Tangle is a bitcoin transaction technology similar to Blockchain. A directed acyclic graph (DAG), which resembles a distributed ledger, is used here. DAG is not governed by any outside body, such as a bank or financial organization.

 Concerns about 5G services and aircraft delays

The much-anticipated introduction of 5G services hit a major snag this week after the country's leading airlines warned of massive flight disruptions if the wireless technology was put into operation, especially around the nation's airports, almost 11 months after the country's leading telecommunications companies won bids for $81 billion worth of C-band radio spectrum to roll out 5G services. On the eve of the planned launch on January 19, AT&T and Verizon reached an agreement to postpone the launch of the new wireless service near major airports.

Despite the commitments of the two major telcos, several domestic and international airlines flying to the United States have announced major rescheduling as well as the possibility of cancellation of flights to a number of destinations, citing warnings from the Federal Aviation Administration (FAA) and aircraft manufacturers that the accurate functioning of radar altimeters in some aircraft may be harmed by 5G radio frequencies. The altimeters offer information on an aircraft's height and are an important aspect of pilots' flight operations, especially when attempting low-visibility landings in bad weather. The fact that both 5G services and some aircraft equipment operate on the same C-band radio spectrum, with only the frequencies shifting, is at the root of the impasse. The FAA has stated that it is working with altimeter manufacturers to assess data from wireless businesses in order to ascertain the reliability of each model and, if necessary, have the devices upgraded or replaced.

The fact that the world's greatest economy is already facing large-scale domestic and international air travel interruptions as a result of the comparatively late roll-out of 5G telecom services highlights the US market's unique difficulties, particularly the specific frequencies granted for 5G. South Korea, China, Japan, and several European countries have already successfully deployed 5G services, and US telcos have pointed to the lack of issues in these jurisdictions as proof that the FAA and airlines need to do more to find solutions to the deployment of wireless technology near airports.

The FAA has compared the specifics of the anticipated 5G roll-out in the United States to the situation in France on its website, claiming that some important distinctions pose concerns. For one thing, the aviation regulator claims that buffer zones proposed for U.S. airports only safeguard the last 20 seconds of flight, whereas in France, the last 96 seconds of flight are protected from 5G signal disruption. In addition, 5G power levels in France are lower, despite the fact that even the projected temporary national lower power levels in the United States are expected to be 2.5 times more strong. U.S. President Joe Biden and his administration will have their work cut out for them in hammering out a long-term solution to this standoff so that the already pandemic-affected global travel and trade sectors are not further disrupted.