This article originally appeared on Extreme Tech by Ryan Whitwam.
The US led the charge on 4G LTE, which gave US companies significant power in the global economy. LTE is now mature, and telecom companies are moving aggressively to roll out 5G networks — Verizon just launched theirs yesterday, in fact. A new report from the Department of Defense warns that without major changes in policy, the move to 5G will benefit China much more than the US.
According to the report, titled “The 5G Ecosystem: Risks & Opportunities for DoD,” several vexing issues in 5G boil down to physics. The US, like most countries, has regulators to manage the wireless ecosystem and ensure there are no conflicting signals that cause interference. That’s why companies like AT&T and Verizon have to buy spectrum licenses. In the US, some of the more desirable 5G frequencies are used exclusively for Department of Defense projects. In China, those frequencies, known as sub-6, are open for 5G deployment.
The US mobile carriers are focused mainly on millimeter wave (sometimes called mmWave) at frequencies at up to 39GHz. That’s more than 10 times higher than the highest LTE frequencies. The upshot is you can fit a lot of data in that signal, but it won’t pass through obstacles very well. In China, mobile networks are using sub-6 (6GHz and lower) frequencies as the backbone of 5G. These bands don’t have as much theoretical throughput, but other elements of the 5G standard like 3D beamforming still make them better than LTE.
The DoD sees a possible future in which other countries push ahead with sub-6, making that the de facto standard. Chinese firms like Huawei and ZTE will manufacture the network equipment and phones, and the US will continue focusing on mmWave in its own little bubble.
The Department of Defense isn’t willing to give up all its 3GHz and 4GHz spectrum for commercial development, but it says changes are necessary. The study proposes the DoD release the 3.2-3.6 GHz range and the 4.8-5.0 GHz range. These are both actively in development for 5G in China. Deploying them in the US would give US companies a competitive leg up. However, carriers are already deep into the development of mmWave 5G. It will take time to get more sub-6 frequencies online. Currently, T-Mobile is the only carrier talking openly about using lower frequencies for 5G in the US.