Self-routing Network Research Articles

Crossover minimization in directional-coupler-based photonic switching systems

Methods of design directional-coupler-based switching networks with minimum number of crossovers are presented. Also presented is a modular construction scheme that allows large switching networks (with minimum of crossovers) to be built using identical chips containing smaller networks of the same type. The total number of crossovers and the maximum number of crossovers between an inlet-outlet pair have been analyzed in three major self-routing networks. Since many networks are based on these topologies, the results can be applied extensively to the study of many other switching networks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The Batcher-banyan self-routing network: universality and simplification

It is shown that the Batcher-banyan network performs as a universal self-routing switch when inputs with unassigned destinations are present. This is demonstrated by first proving that banyan networks can realize permutations represented by bitonic sequences, and then noting that the sorted output of the Batcher network can be viewed as a bitonic sequence. Two methods are proposed for reducing the complexity of the Batcher-banyan network. In the first method, one stage of the banyan network is eliminated by assigning proper destination tags to the unassigned inputs. In the second, a self-routing switch based on the binary-radix sorting scheme is shown to be more economical for a small number of lines.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Performance of an 8×8 LiNbO 3 switch matrix as a gigahertz self-routing switching node

The performance of an LiNbO3 integrated-optic crossbar switch as a node in a gigahertz self-routing network is measured. Switch throughput supports 12.5 Gbit/s signals with a measured switching speed of 1.33 GHz. Crosstalk due to RF/ acousto-optic coupling and modulation depth are reported at 1.33 GHz. Optical self-routing of l00 Mbit/s information using the 8×8 switch is demonstrated.

A centrally controlled shuffle network for reconfigurable and fault-tolerant architecture

The paper describes a multistage shuffle interconnection network which is controlled by a central monitor. A control code broadcast by the monitor to all the basic switching elements of the network simultaneously, makes the network dynamically reconfigurable. The control code plays three vital roles. Firstly, it establishes conflict-free paths between several source-destination pairs. Thus the problem of collision, a major obstacle of a self-routing network, is completely eliminated. Secondly, the direct paths are established in one clock period irrespective of the number of stages. This makes the system faster. Thirdly, the control code also acts as a grouping code for executing a table of arbitrary data exchange requests between nodes in minimum number of passes. It is also shown that the network can be made fault-tolerant by the addition of an extra stage. Any single fault and some multiple faults in the intermediate stages can be tolerated by this scheme. Moreover, the switching from the faulty state to the fault-free state can be done in a single clock period, thus enabling fast fault-tolerant reconfiguration.

Self-routing fibre-optic networks and switches using multitailed receiver/transmitter units

Using a fibre-optic component consisting of one or more receivers and input ports and one transmitter with one or more output ports, with a circuit in between, self-routing is possible in densely meshed networks and in moderately blocking switches.

The Load-Sharing Banyan Network

Banyan networks, as well as many other self-routing networks, have a simple and regular topology, and can be easily diagnosed and maintained. However, like many other self- routing networks, Banyan networks have only one path between each input and output pair. Failures of a single link or node will make many paths unavailable, and certain traffic patterns can cause severe congestion in the networks.

A Self-Routing Benes Network and Parallel Permutation Algorithms

A Benes permutation network capable of setting its own switches dynamically is presented. The total switch setting and delay time for the N input utput self-routing network is O(log N). It is shown that the network is capable of performing a rich class of permutations. The self-routing scheme leads to efficient O(log N) parallel algorithms to perform the same class of permutations on cube connected and perfect shuffle computers.