customers per $2,000 building. $1,500 $1,000 Figure 10-15 Two 100-Mbps Customers/Building Two 100-Mbps customers per $2,000 building. $1,500 $1,000 Practical Design and Economic Parameters Figure 10-16 Four 100-Mbps Customers/Building Four 100-Mbps customers per $3,000 building. $2,500 $2,000 $1,500 $1,000 Figure 10-17 One 1,000-Mbps Customers/Building One 1,000-Mbps customer per $2,000 building. $1,500 $1,000 Figure 10-18 Two 1,000-Mbps Customers/Building Two 1,000-Mbps customers per $3,000 building. $2,500 $2,000 $1,500 $1,000 Chapter 10 10.4.4 Key Conclusions Some major, perhaps critical, points can be synthesized from an analysis of this section. Using the baseline case in Section 10.4.1 and the sweet spot for two or four 100-Mbps TLS customers per building, where a positive profit of 5 to 25 percent can be realized, the cost allocations for a carrier can be determined, as shown in Table 10-14. Figures 10-19 and 10-20 represent the information in Table 10-14 graph- ically. Building access is the dominating cost in a building situation with two customers; SGA and operations costs are the next two costs to follow; fourth in line are the building riser costs (the expense of wiring the building for the two customers); fifth in line are NOC-related costs. Interestingly, none of the hot buttons of the current technology developers address these issues (from this list, a reduction in operations cost would be of interest). None of the bandwidth conservation ideas of Resilient Packet Rings (RPRs) embod- ied in Switched Multimegabit Data Service (SMDS), IEEE 802.6, and other newer technologies seem to have any relevance to the profit-making line. SGA and operations costs are the first two dominating costs in a build- ing situation with four customers. In a way, working the building very hard Table 10-14 Two Customers Four Customers Summary of Cost Elements per Building per Building Allocated Costs Allocated ring cost per building/MRC Allocated spur cost per building/MRC $1,500 $1,500 Allocated CO equipment cost per bui