New Apple 'iPhone 12' to offer 5G speeds US networks can't deliver

5G will finally get its U.S. closeup with the expected debut of Apple Inc's next iPhone on Tuesday. But the blazing speeds promised will not materialize for most people.

The device, dubbed the iPhone 12 by analysts, can tap into 5G, or fifth generation wireless technology, that theoretically operates as much as 10 to 20 times faster than current 4G wireless networks. [nL1N2H0004] Using the next iPhone or any 5G enabled device on today's network, however, will be "like having a Ferrari ... but using it in your local village and you can't drive to up to 200 miles per hour, simply because the roads cannot maintain those speeds," explained Boris Metodiev, associate director of research firm Strategy Analytics.

Apple, which is expected to unveil the new phone at a virtual event on Tuesday, will need to walk a tightrope between enticing consumers to upgrade their phones while not overpromising what 5G can do today. Current 5G U.S. networks mostly use low-band wireless spectrum, or airspace, that is slower than high-band spectrum, but more reliable over longer distances. It will likely take years before the massive speed boost phone carriers promise will make augmented reality and real-time cloud gaming seamless. Several U.S. telecom operators have deployed networks based on lower spectrum bands, with slightly higher speeds than 4G. A noticeably faster variant of "midband" 5G is also being rolled out, but it is unlikely to reach three-quarters of Americans until 2025, estimated longtime Apple analyst Gene Munster of venture capitalist firm Loup Ventures.

The fastest speeds touted by carriers are a type of 5G called millimeter Wave, or mmWave, that work over shorter distances.