In an effort to secure larger blocks of contiguous spectrum, U.S. wireless carriers AT&T and T-Mobile have agreed to trade “certain PCS and AWS-1 licenses in various markets,” according to an FCC filing.

Identical amounts and types of spectrum will be swapped in each market to create “larger blocks of contiguous spectrum and aligning spectrum blocks across markets.” The exchanges will occur through lease agreements between four AT&T affiliates and two T-Mobile affiliates and will include airwaves in San Antonio and Austin, Texas, Phoenix, Ariz., Hartford, Conn., Boston, Mass., Tulsa, Okla., Minneapolis-St. Paul, Minn. and Puerto Rico and the U.S. Virgin Islands, among other areas.

The lease agreement is set to expire on September 15, 2016. The lessor company of each swath of spectrum will retain de facto and de jure control of the spectrum throughout the lease term.

According to the filing, the trades won’t result in any “discontinuance, reduction, loss or impairment of service to customers.”