Just a couple of years ago, the term ROADM was a new word even to those working in the optical networking industry. But now many of service providers are already deploying ROADM products in their networks. They expect deploying of the ROADMs to bring about a great deal of cost saving and effectiveness in networks operation. Better than at least the legacy OADM in all respects. Definitely the ROADMs would. But there are still huge disputes regarding what the term ROADM means and how it should behave So now it seems appropriate to define the term ROADM.

Why do service providers hope to deploy ROADM products in their networks? It's because the existing OADM(Optical Add/Drop Multiplexer, shown in Fig. 1) networks always require a significant amount of truck roll when being reconfigured.

Such manual labor often leads to a lot of increase in OPEX, longer time-to-service, and even careless network failures. So, it is no wonder that service providers have been looking for a new OADM product with reconfigurability which enables automatic and remote network management and removes a great deal of truck roll, otherwise. In order to meet the requrements of service providers, what functionalities should ROADM products have? In this regard, there have been a lot of ROADM architecturs different to each other. But, Solidsystems believes that the so-called ROADM should have the following features to satisfy service providers;

The prime reason why service providers are looking for ROADM is to reduce a lot of manual cost in reconfiguring OADM networks. Once some system vendors provided equipments as shown in Fig. 2 and insisted that those were ROADM.

Of course, this kind of systems could slightly save manual cost and bring about convenience to some extent. However, a significant amount of manual work is still needed, so such systems are not enough to be called as ROADM.

To accomplish no manual intervention in reconfiguring a network, it is required that the ROADMs should have non-blocking connectivity. What is "non-blocking connectivity"? In other words, it means that a node can freely connect to any other node, without any manual intervention. Figure 3 shows what "non-blocking connectivity" is meaning.

In the figure (a), the ROADMs with non-blocking connectivity are configured as the node A connected to D and the node B to C. Then, suppose that the configuration (a) should be changed to as (b). If the each ROADM has true non-blocking connectivity, reconfiguring the network is easily done just by a few of mouse-clicks. It is worth of emphasizing that there is no dispatching of technicians or manual interconnecting of patch cords.

In terms of how to implement the non-blocking connectivity, there are two kinds of ROADM. One is based on electrical switching fabric, the other is on optical switching devices such as WSS(Wavelength Selective Switch), WB(Wavelength Blocker). The former is also able to provide non-blocking connectivity. But it has signicant drawback that it could not effectively handle 40Gbps and 100Gbps signals because in general the commercially available electrical switching fabric can not support such high speed. Instead, ROADMs to use optical switching technology don't have to care about the speed of optical signal. So, recent trend of ROADM architecture is all optical add/drop and optical switching.

Solidsystems believes that the CoreBridge 3200 is the most powerful and efficient ROADM product in the world because it provides the following features that are needed by service providers for their businesses.

Most service providers want to gradually upgrade their networks according to their business circumstances. Even though they are well aware of benefits that ROADM products provide, they might be reluctant to adopt ROADM proucts due to their budget. The CoreBridge 3200 is able to effectively solve these problems. Surprisingly, from an architectural point of view, the CoreBridge 3200's platform is completely identical to that of that of a conventional OADM. That means the CoreBridge 3200 can be operated first as an OADM product. How could it be changed to work as a ROADM? All that is needed is just the replacing of a fixed wavelength channel card with a tunable one for reconfigurabilty. Nothing about the common parts including the EDFAs, Mux/DeMux, etc has to be replaced at all!

Even though the CoreBridge 3200's architecture is very simple, it has fully non-blocking connectivity. As shown in Fig. 3 above, any connections among the nodes in a ROADM networks can be done just by one-clicking. Due to some technical reasons or cost problems, most ROADM products have been supporting partially non-blocking connectivity. Therefore, deploying such systems cannot help dispatching technicians to remote nodes, even though the number of technicians needed would be samller than in case of OADM. o Solidsystems's knowledge, the CoreBridge 3200 is the first to successfully implement the ideal features of ROADM.

• The number of channels : 32
• The Transport Capacity: 32 x 40G = 1280G @ with 40G channel cards
• The Switching Capacity: 32x32 wavelength
• Network Topology: P2P, Ring, Multiring, Ring2Ring, Mesh(with 9 degree directions)
• Maximum Circumference of a Ring : 640km @ SMF
• Recommended Max. Span : 80km @ SMF
• Service Protection : 1+1 O-UPSR
• Supervisory : Out-of-band
• Channel Wavelength : C-band
• Channel Spacing : 50GHz/100GHz

• SDH/SONET: 155M/622M/2.5G/10G/40G
• Data: GbE, 10GbE
• Subrate : NxGbE, MxSTM-N into 10G, 4x10G into 40G

• Rack and Self: 23"
• Power: -48VDC
• Operating Temperature: 0 ~ 50
• Storage Temperature: -20~+80

If you want more detailed technical information, the referece sites, or customization, feel free to contact us anytime. We would be very pleased to send you related documentation.