A framework for Deterministic Delay Guarantee in OBS Networks

In OBS networks, the delay of control packets in the switch control unit (SCU) of core nodes influences burst loss performance in the optical switching and should be constrained. Furthermore, the end-to-end (E2E) delay requirements of premium services need queueing delay guarantee in network nodes throughout the transmission path. For this purpose, a framework for deterministic delay guarantee is proposed in this article. It incorporates the deterministic delay model in the ingress edge node as well as in the SCUs of core nodes. On this basis, the configuration of the assembler and the offset time is addressed by means of an optimization problem under the delay constraints. Scenario studies are carried out with reference to realistic transport network topologies. Compared to statistical delay models in the literature, the deterministic model has advantages in rendering robust absolute delay guarantee for individual FEC flows, which is especially appreciated in the provisioning of premium services. By performance evaluation in comparison with the statistical models, it is shown that the adopted deterministic delay models lead to practical delay bounds in a magnitude that is close to the delay estimations by stochastic analysis

BBU location algorithms for survivable 5G C-RAN over WDM

New 5G radio access network is expected to offer competitive advantages in terms of cost, quality of service and mobility, that make it attractive for service providers. The resilience of this part of the network is consequently essential to provide high availability and service continuity in case of failure. This study focuses on heuristic solutions to design and operate the fronthaul network based on the Centralized Radio Access Network (C-RAN) concept. Facility Location Algorithms (FLA) are proposed to assign primary and backup functionalities to Baseband Unit (BBU) hotels and ensure availability in case of a single BBU hotel or link failure. Sharing techniques are applied to BBU hotel ports and transport wavelengths for hl cost-efficient design. The goal is to minimize the number of active BBU hotels while providing full coverage to all Remote Radio Units (RRU). Numerical results evaluate cost in relation to main design constraints, namely the number of hops allowed to reach primary and backup BBU hotel. The number of BBU hotels is compared for different location algorithms, showing that a proposed extension of a classical FLA, by including resilience, allows to obtain the best results both in terms of BBU hotels and shared ports. However, the need of suitable trade-off between the number of BBU hotels and the required wavelengths is outlined, depending on relative costs