Advanced optical networks

Advanced optical networks

Most of the current broadband network communications are not scalable in a simple way. The interoperability of their network hardware with different vendors, their versatility and adaptability when there are changes in the transport network, is limited. You can get any of these facilities but at a very high cost and in very slow processes. This is due to different factors: coexistence of multiple networks depending on the kind of service, a complex architecture, the bandwidth relocation is very slow and expensive, the protection is mainly provided by SDH, and the networks are regional.

The natural evolution of optical networks requires that the new networks are adaptable to the kind and class of service (IP, ATM, SONET/SDH), that the bandwidth on demand can be provided quickly and efficiently, that they are networks of high availability, of greater capacity and flexibility, of easy growth and with a perspective of global networks.

Most of the recommendations agree that the solution is meshed networks, interconnected by optical switching nodes dynamically reconfigurable and managed by a control plane that provides intelligence to the network. As main advantages, mesh networks have a greater availability in case of failure, in spite of having fewer resources —much fewer number of work sections, more backup— than a classical network interconnected in rings, the supply and deployment are much easier than in this kind of network.

The key element in this kind of network is the optical switch that is capable of converting lambdas (services) dynamically and in real time (according to the needs and bandwidth requirements, quality service, etc) between the subnetworks that compose the mesh. The commercial device is the switching module called ROADM (Reconfigurable Optical Add Drop Multiplexer).

W-onesys’ Proteus platform permits the insertion of ROADM colorless modules of up to 8 ports. The principal aim of these devices is the switching, equalization, optical channel adding and dropping at a DWDM wavelength. The combination of ROADMs with transponders with an optical output at a DWDM tunable wavelength and W-onesys’ network monitors, that evaluate the quality of a certain given link (power, relation signal/noise per lambda, etc), permits the control plane to implement in real time the provision of paths and optical carriers for the channel transport with the bandwidths on demand of up to 10G, and to configurate automatically dozens of optical links.

W-onesys’ solution control plane is based on the GMPLS standard and, therefore, supports interoperability with other vendors. This protocol is based on a minimum number of functions that our equipment supports: finding of neighbor nodes and network resources, path computing and subsequent routing (OSPF), the signalizing (between the control agents in the establishment and maintenance of the connections, through the RSVP-TE protocol) and the management of local resources.