Even though Apple launched its trio of iPhone 11 models a mere four months ago in September, the rumor mill is already looking across the horizon and speculating about 2020 and the upcoming iPhone 12 (some rumors have already begun for the 2021 iPhones). Keep in mind that we don't know what the new iPhones' official names will be -- and Apple has not confirmed anything about them -- so we'll go with the iPhone 12 for now. In addition to adding 3D depth-sensing to its rear cameras and new screen sizes, it's also being speculated that Apple will belatedly include a feature that would make it competitive with its rivals: 5G connectivity.

It will be many months until we approach the predicted launch of the iPhone 12, 12 Pro and 12 Pro Max in September 2020, but check back with this piece often as we will continue to update it with the most probable and compelling rumors.

iPhone 12 could have bigger and smaller screens

One of the more enduring rumors about the upcoming iPhones is that Apple may introduce new screen sizes. One of the iPhone 12s could have a 5.4-inch screen (of the current iPhones, the iPhone 11 Pro has the smallest display, which measures 5.8 inches). And the iPhone 2020 Pro Max could go as large as 6.7 inches (for reference, the iPhone 11 Pro Max has a 6.5-inch display). 

There's also speculation that the iPhone 12's display will have a 120Hz refresh rate. Most phones refresh at 60 frames per second, or 60Hz, but other phones, like the OnePlus 7T and OnePlus 7 Pro, refresh at 90Hz. The gaming handset the Razer Phone 2 has a 120Hz display as well. With a higher refresh rate, a phone feels faster and smoother when scrolling through things like web pages and apps.  

Apple may launch five new iPhones in 2020

With the possibility of new display sizes, rumors that Apple will expand its iPhone line have been swirling around. In December, CNET's Lexy Savvides wrote:

According to JPMorgan analyst Samik Chatterjee, Apple will release four new iPhone 12 models in the fall of 2020: a 5.4-inch model, two 6.1-inch phones and a 6.7-inch phone. All of them will have OLED displays.

These size predictions were also backed this week by analyst Ming-Chi Kuo, who believes the current 5.8-inch size of the iPhone 11 Pro may be going away. So the 5.4-inch and one of the 6.1-inch models will be the lower-end devices, presumably called the iPhone 12. Then the more expensive phones will be the other 6.1-inch and 6.7-inch iPhone 12 Pro and 12 Pro Max, respectively.

The fifth iPhone then will be a sequel to the iPhone SE, which is rumored to look more like the iPhone 8 and we could see as early as the first quarter of 2020. 

Read more: The best ways to sell or trade in your old iPhone in 2020    

iPhone 12 could usher in 5G (or not)

Apple's in no rush to launch a 5G iPhone, and it's likely you won't see one until this year -- or even as late as 2025. Apple analyst Kuo optimistically predicts the company will unveil three 5G phones in 2020. There are a couple of reasons for this. First, Apple usually isn't the first in on mobile trends, preferring instead to perfect an emerging technology before committing to it. Remember that it was behind its competitors in making phones with 3G and 4G LTE connectivity when those networks first launched. 

Second, Apple at one point stopped working with the leading 5G modem provider, Qualcomm, because of a dispute over Qualcomm's licensing fees. The two companies settled their litigation in April 2019 and then agreed to a multiyear 5G chip deal. This led to Apple's previous partner for 5G modems, Intel, to ultimately exit the 5G phone modem business altogether. (Apple later acquired Intel's smartphone modem unit for $1 billion.) Apple is back working with Qualcomm, but it got started too late to launch a 5G phone last year when a few of its rivals released their 5G models, like the Galaxy S10 5G, LG V50 5G and OnePlus 7 Pro 5G.

When it comes to producing a proprietary 5G chip, The Information reported in May 2019 that it would take Apple years to design its own in-house 5G modem. "In interviews with prospective hires for the team, Apple has told engineers that they expect to have their own modem ready by 2025," reported the outlet, citing an anonymous source.

iPhone 12 may have 3D depth sensing in rear cameras

Since the iPhone X, newer iPhones have front-facing cameras that have 3D depth sensing. Known as Face ID, this feature scans your face for unlocking your phone and authorizing digital payments. It's been rumored that Apple may take it up a notch and introduce that same system to the rear cameras. In August, CNET's Vanessa Orellana wrote:

Longtime Apple analyst Ming Chi Kuo (via MacRumors and 9to5Mac) said he expects two of the 2020 iPhones models to have a new time-of-flight camera lens on the back of the phone. The setup would be similar to that of the current True Depth camera system used for Face ID on the front of the phone, except it would use a slightly different type of technology that could allow it to 3D map objects from farther away. This would significantly improve its augmented reality applications and take certain camera features like Portrait Mode to the next level.

It's unclear how many of the 2020 iPhones would be equipped with this feature, if any.

CNET's Vanessa Hand Orellana and Lexy Savvides contributed to this report.