题型:阅读理解 题类:常考题 难易度:普通
陕西省商洛市2019~2020学年高二下学期英语期末考试试卷
Although air travel comes with jet lag, delays and awful food, it offers a brief digital detox—a precious few hours away from the wave of emails, messages and app announcements. But not anymore, In flight Wi-Fi is getting faster and cheaper, and is an increasingly common offering on budget and flagship airlines.
But how does in-flight Wi-Fi actually work? To simplify, there are two ways for an internet signal to reach your device when you're up in the clouds. The first is via ground based mobile broadband towers, which send signals up to the aircraft's antennas (天线). As you travel into different sections of airspace, the plane automatically connects to signals from the nearest tower, so there is (in theory at least) no interruption to your Internet. But if you're passing over large areas of water or particularly remote zones, connectivity can be an issue.
The second method uses satellite technology. Planes connect to satellites in space (35,000 km above the planet), which send and receive signals via receivers and transmitters. Information is transmitted to and from your smart phone via an antenna on the top of the aircraft. These are the same satellites that are used in television signals and weather forecasting. Information is passed between the ground and the plane via the satellite.
All of that technology is expensive. The costs are usually passed on to customers. Over half of the world's aircraft will be equipped with in-flight Wi-Fi within the next few years. It is set to become a billion-dollar industry by 2020. In the near future you'll need to find a better excuse than “Sorry I missed your message—I was on a plane”.
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