GPS, Galileo, BeiDou, and QZSS use CDMA-based signaling and support multiple frequencies for more accurate positioning. Consumer devices typically only receive an L1 signal from GLONASS, so it is less useful on devices with dual-frequency support. GLONASS also uses a different signal architecture, and receivers have to correct for hardware timing delays on a per-satellite basis, which can lead to positioning errors.
Apple did not say why GLONASS support was removed, but dropping it could improve accuracy, reduce processing, and possibly improve battery life.
The Apple Watch Series 12 continues to support GLONASS, likely because the L1-only limitation is less relevant on a single-frequency device.
This article, “Apple Watch Ultra 4 Drops GLONASS Support” first appeared on MacRumors.com
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