But this is not just about faster smartphones. The transition to new fifth-generation cellular networks — known as 5G for short — will also affect many other kinds of devices, including industrial robots, security cameras, drones and cars that send traffic data to one another. This new era will leap ahead of current wireless technology, known as 4G, by offering mobile internet speeds that will let people download entire movies within seconds and most likely bring big changes to video games, sports and shopping.
Officials in the United States and China see 5G networks as a competitive edge. The faster networks could help spread the use of artificial intelligence and other cutting-edge technologies.
Expect to hear more about 5G soon at events like the big consumer electronics trade show CES in January in Las Vegas and MWC Barcelona (formerly the Mobile World Congress) in February in Spain. Wireless service providers including AT&T and Verizon are already talking up 5G. And device makers are previewing gadgets that will work with the technology.
Samsung recently demonstrated prototypes of 5G smartphones that are expected to operate on both Verizon and AT&T networks. Many other manufacturers are racing to follow suit, though Apple is not expected in the initial 5G wave. Analysts predict that iPhones with the new technology won’t arrive until 2020. An Apple spokeswoman declined to comment.
Here’s what you need to know.
What exactly is 5G?
Strictly speaking, 5G is a set of technical ground rules that define the workings of a cellular network, including the radio frequencies used and how various components like computer chips and antennas handle radio signals and exchange data.
Since the first cellphones were demonstrated in the 1970s, engineers from multiple companies have convened to agree on new sets of specifications for cellular networks, which are designated a new technology generation every decade or so. To get the benefits of 5G, users will have to buy new phones, while carriers will need to install new transmission equipment to offer the faster service.
How fast will 5G be?
The answer depends on where you live, which wireless services you use and when you decide to take the 5G plunge.
Qualcomm, the wireless chipmaker, said it had demonstrated peak 5G download speeds of 4.5 gigabits a second, but predicts initial median speeds of about 1.4 gigabits. That translates to roughly 20 times faster than the current 4G experience.
The 5G speeds will be particularly noticeable in higher-quality streaming video. And downloading a typical movie at the median speeds cited by Qualcomm would take 17 seconds with 5G, compared with six minutes for 4G.
Rather than remembering to download a season of a favorite TV show before heading to the airport, for example, you could do it while in line to board a plane, said Justin Denison, a Samsung senior vice president.
Is that the only speed that matters?
No. There’s another kind of speed, a lag known as latency, that may become even more important with 5G.
Issue a command now on a smartphone — like starting a web search — and the response isn’t exactly immediate. A lag of 50 to several hundred milliseconds is common, partly because signals often must pass between different carrier switching centers; 5G, which uses newer networking technology, was designed to reduce latency down to a few milliseconds. It was also designed to deliver signals more reliably than earlier cellular networks, which today frequently drop bits of data that aren’t essential for tasks like watching movies on a phone.
That improvement could bring many benefits, notably in fields such as virtual reality. The highest-quality VR applications now typically require bulky headsets that are connected by wire to nearby personal computers that generate 3D images. With 5G, that would be off-loaded wirelessly to other machines, freeing users to move and making it easier to develop goggles the size of eyeglasses, said Cristiano Amon, president of Qualcomm’s semiconductor business.
In the related field of augmented reality, people could point a smartphone camera at a football game and see both live video on the display and superimposed player statistics or other data, said Patrick Moorhead, an analyst at Moor Insights & Strategy.
穆爾咨詢和戰略公司(Moor Insights & Strategy)分析師帕特里克·穆爾黑德(Patrick Moorhead)說，在增強現實(AR)的相關領域，人們可以用智能手機的攝像頭對準一場足球比賽，在顯示屏上觀看直播視頻的同時，可以看疊加的球員統計數據或其它數據。
And 5G’s impact extends to medicine and other fields that increasingly rely on high-speed connections.
“If you talk about remote surgery or connected cars, you don’t want latency times to be too long,” said Fredrik Jejdling, an executive vice president at Ericsson, a maker of cellular equipment.
When will 5G be here?
The answer for smartphone users in the United States appears to be by the second quarter of 2019; precise timing is uncertain.
Countries expected to follow the United States with 2019 rollouts of 5G include Britain, Germany, Switzerland, China, South Korea and Australia, according to a timetable compiled by Qualcomm.
Will consumers see the full benefits of 5G?
Verizon and AT&T will introduce their 5G offerings with the first use of high frequencies that are known by the phrase “millimeter wave.” Using this, the wireless providers can pump data at high speeds, but the signals don’t travel as far. So the two carriers are expected to first target densely populated areas — “parts or pockets” of cities, as AT&T’s Fuetsch put it.
Sprint and T-Mobile plan to start with lower frequencies. The result may be somewhat slower initial speeds but broader range, said Michael Thelander, president of Signals Research, a wireless consultancy.
Sprint和T-Mobile計劃從較低的頻率開始。無線咨詢公司信號研究(Signals Research)的總裁邁克爾·泰蘭德(Michael Thelander)說，結果可能是初始速度有所減慢，但覆蓋范圍更廣。
Still, 5G’s full benefits aren’t expected until U.S. carriers upgrade key central switching equipment, which may not happen until late 2019 or sometime in 2020.
So should I buy a smartphone that works with 5G right away?
You have a lot to consider. For example, while Verizon and AT&T plan to later add 5G services based on lower frequencies that offer wider coverage, the first 5G handsets may not work with those portions of their networks. So the reach of 5G signals for those phones may remain limited.
“I wouldn’t buy a 5G phone until it supports 5G in one of the lower-frequency bands,” Mr. Thelander said. “For all operators but Sprint, this means at least late 2019, and more likely 2020.”