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Table 7. Trunk Line Alternatives <br />5.3 Unserved Area Alternatives <br />Table 8 includes a comparison of feasibility, advantages, and disadvantages for the four <br />alternatives for unserved areas: twisted pair copper cable, fiber optic cable, wireless, and leased <br />services. There are 35 traffic signals that are not currently connected to the communications <br />network as well as planned ITS devices that are not located near existing communications <br />infrastructure. <br />Figure 10 and Figure 11 conceptually depict how trunk line Alternatives 1 and 2, respectively, <br />would work in a network with the four unserved area alternatives. Installing fiber optic cable to <br />the unserved areas was not considered for the trunk line alternative with twisted pair copper <br />cable because it is more logical to use one of the other three alternatives. <br />DKS Associates Eugene Master Traffic Communications Plan March 2008 , <br />Page 27 <br />Alternative 1: <br />Twisted Pair Copper Cable <br />Alternative 2: <br />Fiber Optic Cable <br />• Install Ethernet over copper devices <br />Replace all existing copper cable with <br />in each device controller cabinet <br />fiber optic cable. <br />(traffic signals, CCTV cameras, etc.), <br />Replace some junction boxes to <br />at Roosevelt, and at RIS. <br />accommodate fiber bends and <br />Feasibility <br />accommodate spare fiber optic cable. <br />• Install Ethernet switches: edge <br />switches along each corridor, several <br />middle switches throughout City, and <br />central switches at Roosevelt and RIS. <br />• Lower cost <br />• Utilizes existing conduit <br />• Utilizes existing infrastructure (conduit <br />• Higher bandwidth (1 Gbps) <br />and twisted pair copper cable) <br />• Extra capacity for future planned <br />• Provides more bandwidth to traffic <br />system expansion <br />signals than existing FSK modems: <br />• Robust reliability when multiple fiber <br />Advantages <br />10 Mbps per pair up to 80 Mbps is <br />optic corridors are linked <br />possible in some cases. <br />• Sharing opportunities with ISD that <br />support both traffic devices and City <br />facilities <br />• Sharing opportunities with ODOT for a <br />robust multi -path system <br />• Existing copper cable is aging, <br />• Higher cost <br />requiring increased maintenance <br />• May not be feasible to pull fiber optic <br />effort and will need to be replaced <br />cable into some of the existing <br />• Lower bandwidth (80 Mbps <br />conduits, which may result in <br />maximum) for video transmission than <br />construction add - ons <br />Disadvantages <br />fiber optic cable <br />• Limited capacity for a large quantity of <br />cameras or other ITS devices in the <br />future <br />• Subject to electromagnetic <br />interference <br />• Maintenance of both alternatives is comparable. <br />City staff currently performs <br />maintenance on the twisted pair copper <br />cable network. They would also be able to <br />Notes <br />maintain a fiber optic cable network within the same capacity with some initial <br />training and new tools and equipment that support fiber optic cable maintenance <br />activities. <br />5.3 Unserved Area Alternatives <br />Table 8 includes a comparison of feasibility, advantages, and disadvantages for the four <br />alternatives for unserved areas: twisted pair copper cable, fiber optic cable, wireless, and leased <br />services. There are 35 traffic signals that are not currently connected to the communications <br />network as well as planned ITS devices that are not located near existing communications <br />infrastructure. <br />Figure 10 and Figure 11 conceptually depict how trunk line Alternatives 1 and 2, respectively, <br />would work in a network with the four unserved area alternatives. Installing fiber optic cable to <br />the unserved areas was not considered for the trunk line alternative with twisted pair copper <br />cable because it is more logical to use one of the other three alternatives. <br />DKS Associates Eugene Master Traffic Communications Plan March 2008 , <br />Page 27 <br />