Apple’s Cellular Evolution: iPhone 17 and iPhone Air Debut Along With New N1 Wi-Fi an C1X Cellular Connectivity Chips

Yesterday,  Apple announced this year's batch of new iPhone models: the iPhone 17, iPhone 17 Pro & Pro Max, and the super-slim iPhone Air.

Every other site on the Internet will be talking about the new cameras, batteries, screen durability, case colors, and video features.

But here at the Mobile Internet Resource Center - we have made it a tradition to look at the newest iPhones every year strictly through the lens of connectivity capabilities.

And there are certainly some interesting twists and mysteries to report on this year!

Join us in our annual deep dive into just what is new from the connectivity perspective in this year's batch of iPhone updates.

Apple’s Slow Split From Qualcomm

Our annual look at new iPhone models used to focus on the latest cellular capabilities enabled by the newest generation of Qualcomm cellular modems.

In the 5G era, Apple had been evolving in lock-step with Qualcomm's latest flagship modem chips (links go to our annual analysis):

• iPhone 12 - Qualcomm Snapdragon X55
• iPhone 13 - Qualcomm Snapdragon X60
• iPhone 14 - Qualcomm Snapdragon X65
• iPhone 15 - Qualcomm Snapdragon X70

But then last year, instead of the expected X75 - teardowns of the iPhone 16 series revealed a mysterious Qualcomm SDX71M modem chip.

Neither Apple nor Qualcomm has been willing to go on record talking about this chip, leaving analysts to puzzle over a mystery chip that seems to be custom-made for Apple, with no publicly available information published.

Even a year later, it remains unclear whether this chip is a "5G Advanced" chip like the X75, with support for the 3GPP Release 18 standards. Or whether it is just a somewhat more advanced version of the X70 found in the iPhone 15.

Meanwhile, it has been no secret that Apple has been working behind the scenes to develop a 5G modem of its own, aiming to end its reliance on Qualcomm.

Apple jumpstarted this development effort by acquiring Intel's entire cellular modem team in 2019 - and that investment at last emerged from the lab in the form of the C1 Modem debuting in the low-end iPhone 16e model released in February 2025.

Despite this being a gigantic technical achievement, Apple barely mentioned the C1 in the iPhone 16e launch, only saying that the custom chip helped improve battery life. The C1, however, lacked mmWave support and couldn't reach the same peak performance levels as the latest Qualcomm chips - but for most average users, the real-world results have proven more than adequate.

Up next for Apple's modem team is the all-new iPhone Air, which debuts the new C1X modem:

"iPhone Air also features C1X, a new cellular modem designed by Apple. C1X is up to 2x faster than C1, and for the same cellular technologies, it is even faster than the modem in iPhone 16 Pro, while using 30 percent less energy overall. This makes C1X the most power-efficient modem in an iPhone."

The C1X seems to be a solid evolution of the C1 - though it still lacks mmWave support, and it appears to be more focused on energy efficiency than trying to rival Qualcomm in raw performance.

In particular, on T-Mobile's network, there is some potential for the C1X to lag behind Qualcomm modems on towers that are pushing the most advanced 5G carrier aggregation technologies.

We are eager for real-world testing to see what sort of practical differences emerge.

Apple has not indicated whether the C1X is 3GPP Release 18 compatible, meaning it may not be ready to take advantage of future 5G Advanced cellular network features.

As for the iPhone 17 and 17 Pro, it seems that Apple is still sticking with Qualcomm (and mmWave) for at least one more generation.

But just which modem chip?

Will it be the X71 again? The X75? Or the flagship 5G-Advanced X80 that is powering the latest Android flagships?

Some potential guesses:

• Apple C1X - Not likely. Apple's press releases make it clear that the C1X is exclusive to the iPhone Air, and Apple has not mastered mmWave technology yet. Next year it is likely a C2 will take Apple closer to full Qualcomm parity.
• Qualcomm SDX71M (Again) - This is a possibility, but Apple is claiming that the C1X outperforms the iPhone 16 Pro under certain circumstances. It would be awkward for Apple's flagship iPhone Pro 17 to stay stagnant and be outclassed by the iPhone Air.
• Qualcomm Snapdragon X80 - Qualcomm's flagship modem for 2025 is the most advanced cellular modem currently in existence, supporting 6x 5G download carrier aggregation. But if Apple were using this modem, they might have claimed "5G Advanced" as a feature on their specs page, confirming compatibility with the latest 3GPP Release 18 cellular standards.

Until the first teardowns and field tests come in, all we can do is guess.

