Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks ...Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks under contiguity and continuity of available spectrum constraints. Two main hypotheses are used in this paper for backup paths computation. In the first case, it is assumed that backup paths resources are dedicated. In the second case, the assumption is that backup paths resources are available shared resources. The objective of the study is to minimize spectrum utilization to reduce blocking probability on a network. For this purpose, an efficient survivable Hybrid Protection Lightpath （HybPL） algorithm is proposed for providing shared or dedicated backup path protection based on the efficient energy calculation and resource availability. Traditional First-Fit and Best-Fit schemes are employed to search and assign the available spectrum resources. The simulation results show that HybPL presents better performance in terms of blocking probability, compared with the Minimum Resources Utilization Dedicated Protection （MRU-DP） algorithm which offers better performance than the Dedicated Protection （DP） algorithm.展开更多
The Tarim River is a typical inland river in arid area without runoff yield of itself, and water resources are all supplied by its headstreams. The method of time series analysis is applied to annual runoff series of ...The Tarim River is a typical inland river in arid area without runoff yield of itself, and water resources are all supplied by its headstreams. The method of time series analysis is applied to annual runoff series of three headstreams, namely the Aksu River, Yarkant River and Hotan River to analyze their dynamic variations. A model is established to estimate water consumption in the headstream areas. Quantitative results indicate that both total annual runoff of headstreams and water consumption in the headstream areas have an increasing trend. The dynamic trends of annual runoff of hydrologic stations along the mainstream of the Tarim River are also presented to estimate the intermittence drying-up time at each station. Water consumption model of the mainstream area is used to analyze the characteristics of water consumption in the upper and middle reaches. It is shown that water consumption in each river reach of the mainstream decreases with the decrement of inflow and increases with human activities.展开更多
文摘Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks under contiguity and continuity of available spectrum constraints. Two main hypotheses are used in this paper for backup paths computation. In the first case, it is assumed that backup paths resources are dedicated. In the second case, the assumption is that backup paths resources are available shared resources. The objective of the study is to minimize spectrum utilization to reduce blocking probability on a network. For this purpose, an efficient survivable Hybrid Protection Lightpath （HybPL） algorithm is proposed for providing shared or dedicated backup path protection based on the efficient energy calculation and resource availability. Traditional First-Fit and Best-Fit schemes are employed to search and assign the available spectrum resources. The simulation results show that HybPL presents better performance in terms of blocking probability, compared with the Minimum Resources Utilization Dedicated Protection （MRU-DP） algorithm which offers better performance than the Dedicated Protection （DP） algorithm.
基金This work was supported by State Key Project of the 9th Five-Year Plan (Grant No. 96-912-02-02) the Special Funds for State Major Basic Research Project (Grant No. G1999043500).
文摘The Tarim River is a typical inland river in arid area without runoff yield of itself, and water resources are all supplied by its headstreams. The method of time series analysis is applied to annual runoff series of three headstreams, namely the Aksu River, Yarkant River and Hotan River to analyze their dynamic variations. A model is established to estimate water consumption in the headstream areas. Quantitative results indicate that both total annual runoff of headstreams and water consumption in the headstream areas have an increasing trend. The dynamic trends of annual runoff of hydrologic stations along the mainstream of the Tarim River are also presented to estimate the intermittence drying-up time at each station. Water consumption model of the mainstream area is used to analyze the characteristics of water consumption in the upper and middle reaches. It is shown that water consumption in each river reach of the mainstream decreases with the decrement of inflow and increases with human activities.
