A repeater (100, 200, 510, 710) with redundancy functions for a distributed antenna system, the repeater (100, 200, 510, 710) comprising: downlink repeater circuitry to interface communications from base stations (102, 110, 530, 540, 730, 740) to user equipment (114, 115); uplink repeater circuitry to interface communications from the user equipment (114, 115) to the base stations (102, 110, 530, 540, 730, 740); at least one memory to store a primary configuration (127, 512, 712) that sets out parameters for interfacing communications between the repeater (100, 200, 510, 710) and a primary base station (102, 530, 730) of the base stations (102, 110, 530, 540, 730, 740) along a primary communication link and at least one secondary configuration (128, 514, 714) that set out parameters for interfacing communications between the repeater (100, 200, 510, 710) and one of the primary base station (102, 530, 730) of the base stations (102, 110, 530, 540, 730, 740) and at least one secondary base station (110, 540, 740) of the base stations (102, 110, 530, 540, 730, 740) along a secondary communication link; and a controller configured to implement the at least one secondary configuration (128, 514, 714) to communicate with the one of the primary base station (102, 530, 730) of the base stations (102, 110, 530, 540, 730, 740) and the at least one secondary base station (110, 540, 740) of the base stations (102, 110, 530, 540, 730, 740) along the secondary communication link upon the detection of a switching condition indicating abnormal communications on the primary communication link and carriers are available in the secondary communication link, wherein the at least one secondary configuration (128, 514, 714) includes at least a gain associated with the secondary communication link, characterized by further comprising: a detection function configured, when using a common antenna for communications with each of the base stations (102, 110, 530, 540, 730, 740), to monitor communications in the primary communication link based on a measured receive signal strength indicator, RSSI, the detection function further configured to monitor in a background a RSSI in one or more carriers of the secondary communication link using a cyclic cross check using free filter resources of a digital signal processor, DSP, to check the RSSI of the one or more carriers in the background. downlink repeater circuitry to interface communications from base stations (102, 110, 530, 540, 730, 740) to user equipment (114, 115); uplink repeater circuitry to interface communications from the user equipment (114, 115) to the base stations (102, 110, 530, 540, 730, 740); at least one memory to store a primary configuration (127, 512, 712) that sets out parameters for interfacing communications between the repeater (100, 200, 510, 710) and a primary base station (102, 530, 730) of the base stations (102, 110, 530, 540, 730, 740) along a primary communication link and at least one secondary configuration (128, 514, 714) that set out parameters for interfacing communications between the repeater (100, 200, 510, 710) and one of the primary base station (102, 530, 730) of the base stations (102, 110, 530, 540, 730, 740) and at least one secondary base station (110, 540, 740) of the base stations (102, 110, 530, 540, 730, 740) along a secondary communication link; and a controller configured to implement the at least one secondary configuration (128, 514, 714) to communicate with the one of the primary base station (102, 530, 730) of the base stations (102, 110, 530, 540, 730, 740) and the at least one secondary base station (110, 540, 740) of the base stations (102, 110, 530, 540, 730, 740) along the secondary communication link upon the detection of a switching condition indicating abnormal communications on the primary communication link and carriers are available in the secondary communication link, wherein the at least one secondary configuration (128, 514, 714) includes at least a gain associated with the secondary communication link, characterized by further comprising: a detection function configured, when using a common antenna for communications with each of the base stations (102, 110, 530, 540, 730, 740), to monitor communications in the primary communication link based on a measured receive signal strength indicator, RSSI, the detection function further configured to monitor in a background a RSSI in one or more carriers of the secondary communication link using a cyclic cross check using free filter resources of a digital signal processor, DSP, to check the RSSI of the one or more carriers in the background.