智能楼宇

为何商业音视频项目越来越多地使用光纤

Bob Ferguson

A change has been taking place in AV applications over the past few years. Recently, twisted-pair cabling has been the go-to for video distribution. But, as video quality and bandwidth requirements increase, and distance between source and display grows, fiber infrastructure is starting to show up in more commercial AV applications.

There are a few reasons why the addition of fiber is becoming noticeable – and we’ve outlined some of them here.

1. Fiber Futureproofs Against Increasing Commercial AV Bandwidth

Video bandwidth has skyrocketed with the move from 1080p images to 4K – and with the addition of HDR and deep color information. If we can avoid compression on that huge data stream, we can eliminate errors.

 

Traditional copper networks are reaching their current limits. Fiber, on the other hand, can handle 25 Gbps and beyond. As more bandwidth is needed in the future, more data, audio and video can be transmitted over the same fiber optic cable with just a few component changes – instead of having to replace the cable itself.

 

2. Fiber Carries Audio and Video over Longer Distances than Copper

Even the best copper systems start to limit distance at 100 m/330 ft. Fiber is a great choice for longer runs; the light running through the fiber doesn’t suffer from the same attenuation limits as electricity cabling. It can easily extend 10 times beyond that distance, which is ideal for campus-wide AV systems, large conference centers and lecture halls.

 

3. Fiber Resists Performance Interference

One of the biggest hazards for an AV signal is interference from an outside source. Electrical signals can pick up noise – especially from other AV cables, because they typically operate at the same frequency. The light in a fiber cable is immune to this type of interference because it doesn’t pick up or give off this type of noise.

 

It’s important to note, however, that electrical noise can come from other things, too, like radio frequency, lightning strikes, temperature variations or electromagnetic interference from wireless access points, lighting fixtures or HVAC systems.

 

4. Fiber Offers a More Manageable Size

Smaller in size and weight than copper cables, many AV designers and installers find fiber optic cables to be easier and faster to transport and install for AV projects.

 

Picking the Right Kind of Fiber for Commercial AV Projects

Just as with category cable, choosing the type of fiber cable to use in a commercial AV project makes a difference in overall performance. Factors such as where and how the cable is being used need to be taken into consideration.

 

The first decision to make is whether your fiber system will be part of your building network infrastructure or if you’ll place separate point-to-point systems between AV devices. You may need to match equipment to existing cabling.

 

The next step is choosing between singlemode and multimode fiber (or maybe both). This decision is typically governed by the types of systems and parameters you need. A lot of AV equipment – especially on the professional side – is only available in singlemode. More systems, however, are beginning to offer designers a choice.

 

Generally speaking, singlemode fiber is a slightly more expensive system (the cable, however, is actually cheaper) but offers longer distances and more bandwidth. With multimode fiber, you have a few choices when it comes to glass grade and size. Typically, multimode is used for shorter distances, and is readily found within a building. As technology advances, the differences between singlemode and multimode become fewer.

 

Next, consider how you’ll protect your fiber cable. (Remember: Fiber optic cable is made up of small ribbons of glass the size of a human hair.) To do this, there is a wide variety to choose from when it comes to cable, connectors, faceplates and enclosures. If you’re not sure what you’re looking for, consult an expert. Belden is happy to walk you through your choices.

 

The last step is to consider your future requirements. As you can imagine, it’s expensive to go back and replace the infrastructure once it’s installed.

 

When starting your next commercial AV project, remember that fiber may be a viable option for audio and video distribution. You can learn about Belden’s fiber solutions here, and stay tuned for our upcoming webinar on using fiber in AV projects.