GLONASS support will be removed for the upcoming Apple Watch Ultra 4. The previous iteration supported GLONASS, GPS, BeiDou, Galileo, and GPS. These use signaling and several frequencies for positioning to be accurate, and GLONASS is not that good a feature for gadgets that already have dual-frequency support.
The reason why GLONASS support has been dropped by Apple was not explained, but it could minimize the processing time, resulting in better battery life and better accuracy. The new Apple Watch Series 12 will still have support for GLONASS because the L1-only constraint is less pertinent on a device with single-frequency.
A different architecture for receivers and signals is used by GLONASS, meaning that corrections have to be made per satellite, and errors in positioning are possible. The Apple Watch Ultra 4 was announced alongside the Apple Watch Series 12, AirPods 5, iPhone Duo, and iPhone 18 Pro and iPhone 18 Pro Max models.
