Leaked KDK: iPhone 17e Likely Uses Apple C1 Modem
• iPhone 17e appears to reference Apple’s first-generation C1 cellular modem in leaked macOS Kernel Debug Kit code. • The same leak shows iPhone 17e entries omitting Apple’s N1 wireless chip. • For the iPhone 18 Pro, Apple seems undecided between C1X and C2 modem variants. • The macOS KDK that revealed these details was accidentally published and later pulled by Apple.
What the leak revealed
Code lifted from a version of Apple’s macOS Kernel Debug Kit (KDK) — a developer kit Apple later removed from public download — includes internal strings and device identifiers that point to modem assignments for upcoming iPhone models.
iPhone 17e: C1 modem, N1 absent
The leaked KDK references a C1-series cellular modem tied to an internal iPhone 17e identifier, suggesting Apple may ship a phone using its first-generation C1 modem technology.
Notably, the same files do not reference Apple’s N1 wireless chip for that model. Public details about N1’s exact role have been limited, but its absence in the 17e entries implies a different wireless configuration for that SKU.
iPhone 18 Pro: C1X versus C2 still under consideration
For the higher-end iPhone 18 Pro, the KDK contains entries pointing to both C1X and C2 modem designations. The presence of both names suggests Apple has not finalized which modem variant will ship in the Pro model and may be evaluating trade-offs between the two designs.
What C1, C1X, C2 and N1 mean for users
Apple’s move to its own cellular modem silicon (C1 family) is a multi-year strategic shift away from third-party modems. First-generation C1 hardware likely prioritizes baseline cellular capabilities and integration with Apple’s system-on-chip and software stack.
C1X and C2 appear to be iterative or higher-performance modem variants. A C1X could represent a refined C1 with incremental improvements, while a C2 may offer more substantial upgrades in areas such as power efficiency, peak throughput, or carrier feature support.
Why the leak matters
Modem choice affects battery life, cellular speeds, and compatibility with advanced carrier features (for example, mmWave, carrier aggregation, and private 5G features). Apple controlling the modem roadmap could accelerate feature integration between iOS, the A-series/S-series silicon, and radio firmware.
What to watch next
Apple has pulled the KDK release, and the company typically refines hardware plans until close to product release. Expect additional leaks or official confirmations as Apple prepares product announcements for the iPhone 17e and iPhone 18 Pro cycles.
