Multiservice Provisioning and Quality of Service Guarantee in WDM Optical Code Switched GMPLS Core Networks

In this paper, we propose a new scheme to provide multiservice transmission on generalized multiprotocol label switching (GMPLS) networks using optical code-division multiplexing (OCDM) in each wavelength of a wavelength-division multiplexing system. To provide multiservice transmission in a typical GMPLS network, we propose to classify the fiber bandwidth into a number of waveband and consider the wavelengths of each waveband for a specific class-of-service such that the corresponding codes to be used are designed based on the characteristics of the class-of-service. The traffic behavior of the network is examined using Erlang's model, and the probability density functions (PDF) of the number of occupied labels in a link are obtained. To evaluate the PDF of the number of occupied labels in each wavelength, two scenarios are considered: path establishment without traffic management and path establishment with traffic management. In the first scenario, connected paths are divided among wavelengths randomly; while in the second scenario, a controlling mechanism manages distribution of the connected paths so that all wavelengths have the same number of connected paths. To analyze the performance of the system, end-to-end bit error rate, probability of outage, and blocking probability are investigated. The obtained results reveal that path establishment with traffic management results in better performance. Furthermore, to guarantee the desired quality of service (QoS), a controlling mechanism is proposed to limit the number of connected paths based on the activity coefficient of the connections. We show that using such controlling mechanism the desired QoS is guaranteed.