is still within the realm of TDM technology and the cost advantages of opti- cal amplification cannot be fully exploited because of the shorter distances. As such, WDM technology must bring a richer set of values to meet the diverse challenges of the local network."13 In long-haul networks, the major portion of the network transport cost is due to the numerous regenerators along a link (typically every 35 to 70 miles). Normally, not only do you need to do the amplification, but you also need an O-E conversion, followed by an E-O conversion (resulting in a full O-E-O conversion). Utilizing OLAs reduces this cost by eliminating the O-E-O conversion. As the cost of optical amplifier technology drops, WDM becomes increasingly more economical in long-haul networks. However, in local networks, where distances are shorter, the bulk of the core network transport cost is due to the multiplexers and crossconnects. In the access network, it is the cost of the fiber spur. Hence, reductions in the cost of these components will prove advantageous to the bottom line. The one major fac- tor driving the potential success of DWDM in metro access/metro core is the cost per unit (specifically per lambda) per building. The cost per lambda should be in the range of $2,000 to $10,000; the cost per building should be in the range of $10,000 to $20,000; and the system should carry 4, 8, or 16 protected lambdas (8, 16, or 32 distinct lambdas). It is important to consider how many broadband customers actually reside in one building. The model of Chapter 1 indicated the results of Table 5-4.16 It is worth noting that a carrier that needs to connect approximately 300 buildings using 36 metro access rings of 8 buildings each and can pick up 5 to 10 broadband customers per building has a financial advantage over a follow-on carrier that needs to connect the same 300 buildings with an overlay of 36 new rings and only pick up 1 or 2 broadband customers per building. If the building had 3 broadband customers, the economics begin to work, but only