A new Apple Watch with space for a SIM card and the ability to make phone calls is on the cards and could arrive before the end of 2017.

These are the latest rumours coming from technology analysts and sources inside Apple's global supply chain, who can often give clues about future products the iPhone maker might be working on.

First there is semiconductor analyst Christopher Rolland, who recently travelled to Asia to speak to several of Apple's component suppliers.

These conversations have led Rolland to believe Apple will add a SIM card slot and cellular functionality to the next Watch, meaning it can make calls, send/receive iMessages and connect to the internet without being tethered to an iPhone.

Rolland said in a note published by Barron's: "We understand a model of the next Apple Watch will include a SIM card, and therefore is likely to support LTE [also known as 4G]."

Continuing to address other aspects of the upcoming wearable, Rolland said: "We understand some issues remain, including battery life and form factor size, but significant progress has been made." The analyst speculates how the third-generation Watch could make phone calls with Apple's wireless AirPod earphones.

Next up, sources of DigiTimes says a next-generation Apple Watch will begin shipping "in the second half of 2017". The publication adds that Apple will continue to produce and sell the second-generation Watch alongside the new model, just as the second is currently sold alongside a slightly updated version of the original Watch.

It is likely that the next Watch will launch at the same time as the upcoming 2017 iPhone, thought to be called the iPhone 8. If Apple sticks to its usual schedule this will be around the second week of September.