Apple Watch Series 3 with LTE will be exclusively compatible with iPhone 6 and later
During the event of presentation of the iPhone 8 and iPhone X, Apple also announced the new Apple Watch Series 3 with and without LTE connectivity. These new smartwatch will have watchOS 4 already installed, so will require the presence of iOS 11 on iPhone. In particular, you will need an iPhone 6 or later to be able to use the model with LTE connectivity.
As has happened in the last few years, to be able to use the Apple Watch to your iPhone must have the latest operating system iOS. This year the rule will not change, and to be able to use the Apple Watch with watchOS 4 need iOS 11 installed on your iPhone. Giving a look at the list of compatible devices with iOS 11, you will discover that you will need at least an iPhone 5s to be able to use your smartwatch with watchOS 4. In fact, from the list of requirements on the Apple website, you will discover that it is the iPhone 5s the device is the most dated to work with the new Apple Watch 3 Series.
The matter is slightly different if we look at the Apple Watch Series 3 with LTE connectivity. This new model, presented simultaneously with the iPhone 8 and iPhone X, will be equipped with a compartment for the SIM to be able to make calls, write SMS and connect to the internet. Unfortunately, however, to use this model of smartwatch you will need an iPhone 6 or later.
We should also remember that the model Series 3 with LTE is not yet available in Italy for a lack of agreements with Italian operators.
The article Apple Watch Series 3 with LTE will be exclusively compatible with iPhone 6 and the next comes from iSpazio.