Issue link: https://www.e-digitaleditions.com/i/1066130
54 I ICT TODAY 0% 24 Port 48 Port 72 Port 50% 100% 150% 200% 300% 250% 400% 350% 450% 500% One-Segment Two-Segment Three-Segment Relative Cost of MPO based Structured Cabling FIGURE 3: Relative cost of a cabling and connectivity infrastructure for PSM4 (MPO) based optical transceivers compared to that of a CWDM4 (Duplex-LC) for varying port densities and number of segments. TABLE 2: Link components cost and design assumptions used in the total cost of ownership analysis. Parameter Value Number of Segments 2 Total Link Length 300 ft. Panel Density per 1RU 72 Number of transceivers per Link 2 Relative cost (CWDM vs. PSM4) 30% Relative Cost (400G vs 100G) 300% Figure 3 plots the relative cost of structured cabling for different numbers of segments and port densities. Furthermore, it shows that the MPO-based infrastructure has around 3.6x to 4.6x more cost associated with it when compared to a Duplex-LC infrastructure. The higher cost of the MPO-based infrastructure for PSM4 is originating from the 4-fold increase in the number of optical fibers when compared to a 2-fiber based Duplex- LC infrastructure. As the number of segments increase, the number of connectors also increase, thereby increasing the cost differential. The data shown in Figure 3 also indicates that the cost of a link per port does not vary with the port density (based on the products from a single manufacturer) but varies with the number of trunk segments. TOTAL COST OF OWNERSHIP Thus far, the relative cost differentials between the two optical fiber architectures for optics and cable/connectivity have been addressed independently. In this section, the total cost of the link, which comprises the optical fiber transceivers and structured cabling infrastructure connecting them, is discussed. Two build scenarios are considered for total cost analysis: • The calculated total cost of a link in a new build scenario comparing the cost in terms of $/Gb/s for both 100 Gb and 400 Gb • The total cost when a migration from 100 Gb to 400 Gb is considered Table 2 lists all the assumptions made for total cost analysis. For a new build scenario, Figure 4(a) plots the relative total cost of ownership for 100G (Gb) links based on both CWDM4 and PSM4 architectures. The results indicate that at 100 Gb, CWDM4 is the cost-effective solution to build 100 Gb links, whereas a 100 Gb-PSM4 link might cost around 30-40% more than a CWDM4 link. If a CWDM4 link costs $1, a PSM4 link costs approximately $1.36. Another point to note is that for a CWDM4 based link, 80% of its cost is in optical fiber transceivers and 20% in cabling infrastructure, whereas a PSM4 based link has 60% of its cost in the transceivers and 40% in the physical infrastructure. This cost distribution may be helpful when infrastructure re-use for higher speed is considered. When comparing the two 400 Gb options, a different conclusion is reached. In the case of 400 Gb, the optical fiber links incorporating