The third-generation Apple Watch, set to launch this fall with LTE support for the first time, is unlikely to support phone calls, KGI Securities analyst Ming-Chi Kuo told investors in a note shared this morning.

According to Kuo, while a voice service that replaces the iPhone's calling functionality is "feasible," he believes Apple must first work on improving the "user experience of data transmission." As a result, he says the Apple Watch "probably" won't support traditional phone calls "this year."

This has two benefits: (1) negotiations with mobile operators will be more simple and the chances of cooperation with mobile operators will improve; and (2) 3G connectivity can be scrapped, simplifying the antenna design and facilitating internal design. However, we think there is a chance that users may use LTE Apple Watch to access VoIP services, such as FaceTime and Skype.

The watch could, however, support VoIP services like FaceTime and Skype, as FaceTime audio calling is already supported on current Apple Watch models.

Kuo also says that based on a lack of internal space, the LTE Apple Watch is likely to use an eSIM instead of a physical SIM slot, with the device set up to share the same phone number with an iPhone. He warns that LTE connectivity in the Apple Watch could be limited to specific countries and markets as not all mobile operators support that particular business model.

Rumors have already suggested that the major carriers in the United States, including Verizon, AT&T, and T-Mobile, will support and sell the upcoming LTE Apple Watch.

Though Apple is currently embroiled in an ongoing patent dispute with Qualcomm, Kuo believes Apple will use Qualcomm chips in the Apple Watch because Qualcomm's technology is superior to Intel's with smaller chips that consume less power.

Finally, Kuo predicts Apple has no intention of developing an Android app for the Apple Watch at this time, given that it would be difficult to have the same deep integration between Apple Watch and an Android phone that's possible with the Apple Watch and iPhone.

The third-generation Apple Watch is expected to be introduced in September alongside new iPhones. LTE connectivity is expected to be the main selling point for the device, and while there were some rumors pointing towards major design changes, Kuo has previously said there will be no "obvious change" to the form factor.