A repeater with redundancy functions for a distributed antenna system, the repeater comprising: downlink repeater circuitry to interface communications from base stations to user equipment ; uplink repeater circuitry to interface communications from the user equipment to the base stations ; at least one memory to store a primary configuration that sets out parameters for interfacing communications between the repeater and a primary base station of the base stations along a primary communication link and at least one secondary configuration that set out parameters for interfacing communications between the repeater and one of the primary base station of the base stations and at least one secondary base station of the base stations along a secondary communication link; and a controller configured to implement the at least one secondary configuration to communicate with the one of the primary base station of the base stations and the at least one secondary base station of the base stations 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 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 , 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 to user equipment ; uplink repeater circuitry to interface communications from the user equipment to the base stations ; at least one memory to store a primary configuration that sets out parameters for interfacing communications between the repeater and a primary base station of the base stations along a primary communication link and at least one secondary configuration that set out parameters for interfacing communications between the repeater and one of the primary base station of the base stations and at least one secondary base station of the base stations along a secondary communication link; and a controller configured to implement the at least one secondary configuration to communicate with the one of the primary base station of the base stations and the at least one secondary base station of the base stations 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 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 , 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. <EOS>