Samsung hasn't launched any Windows Phones for AT&T in the past year, but there are new hints suggesting the company may renew its support. An unannounced SGH-i187 phone has surfaced at the FCC with AT&T-compatible GSM, HSPA and LTE frequencies. While the filing doesn't reveal the OS, the i187 name last appeared in benchmarks for a Windows Phone; if the tests are authentic, we're looking at a mid-range handset with a 720p screen and a Snapdragon 400. We don't know if or when Samsung will ship the i187 to AT&T, but it could bring some diversity to a Windows Phone lineup that's increasingly Lumia-centric.