Fiber Optic Service FAQ, Part 3

Here are more frequently asked questions and answers about fiber optic service for your business You may also be interested in the first and second lists of fiber FAQs.

Q: What is a lit building?

A: This is a building that already has fiber installed and “lit” for service. Usually only a single carrier lights each building. If your building is lit, you can easily get bandwidth services from that carrier.

Q: What are wavelength services?

A: A wavelength or Lambda is a particular color of laser light that carries the signal through the optical fiber. Early fiber systems used only a single light beam. Today, multiple beams travel the same fiber strand using a process called WDM or Wavelength Division Multiplexing. You can lease an entire wavelength for your exclusive use if you wish.

Q: Why would you lease a wavelength rather than just buying bandwidth?

A: Leasing a wavelength gives you high bandwidth dedicated to your use. Typically each wavelength supports 10 Gbps. You can decide whether to use SONET, Ethernet or some other protocol over the wavelength because the service does not share traffic with other users.

Q: What is dark fiber?

A: This refers to fiber strands that have been installed but not lit for service. Most fiber optic cable has dozens or hundreds of fiber strands all bundled together. Carriers that have extra strands they aren’t using will often lease them to other carriers or businesses that need the capacity.

Q: What’s the advantage of dark fiber?

A: Bandwidth is nearly unlimited and security is high because there is no traffic on the fiber strand other that what you provide.

Q: What protocols does dark fiber support?

A: Anything you can generate, including SONET, Ethernet, Fibre Channel and others. By using Wavelength Division Multiplexing, you can assign a different protocol to each wavelength and they won’t interact.

Q: Why wouldn’t you select dark fiber?

A: You’ll need to provide the termination equipment at each end, which can be rather expensive. On wavelength and other bandwidth services the carrier does this. Also, there may not be any dark fiber available on the route you have in mind.

Q: How does fiber support cloud services?

A: Cloud communications are bandwidth intensive. All the traffic that used to run to your in-house data center now goes over a WAN (Wide Area Network) connection to the cloud. You need high bandwidth and low latency connections for this to work properly, just what fiber is good at.

Is fiber bandwidth service the right solution to your business needs? Compare costs and service options for the fiber optic service options available for your business locations.


You may also be interested in reading Fiber Optic Service FAQs, Part 1 and Part 2.

Fiber Optic Networks Need Denser Wavelength Multiplexing To Meet Demand

Just when you thought that businesses were hunkering down for the worst recession ever and wouldn’t need more capacity for a decade, fiber optic network carriers are scrambling to meet demand. But they’re not going nuts and digging trenches everywhere. Instead, they are taking the smart approach of using technology to increase bandwidth on their installed facilities.

XO Communications, a major fiber optic network carrier, recently announced that it is installing new optical line equipment from Infinera to double its capacity per fiber strand. The Infinera Line System 2 doubles the number of channels for C-band fiber optic systems (1550 nm) from 80 to 160 channels. For XO, this will create an additional optical capacity of 1.6 Terabits/second (Tbps) on their nationwide network.

What is XO hoping to do with all this additional bandwidth? They are using it to support their carrier to carrier services called “Carrier Wavelength FLEX” and “10 Gigs in 10 Days.” With the new Infinera hardware and software, XO Communications will be able to provision any service from 1 Gbps to 40 Gbps between any two points on the network in 10 days or less. In the future they plan to up that to 100 Gbps.

What XO is doing is really two initiatives at once. One is doubling capacity and making it scalable for future expansions. The other is speeding the process of provisioning service so that their customers, other carriers and businesses, can respond more quickly to marketplace needs. You might say that faster is better all the way around.

Certainly, XO Communications is making a move to position itself as a provider of choice as demand for bandwidth picks up. But they may also recognize that business coming out of this turndown may look somewhat different than it did going into the slide.

For one thing, technology is being seen by all size operations as a way to improve productivity at lower risk and lower cost that simply staffing up. Technical solutions can drive cost out of a process and reduce the amount of labor needed to support a given business level. Telecommunication capability is more vital than ever as solutions migrate toward the “cloud” and business entities are coupled more and more tightly.