We will update this post when the modem chip inside the iPhone 17 lineup is confirmed.

iPhone 17 & iPhone Air Cellular Capabilities

The list of officially supported 5G and LTE bands on the USA version of the iPhone 17 is almost entirely unchanged from the iPhone 16.

Changes are highlighted in bold - the only change to the spec sheet is one 5G band that has been dropped:

• Sub-6GHz 5G Bands: n1, n2, n3, n5, n7, n8, n12, n14, n20, n25, n26, n28, n29, n30, n38, n40, n41, n48, n53, n66, n70, n71, n75, n76, n77, n78, n79
• mmWave 5G Bands: n258 (24 GHz), n260 (39 GHz), n261 (28 GHz)
• 4G/LTE Bands: 1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20, 25, 26, 28, 29, 30, 32, 34, 38, 39, 40, 41, 42, 48, 53, 66, 71

Here are the details on the dropped band:

• 5G Band n76 (SDL 1500) - This is a tiny 5 MHz supplemental download-only band that had been only slated for use in Europe, and to date, no European carriers have deployed band n76 coverage. This band is probably never going to be put into real usage, and will not be missed.

The iPhone Air has the C1X modem and has almost identical specs. Differences with the iPhone 17 are in bold:

• Sub-6GHz 5G Bands: n1, n2, n3, n5, n7, n8, n12, n14, n20, n25, n26, n28, n29, n30, n38, n40, n41, n48, n53, n66, n70, n71, n75, n76, n77, n78, n79
• mmWave 5G Bands: None
• 4G/LTE Bands: 1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 17, 18, 19, 20, 25, 26, 28, 29, 30, 32, 34, 38, 39, 40, 41, 42, 48, 53, 66, 71

As mentioned earlier, n76 support is not important, but it is interesting to note that the Air has it and the 17 does not.

The big thing missing is mmWave 5G support - super high-speed but super short-range cellular spectrum that has failed to live up to its early hype.

It seems that AT&T, T-Mobile, and Verizon have slowed their mmWave rollouts in urban areas and stadiums to a seeming halt, and mmWave coverage has not increased much anywhere over the past year. And outside the USA, mmWave has failed to catch on at all so far.

So for now, ditching mmWave is not much of a loss.

In the future, mmWave may matter once again - and unconfirmed leaked roadmaps indicate that Apple plans mmWave support in the 2026 modem release that will at last fully replace Qualcomm across the product line.

Other iPhone 17 Cellular Notes - eSIM and International Alternatives

In the USA, the iPhone 17 and iPhone 17 Pro models should have identical cellular capabilities and internal 4x4 MIMO antennas, no matter which carrier you buy from.

If you buy directly from Apple, the iPhone 17 will be sold unlocked and capable of use on any US carrier that supports eSIM.

Like the iPhone 15 and 16, the USA model of the iPhone 17 is eSIM only - and now the Canadian / Mexican model has also ditched physical SIM cards too!

But now, for the first time, giving up the SIM slot comes with an advantage - the eSIM-only models have noticeably larger batteries than the European and Chinese models that still have physical SIM slots.

The iPhone Air is eSIM only, worldwide. 

International Models Remain Limited - No mmWave or 600 MHz Cellular!

Despite the lack of a physical SIM slot, the iPhone 17 models sold in the United States continue to have some significant advantages.

In particular, Apple has retained mmWave 5G support as an exclusive capability for phones destined for the USA.

Ultra-high-frequency mmWave 5G signals enable amazingly fast performance, but the signal is exceedingly short-range and requires specialized antenna modules to receive.

Because mmWave is expensive to implement (and has been very slow to deploy), many lower-priced 5G devices have excluded this capability entirely. And since mmWave antennas need to be physically close to the modem, mmWave has never been practical on cellular routers either, making it a technology that has yet to really live up to its potential.

To date, Apple has only included mmWave support on iPhone models sold within the United States, and this continues with the iPhone 17 lineup.

Only the iPhone 17 and 17 Pro support mmWave - the iPhone Air does not.

The international iPhone 17 variants will be mostly identical to the USA version, other than some minor differences in cellular and battery capability:

• Canada / Mexico / USVI / Japan / Middle East Model - Lacks all mmWave bands (n258 / n260 / n261) and adds Japanese 4G bands 11 and 21. This model is now eSIM only, dropping the physical SIM slot like the USA version.
• Other International Models - All the various other international models lack mmWave bands and also lack 600 MHz n71 and b71 (T-Mobile's long-range coverage) and AT&T FirstNet (Band 14 and n14), as well as some other minor 4G and 5G bands. 

