Systems and methods for dynamic use of remote units in a wireless communications system (WCS) include a digital routing unit (DRU) that sums incoming (uplink) signals from the remote units that have active user equipment, while suppressing signals from the remote units that do not have active user equipment. Similarly, the DRU only sends outgoing (downlink) signals to the remote units that have active user equipment. The selective summing of uplink signals improves the gain at the DRU, which allows optimization of the dynamic range of the DRU. Likewise, by selectively sending streams to the remote units, power consumption at the remote units may be reduced, which may allow for smaller, less expensive remote units to be deployed.