Early drop and wavelength grouping schemes for providing absolute QoS differentiation in optical burst-switched networks

A number of schemes have been proposed to support QoS in optical burst-switched (OBS) networks. Most schemes only support relative QoS differentiation instead of absolute QoS guarantee. However, absolute QoS differentiation is a basic requirement for many delay and loss sensitive applications. In this paper, we propose two mechanisms for providing absolute QoS differentiation in OBS networks, an early drop mechanism, which selectively drops non-guaranteed traffic, and a wavelength grouping mechanism, which manages wavelengths for guaranteed traffic. We show that the combination of these two mechanisms not only outperforms other schemes in providing loss guarantees, but also improves the loss performance of nonguaranteed traffic.