The race to capitalize on the growth of 5G in 2020 is heating up. 

And while most agree that Qualcomm (QCOM) - Get Report currently has some of the best technology to supply many end-market 5G device makers, there are two potential headwinds in Qualcomm's mid-to-long-term positioning in 5G, as noted by one semiconductor analyst.

The root of the issue is that the ramp up in sales of 5G-enabled devices is likely to be slower than that for 4G, according to Rasgon. Companies, as well as analysts, are expecting a range of 175 million to 225 million 5G devices to be delivered in all of 2020 and while Rasgon doesn't believe that's a disappointing number, it's not huge. By comparison, Apple is expected to deliver a total of 278 million devices -- both 5G and non-5G - in all of 2020, according to analysts polled by FactSet.

Importantly, at Qualcomm's analyst day on Tuesday, management said it's looking for 5G units in 2022 of 750 million, cementing the expectation that 5G is a clear growth market.

But with the initial growth trajectory in mind, Qualcomm will have to take meaningful market share and here there are two key issues to monitor.

The first, according to Rasgon, is "how sustainable is the Apple business, because Apple bought Intel's (INTC) - Get Report modem business?" Rasgon said. Apple is one of Qualcomm's biggest customers, but in late July, Apple (AAPL) - Get Report announced it was  buying Intel's modem chip unit for about $1 billion. If Apple indeed plans to use the acquisition to make its own 5G modem chips, this would mean fewer chip sales from Qualcomm to Apple. 

Apple isn't expected to sell 5G iPhones until the second half of 2020, but 2021 is expected to be a big year for Apple's 5G devices.

"The second question is how does the competitive environment evolve?" Rasgon said. "Forward a few years, does the competition get good enough?" Right now, Taiwanese chip maker, MediaTek, China-based HiSilicon and Samsung (SSNLF) all stand to compete with Qualcomm on 5G chip sales.

Another question related to market share is how much of the roughly 200 million 5G-enabled devices expected to ship in 2020 will need millimeter wave chips? Qualcomm has an advantage at making that type of chip, so should that product be in high demand from device makers, Qualcomm may be able to expect to take a lot of market share. Management did say on its earnings call "[in] the United States market, all of the devices they have launched, there is a requirement for millimeter wave."

For 2020, China will be driving the initial 5G ramp, according to Rasgon.

Qualcomm shares are up 50% year-to-date, as investors have looked past a few quarters of declining revenue for what 2020 has in store. 

Apple is a holding in Jim Cramer'sAction Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells Apple? Learn more now.