## 3 Fixed Wireless Access
### 5G-Based FWA Prospect  
It is remarkable that for the wireless technology to meet the service demands of fixed broadband regarding better system capacity, as well as enhanced user data rates, it also has to exploit a broader spectrum. Consequently, it has to make use of the highly exploited legacy cellular bands in which there have been notable spectrum shortage challenges and also has to exploit the underutilized higher frequency bands [8, 27, 262, 263]. This will facilitate network elements massive connection by means of a simple, cost-effective, and low-energy consuming solution [4]. As a result, to realize better system capacity and enhance user data rates, the 5G FWA networks are also anticipated to employ mm-wave bands.  
In addition, the band options include 3.5 GHz, 28 GHz, 37 GHz, 39 GHz, and 70 GHz, with greater portions of the spectrum gaining considerable attention [9, 27, 252]. However, radio propagation conditions at higher frequency bands are relatively demanding. Therefore, operation at the bands demands the BF technique. The BF technique is capable of compensating for the associated path loss of mm-wave bands. In addition, apart from the fact that the technique helps in addressing the coverage issues by producing narrow beams, the generated beams may be easily redirected as demanded. Moreover, with multi-user MIMO (MU-MIMO) scheme, signals emanating from multiple user terminals may be concurrently multiplexed on the same frequency and time  
In addition, the required system performance and coverage are mainly contingent on factors such as the employed frequency band, terminal antenna placement, and the operating environment [8; 27; 267; 270]. For instance, low-frequency FWA solution such as 3.5 GHz provides a lot of suitable mobile coverage, leading to relatively extended reach. Although the solution offers smaller obtainable bandwidth, implementation of MU-MIMO and massive BF offers suitably high spectral efficiency (SE) for the cell. This makes the low-frequency band FWA a promising solution for video service delivery and home broadband connectivity. Besides, this will help in facilitating the envisaged massive connections for billions of people in remote and rural areas. On the other hand, the high-frequency FWA solution such as 28 GHz offers comparatively lower cell range (covers shorter geographic distance). This is a result of severe propagation and environmental conditions. Therefore, the achievable ranges in this band are contingent on the following factors [27; 150]:  
1. Terminal antenna placement
2. Density and height of the obstacle (foliage density, trees, and buildings)
3. BS antenna height and placement.  
Furthermore, in view of the fact that high-frequency band FWA is more susceptible to diffraction losses as well as building penetration losses, rooftop terminal placement is capable of offering a wider range because of the elevated LoS between the terminals and the BS. Note that the employment of indoor and outdoor wall-mounted terminals can considerably reduce the range. Moreover, to make high-frequency band FWA efficient for fixed wireless applications and services in urban and dense suburban areas, the system capacity can be enhanced by employing greater bandwidth, as well as a massive number of antennas for substantial BF realization as depicted in Figure 12. This will help in achieving higher beam gain that is capable of mitigating the inherent higher path loss at mm-wave frequencies and aids in supporting multiple streams of signal to multiple users (MU-MIMO) [5; 69; 271].  
Figure 11: FWA deployment scenario (adapted from [27; 252]).