Optical Awareness

Optical local area networks (OLANs) have been the subject of these columns for several months, and before that I discussed networks. This month’s column ties together some loose ends to help you understand the OLAN concept better. It should also help you explain it to your customers, so they understand the differences and advantages of OLANs.

Comparing OLANs and structured cabling is like comparing apples and oranges, or networks and cabling. When I discuss OLANs—either fiber to the office or passive OLANs—I am referring to networks. By “networks,” I mean communications systems that allow us to plug devices in to communicate with each other. They include optical fiber cabling, splitters for passive OLANs and the electronics that connect over the cabling and provide jacks for plugging in standard Ethernet network devices. The cabling for an OLAN is just another option of structured cabling as in the TIA-568 or ISO/IEC 11801 standards.

Structured cabling was a standardized cable system designed to enable various types of networks to operate over the cabling. The advantage of structured cabling was you could design and build equipment, based on the predictable specifications of the cabling system, for local area networks (LANs), security systems, building management systems or whatever you wanted to use to communicate with other devices.

To build a LAN comparable to an OLAN, you need to add Ethernet switches in the main computer room and every telecom room near the users. Once you connect these electronics, you have a LAN that can be compared to an OLAN or vice versa.

Comparing optical to copper networks has always been confusing, simply because the devices you want to connect to the network already have Ethernet ports for Cat 5 unshielded twisted-pair copper cable. If you want to compare copper to fiber cabling, you have to include the cost of a media converter, which converts fiber to copper signals and allows those devices to connect. The media converter cost always skewed the comparison toward copper, even though the cabling costs were comparable.

For a more legitimate comparison, consider the network cost, including the cabling and the Ethernet electronics. With traditional suppliers of Ethernet switches, the costs were still skewed, as the relative costs of ports favored copper. While a copper port might cost $5, a multimode fiber port would cost more than $500; a single-mode fiber port would cost $5,000 or more. There is no comparison.

When OLANs started using equipment developed for millions of fiber-to-the-home (FTTH) subscribers, the cost of networking equipment plummeted. Recent estimates say Google Fiber’s cost of connecting a home with gigabit service is just over $400, including electronics and installation labor. That’s the power of volume in any tech product.

When you price OLANs and networks using copper (or copper with a fiber backbone), you typically find the OLAN costs about half as much. It can be higher if the number of users is low or the LAN is confined to one building or floor. It can be much lower if the LAN is very large or connects multiple buildings. Sandia National Labs, with 265 buildings in a city-sized area, is an example where OLANs are ideal, as are school systems and metropolitan networks.

The fact that the network purchase must be considered at a higher level (in network jargon, the cabling is “Level 1,” and the networking electronics are “Level 2”) means that the contractor will likely partner with equipment suppliers and deal with the facility’s information technology (IT) people. The decision-maker may be the IT manager or IT consultants; when an OLAN sale is being made, it’s usually at the IT manager’s level. In a large company, a chief financial officer or chief information officer may make the final decision.

Based on several years of OLAN experience and watching acceptance grow, I suggest that contractors working in the structured cabling business learn about this technology. It’s not just the installers that need to learn. I would start at the top, since the boss needs to understand OLANs to make the case for being in the business. Then, the salespeople need to understand how to help the customer choose between traditional networks and OLANs. Following that, the technical people will need to get trained at their level.

Several seminar and webinar series are available from vendors and the Association for Passive Optical LAN. Also, The Fiber Optic Association offers a free OLAN self-study program at Fiber U.

About the Author

Jim Hayes

Fiber Optics Columnist and Contributing Editor
Jim Hayes is a VDV writer and trainer and the president of The Fiber Optic Association. Find him at www.JimHayes.com .

Stay Informed Join our Newsletter

Having trouble finding time to sit down with the latest issue of
ELECTRICAL CONTRACTOR? Don't worry, we'll come to you.