Apple has updated the technical specifications for its latest wearable devices, revealing that the Apple Watch Ultra 4 no longer includes support for the GLONASS satellite navigation system. In contrast, the Apple Watch Series 12 continues to maintain compatibility with this Russian positioning network.
The Apple Watch Ultra 4 currently supports four navigation services: GPS, Galileo, QZSS, and BeiDou. This represents a reduction in capabilities compared to the previous generation, the Apple Watch Ultra 3, which supported five systems including GLONASS.
Industry analysts note that GPS, Galileo, QZSS, and BeiDou utilize CDMA signal transmission, which allows for multi-frequency support and higher precision. GLONASS traditionally relies on FDMA, which complicates integration for dual-frequency consumer devices.
Furthermore, the signal architecture of GLONASS requires hardware timing adjustments for individual satellites, which can introduce positioning errors. By focusing on CDMA-based systems, Apple aims to streamline the positioning hardware in its newest Ultra model.
