Apple is expected to unveil the new iPhone 7 at its annual launch event held on September 7.
The iPhone 7 launch comes just as rival Samsung has recalled its flagship Galaxy Note 7 over battery explosion.
Many commentators expect Apple to have ditched the headphone jack, leaving only one port.
According to a new research, the iPhone 6S was the world’s bestselling handset.
The study, by Strategy Analytics, said 14.2 million copies of the iPhone 6S shipped between April to June, accounting for 4% of the market. By contrast, the Samsung Galaxy S7 Edge shipped 8.3 million units over the same period.
However, both fell short of the earlier iPhone 6, which shipped 26.3 million units over the same months in 2015.
Dropping the headphone jack in the iPhone 7 would encourage consumers to use Bluetooth headphones or buy those compatible with Apple’s Lightning port, which is also used for charging.
However, old gear would not be completely obsolete, as Apple is expected to include an adapter jack.
Camera quality is expected to be improved and this time round the upgrade might mean a two-lens clicker for some of the bigger models.
Other handsets’ dual-lens camera can take pictures with two different exposures, then combine the two images for improved picture quality – but it is unknown how Apple would implement the feature.
Other expected change includes increased storage and better speakers.
The iPhone 7 is also said to be water resistant, handling submersion for up to 30 minutes – a feature already offered by several of Apple’s Android competitors from the likes of Samsung or Sony.
Apple is thought to be sticking with its two sizes, meaning there would be an iPhone 7 and an iPhone 7 Plus.
Neither is the design thought to be changing much, giving it the same overall look as the current models.
Rumor has it there will be more colors available, for instance reintroducing black as an option.
While the new models will be revealed to the world at the launch, consumers will have to wait a few weeks before they are shipped. Pre-orders are expected to open on September 9.
Samsung beat Apple by releasing its Galaxy Note 7 in August. The phone was well received by users and critics alike and started selling well.
But then reports about batteries heating up and sparking some fires prompted Samsung to launch an embarrassing recall last week – just days before the iPhone 7 launch.
While Samsung’s battery problems might tilt some prospective buyers toward the iPhone 7, Apple depends on the ongoing success of its smartphones as they have become its biggest source of revenue.