There used to be time when I waited for good things to come from above. I waited for society to improve the Internet connection. I waited they would improve the work situation. I waited for lot of things and they never came.

I have waited fiber connections for 15 years. One evening I started to wonder why I don't have one yet and begun to study the subject. Here's what I've learned so far.


Single-mode fibers can transmit infrared laser light with very little loss.

Nobody either knows what is the throughput of a fiber but it is observed to be doubling every 9th month. The theoretical capacity is believed to be hundreds of terabits per second. So far we can do 100Gbps in commercial setting with Dense Wavelength-division Multiplexing. In lab environment 56Tbps have been obtained with over 100km distances.

Last time I heard a radio link reach Tbps speeds, the transmitter and receiver was 100 meters apart. Radio links have the big problem that the available bandwidth is shared with everyone on the area. These kinds of lab results are extremely difficult to upscale.

In fact if we used laser communication in open air we would face problems too. Air is very good at dispersing laser light. For this exact reason laser guns have been infeasible as well. Compared to projectile guns you need too much energy to damage the target.

"The Internet of tubes" is hilariously correct if you bring it down to hardware concepts. Fiber traps a light into conduit with means of refraction. To get an idea of what happens you can look to the calm sea or lakes. When you look in steep enough angle you'll see the reflection of of the clouds or trees. Scientists figured out that if this conduit is thin enough, it provides a very low-loss cable for transmitting light.

Fibers are made from glass far thinner than a strand of your hair and they are coated with various industrial materials to protect the fiber inside from elements. Glass fibers are especially sensitive to water. Today the coatings around the fiber cost more than the fiber inside it so usually a single cable carries several fibers inside itself. It can be low as 2 or high as 400.

Although it's made of glass a very thin strip of glass is extremely flexible and the strength of the cable depends on the other materials used.

Modern fiber based equipment can do it over hundreds of kilometers without amplifying the signal in middle. With signal amplification it can go even further and to do that there are optical amplifiers that can directly amplify the light that passes through them.

There's no case where modern fiber technology would have deteriorated unusable yet. Although decades have passed from picking it up. Nobody knows what is the lifetime of a fiber line because not a single one has failed for natural causes yet.

Fiber networks are believed to last for at least 40 or 60 years and longer before they need to be replaced. Also there has been so much single-mode fiber deployed so far that the optics will be designed in their terms.


Wavelength-division multiplexing is used in modern Internet backbone links today. This technology participates to bringing through a message when you are doing a long distance call that crosses continents. It may go this way even if you used a cell phone today. Radio is too relying on weather to provide high-bandwidth low latency and long distance communication links.

And yes, the Internet infrastructure is perfectly capable of relaying phone calls even from cell phones. It's all you need in order to communicate with others today. Read about VoIP if you don't believe me.

How xWDM works

The WDM multiplexes number of optical carrier signals into single optical fiber using different wavelengths. This allows multiplication of capacity and bidirectional communication over single fiber.

The different wavelengths travel different speeds in a fiber, causing dilation effects. In WDM the signals are so small-band signals that in individual signals it doesn't matter, but every individual channel has slightly different latency. This doesn't matter though because the difference is small and IP protocol divides the packets into segments that can arrive out of the order where they were transmitted. Every individual link can transmit a packet without worrying the rate or operation of the others.

The units in the end of WDM are called transponders and the tool to join or split the signals into single fiber is a mux or demux.


There is a Gigabit Passive Optical Network technology that allows greater flexibility on fiber than copper ever had. We can split and join optical lines to provide access to many tens of homes via one fiber. This is also constantly improving over time and the old PON hardware doesn't need to be dismantled to deploy new PON hardware. This technology can handle up to 20km distances from the powered communication center to home.

How xPON works

The infrared lasers used in PON hardware have very specific frequency bands they emit. You can shift those frequency bands to allow multiple communication channels via a single fiber.

There are passive optic splitters that can split a single fiber and divide light passing through between several outgoing fibers with minimal signal loss. This same splitter can operate in reverse and merge the signals. And it doesn't require electricity to function.

Combined these tools let you provide above gigabit Internet speeds to groups of 32 homes via a single cord of single-mode fiber within 10 kilometers, and to 16 homes within 20 kilometers.

Fiber provides very secure channels

Fiber cables eliminate one way to listen ongoing communication compared to copper.

The problem with copper is that when it's used for communication it also behaves as a both radio transmitter and a receiver. This allows you to tap into copper lines and listen to the messages inside without changing the signal strength.

Fiber signals are optical and you must break the cable to get access to them. This can be noticed by the ISP and the customer. If it is fixed by someone else than the ISP technician it raises suspicions and the spy gets detected.

Besides fibers provide enough capacity to provide stronger encryption. Even if they were listened to, the listener would require expensive equipment to decrypt the message as long as he doesn't have access to your or your recipient's key files.

Working with fiber technology

Like high-power electric lines, fiber lines require specific knowledge about the technology for you to operate safely with them. Also there's some basic safety rules you should know. Although there are no high voltages present, the materials related to this tech aren't safe during installation or config.

The first thing to understand is you should never look into the fiber end if you don't know whether the fiber is live or not. You don't see the infrared laser light but in high power links it is very capable of frying your eyes out. At home xPON links watching into fiber ends should be safe as the light quickly disperses in air but as a rule of thumb you shouldn't point a fiber to your eyes.

Also the trash resulting from working with fiber should be treated with same seriosity as you treat other glass trash. It should be disposed properly as it is dangerous if it enters intestinal tracts or mucous membranes in your eyes or nasal tracts.

You should not eat, or hold small children around, or hold your lunch around where you cut and splice fiber. Also ensure that the fiber cuts you do immediately end up to a trash bin or a sticky tape where you can dispose them safely. These things are effectively small needles and they may even kill the person who ingests them by accident.

Besides don't eat small baby children because that'd be bad advertising for your employer. This is explicitly mentioned because sometimes it feels older ISPs around the world hire trolls as customer support.

You should use safety glasses when working with fiber to ensure the glass shards do not enter your eyes while you are working, and keep your mouth shut when you cut.


Large scale fiber networks are possible because the low frequency lasers have gotten much cheaper than they were, and the fiber technology has been standardized to great lengths.

Today you could deploy a modern and cheap-to-upgrade fiber network that averages to $3000 per customer even in not very dense towns. It is pure incompetence that this has not been done yet - remember that this technology is new and your ISP is actually incompetent because they haven't studied to stay competent.

Single-mode fiber infrastructures could handle our communication infrastructure needs for decades, possible centuries if somebody started to deploy them on a scale.

I was waiting for that moment. It didn't come. It probably won't come until I do something for it.

Btw. I got lots of help from Nestor cables company to figure this out. They were happy to supply me with resources and links to get all the lovely details down. They sell the fiber line equipments to build fiber networks.

Similar posts