The nature of many business services is also changing in a way that demands more bandwidth. Take television and video production, for instance. High definition and, soon, 3D images are far more demanding on digital bandwidth than lower resolution products. The health care industry seems destined for a complete move from paper forms and photographic processes to all-electronic generation, transmission and storage. Certainly, this will improve productivity and take incremental cost out of the processes, but there will be big infrastructure investments to be made before the massive cost savings can be realized.

New Dense Wavelength Division Multiplexing (DWDM) equipment, such as Infinera’s Line System 2, will be critical to all carriers as they look to increase capacity over their installed base of fiber optic strands. XO is simply getting a jump in upgrading their network before the mad scramble begins. That could be any time now.

If you are feeling bandwidth constrained in your business operations, you should know that lease prices per Mbps have dropped considerably recently. You may be able to upgrade to the level of service you need without the jaw dropping cost you are anticipating. How do you find out for sure? Get a quick and complementary fiber optic bandwidth service quote through our GigaPackets service. Our Telarus expert consultants will be happy to review the complete range of solutions available for your location.

Many Wavelengths to Serve You

What happens when you max out the capacity of your network but still need more bandwidth? You have to go with a faster network, right? You may have to go with faster NIC (Network Interface Cards) and Ethernet switches for every node. What you don't want to do is run out of capacity on your lines. When you've got all you are going to get out of your structured wiring system, it gets expensive, really expensive, to upgrade that network. But what if you could just add some more signals into those same cables and multiply the bandwidth 32 or even 160 times? If your network is fiber optic based, you can do just that.

The magic is in a process called WDM or Wavelength Division Multiplexing. We think of fiber optic networks as having a beam of light at one end and a receiver at the other. The transmission electronics modulates a laser beam with our data stream and a photodiode at the other end converts the modulated light back into electrical pulses. What WDM does is send multiple beams down the same fiber optic cable in parallel. Two beams gives you 2x the capacity, four beams gives 4x, and so on. This process is so well developed that you can send 16 to 160 separate beams simultaneously to support enormous bandwidths.

Fiber optic networks are much faster than copper-based networks to begin with. Gigabit Ethernet over copper can be a challenge within an office environment. Forget long haul. T3 is the highest of the copper T-Carrier systems at 45 Mbps and is usually only deployed over a few miles. T1 lines can reach out to just about any distance using regenerators, but the bandwidth is limited to 1.5 Mbps. Compare that to typical long haul fiber bandwidths of OC-48 at 2.5 Gbps or OC-192 at 10 Gbps. Some carriers are upgrading their core rates to the OC-768 level of 40 Gbps.

In the world of copper transmission lines, frequency division multiplexing (FDM) is the equivalent of fiber optic WDM. FDM is what Cable TV companies use. Each channel has its own carrier and occupies its own narrow band of frequencies in the spectrum. More than 100 standard TV channels of 6 MHz each can be carried on a typical cable system. Some of these channels are assigned to broadband Internet services rather than television transmissions.

Wavelengths are also different frequencies which, in the optical (including infrared) parts the spectrum, represent different colors. They are also called lambdas after the Greek letter representing wavelength. Light split from a prism demonstrates that many different colors can exist simultaneously in a single beam without interference.

There a two general categories of WDM. CWDM or Coarse Wavelength Division Multiplexing uses up to 16 different wavelengths within an individual single mode fiber strand. DWDM or Dense Wavelength Division Multiplexing uses up to 160 wavelengths in a fiber strand and requires more precisely controlled lasers. But at 10 Gbps capacity per wavelength, a system with 160 wavelengths offers well over a Terabit/second bandwidth.

WDM schemes are found in long haul carrier core networks where the cost of installing hundreds or thousands of miles of fiber optic cable far exceeds the cost of new electronics to increase capacity by adding more wavelengths on the same fiber. WDM or CWDM is also installed on dark fiber when customers need the extra capacity in metropolitan (MAN) networks.

Thanks to WDM and competitive carrier build-outs, fiber optic bandwidth is more affordable than ever. That's especially true for the new Ethernet over fiber services available to businesses in major metropolitan areas.