This Industry Overview was compiled by Sergiu Nedevschi, Co-Founder and CSO of Tarana Wireless.
Fixed wireless access (FWA) networks have long been used to provide basic internet service in areas with no fiber or coax infrastructure. Unfortunately, as the demand for faster internet service continues to grow, these legacy FWA solutions are significantly challenged by barriers that block wireless signals and severely limit the utility of these networks. These obstaclesIt takes many forms, including buildings and other structures, trees, moving vehicles, and terrain features. Data collected by the cellular network industry over many years indicates that approximately 90% of all commuting routes within 350 yards of a tower will be blocked. This is called Line of Sight (NLoS) communication, not Line of Sight (LoS).
NLoS deployment significantly reduces connection reliability, speed, and range for legacy FWA systems. These short distances reduce the coverage that a single base station can serve, but also increase costs because more base station and tower space is required for a given coverage objective. Slower bandwidth limits the service levels operators can provide to customers and the average revenue per user.
NLoS connections attempted with older FWA technology are also more susceptible to degradation from changing conditions, such as trees moving in the wind. As a result, it is often very difficult to maintain customer satisfaction and performance consistency with these networks. Unlike FWA mobile networks, you can move your phone to a location with a stronger, more reliable signal. Unfortunately, if the connection is poor, you cannot easily move your home.
A good fixed wireless system requires an approach to combat NLoS, as it is often impractical to cut down trees or move a neighbor’s house to avoid obstructions. Furthermore, due to either limited space availability or the high cost of households served by building a large number of sites, it is rarely feasible to place base stations close to target homes in the hope of obtaining clear lines of sight.
Next-generation fixed wireless access (ngFWA) networks overcome most of the problems associated with NLoS links by using a distributed massive multiple-input, multiple-output (DM-MIMO) architecture at the base node (BN) in the tower and at the remote control unit. node (RN) at the subscriber’s home. In this approach, each device has multiple independent antennas that can be used in combination to form the best switching transmission patterns between them.
These examples involve a signal processing technique, commonly known as beamforming, that uses discrete elements in the antenna arrays of BN and RN to direct radio energy to the most productive paths between them. This increases the total signal strength “picked up” by the receiver and reduces the effect of attenuation or self-interference. ngFWA uses a new class of unique beamforming approaches in a closed-loop process, where BN and RN work together over time to find and maintain the best beamforming solution to provide improved link throughput, stability, reliability, and low latency.
A key requirement for ngFWA is the ability to transmit an optimized pattern along the three key dimensions of space, time and frequency to make the most of the conditions present in the “channel” between the BN and RN. The optimized transmission counterpart of NgFWA beamforming involves multiple antenna arrays at the receiver that capture signals from different arrivals, delays, amplitudes, and phases to combine multipath signals and reconstruct the original signal with very high accuracy. This essentially perfect reconstruction of multipath signals results in a stronger connection because all available energy is used and it is important to take advantage of diffraction and reflection around objects that may interfere with the signal.
All of these features work together to achieve reliable, stable, and high-speed connections spanning unprecedented distances for non-line-of-sight, line-of-sight, or near-line-of-sight. Connections not previously possible with ngFWA are now available, meaning wireless providers can offer faster, more reliable service to a wider customer base with lower infrastructure costs, significantly reducing the need to build new towers or install more base stations.
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Categories: Industry Overview · Telecommunications Equipment · Wireless