BROADBAND COMMUNITIES is the leading source of information on digital and broadband technologies for buildings and communities. Our editorial aims to accelerate the deployment of Fiber-To-The-Home and Fiber-To-The-Premises.
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60 | BROADBAND COMMUNITIES | www.broadbandcommunities.com | JANUARY/FEBRUARY 2014 TECHNOLOGY anchor institutions and cell towers with direct fber. Many cities have existing assets and infrastructure, such as rights-of-way, poles, ducts and unlit fber, that can be used for Internet networks. Tey may also have reasons to prefer certain cable routes and equipment sites – for example, they may prefer to place outdoor cabinets at street intersections rather than mid-block or route new fber cables through a city-owned conduit. Tese assets and preferences can be incorporated into the project fle's constraint layer, which overlays the roads and streets. Te software will use, wherever possible, the routes and sites in the constraint layer as it plans the new fber and equipment for the city's network. Finally, demand layer data is gathered and loaded into the project pile. Demand data is derived from public and commercial databases and geocoded for the project fle. Demand data can be segmented by customer class – households, business locations, community institutions or wireless sites. Customer classes can be further qualifed according to the services available to each class. Residential households and small business locations can be expressed as "demand points" or "census blocks" in the GIS layer. Customer classes can be color-coded for easy visualization in the project fle. Once the project fle is assembled, the planner can choose the architecture and technologies to use and can establish design rules for their application. Tese architecture and technology choices are defned in connection models, which specify the logical and physical elements of the network – that is, the network nodes and the fber cable links. Te planner can choose diferent connection models for diferent customer classes or for customers in diferent geographic areas. Once the user has chosen the connection models and set the design rules, the software computes an optimized network of nodes and links to connect demand points to the central node of the network. In the example given, the optimized solution will consist of several remote optical line terminals (OLTs) positioned so that, ultimately, all households and small businesses are reachable by GPON connections from the remote OLTs and all community institutions and cell towers are reachable by direct fber connections. Once an optimized set of network nodes has been located on the GIS layer, the software computes an optimized set of fber cable links to connect the nodes to the network. Figure 4 shows one of the three fber trees required to connect the remote OLTs, community institutions and cell towers in the example city. When the backbone fber and remote OLTs are in place, the city can plan, engineer and build the distribution networks for the remote OLTs at its own pace and based on its own priorities. Advanced planning software such as NOCPlan XS will plan a gigabit city network in just minutes, using points and clicks. Tis represents a small fraction of the time and efort required by the old map-and-calculator method. It can also assign physical properties and costs to links and nodes to produce a bill of materials and detailed cost estimate for the project. Alternative scenarios can be quickly and easily modeled, and the planner can choose Figure 2: The demand layer shows where customers are likely to demand services. Figure 3: Remote OLTs are positioned so that fber can reach all households and businesses. BBC_Jan14.indd 60 1/27/14 1:47 PM