Análise do impacto de técnicas de sobrevivência em redes ópticas elásticas de telecomunicações

Abstract

A blocking in optical networks is an event where a requested is not established due to network unavailability of resources. It is often used as a parameter for evaluate the network performance. A high blocking rate indicates that the network is not suitable for a given traffic demand. Survivability is a characteristic of actual telecommunication networks, which allow the operation even in the event of link or node failures. In order to a network survive, spare capacity is employed to avoid blocking. The amount of spare capacity must be planned in order to cope with the expected performance, costs of maintenance, complexity of control and capital expenditure. In the recent Elastic Optical Networks, the routing and spectrum assignment problem evolved to a more complex problem, that is the routing, modulation and spectrum assignment. This problem imposes new constraints to the traffic engineering task. In this work we investigated the relationship between protection strategies to the network with other properties affected by it. We compare the blocking rate and resource utilization rate considering both shared and dedicated protection strategies. Furthermore, we analyze special characteristics of the blocking events to both type of protection. In the most of simulated networks, the blocking rate of the shared protection was around 0,5 of the dedicated protection. In some cases, the rate was 0,3. With respect to the resource utilization there is not a considerable difference between two strategies, in a absolute perspective. However, bringing the comparsion to blocking rate and link fragmentation, we saw that the impact was very significant. With the dedicated protection, some networks was a fragmentation around 0,8, while in shared protection the fragmentation was around 0,6, 0,5 and 0,3. Using shared protection, the networks Memorex, Metrona and RNP was average load increased by around 50% in comparsion to dedicated protection. These results allow us say that dedicated protection causes a high impact in the network and requires a large amount of resources to allow a equivalent performance.