В Америке нет сетей с поддержкой rev. B. Только A
В 6s стоит вот это:
The MDM9635M enables high-resolution video streaming and ultra high-speed download speeds and supports LTE Advanced carrier aggregation for both LTE TDD and FDD Category 6, along with dual carrier HSUPA and dual band multi-carrier HSPA+.
“The LTE Cat 6 device is designed to provide consumers with download speeds of up to 300 Mbps and more efficient power consumption,” according to Qualcomm.
The modem is backwards compatible with major cellular technologies including WCDMA /MC-HSPA, CDMA 1x/EVDO Rev. B, GSM/EDGE and TD-SCDMA.