Availability model of optical communication network for ship´s engines control

The paper presents the implementation of optical communication network in ship´s engines controlling system. An availability model of communication network is presented with the introduction of protection strategies, and the results of the availability calculation of the unprotected network and network with cable paths protection are compared. The failures of real optical communication network built in a ferryboat are analyzed and the information about failures rates and mean time to repair are obtained. The analysis of sensitivity has determined the impact of failure rates of network´s components on the overall availability. In addition to the standard parameters required for calculating the availability, the additional impact factors on availability based on the method of network construction are defined and evaluated. Based on the obtained results, the method of protecting cable paths is proposed, which would contribute to the overall reliability of ship´s systems and of a ship as a whole.