Separated Unicast/Multicast Splitter-and-Delivery Switch and Its Use in Multicasting-Capable Optical Cross-Connect (original) (raw)

Required Density of Multicast Capable Optical Cross-Connects to Assure Efficient Multicasting

2011

Many algorithms are developed to deploy multicast in optical networks. Those algorithms are designed to resolve the main issue of multicasting in optical networks, which is not all optical cross-connect in the network are capable to split an incoming light signal to more than one output interface. Some of those algorithms are based on additional signaling exchanged to generate the appropriate multicast trees, some use rerouting to source, and some generate multiple multicast trees for the same multicast group. The performance of those algorithms depends basically on the number and location of multicast capable cross-connects. A multicast capable cross-connect (MCOXC) is an optical node equipped with light splitter that allows splitting an incoming light signal to any two or more output interfaces. This paper studies how many nodes in optical networks must be equipped with light splitters to assure good performance of multicast algorithms in sparse splitting networks. This depends ba...

Nonblocking Four-Stage Multicast Network for Multicast-Capable Optical Cross Connects

Journal of Lightwave Technology, 2000

In this paper, we investigate the four-stage multicast network with only two multicast stages (the second and output stages) being multicast-capable, which is called 4(2 m)-stage multicast network. We first derive the sufficient wide-sense nonblocking (WSNB) and rearrangeable nonblocking (RNB) conditions for the 4(2 m)-stage multicast network. The WSNB and RNB conditions are also presented for multicast request with limited multicast degree. The 4(2 m)-stage multicast network needs at least O(N 3 / 2) crosspoints to be WSNB and RNB, which is a lower bound than the three-stage Clos network with two multicast stages and the same bound with the four-stage network with three multicast stages. Then we design full and partial multicast-capable optical cross connects (MC-OXCs) applying the 4(2 m)-stage multicast network. The proposed WSNB full MC-OXC with two multicast stages is power efficient in reducing splitting loss and has lower multicast cost, compared with the one having three multicast stages. Partial MC-OXC with only one multicast stage is proposed to further reduce the multicast cost and splitting loss. The RNB MC-OXCs with one or two multicast stages provide better performance at the respects of crosspoints, multicast cost, and splitting loss than their WSNB counterparts.

Cost-effective constructions for nonblocking WDM multicast switching networks

IEEE International Conference on Communications, 2004

Constructing wavelength division multiplexing (WDM) multicast switches with inexpensive components and low complexity is an important problem in optical networking, as multicasting is one of the key requirements of emerging bandwidth-intensive applications such as video conferencing, video on demand and online gaming. In this paper we present several new cost-effective designs for constructing nonblocking WDM multicast switching networks. More specifically, we provide a wide-sense nonblocking switch architecture, which uses fewer semiconductor optical amplifiers than existing architectures. In addition, for the first time we have presented a rearrangeably nonblocking WDM switch architecture using array waveguide grating routers and wavelength converters.

Tap-and-2-Split Switch Design Based on Integrated Optics for Light-Tree Routing in WDM Networks

Journal of Lightwave Technology, 2000

This paper presents a novel cost-effective multicastcapable optical cross connect (MC-OXC) node architecture that features both tap-and-continue and tap-and-binary-split functionality. This architecture provides an interesting balance between simplicity, power efficiency and overall wavelength consumption with respect to models based on TaC (Tap and Continue) or SaD (Split-and-Delivery). The main component of this node is a novel Tap-and-2-Split Switch (Ta2S). In this paper, we propose and analyse an implementation of this switch based on integrated optics (namely, MMI taps and MZI switches), and we characterize and compare it with other alternatives implemented with the same technology. The study shows that, thanks to the presented Ta2S design, the 2-Split Tap Continue (2STC) node scales better in terms of number of components than the other alternatives. Moreover, it is more power efficient than the SaD design and requires less wavelengths than TaC thanks to the binary split capability. On the other hand, simulation results reveal that the 2-split condition does not add a significant additional wavelength consumption in usual network topologies with respect to SaD.

Performance evaluation of a WDM optical packet switch with multicast capability

2009 7th International Conference on Information, Communications and Signal Processing (ICICS), 2009

This paper investigates a WDM optical packet switch with multicast capability which is based on a broadcastand-select architecture. The switch enables to deliver simultaneously multiple optical packets destined for the same output fiber of the switch. The simulation results show that the presented WDM optical packet switch can achieve much better performance on packet loss probability and average delay with fewer fiber delay lines in comparison with single wavelength optical packet switches.

