The rollout of fifth-generation (5G) wireless networks has already begun around the globe, and it won't be long before we start seeing 5G-capable smartphones hitting the market. Goldman Sachs estimates that sales of 5G smartphones could hit 120 million units next year, which is a significant bump over its earlier shipment forecast of 50 million units.

The investment bank has upgraded its forecast based on China's successful 5G rollout, while 5G deployments in the U.S. will also be a catalyst. Apple (AAPL -2.19%) and Ericsson (ERIC -2.04%) are two stocks that could help investors make money from this coming 5G smartphone revolution. Let's see why.

Abstract image showing hands holding a smartphone and denoting connectivity.

Image source: Getty Images.

Apple's 5G iPhone could be a hit in China

Apple has found the going tough in China lately thanks to declining smartphone sales in the country, but the iPhone 11 shows that the Cupertino tech giant hasn't lost its mojo. Reuters reports that iPhone 11 pre-orders on Chinese e-commerce platform are up 480% as compared to last year's iPhone XR.

Alibaba's e-commerce platform has also reported a 335% increase in iPhone 11 sales as compared to last year's devices. Supply chain checks by analysts and investment banks also indicate that the device is in strong demand in China and other parts of Asia.

It looks like Apple's decision to lower the price of the entry-level iPhone model has worked wonders in China, encouraging customers to upgrade their older iPhone models. But what's worth noting is that demand for the iPhone 11 seems to be strong despite the lack of 5G.

Apple's rivals have already included the new wireless capability in some of their flagship devices, but that doesn't seem to have affected the popularity of the iPhone 11. The $699 price tag of the base model iPhone 11 is probably helping Apple keep its user base from defecting to rivals and set the stage for the launch of a 5G device next year.

Noted Apple analyst Ming-Chi Kuo of TF International Securities believes that a 5G iPhone is coming in 2020. The Mac maker has already settled its dispute with Qualcomm and is reportedly working on an in-house modem following the acquisition of Intel's smartphone modem business. But more importantly, Apple seems to have a plan to bring an affordable 5G device to the market.

According to Kuo, Apple could launch a smaller 5.4-inch iPhone next year with 5G support. A smaller screen could be Apple's strategy of keeping costs lower so that users don't have to pay a heavy premium for a 5G device. In fact, Kuo estimates that all of Apple's 2020 iPhones will come with 5G support, according to a research note seen by MacRumors, and that will include a lower-cost device that will help it compete with Android offerings.

So don't be surprised to see Apple corner a nice share of China's 5G smartphone market next year with a value-for-money offering that could knock down the price barrier the current crop of 5G smartphones suffer from.

Ericsson is making a killing in China's 5G market

5G smartphones can only run on 5G networks. So it makes sense to take a look at Ericsson, because it is playing an important role in setting up high-speed networking infrastructure in key markets.

A Chinese government source had said earlier this year that China could invest between $130 billion and $218 billion in building 5G networks between 2020 and 2025. While Chinese firms such as Huawei usually enjoy preference in getting contracts from the country's telecom companies, Swedish telecommunications giant Ericsson is also making its presence felt over there.

Ericsson has picked up a third of China Mobile's 5G network equipment contracts reportedly valued at $2 billion. More importantly, the Swedish giant beat local players such as ZTE and international rival Nokia, which got a much smaller share of the pie. China Mobile has clarified that it will keep working with international suppliers to deploy its 5G networks, so there's a good chance that Ericsson will keep winning more business over there.

But China is not the only happy hunting ground for Ericsson. The company has been selected as the primary vendor for the rollout of Japanese telecom operator KDDI's 5G network, which is expected to go live in March 2020. Given that KDDI is reportedly going to invest $4 billion in this rollout, Ericsson could get a shot in the arm.

The company reported a 7% increase in its revenue in the second quarter of 2019, while total sales in the first half of 2019 have increased by 11.2%. The new 5G contracts should help Ericsson boost its sales both in the short and the long run, because investments in the high-speed network are going to be spread out over a few years, as we saw earlier.

As such, now might be a good time to buy into Ericsson: Its forward price-to-earnings (P/E) ratio of 15 is well below the five-year average of 23, and analyst estimates compiled by Yahoo! Finance indicate impressive earnings growth in the future.

So anyone looking to take advantage of the hot 5G trend should take a closer look at Apple and Ericsson, as they could turn out to be top growth stocks thanks to this catalyst.