Recently, there’s been tremendous growth in the delivery of next-gen services. This growth is due in large part to the considerable number of operators who have transitioned to NGN (next-generation networks). But has this evolution helped drive optical networking strategy as well? Absolutely! The evolution to NGN has dramatically affected the way optical networks are now being designed and implemented, and vendors and operators alike are looking for innovative ways to cost effectively address an almost insatiable demand for new services.
Today, all operators – whether mobile operators transitioning to 3G and beyond or cable operators delivering triple play services – are going through the evolution to IP-based next-generation networks. But we must consider how this transition can be performed optimally, and what effect it might have on optical networks.
First, the transition should take place gradually, at the customer’s pace. Past investments should be leveraged and traditional services must run alongside new next-gen services. Next, the transition should be cost efficient, reducing the total cost of the network while increasing revenue opportunities. In this situation, the optical network needs to continually become more flexible and scalable, reducing the provisioning time of new services to hours rather than days. And it must also be denser, reducing capex through fewer platforms.
At their core, next-generation optical networks must feature flexible designs, multi-service capabilities and high capacity.
Essential trends for NGN
So what are the trends that optical networks must include to meet the needs of next-generation operators? Certainly there are many, but here we’ll focus only on the major ones.
The first trend we’ll examine is the increasing flexibility of networks. More and more, ROADMs (reconfigurable optical add-drop multiplexers) are being used to achieve this flexibility. With their mesh capabilities and ability to transparently connect any color to any port, ROADMs can reduce the turn up of new services from days to just hours. This enables operators to improve competitiveness and increase revenues. And ROADMs are spreading not only to the core but also the edge, and it’s likely that as prices get lower and capacity increases, they’ll also extend to the access point, providing true end-to-end, access-to-core flexibility.
Another trend – this one’s being driven by operators’ need to reduce capex – is the convergence of packet capabilities with DWDM (dense wavelength division multiplexing) and SONET (Synchronous Optical Network)/SDH (Synchronous Digital Hierarchy) under a single multi-service platform and managed by a single multi-layered, multi-technology management system. This convergence brings a number of benefits, namely a need for fewer platforms in the network, fewer spare parts and less technical staff. It also helps future proof the installed infrastructure and make it receptive to a next-gen implementation that’s based on pure Carrier Ethernet over DWDM. In this case the operator can easily leverage the existing infrastructure by simply uninstalling the SONET capabilities and keeping the pure packet and optics infrastructure.
An additional shift the industry is witnessing is the build-out of the “all optical” OTN (Optical Transport Network)–compliant infrastructure. The OTN enables transparent delivery of any service at any protocol above the optical network. This helps operators achieve maximum revenues over capex investment, and reduce provisioning time. What’s more, the OTN allows interoperation between vendors, making multi-vendor networks possible. And finally, because OTN enables optical switching, it can dramatically reduce the cost of deploying Ethernet-switched networks.
The last trend we’ll discuss here is the utilization of high-capacity links along the DWDM network. These 40 Gbps and 100 Gbps links are crucial to maximizing existing infrastructure, and common practice shows that upgrading interfaces by just one level can bring up to two and a half times in capex savings versus their lower-capacity counterparts. Yet another reason for this trend is that core router vendors are already bringing to market core-to-core routers with 40G links. Transferring those links over DWDM networks makes it necessary for operators to implement 40G links in their networks as well.
The transition to NGN has affected the industry in many positive ways, including the impact it’s had on optical networking strategy. The multi-service capabilities, greater flexibility and higher capacities of current solutions have led to increased interoperability, improved service delivery and lower costs for operators. And there are surely many more advancements to come.
What are your thoughts? How do you think the NGN evolution has affected optical networking strategy? Which trends are must-haves for next-gen operators? What developments will the future hold? Please share your views.
Oren MarmurHead of Optical Networking Line of Business
ECI Telecom