A study in photonic switched networks considering link failure and ingress buffering

Abstract

In this paper we study the behavior of traffic in Metropolitan Access Optical Networks with technologies of optical packet/burst switching (OPS/OBS), using computer modeling and simulations. We analyze network performance and the impact of link failure when electronic buffering at ingress (client input) to optical network is implemented. Mesh and ring topologies are chosen and parameters packet loss fraction and average number of hops are adopted for performance metrics. The use of minimum electronic buffering at ingress is demonstrated to improve access to the optical layer, and necessary to keep the packet loss fraction low and throughput high with low latency. We also show that optical buffering is not necessary for adequate network performance.

Proposition of a Hybrid Topology for Photonic Switched Optical Networks

“…1). The MS mesh topology is attractive for optical networks because it has high connectivity, traffic flexibility, and robustness to failures [2,4]. We adopt further distributed switching, where optical packets are routed asynchronously through the network, directed only by header information.…”

“…The optical nodes are interconnected with unidirectional links; so that each link connects an output port from one node to an input port in the next node. The classical MS is 2x2 (2-input/2-output) nodes, that is in graph theory a grade-2 node; another configuration is 3x3, that is grade-3 [4]. The hybrid networks proposed here ( Fig.1) are a composition of grade-2 and grade-3 aiming at optimizing performance at the core nodes (grade3) and optimizing cost at edge nodes (grade2).…”

Analysis and characterization of semiconductor optical amplifiers for application in photonic switching networks

“…However, the effective utilization of SOAs requires a thorough understanding and characterization of device parameters and dynamic features so that their impact on system performance can be acknowledged. It is our interest to apply SOA devices as high performance photonic switches in optical packet (OPS) and burst (OBS) switching networks [3][4][5]; Fig.1.…”

“…Besides the excellent performance of SOAs as photonic switches, a concern exists that noise and ASE (amplified spontaneous emission) accumulation when multihopping over various optical nodes occurs in OPS/OBS networks [4][5][6]. On the other hand, by considering metro-access optical networks with as many as 36 optical nodes a limited average number of hops results [4,5], and noise accumulation may be mitigated and its impact on system performance controlled. This paper is organized as follows.…”

“…This paper is organized as follows. In the next section, the operation of SOAs as photonic gates [5] is presented; in sections III and IV the SOAs characteristics are investigated, presenting results on gain, spectral amplification and noise figures with different laser sources. Discussions and conclusions follow.…”