A Novel Multistage Network Architecture with Multicast and Broadcast Capability

The Journal of Supercomputing, 2006

In this paper, a new class of optical multistage interconnection network (MIN) architecture is presented, which is constructed utilizing a modularization approach rather than the traditional recursive or fixed exchange pattern methods. The modified architecture consists of an input module, an output module, two point-to-point (PTP) modules, and one modified multicast/broadcast (M/B) module(s). We also implement the multicast/broadcast module with WDM technique, which reduces the hardware cost required for multicast and the re-computation cost for a new connection. We show that it has the best application flexibility and provides multicast function without imposing significant negative impacts on the whole network. A new multicast connection pattern is also proposed in this paper, which makes it practical and economical to apply amplification in space-division networks. Compared with existing multicast architectures, this new architecture with Dilated Benes PTP modules has better performance in terms of system SNR, the number of switch elements, and system attenuation in point-to-point connections. Moreover, the multicast/broadcast module adopts wavelength division multiplexing (WDM) technique to increase its multicast/broadcast assignment. As a result, given m available distinguished wavelengths, one M/B module can support at most m M/B requests at the same time. The new proposed M/B module with WDM is more practical and economical to apply amplification in space-division networks.

Power-efficient design of multicast wavelength-routed networks

IEEE Journal on Selected Areas in Communications, 2000

In this paper, we introduce the power-efficient design space for multicast wavelength-routed networks. The power-efficient design space is based on the impact of power on the overall design of wavelength-routed networks. Two cross-connect architectures on this design concept are investigated. One is an existing architecture called splitter-and-delivery (SaD). The other is a new architecture called multicast-only splitter-and-delivery (MOSaD).

Effect of Splitting Factor on Multicast Trees in Optical Networks

HAL (Le Centre pour la Communication Scientifique Directe), 2011

Enhanced optical switches structure can now handle multicast routing in the optical layer. For an optical node to be able to do branching in the physical layer, it must be equipped with a light splitter. Light splitters are expensive equipment. A lot of work had been done in order to reduce the cost of implementing splitters within the network. Moreover, the internal structure of a splitter is enhanced to reduce its cost, and the power loss resulted of multiple splitting. Efficient placement of splitters in the network leads to a reduction in the cost of the network design, and the cost of the generated trees. The splitting capability of each splitter plays an important role on how much branching can be done on the optical node. Also, the splitting capability affects the power loss done on each branching node, and consequently the final power received by each member. This paper studies the effect of the splitting factor on the cost of the generated trees and the value of the power received by each of the multicast group members. I.

Free Space Optical Multicast Crossbar

2016

Enabling multicast in optical networks requires the use of multicast-capable optical switches. In this paper, we propose a new class of multicast-capable FSO switches. Our design exploits non-movable tri-state switching elements (TSEs) that support signal splitting and switching simultaneously and seamlessly, and thus, separate splitting stages used in the conventional multicast switches are not needed. It follows that the propagation loss that may be encountered by an optical beam passing through a splitting stage followed by a crossbar (e.g., SaD-based switches) can be avoided in the proposed switch since the beam passes only through the crossbar. The proposed FSO switch is analyzed and compared to conventional architectures in terms of hardware complexity, power loss, and cost. We show that, an NxM switch requires only NM non-movable T-SEs. Comparison with existing optical multicast switches shows that the proposed switch provides multicast capability with substantially lower hardware complexity and a comparable performance. Cost analysis for the proposed switch shows that its switching cost is lower than existing switches even if the cost of the T-SE is 1.2 to 2.2 times that of MEMS mirror.

Impact of the number of SAB on architectures that support unicast/multicast traffic in WDM networks

International Journal of Communication Networks and Distributed Systems, 2010

Optical transport networks (OTN) should be prepared to jointly handle both multicast and unicast traffic. Both opaque and transparent architectures are available to handle these types of traffic. Light-trees have been proposed as a way to transport information in a transparent manner. The light-tree however, may route unwanted information through some links while performing grooming of unicast and multicast traffic. To solve this problem we propose S/G light-tree with the goal of optimising the resources from the point of view of the number of wavelengths and available capacity. S/G light-tree uses detection systems (DS) and splitter and amplifier banks (SABs) to determine when unicast traffic should not be routed jointly with a multicast one by eliminating it optically from the link. This article proposes an online heuristic with grooming policies which allows for the analysis of the effects of the number of SABs on the blocking probability in OTN with dynamic traffic.