Service differentiation using hybrid shared optical buffers in transparent optical networks

Abstract

This paper proposes a novel service differentiation mechanism utilizing optical buffers in transparent optical networks. We first introduce fiber delay line (FDL)-based optical buffers and propose a hybrid shared optical buffered node. Based on the proposed buffer, diverse service requirements can be satisfied by assigning different priorities on accessing the buffer. Since the blocking performance is affected by the basic delay unit of FDL represented by a ratio of the burst length, this paper also takes into account the effect of the burst assembly process on the buffer performance. By dynamically adjusting the burst length under the changing traffic load, optimal performance of the proposed optical buffer can be achieved. Our simulation results show that diverse service requirements can be satisfied in terms of burst blocking probability and buffering delay time.

On the design of asynchronous optical packet switch architectures with shared delay lines and converters

“…-Deflection Routing. Space deflection is a multiple-path routing technique [10,18,19]. This technique is typically applied on the network level rather than on the switching level as in case of FDLs and WCs.…”

“…In this technique, contended packets are directed to an output port that differs from the one requested, given that these deflected packets will eventually be routed to their destinations in subsequent switching nodes. The effectiveness of deflection routing depends on the network topology and the traffic pattern [10,19]. It is worth noting that deflection routing could cause packets to arrive out of order, which may lead to more complex processing at the destination nodes.…”

“…It is worth noting that deflection routing could cause packets to arrive out of order, which may lead to more complex processing at the destination nodes. In the Feed-Forward approach, the following three subconfigurations are possible: -FDLs without WCs (i.e., Block 2 only) [19][20][21][22], -WCs with no FDLs (i.e., Block 1 only), -Combined WCs and FDLs [10,16].…”

“…-FDLs without WCs (i.e., Block 2 only) [3,19,21,22], -WCs with no FDLs (i.e., Block 1 only) [17], -WCs and FDLs [23]. FDLs and WCs in both the FF and FB configurations can be either dedicated or shared among the node and various ports [3,10,16,19,22,23].…”

“…FDLs and WCs in both the FF and FB configurations can be either dedicated or shared among the node and various ports [3,10,16,19,22,23]. A dedicated resource can be used by only one particular and fixed wavelength link in the architecture, whereas a shared resource can be accessed by several wavelength links whenever it is free.…”