美国最大的两家无线公司周二表示，他们将推迟一些机场附近的高速5G移动服务的启用时间。
The move came after several major airlines in the country warned that deploying 5G service near the airports could be "catastrophic."
在此之前，美国几家大型航空公司警告称，在机场附近部署5G服务可能会是灾难性的。
In a letter to federal officials on Monday, the heads of 10 airlines including American, Delta, United, and Southwest said 5G will be more disruptive than they originally thought. They wrote that "more than 1,100 flights and 100,000 passengers" could be affected daily with cancellations and delays. They said, "the nation's commerce will grind to a halt."
在周一发给联邦官员的一封信中，包括美国航空、达美航空、联合航空以及西南航空在内的10家航空公司的负责人表示，5G将比他们最初想象的更具破坏性。他们写道，“每天有超过1100架航班和10万名乘客”可能会受到航班取消和延误的影响。他们表示，“美国的商业（航班）将陷入停顿。”
The airlines asked that 5G could be deployed everywhere in the country except within "3.2 km of airport runways" at some important airports.
航空公司提出，5G服务可以部署在全国各地，但是要排除一些重要机场的跑道的3.2公里内范围内。
On Tuesday, AT&T, one of the largest wireless providers in the U.S., said it would "temporarily" delay turning on 5G transmitters at some airports. The company said it would work with the federal government to settle the dispute.
周二，美国最大无线服务提供商之一的AT&T公司表示，将临时推迟在一些机场开启5G发射机。该公司表示将与联邦政府合作解决这一争端。
The nation's largest wireless company, Verizon, said it will launch its 5G service. But the company added, "we have voluntarily decided to limit our 5G network around airports."
美国最大的无线公司Verizon称其将推出5G服务。但是该公司补充说：“我们自愿在机场附近限制我们的5G网络。”
Two weeks ago, the wireless companies had also agreed to reduce the power of 5G transmitters near 50 airports in the U.S. for six months.
两周前，无线公司还同意将美国50个机场附近的5G发射机的功率降低6个月。
AT&T and Verizon were planning to start their 5G service Wednesday. The start of the high-speed service has been delayed two times since early December.
AT&T 和 Verizon公司原计划在周三启动它们的5G服务。自12月初以来，这种高速网络服务的启动已经被推迟了两次。
Airliners say the C band is too close
航空公司称C波段太接近
The new 5G network promises faster internet speeds and larger network capacity. 5G, which stands for fifth-generation, is about 10 times faster than the existing 4G network.
新的5G网络承诺提供更快的网络速度和更大的网络容量。代表第5代的5G网络比现有的4G网络快10倍左右。
The 5G network runs on a radio spectrum known as the C band which airline companies say could interfere with the operation of some altimeters. An altimeter sends radio waves from an airplane to the ground to measure how far above the ground an airplane is traveling. Pilots use it to help with landing planes and identifying dangerous changes in wind speed and direction known as wind shear.
5G网络在C波段无线电频段上运行，航空公司称该频段可能会干扰某些高度计的运行。高度计将无线电波从飞机上发送到地面，以测量飞机在距离地面多高的高度上飞行。飞行员使用它来帮助飞机降落并识别风速和风向的危险变化，即风切变。
Wireless companies say 5G is safe
无线公司称5G是安全的
Verizon and AT&T have argued that 5G has been deployed in about 40 other countries without interference issues.
Verizon 和 AT&T公司辩称，5G服务已经在大约40个其它国家部署，没有发生干扰问题。
CTIA is a U.S. wireless trade group. It said in a filing with the Federal Communications Commission, "Wireless carriers in nearly 40 countries throughout Europe and Asia now use the C band for 5G, with no reported effects on radio altimeters that operate in the same internationally designated 4.2-4.4 GHz band."
美国无线通信和互联网协会是美国的无线贸易组织。它在提交给美国联邦通信委员会的文件中表示，“欧洲和亚洲近40个国家的无线运营商现在将C频段用于5G，没有爆出对无线电高度计产生影响，它们都在国际指定的同一个4.2到4.4GHz频段内运行。”
The Federal Aviation Administration, or FAA, oversees airline safety in the U.S. The agency said on Sunday it had cleared an estimated 45 percent of the U.S. commercial airplanes to perform low-visibility landings at many airports where 5G will be deployed. The airlines, however, noted on Monday that the list did not include many large airports.
美国联邦航空管理局负责监督美国的航空安全。该机构周日表示，它已经批准估计45%的美国商用飞机在许多将部署5G服务的机场进行低能见度着陆。然而，航空公司周一指出，这份名单不包括许多大型机场。
The FAA expects to issue more approvals before Wednesday. And the agency added it "continues to work with the aviation industry and wireless companies to try to limit 5G-related flight delays and cancellations."
美国联邦航空管理局预计将在周三前发布更多审批。该机构还表示，它“继续与航空业以及无线公司合作，试图限制与5G相关的航班延误与取消。”
Why is 5G not an issue in other countries?
为什么5G服务在其它国家不成问题？
In Europe, 5G network operates in a 3.4 to 3.8 GHz range. That spectrum is slightly lower than the range set to be deployed in the U.S.
欧洲的5G网络运行在3.4到3.8GHz的范围内。该频段略低于将在美国部署的频段范围。
The European Union Aviation Safety Agency (EASA) said on Dec. 17 the issue was specific to U.S. airspace. The agency added, "At this stage, no risk of unsafe interference has been identified in Europe."
欧盟航空安全局于12月17日表示，该问题仅限于美国领空。该机构补充说：“现阶段，欧洲尚未发现不安全干扰的风险。”
In South Korea, the 5G mobile communication range is from 3.42 to 3.7 GHz. There has been no report of interference with radio waves since the start of the high-speed network in 2019.
韩国5G移动通信在3.42到3.7GHz的范围内运行。自2019年这种高速网络开通以来，尚未收到无线电波干扰的报道。
I'm Jill Robbins.
我是吉尔罗宾斯。(51VOA.COM原创翻译，请勿转载，违者必究！)