Apple's iPhone 5 was one of the first real stress tests for carriers' new LTE networks, and now it has its first service to really stretch the limits of 4G: iTunes Radio.

Apple unveiled its much-anticipated streaming music answer to Pandora Monday along with a revamped iOS 7. Like Pandora, Spotify and other over-the-top mobile apps, iTunes Radio lets users create radio stations around songs or artists they like, look up songs and tap into their social networks to access what friends are listening to and share their tunes.

Unlike competing services, however, iTunes Radio won't be an app that other devices can download. Rather it will be a native service baked into iOS 7, free with ads or bundled into the US$25 annual iTunes Match service for ad-free listening.

Sure, streaming music services have been around -- and popular -- for some time now, but Apple has a tendency of taking things to the next level. Just look at what the Apple App Store did to apps and FaceTime did to video chat. It's possible that iTunes Radio will now do the same to streaming music. Given that the iPhone 4S and 5 were shown to be the biggest data hog on 3G networks across Europe, this might cause the wireless operators to stop and think what it means for their already over-burdened networks. (See iPhone 5 is Top Euro Data Hog and iPhone 4S is Most Data Hungry, Study Finds.)

Music is a much more mobile app than say, FaceTime. Given the iPhone family's undeniable popularity and the fact that iTunes Radio works over LTE, where usage is typically amplified, it'll likely put some pressure on carriers' new networks. At the very least, Apple's iTunes Radio will be a good warm-up as the operators brace for Apple's next smartphone launch, looking more and more like it's coming this fall.

— Sarah Reedy, Senior Editor, Light Reading