The singlemode fiber systems can be preterminated or field-terminated, and manufacturers have taken measures to ease the process for installers.
The value proposition for deploying a passive optical local area network (POLAN) has been made to enterprise organizations for several years. Groups like the Association for Passive Optical LAN (APOLAN; www.apolanglobal.org) have carried the message of money, energy and space savings as reasons it would be worthwhile for enterprises to deploy passive optical LANs. When the APOLAN announced its formation in 2013 the group said, “Passive optical LAN serves as the optimized means to deliver voice, video, data, wireless access, security and high-performance building automation for the federal government and commercial enterprise … The deployments of passive optical LAN to date have demonstrated significant cost and performance advantages compared to traditional Ethernet designs, and the optical foundation futureproofs the network for any new bandwidth demand.”
A significant part of the passive optical LAN’s value proposition comes from the active components used in the network, as well as the architecture of that active gear along with the network’s passive components. In one part of its Reference Guide to Fiber Optics, the Fiber Optic Association (FOA; www.thefoa.org) explains, “Passive optical LANs use standard FTTH architecture and protocols, which are quite different from typical LANs … Passive optical LANs use optical splitters to divide the optical signal to allow up to 32 devices [optical network terminals; ONTs] to be connected to one port on the optical line terminal [OLT] that is the center of the LAN. Downstream, the splitter splits the signal to all the devices and upstream it combines them into one fiber, allowing bidirectional signals on one singlemode fiber. Each ONT is usually a four-port Gigabit Ethernet switch in a LAN, but it can also be a switch for multiple phone lines or even a FTTH triple-play (phone/Internet/TV) converter.”