The Digital Pen: Mapping and Data Acquisition

Context
The context for this paper is based upon project experience derived from the Consumer Broadband Initiative launched by Pacific Bell in November 1993. The $16 billion dollar broadband project called for deployment of a new hybrid fiber-coax network which would support voice, high speed data, and video services over a single wire feed. Two key factors of the project created the opportunity and necessity to deploy the most current AM/FM field technology available in the market place.

The business case dictated expense savings by creating an intelligent network to reduce operation and maintenance expense. Therefore, advanced system applications were mandatory to create the intelligence of the network.
The broadband hybrid fiber-coax architecture required an accurate landbase and facility mapping application to properly design and deploy the network.

It is important to understand the characteristics of the fiber-coax architecture and the nature of “Radio Frequency Design” (RFDesign) to appreciate the critical role the design and mapping systems would play in creating the new broadband network. In very basic terms, every phone is connected to the telephone company’s central office (CO) by a pair of twisted copper wires. If that CO serves 20,000 phones, then a network of 20,000 individual copper wires span the geography served by the CO. With the hybrid fiber-coax architecture, fiber-optic cable extends to the various regions and neighborhoods served by the CO. The specifications of the network architecture dictate how far the fiber extends to the consumer, and when the transport medium switches from fiber to coax for final distribution to the consumer. The Pacific Bell architecture called for the fiber to extend into a CO service region called a node boundary. which would serve approx !imatel y 500 residences.

The mapping challenge was therefore to define accurate node boundaries, with accurate address and service line requirements so the network could be designed for maximum efficiency in both deployment and long term operational efficiency. To accomplish this task, an accurate landbase was obviously necessary to get accurate service line counts within each node. And, an accurate field inventory of existing plant (poles, conduits, etc.) was required so the new network design path could be routed to “piggy back” the existing plant where possible.