Patent ID: 8538261
Filing Date: 2013-09-17
Classification: H04B,H04J,H04Q

Abstract:
1. A method for protecting an optical network system comprising a first optical network device, an optical distribution network, and a first and second optical line termination device, the first optical network device communicating with the first optical line termination device on a first connection via the optical distribution network and a first optical fiber trunk connected to the first optical line termination device, and the first optical network device having a second connection to the second optical line termination device via the optical distribution network and a second optical fiber trunk connected to the second optical line termination device, wherein the optical network system further comprises a second optical network device communicating with the first optical line termination device and the second optical line termination device via the optical distribution network and the first and second optical fiber trunk, respectively, wherein the method comprises the steps of: detecting communication failure between the first optical network device and the first optical line termination device; initiating switching of functionality from the first optical line termination device to the second optical line termination device; sending a control message from the second optical line termination device to the first optical network device such that the first optical network device is prevented from moving into initial state; determining and setting timing settings for the first optical network device; sending a control message from the second optical line termination device to the second optical network device such that the second optical network device is prevented from moving into initial state; and determining and setting timing settings for the second optical network device, wherein the step of determining and setting timing settings for the second optical network device comprises calculating the timing settings based on measured timing settings for the first optical network device.