Passive Optical LAN (POL) vs Traditional LAN


Scale and reach are the two distinct advantages to using POL over traditional switched copper LANs. Reach is accomplished through the use of single-mode fiber in the cabling plant as it provides a footprint of 12.4 miles as opposed to the 300-foot limitation of copper. Scale comes from the fact that POL is a point to multipoint technology. Single-mode fibers connect to Passive Optical Network (PON) ports on the Optical Line Terminal (OLT), reach into the enterprise, and then terminate into a passive optical splitter, turning the one single-mode fiber into 32 fibers. Each of these can terminate into a 4-port Optical Network Terminal (ONT), providing a total of 128 Ethernet ports. In contrast, a traditional LAN would require 128 home runs of copper to accomplish what POL provides with 33 total fibers. Keep in mind, there are different models of ONTs (2,8,16, and 24-port) that can provide more ethernet ports than a typical 4-port ONT.


When drawing comparisons between Passive Optical LAN and a typical switched copper infrastructure solution, it is vitally important to ensure that all comparable aspects of each solution are taken into consideration. POL represents a true evolution of LAN connectivity by pushing the Ethernet edge out of the telco closets and to the end-user. Unlike a traditional infrastructure with the demarcation between the switches aggregated in the telco closets and the home runs to the end user, the POL solution is inclusive of the fiber connectivity. Therefore, a POL system is a turnkey approach to the traditional copper cabling and the distribution and workgroup switches. An accurate comparison must take into consideration each of the following components and activities:

Workgroup access switches

  • Switches
  • Transceivers
  • Patch cables
  • Maintenance
  • Professional services (rack/stack, configuration, documentation)

Structured Cabling

  • Copper Cabling
  • Fiber backbone
  • Racks
  • Patch Panels/Cable Management
  • Faceplates, jacks, etc.

Based on an accurate comparison, taking all of the above factors into considerations, capital expenditure savings should be 25%-55%.

Operating expenses will also be drastically reduced. The most significant contributor to these savings is the reduction in power consumption that comes from the elimination of the workgroup access switches. The removal of the switches reduces or eliminates the impact on UPS and HVAC in the closets. Lastly, maintenance costs associated with the switches, UPS, and HVAC are reduced or eliminated.”