AT&T and Verizon said Tuesday they would delay lighting up its 5G signals near a limited number of airports after renewed opposition from the aviation industry over concerns about signal interference.

Why it matters: The CEOs of leading airlines warned of catastrophic disruption to flights if AT&T and Verizon deployed 5G as planned this week.

The CEOs of leading U.S. air cargo and passenger carriers on Monday warned the Biden administration there could be "catastrophic disruption" after AT&T and Verizon deploy a new 5G service this week.

Driving the news: They said in a letter to Transportation Secretary Pete Buttigieg and other top federal officials ahead of the C-Band 5G service's deployment Wednesday that "the nation's commerce will grind to a halt" and "could potentially strand tens of thousands of Americans overseas."

It's been long known that trees can slow down some 5G signals. A recent federal study aims to figure out just how much, in order to create more accurate signal strength prediction models.

Why it matters: 5G has the potential to supercharge wireless networks, but its rollout has revealed a range of complex challenges.

An Alphabet-backed company wants to rethink how 5G services are delivered to ensure communities don't fall into a wireless digital divide.

Why it matters: The internet has become necessary infrastructure during the pandemic, but ubiquitous 5G service has been slow to fully develop in the U.S.

Back in 2018, White House National Security Council official Gen. Robert Spalding wrote a controversial PowerPoint deck on how the U.S. government could play a greater role in building 5G networks. Now Spalding has left government and military service and landed $20 million to bring some of his vision to life via a private company.

How it works: The startup, Sempre, aims to offer a more secure, smarter alternative to the traditional cell tower, adding computing power at the edge and making the cell tower itself more resilient to attacks.

The largely successful U.S. effort to hobble China's Huawei has benefitted a host of other tech companies — from smartphone makers such as Apple and Xiaomi to chipmakers like Qualcomm to network vendors including Nokia and Ericsson.

Yes, but: The massive disruption to the industry furthered an industry wide mismatch between supply and demand, exacerbating the global chip shortage.

The Federal Communications Commission on Monday said it had approved Verizon's $6 billion purchase of wireless company TracFone, after the companies agreed to conditions meant to protect consumers.

Why it matters: The FCC was the last regulatory hurdle for Verizon, which expects to close the transaction in the coming days.

President Biden signed into law Thursday a bill that requires the Federal Communications Commission (FCC) to secure telecommunications systems against potential foreign threats to national security.

Why it matters: In recent years, lawmakers have increasingly voiced concerns about Chinese telecom giants' operations in the U.S., and possible surveillance by the Chinese government.

The Federal Communications Commission voted Tuesday to revoke authorization for China Telecom's U.S. subsidiary to operate in America, citing national security concerns.

Why it matters: The state-owned China Telecom is one of the largest telecommunications companies based in China. It has provided services in the U.S. for nearly 20 years but must now cease operations within 60 days.

Better sensors, more intelligent AI, and the coming wave of 5G wireless could finally fulfill the promise of the smart city.

Why it matters: How we organize, run and power our cities will be increasingly important in the years ahead, as urbanization expands and the damaging effects of climate change compound.