Bell Canada has recently installed optical fibre connections in my neighbourhood. It is based upon a Passive Optical Network (PON) and promises to deliver up to 1.5 Gbps to each home. This Fiber-to-the-Home solution is a huge leap compared to the copper wire, twisted pair DSL internet connection that I have today.
The DSL only provides up to 15 Mbps down and 3 Mbps up. The PON solution is just $5 per month more. So, I think that I will upgrade to fibre and get ride of the copper. The time is here. The days of copper interconnects as shown in the top photo are now officially dead. So, I thought that I would share some information about PON. Bell is about to help me make the next major optical fibre transition in my career. Albeit this time as a consumer. To be honest, I never expected this to happen in my lifetime – to see fibre to my home. But, technology moves so fast, that you must keep pace or forever be lost and struggling to keep up.
Optical Fibre communication is a method of transmitting information from one place to another by sending pulses of light through an optical fibre. The light forms an electromagnetic carrier wave that is modulated to carry information. Fibre is preferred over electrical cabling when high bandwidth, long distance, or immunity to electromagnetic interference are required.
My personal journey with optical fibre began in 1980, a story that started 39 years ago. First as a learner, then as a seller, followed as a designer, next as an builder, and now as a consumer. The circle is now complete. Or, should I say, “loop”?
Analog Links
During my 40+ years in the communications industry, optical fibre has been a part of it since the beginning. The first project that I was involved with was helping to design optical fibre links for the 1980 Olympic Games in Lake Placid, New York. I joined the team late in January 1980 as most of the real work had already been completed in the Fall of 1979. The Games ran during the last two weeks of February 1980. These links were used on the ski events to bring camera signals down Whiteface Mountain, one of the key venues there.
My next project was in Saskatchewan for the local telephone company – SaskTel. In 1982, we helped to design the first link of the fibre optic Broadband Network (BBN), between Regina and Yorkton, which was inaugurated in January of that year.
In 1984, work continued for SaskTel, when we helped to design the world’s longest commercial fibre optic system, 3,268 kilometres, initially connected 52 of Saskatchewan’s largest communities. SaskTel was the first in the world in 1984 in completing what was then the longest commercial fiber optic network.
These were all analog links powered by LEDs and received with APD. As the representatives of the Grass Valley Group, a California video and advanced technology company owned and started by Dr. Hare after he depart the famous Hewlett-Packard team and launched his start-up in the western foothills of the Sierra Nevada mountain range, by extension, we had the privileged to be involved with some amazing technology of the day.
Later, GV was owned by global technology juggernaut, Tektronix Corporation. Tektronix was leading the world in the day with 850nm multimode links that could cover 2-3 kilometres per hop. Material dispersion and Chromatic dispersion degraded the links if you tried to push it much further. An avalanche photodiode (APD) was used as a highly sensitive semiconductor electronic device that exploits the photoelectric effect to convert light to electricity. APDs can be thought of as photodetectors that provide a built-in first stage of gain through avalanche multiplication. From a functional standpoint, they can be regarded as the semiconductor analog of photomultipliers.
Digital Links
Next, optical fibre links changed the world again as SONET and ATM links evolved in the 1990s and 2000s, and early day analog links like I worked with fell by the wayside replaced by better, higher performing digital links. In the 2000s, even SONET and ATM limits were being exceeded and newer, faster, more scalable solutions were needed. Today, we see amazing metro and long haul carrier links powered by OTN (Optical Transport Networks), MPLS (Multiprotocol Label Switching), and CE (Carrier Ethernet).
As we near 2020, the return to shorter, lower cost links is happening too. Networks are divided by first mile (core tier), middle mile (distribution tier), and last mile (access tier) connections. All can be delivered with optical connections.
The business of interconnectivity with optical fibre is based upon cost and performance.
For the vital access tier, the connection to the home or business, the costs must be affordable and the data rates need to exceed the expectations of the users to justify the costs. If a carrier can deliver an end-to-end optical network, then the scalability will be a powerful driver to reduce costs and deliver performance.
Passive and Active Optical Networks
The advent of Passive Optical Networks (PON) is now well upon us. PON is the primary access tier technology used to create links for FTTH (Fiber To The Home).
Fiber optics uses light signals to transmit data. As this data moves across a fiber, there needs to be a way to separate it so that it gets to the proper destination.
