Apple on Wednesday formally introduced its first in-house developed 5G modem that will be used in the company's new $599 6.1-inch iPhone 16e smartphone, aimed at the mainstream audience. The modem is the first fruit from Apple's acquisition of Intel's 5G modem business unit six years ago.

Apple says its C1 is the "most power-efficient modem ever on iPhone" and delivers "fast and reliable 5G connectivity." Indeed, the modem supports most key 4G and 5G technologies, including sub-6 GHz 5G with 4x4 MIMO, Gigabit LTE with 4x4 MIMO, FDD-LTE, TD-LTE, as well as 3G and 2G capabilities for compatibility.

Yet, the company does not disclose how this energy efficiency was achieved. Apple could use its own custom Arm or RISC-V-based cores with optimized power consumption. Also, the company uses one of TSMC's 4nm-class process technology (presumably N4P) to make C1 chips (according to an interview with Reuters), which assists in reducing power consumption. Since Apple tends to tightly integrate its hardware (C1) and software (iOS 18), it can enable its own proprietary power states that allow it to cut power consumption without performance degradation.

For now, Apple's C1 is used exclusively inside the iPhone 16e, which is a mainstream handset that does not support a number of performance-enhancing yet power-hungry capabilities, such as Wi-Fi 7, mmWave 5G, TDD (time division duplex) 4G and 5G networks, and DC-HSDPA.

mmWave 5G can deliver very high data rates, but to achieve them, the phone has to pack phased-array antennas and rely heavily on beamforming. 5G handsets with mmWave support must constantly adjust beams and manage multiple antenna elements in real-time, which means greater signal processing, more frequent power amplifier usage, and higher power consumption.

TDD networks use a single frequency channel for both uplink and downlink transmissions but at different time intervals, which adds flexibility and improves spectrum efficiency, making them beneficial in dense urban areas. However, TDD networks require strict timing synchronization between the phone and the base station, as well as switching between UL and DL, so the phone has to continuously adjust its transmission timing and radio circuits, which adds processing overhead and increases power consumption. Also, in weak signal areas, a phone has to increase its transmission power to maintain a connection, which is more taxing in TDD than in FDD.

The same applies to DC-HSDPA: the feature increases data rates by using two carrier frequencies instead of one, which inherently means that the device's radio components are working harder, leading to increased power consumption. However, this can all be optimized.

By: DocMemory
Copyright © 2023 CST, Inc. All Rights Reserved