To limit the number of components in the protection switching process and to accordingly reduce the protection cost, a new reliable Wave Division Multiplexing/Time Division Multiplexing Passive Optical Network (WDM/TDM-PON) architecture with cost-efficient hybrid protection was proposed. Firstly, the logic decision unit, protection path control unit and backup transceiver unit were designed in Optical Line Terminal (OLT) to only switch failure components to their backups in Wave Division Multiplexing (WDM) segment. Secondly, by employing the cross bus structure in Time Division Multiplexing (TDM) segment, fast protection switching was achieved in a distributed manner. According to the analytic results of the hybrid protection, the proposed architecture can provide fast and full protection in recovery time of 1.5 to 2.4 ms against Feed Fiber (FF), Distribution Fiber (DF) and Last Mile Fiber (LMF) failures. Certainly, the proposed architecture can also significantly reduce the protection overhead, and achieve great scalability.

When urban waterlogging disasters occur, the scientific deployment of rescue resources can improve the efficiency of urban emergency rescue, and minimize disaster losses. In view of the fact that urban routes are affected by terrain, road conditions and the seriousness of waterlogging, the authors introduced the connected coefficient and the unblocked coefficient, so as to better reflect the urban route conditions and waterlogging disaster. Considering that the ant colony algorithm has some disadvantages, such as slow convergence, easy to fall into local optimum, by randomly selecting the affected areas and introducing a pheromone update operator strategy the ant colony algorithm was improved, which is used to solve the route optimization model. Empirical analysis shows that the improved ant colony algorithm of solving urban waterlogging rescue route optimization has better result.