Mike Grice – Senior VP Technology, All Systems Broadband (www.go-asb.com)
Perhaps the most lucrative of offerings that network operators can provide are those required by business customers. Increasingly, operators are answering these needs with a fiber-based solution. Of course, network topologies, operations, and legacy equipment vary, meaning that there is not a single “one size fits all” solution. This article explores some passive elements used in fiber architectures, and how they might help to enable increased bandwidth to provide business services.
RFOG, or Radio Frequency over Glass, is often an attractive alternative for operators because it fits well with existing head end infrastructure, as well as customer premises equipment. Essentially, RFOG moves the fiber much deeper into an HFC network, and closer to the business customer. A typical RFOG architecture often includes passive devices such as WDM, splitters/couplers, connectors, and of course fiber. This protocol of choice allows for a cost-effective optical deployment for operators with legacy analog systems.
A second popular choice for extending fiber deep into a network is the Ethernet Passive Optical Network (EPON). Because of its completely passive architecture between the head end and customer’s premises, EPON is capable of higher data rates, and therefore can present greater revenue opportunity to the service provider. Like RFOG, passives in an EPON system typically include splitters/couplers and connectors, in addition to the fiber itself.
In either scenario, passive devices will help enable the network, and can quickly add needed capacity to meet critical service opportunities when needed. The two most common categories of fiber passives are Wavelength Division Multiplexers (WDM) and Splitters/Couplers.WDM devices enable service providers to realize greater capacity, as well as custom applications, from deployed fiber. Typical WDM devices are either Coarse (CWDM) or Dense (DWDM) depending on the granularity of the filters that groom the signals. One of the real advantages of WDM technology, and one of the reasons they are so attractive for enabling business class services, is the ability to mix and designate uses of the various wavelengths.
A knowledgeable vendor is the best resource for guidance in incorporating WDM into fiber networks. By consulting with a designer of WDM passive optical circuits, the service provider can create customer-focused solutions that fit well with existing operations.
When looking to effectively deploy a passive optical access network that will likely include business customers, quality splitters/couplers are required. Although they are completely passive, the splitter allows the efficient deployment of fiber to all customers throughout a service area, without the need to run a separate fiber for each. Data capacity of fiber is then shared between all connected customer sites and can be varied as needed simply by varying the electronics at each end. This approach allows a much quicker response to new service opportunities for businesses since no work is required in the outside plant. Because these passive devices are installed as a permanent part of the fiber optic network, superior design, quality of manufacture, and reliability are the primary variables to look for when choosing a splitter.
When faced with new revenue opportunities from business customers, service providers should continue to push fiber deeper into their access networks, using passive components to extract more value from the fiber investment. By partnering with a vendor experienced in creating custom design of quality WDM and other passives circuits, the network operator can evolve its network to be an even greater asset towards gaining new customers and simplifying network operations.