The whys and hows of PON

Passive optical networking represents an attractive alternative for today's competitive service providers because it lets them shed their reliance on the incumbent's copper access network and provides a solution for offering a wide range of flexible service offerings that cannot be matched - on a service or cost level - by copper-based technologies. The benefit of this type of architecture is that service providers can build it inexpensively and, because there are no electronics in the outside plant, do not need to maintain, power or upgrade the network - which saves a considerable amount of time and money.

In addition to the obvious cost benefits, another key benefit to service providers is their ability to leverage their existing fiber infrastructures to increase their market share in a given region. While most facilities-based service providers have dark fiber running by businesses or terminating at a business cluster/office park, in most cases, they do not have enough spare dark fiber available to serve each business.

With passive components such as splitters and couplers, however, a service provider can complete an incremental extension of the existing fiber, then fan it out as needed to optically serve each of the businesses in the vicinity. As a result, service providers can drastically increase the amount of customers served by their initial fiber deployment. Most important, service providers will be able to easily retain these customers because, once they bring fiber to the business, from then on they own the revenue stream from that business.

Deploying an optical access network (OAN) based on PON enables service providers to offer business users a full range of bandwidth services - from 64 kb/s, to 100 Mb/s, to dedicated wavelengths. An OAN provides a service platform that supports many different service types and allows enterprise customers to increase their bandwidth as they need it - either on a permanent or temporary basis.

The optical access switch aggregates broadband services, performs ATM and IP switching and provides a standard WAN interface to the public network and the Internet.

Packet and cell traffic consisting of broadband voice and data services is transported over a low cost passive optical infrastructure.

Finally, customer premises-based intelligent optical terminals terminate the optics and provide the enterprise with flexible bandwidth - 64 kb/s to 100 Mb/s to individual wavelengths - and a range of service interfaces.