CTIA’s annual industry survey has found that wireless network investment reached $30 billion last year — the third year in a row of increasing investment, and a five-year high that comes as carriers transition their networks to 5G. The number of operational cellular sites in the U.S. has rapidly increased over the past two years, the survey found, and data-only devices such as hot spots, smart watches and other IoT devices now represent more than 40% of the wireless device base.