, EIS and SNR, Qorvo enables better uplink and downlink budgets, with uplink improvements of 18 dB and downlink improvements of 10 dB. These enhancements can result in a fourfold increase in coverage area and a threefold increase in user capacity per cell site, all while reducing the deployment cost per square kilometer by 70%. This progress not only enhances data rates and QoS but also makes FWA and CPE deployments more economically viable for both carriers and consumers.
Qorvo’s layered approach, which integrates mid-band and mmWave frequencies, optimizes spectrum utilization to balance coverage and capacity in diverse environments, ranging from dense urban areas to rural regions. Mid-band frequencies provide foundational, broad coverage, while mmWave adds high-capacity, gigabit-level speeds in high-demand areas. The versatility of Qorvo’s solutions, applicable across both gNodeB and CPE markets, underscores their scalability and cost-effectiveness. With these innovations, Qorvo is paving the way for more efficient, reliable, and future-proof networks, empowering carriers to meet the connectivity demands of both today and the upcoming 6G era.
Additionally, you can find more information on this subject by visiting our Qorvo Design Hub, which offers a rich assortment of videos, technical articles, white papers, tools, and more. For technical questions, please visit Qorvo.com or contact Technical Support.
About the Authors
Our authors bring a wealth of technical expertise in developing and optimizing wireless solutions. With a deep understanding of customer needs and industry trends, they collaborate closely with our design teams to drive innovation and deliver cutting-edge solutions that support industry-leading products.
Thank you to our main contributors to this article: Peter Moosbrugger (Director, Advanced Antenna Technology), Ian Gresham (Qorvo Fellow) and David Schnaufer (Corporate Technical Marketing Manager) for their contributions to this blog post, which ensures our readers stay informed with expert knowledge and industry trends.
