Marko Zivkovic, reporting for AppleInsider:

For the U.S. variant of the iPhone 18 Pro, which will feature mmWave compatibility, Apple seemingly plans to use Qualcomm modem hardware.

Multiple Qualcomm components, including the SDX80M, SDR875, QDM8771, QDM8720, PMK75, PMX75, and QET7100A, are referenced in a bill of materials related to the iPhone 18 Pro model Apple plans to sell in the United States.

As for the iPhone 18 models which will be sold elsewhere, Tata documentation suggests these configurations will use Apple’s proprietary C2 modem. While this approach may sound unusual, there is at least one possible explanation.

Apple’s current in-house modems, the C1 and the C1X, do not support 5G mmWave, and it looks as though the C2 will continue this trend. Until Apple develops a modem compatible with mmWave, it looks as though the company will offer mmWave support to iPhone 18 Pro users by using Qualcomm hardware.

I think Apple made the right choice in developing the C2 modem without support for 5G millimeter wave (“mmWave”), the technology that enables ultra-high-bandwidth connections in limited areas. Millimeter-wave signals — known by carriers as ultra-wideband — are extremely high-frequency and can be interrupted by even atmospheric attenuation. They cannot permeate through walls or people and do not work across long distances. This makes them unsuitable for most cellular transmissions; carriers instead use the lower-frequency C-band to transmit slightly slower but more reliable 5G signals. (Confusingly, carriers also refer to this as “ultra-wideband.”) The three major carriers — Verizon, AT&T, and T-Mobile — have installed 5G ultra-wideband antennas in city downtowns across the United States. Some sports arenas and airports have also been outfitted with the technology to limited success.

During Apple’s “Hi, Speed” October 2020 keynote, which introduced iPhone 12 with 5G, the company incessantly touted 5G ultra-wideband as the future of mobile communication. So let’s take a step back for a minute: Was the rollout of 5G ultra-wideband all that successful? Is it really everywhere? For one, Verizon, with which Apple partnered during the keynote, has since removed the map on its website that showed where 5G millimeter-wave was available. The coverage map now only marks certain metropolitan areas as “5G ultra-wideband capable” cities, while refusing to discriminate between the much slower C-band and millimeter-wave connectivity. There is, however, a map buried on a subdomain (gismaps.verizon.com) that shows the millimeter-wave rollout, and it’s quite underwhelming.

The map shows that Verizon still has not rolled out 5G millimeter-wave on even some of the most population-dense Manhattan streets. This is not malfeasance: It’s more likely that Verizon, sometime in the last six years, determined that it was either impractical or impossible to bring 5G millimeter-wave to most streets and instead slowly phased out the advertising. Nowadays, Verizon hardly even mentions 5G because it is, even on C-band, mostly a waste of battery. I have never once connected to millimeter-wave in these six years — despite living in an “ultra-wideband capable city” — and I assume most Americans are the same. If not for New York, where would people be most likely to take advantage? 5G millimeter-wave was a profound waste of everyone’s time and money, and the carriers know it. Betteridge’s law of headlines strikes again.

What isn’t a waste of time and money, though, is Apple’s C-series modems, which have performed equally as well as the Qualcomm modems — if not a bit better — while using less energy. If the carriers, Apple, and customers all somewhat agree that 5G millimeter-wave is a profound waste of resources, why even ship it at all? Carriers don’t even make a distinction between the two flavors of ultra-wideband anymore, and almost no one who buys iPhone 18 Pro will even know the difference. How many people are standing in Times Square running internet speed tests? I think people, including the carriers, would be happy to trade a technology hardly anyone uses for an hour of extra battery life a day with the C2 modem. I think it’s a mistake that Apple hasn’t recognized this and used the C2 in all iPhone models.