Patent ID: 8923701

Claim:
A wireless communications link comprising: a radio frequency communications link and a free space optics communications link arranged for parallel transmission of traffic; a switch arranged to operate in one of a normal mode in which the switch is arranged to aggregate the links to form a link aggregation group and to route received traffic for transmission on the link aggregation group, a first protection mode in which the switch is arranged to route received traffic for transmission on only the free space optics communications link, and a second protection mode in which the switch is arranged to route at least some of said received traffic for transmission on only the radio frequency communications link; a link monitoring apparatus comprising a radio frequency signal monitoring apparatus arranged to measure a first signal quality parameter for the radio frequency communications link and an optical signal monitoring apparatus arranged to measure a second signal quality parameter for the free space optics communications link, and further comprising an alarm apparatus arranged to generate and transmit a first alarm signal in response to the first signal quality parameter having a value below a first threshold value and further arranged to generate and transmit a second alarm signal in response to the second signal quality parameter having a value below a second threshold value; and a controller arranged to receive one of a said first alarm signal, a said second alarm signal and an indicator indicating that the first signal quality parameter is above the first threshold value and the second signal quality parameter is above the second threshold value, and the controller further being arranged to generate and transmit a control signal to cause the switch to operate in one of the first protection mode when a said first alarm signal is received, the second protection mode when a said second alarm signal is received, and the normal mode when a said indicator is received.