As an electronics giant, Sony (SONY 1.10%) has certainly seen better days: Once industry-leading, many of its most well-known products have long been outclassed.

Sony's Walkman was overtaken by Apple's (AAPL 1.27%) iPod a decade ago -- its TV business has been a consistent source of red ink for just as long. Unable to run it profitably, Sony sold off its Vaio PC division earlier this year.

There is, however, one bright spot among Sony's many struggling electronics: Its latest video game console. Sony's PlayStation 4 has set sales records, and consistently outsold its competition, often by a ratio of three-to-one.

Now Sony is looking to extend its video game dominance into other product categories -- its newest mobile devices interface directly with the PlayStation 4. Given the popularity of Sony's console, this unique feature could give Sony's products a leg up in a market that's thus far been dominated by Apple and Samsung (NASDAQOTH: SSNLF).

Sony adds remote play to Xperia
Like a DVD player, video game consoles have traditionally required a connected TV to function. That's understandable, but somewhat of a major limitation -- as long as that console is in use, the TV it's attached to is fully occupied. At the same time, (and perhaps even more limiting) games can only be enjoyed while sitting directly in front of that TV.

Sony's PlayStation 4, though, is an exception: Using remote play, PlayStation 4 games can be streamed wirelessly to a compatible device. In other words, a PlayStation 4 owner can, if they so choose, enjoy their games while someone else watches a movie on the TV, or play their PlayStation 4 in a different room of the house -- perhaps one that lacks a TV entirely.

Right now, the only remote play-compatible device is Sony's Vita -- a $200 handheld console that's largely been a commercial failure. But that's about to change: Later this year, Sony's next-generation mobile devices will go on sale -- and all will offer remote play functionality.

This list includes Sony's flagship Xperia Z3 smartphone, as well as the slightly smaller Xperia Z3 compact and the Xperia Z3 tablet. Paired with a controller, these devices offer PlayStation 4 owners the ability to play their games without a dedicated TV.

Sony's mobile division has been struggling
Sony's mobile division hasn't been a total failure, but it has fallen short of the company's expectations, and has largely been overshadowed by Apple and Samsung.

When Sony reported its first quarter results in July, it cut its outlook for smartphone sales -- Sony now expects to sell just 43 million smartphones this year, fewer than the 50 million it had anticipated in May. Worse, Sony said its mobile division lost money and will only break-even in 2014 -- it had previously been a source of profit amid otherwise poor results.

In contrast, Apple and Samsung sold more than 150 million and more than 300 million smartphones, respectively, last year. Both firms have consistently generated billions in profits in recent quarters, with the bulk of their earnings coming from sale of smartphones and tablets.

80 million reasons to believe in Sony
Can Sony's mobile division overtake Apple and Samsung? In the near-term it doesn't seem likely, but remote play functionality could help Sony poach many of both companies' best customers.

Last month, Sony said that it had sold more than 10 million PlayStation 4 consoles to end-consumers -- a stunning achievement given that the console had been on the market for fewer than nine months. Its predecessor, the PlayStation 3, initially struggled, but went on to sell more than 80 million units worldwide. Given its impressive early sales, the PlayStation 4 could ultimately sell as well as, or much better than, the PlayStation 3.

With the added perk of remote play, many PlayStation 4 owners could opt for Sony's mobile devices over rival products from Apple and Samsung.

If so, it could be particularly devastating to the South Korean tech giant, as Samsung's mobile products, like Sony's, are powered by the Android operating system. Apple, with its control of iOS, is a bit more insulated, but dedicated gamers could still find the added functionality too enticing to pass up. Obviously, there are many more smartphone and tablet owners than there are PlayStation 4 owners, but remote play could still conceivably convert millions of buyers -- and given the PlayStation 4's relatively high price tag ($399), more valuable buyers at that.

Only time will tell if remote play emerges as a must-have feature, but with Sony's new hardware-based ecosystem, continued strong PlayStation 4 sales should be seen as a positive for its mobile business -- and a slight negative for its rivals like Apple and Samsung.