How Do I Choose Between Singlemode and Multimode Fiber?
When deciding if singlemode or multimode fiber is right for you there are a few things to consider, including distance, future needs, and budget.
If you are installing a new fiber backbone, you will likely want singlemode cable unless you have short distances between closets. As backbone bandwidth requirements go up, the need for singlemode also increases. However, since you are probably working with a limited budget, there are choices you can make to achieve your desired results.
In terms of cable, singlemode fiber is not much more expensive than multimode fiber. The cost increase usually comes from the kind of optics needed for your switching infrastructure. The longer the distance you need to cover, the more expensive the optics.
The key here is knowing your short- and long-term requirements and choosing fiber that will give you the longest life based on those requirements. Singlemode will enable you to scale your backbones to 40gig, 100gig, and beyond, over long distances. Multimode is just not up to that task. So, if you are installing new fiber singlemode should be a strong consideration.
If you have an existing fiber plant and you want to implement 10gig, you’ll need to take a close look at the type and capabilities of the current fiber. In general, the older the fiber, the shorter the range.
Read more details on 10gig requirements
OM1 fiber has a core size of 62.5µ. For 10gig applications with a short haul optic, this can only be certified for about 100ft.
OM2 fiber has a core size of 50µ. With a long-range optic on a switch, this can be certified for almost 700ft. That will work in many scenarios. You just have to be ready to spend more money on the optics in order to use this fiber.
OM4 fiber is even higher-grade fiber, with a core size of 50µ. With short haul optics, this can be certified for over 1200ft.
So, you can see that the type of multimode fiber determines capabilities, and it’s important to look at this closely.
optical fiber core diameters
Before implementing a new network infrastructure, you should re-certify your fiber to ensure it is capable of the bandwidth requirements. In many cases the fiber may still be good, but the terminations have degraded over time. Re-terminating will bring them back into compliance.
Additionally, there are new products available that allow you to turn older multimode solutions into a singlemode infrastructure by changing the way the light is transmitted. This can further extend the life of your multimode fiber and keep you from installing all new fiber.
Read more about Panduit OneLink
In summary, there are three things that will determine the type of fiber you’ll use:
1. How much distance you need to cover
2. How much you want to future proof your investment
3. How much you are willing to spend for optics to run on the fiber
Remember, if you have the budget, singlemode is always the better investment as it gives you both distance and the option for faster speeds in the future.