ADVANCED RF - The SDR is an over-the-air repeater system that can incorporate up to four (4) modules in one chassis. Current supported frequency bands are SMR800, SMR900, PCS, BRS (FDD), BRS (TD-LTE), Cellular, 700 MHz (Lower A, Lower, B, Lower C, Upper C), and AWS. brbr The SDR-NMS is the chassis and network management system. Supports up to four (4) SDR modules, purchased separately.