5G is Coming! Wait – What’s 5G?

[Commentary] After the successes of 3G and 4G mobile services, something called 5G was inevitable. It’s still a ways off, but the outlines are taking shape. The hallmark of 5G mobile service will be blindingly fast data speeds, possibly in the gigabit-per-second range, faster than most US wired Internet services today, along with extremely short response times (“latencies”) measured in thousandths of a second.

There will be a downside. Very high data speeds take up a lot of radio bandwidth. To find sufficient bandwidth, designers will have to look toward the upper end of the usable spectrum. The Federal Communications Commission is now evaluating the 28, 37, and 39 GHz bands, and may add 24 GHz and possibly other bands. The problem: frequencies in this range do not propagate well, and in particular do not penetrate the materials used in commercial buildings. The old model of a cell tower serving both indoor and outdoor users for miles around – even blocks around – will not work here. A 5G mobile will have to be within a few hundred yards of its base station with nothing substantial separating them. There have been demonstrations in Europe for the last six months or so. Verizon and AT&T have each announced upcoming trials in the United States. But without firm specifications in place, chances are these will not closely resemble the eventual deployments. But when 5G finally does arrive, those cat videos will download in a flash.