The lack of mmWave support is a minor consideration for Canadians who travel to major US cities, where this sort of coverage might make a difference.

Those who spend a lot of time in the USA should avoid all other international iPhone 17 and iPhone Air models, as they lack support for the 600 MHz bands critical for use on T-Mobile and the FirstNet band 14/n14, which is exceedingly valuable on AT&T.

Although you gain a physical SIM slot with the international models, you sacrifice battery life to achieve it.

Wi-Fi and Bluetooth Evolve With The N1 Chip

Apple, in the past, has relied on other companies for Wi-Fi and Bluetooth chips, but all the new phones announced this week are debuting with Apple's new in-house developed N1 chip.

"The iPhone 17 lineup also introduces N1, a new Apple-designed wireless networking chip that enables Wi-Fi 7, Bluetooth 6, and Thread. In addition to powering the latest generation of wireless technologies, N1 improves the overall performance and reliability of features like Personal Hotspot and AirDrop."

Wi-Fi 7 (aka 802.11be) first came to the iPhone lineup last year, evolving the Wi-Fi standard to higher peak speeds and network capacities - assuming you are connecting to a Wi-Fi 7 compatible router.

Wi-Fi 7 simultaneously combines three frequency bands - 2.4 GHz, 5 GHz, and 6 GHz. Other features of the Wi-Fi 7 standard are expected to enable routers to more effectively select channels to avoid interference, as well as introduce new techniques to reduce network latency and improve mobile device battery life. 

For more on Wi-Fi 7 and the state of Wi-Fi technology, see our featured story:

Wi-Fi Industry Update: Wi-Fi Technology Guidance For RVs, Vans, and Boats

Bluetooth 6 is new and great for future-proofing, as it will enable more reliable and lower-latency connections with Bluetooth devices, particularly future peripherals that also fully support Bluetooth 6.

Thread is a wireless standard that will make it easier to set up smart home devices in the future - also nice to have, but not earth-shattering.

The most interesting tease in the N1 is Apple's claim to improve overall performance and reliability when using Personal Hotspot.

We suspect this will mostly come into play in congested areas, where the more tightly integrated radios can better avoid stepping on each other and other nearby devices.

Satellite Connectivity Remains Free, And Comes To Apple Watch Ultra 3

Just like with every iPhone since the iPhone 14 in 2022 - the iPhone 17 lineup (and iPhone Air) comes with built-in and seemingly unchanged satellite messaging support.

And new this year - the Apple Watch Ultra 3 gains satellite messaging too!

Apple promises two years of free satellite access - and since Apple has still not figured out what to charge for satellite messaging and emergency SOS features, they are granting another year of free service to people who already purchased older models:

"Apple is extending free access to satellite features for an additional year for existing iPhone 14 and iPhone 15 users. The free trial will be extended for iPhone 14 and iPhone 15 users who have activated their device in a country that supports Apple’s satellite features prior to 12 a.m. PT on September 9, 2025."

Maybe someday Apple will start to charge for satellite features, but they have punted that decision at least another year down the field.

This is Apple's own satellite service, using legacy Globalstar satellites, which are independent from carrier-provided satellite capabilities like T-Mobile's T-Satellite With Starlink, which launched in July.

For T-Mobile customers, both satellite services can actually co-exist, bringing extreme redundancy when located way off-grid.

Both services are currently limited to just basic text messaging - but starting in October, T-Mobile will be rolling out "2G Style" limited data connections for picture messaging and providing connectivity to compatible apps that have been customized to use the low-data connection - including Apple and Google Maps.

For a deep dive into all the latest satellite connectivity options, be sure to read our recent industry analysis:

2025 Satellite Mobile Internet Update: Starlink, Kuiper, Direct To Cellular, and More!

Concluding Thoughts & iPhone 17 Release Dates

All of the new iPhone models will be available for pre-order this Friday, September 12th, and will ship next week on September 19th.

The iPhone 16 and iPhone 16e are staying in the lineup, too, with lower starting prices making them more affordable for those who aren't interested in being on the cutting edge.

As is the case every year, all the carriers and Apple will have promotions for the new iPhones. Those interested in upgrading should do their research and carefully review the fine print. 

Most promotions require turning in an existing phone and/or agreeing to a service commitment to "pay" for the phone via monthly bill credits. We don't track these sorts of deals here.

In short, carriers intend to entice you to make a long-term commitment to their service in exchange for a free or discounted iPhone.

Make sure you know what you are getting into (and that you are not agreeing to have your phone SIM locked to just one carrier!) - especially if you are the sort of geek who likes to upgrade every year or two.

Bookmark