ty. (Of course, some cities are larger, and other cities are smaller.) Reexamining the market scope of long-haul-based DWDM, you should note that because the traditional voice market has not grown more than a few percentage points a year for the past couple of decades, the growth in long-haul demand must come from either Internet applications or from Chapter 5 Figure 5-4 Access Ring 1 Typical city 00000 arrangement 160 Mbos in 2001. (2001) 16 Buildings per Ring 160 Mbos (2001) Metro Core Ring 160 Mbps (2001) 3,520 Mbps (2001) OC-192 Ring 160 Mbps (2001) TDM SONET 00000 Access Ring 22 wireless networks trunking. Table 5-1 captures the bandwidth requirement assuming an 80 percent per year growth, which was the best estimate of the growth of the Internet at the end of 2001. The interesting thing to note is that if a carrier had an OC-48 between two points and the carrier upgraded that link with a DWDM system with 16 channels, then there would be no need to deploy other hardware for 6 years. If the carrier upgraded the sys- tem with a 32-channel solution, then there would be no additional need to deploy other hardware for 7 years. Clearly, this is not good news for long- haul DWDM manufacturers. Taking this analysis a step further, assume that there are 20 tier-1 net- work service providers (NSPs) in the United States. (The actual number is probably smaller.) The 80 percent aggregate growth of the Internet would then translate into a 4 percent growth per individual NSP, assuming an even distribution. Because of the inefficiencies associated with granularity, we actually assume 2.5 times the growth with each NSP; namely, we assume a 10 percent growth per year per NSP. Further, we assume that a typical national NSP network approximates the one shown in Figure 5-6, which has 9 nodes and 12 links. Dense Wavelength Division Multiplexing (DWDM) Systems Figure 5-5 Access Ring 1 Typical city 00000 arrangement 1168 Mbps in 2005. (2005) 16 Buildings per Ring 1168 Mbps (2005) Metro Core Ring 1168 Mbps 38,544 Mbps (2005) (2005) 