Performance predictability is fundamental to the operation of any service provider. It is the foundation on which processes are built. Processes drive efficiency. So when it comes to deploying wireless technologies on large scale, service providers look for the “cookie-cutter” approach. No matter what a technology is, it will get little if any market traction if it cannot be deployed with relative certainty of performance.
Wide performance variance
Why do I say this? Because I believe there are inflated expectation on the ubiquity of millimeter wave solutions. With the hype of 5G ratcheting up, it is important to make the point that the performance of millimeter wave in anything other than line-of-sight deployments will be difficult to predict with sufficient certainty. The performance of millimeter waves has a high variance that makes it hard to predict. This is unlike low frequency bands where performance is tamed within a relatively narrow variance making it reasonably predictable – at least to a sufficient level required for cost-efficient deployment.
The variance in the performance of millimeter wave comes from the way signals interact with obstacles and different types of materials such as glass and vegetation. The performance could be excellent where there are no obstacles between the transmitter and receiver, or zero when a building stands in the way. High frequency signals are least capable to rounding building edges and corners, or going through a tree or a window. Moreover, the performance will vary depending on size and type of tree or the type of window glass. No signal will go through an infrared reflective glass window. The user will experience different performance behind double-pane and single-pane windows. While these factors impact performance in lower frequencies, the impact is manageable and the variance is lower than in millimeter wave frequencies. All this makes the job of network planners difficult as every connection to every client has to be scrutinized and planned independently. Scalability becomes challenging.
Mitigation technologies are expensive
To address the variability of performance, product designers lean on technology innovations to integrate features that will enhance performance and make the behavior of the solution more predictable. Multiple antenna systems, phased arrays and steerable beamformers are such solutions. But these solutions add cost. They also require space and power which makes them unpractical for customer devices. ASICs are needed to achieve low cost points, but cost is driven by volume which means large scale deployments. In this chicken or the egg problem, vendors have to take a calculated leap of faith. For investors financing such projects, it becomes critical to differentiate hype from reality.
Over the next few days, we will publish the results of our financial analysis of the millimeter wave fixed access use case. Stay tuned!