AT&T Inc., Verizon Communications Inc., and T-Mobile US Inc. are among 38 entities the Federal Communications Commission has approved to bid on high-band airwaves beginning March 14, the agency announced.

The commission said it rejected auction bidding applications from Cox Communications Inc., Frontier Communications Corp., and 20 other entities for licenses in the 24 gigahertz (GHz) band.

Wireless carriers plan to use high-band airwaves to provide 5G services in urban areas. High-band airwaves can carry much more data at faster speeds than the low-band spectrum that powers 4G networks, but don’t travel as far.

The first auction, which covered airwaves in the 28 GHz band and ended earlier this year, raised about $700 million. The FCC plans to hold a third high-band spectrum auction in the second half of 2019.