Currently, cellular networks do all this behind-the-scenes voodoo using the handset's phone number. But what if you're using a multimedia player that doesn't have a number?
"PCs have media access control (MAC) addresses, MP3 players have serial numbers, other devices may have some other unique semantic ID specific to a manufacturing practice or perhaps even an application service married to a dedicated device," writes Jonathan Spinney. "In tomorrow’s converged 4G world, the lack of a uniform user-ID common to all devices requires rewriting or inventing new Location API standards to support holistic service experiences that run across multiple devices."
It's all a bit technical, but what he's basically saying is that as things stand you can buy a ringtone or MP3 using your phone, but future networks -- on paper at least -- aren't smart enough to let you listen to it using your wireless MP3 player.
Reston, we have a problem...
— Dan Jones, Site Editor, Unstrung