对于愿意尝试一下最新技术的电话网络运营商 来说,跳过一代无线技术也许并非是个坏主意.“,”Even as “third-generation” (3G) mobile networks are being switched on around the world, a couple of years later than planned, attention is shifting to what comes next: a group of newer technologies that are, inevitably, being called 4G. More hubris from the technology-obsessed industry? Not exactly. Some 4G networks are operating already, with more on the way. A technology once expected to appear around 2005 is here now. There is no formal definition of 4G, but what such technologies have in common is that they are high-speed wireless networks covering a wide area, designed above all for carrying data, rather than voice or a mixture of the two. They can pipe data to and from mobile devices at “broadband” speed, typically 10-20 times faster than a dial-up modem connection.