The Apple Watch Series 3 adds LTE but at a cost to older iPhone owners —the iPhone 5s won’t be able to set up or communicate with the device at all.
Shortly after the Sept. 12 unveiling event, Apple updated its product page for the Apple Watch to reflect the new unit, and the removal of the Series 2. As part of a footnote at the bottom of the page, Apple notes that while the iPhone 5s on iOS 11 can still be used to configure and communicate with the still-available Series 1 Apple Watch, the new device is limited to the iPhone 6 and newer, regardless if it has LTE or not.
The Apple Watch sports Bluetooth 4.2, as do both the iPhone 5s and iPhone 6. The three technical differences between the Apple Watch models are the LTE radio, the new S3 dual-core processor, and the and W2 wireless chip. Presumably, one of the three factors is the limiting one with the most likely candidate being the W2 wireless chip.
Nothing else besides the Apple Watch sports the W2 chip at present.
AppleInsider has contacted Apple regarding the specific reasons for the iPhone hardware limitation, and will update accordingly.
The Series 3 Apple Watch was demonstrated during Tuesday’s iPhone release event, and now features a LTE radio for phone calls and ultimately Apple Music in conjunction with the wi-fi and Bluetooth for communication. The Series 3 watch without LTE is available for a starting price of $329, with the LTE version selling for $399 and up.