<p>A BRE (30) employs an RF interface for transmitting and receiving RF signals between the BRE (30) and an MDE (200), and the BRE (30) employs a digital signal interface for transmitting and receiving CPRI-compliant digital signals between the BRE (30) and a BDE (300). The BRE (30) comprises a monitor signal interface for notifying the MDE (200) of monitor signals that denote the status of a wireless unit (50). Signals transmitted and received via the monitor signal interface are grounding signals, and differ in type from the signals that are transmitted and received via the RF interface and the digital signal interface.</p>