There are two important types of systems that make fiber-to-the-home broadband connections possible. These are active optical networks and passive optical networks. Each offers ways to separate data and route it to the proper place, and each has advantages and disadvantages as compared to the other [source: FTTH Council].
Passive optical networks, or PONs, have some distinct advantages. They are efficient, in that each fiber optic strand can serve up to 32 users. PONs have a low building cost relative to active optical networks along with lower maintenance costs. Because there are few moving or electrical parts, there is simply less that can go wrong in a PON.
Passive optical networks also have some disadvantages. They have less range than an active optical network, meaning subscribers must be geographically closer to the central source of the data. PONs also make it difficult to isolate a failure when they occur. Also, because the bandwidth in a PON is not dedicated to individual subscribers, data transmission speed may slow down during peak usage times in an effect known as latency. Latency quickly degrades services such as audio and video, which need a smooth rate to maintain quality.
Active optical networks offer certain advantages, as well. Their reliance on Ethernet technology makes interoperability among vendors easy. Subscribers can select hardware that delivers an appropriate data transmission rate and scale up as their needs increase without having to restructure the network.
Active optical networks, however, also have their weaknesses. They require at least one switch aggregator for every 48 subscribers. Because it requires power, an active optical network inherently is less reliable than a passive optical network.
In some cases, FTTH systems may combine elements of both passive and active architectures to form a hybrid system.
How PON Works
It is universally known that fiber optics transmit data by light signals. As the data moves across a fiber, it needs separated ways to arrive at the targeted places. Generally, there are two essential types to realize it: active optical networks (AON) and passive optical networks (PON). They are both able to provide ways to separate data and route it to the proper places. Nowadays, server providers invest billions of dollars in their access networks to meet the ever-increasing demand for high-bandwidth broadband. In addition to technology longevity, server providers also like to see technology evolution to ensure future consumer demands can be met. Consequently, the development of the network PON type is on the rise.
A passive optical network (PON) refers to a telecommunication technology that implements a point-to-multi-point architecture. In that case, unpowered fiber optical splitters can make a single optical fiber serve multiple end-points such as customers. Then there is no need to connect individual fibers between the hub and the customer. The system can be described as fiber-to-the-curb (FTTC), fiber-to-the-building (FTTB), or fiber-to-the-home (FTTH).
A PON architecture consists of an optical line termination (OLT) and a number of optical network units (ONUs). A ONU is a serving cluster of homes configured from a single OLT splitter. Normally, the OLT is placed at the server provider’s central office and the ONUs is put near end users, in Canada they are housed in outdoor pedestals on the curbside. And up to 32 ONUs can be connected to an OLT. The passive optical network simply describes the fact that optical transmission has no power requirements or active electronic parts when the signal is going through the network.
A PON system makes it possible to share expensive components for FTTH. A passive splitter that takes one input and splits it to broadcast to many users, which help cut the cost of the links substantially by sharing, for example, one expensive laser with up to 32 homes. PON splitters are bi-directional, that is signals can be sent downstream from the central office, broadcast to all users, and signals from the users can be sent upstream and combined into one fiber to communicate with the central office.
The Benefits of the Network PON
As early as the year 2009, the network PONs began appearing in corporate networks. Originally, they were designed to connect millions of homes for telephone, Internet and TV services. Afterward, users adopt these networks for their cheap price, fast speed, low power consumption, easy management, etc. Here, the main benefits of PON are listed below:
- Lower network operational costs
- Elimination of network switches in the network
- Elimination of recurring costs associated with a fabric of Ethernet switches in the network
- Lower installation (CapEx) costs for a new or upgraded network (min 200 users)
- Lower network energy (OpEx) costs
- Less network infrastructure
- You can reclaim wiring closet (IDF) real estate
- Large bundles of copper cable are replaced with small single mode fiber optic cable
- PON provides increased distance between the data center and desktop (>20 kilometers)
- Network maintenance is easier and less expensive
- Fiber is more secure than copper. It is harder to tap. There is no available sniffer port on a passive optical splitter. Data is encrypted between the OLT and the ONT.
Conclusion
From what we have discussed above, you may at least have a brief understanding of the passive optical network. In fact, PON has appeared for many years in the telecommunication field and is today the main next generation wired connection for residential users in North America. Now PON is finally making its way into the enterprise, providing opportunities for customers to deploy new infrastructures or new constructions. With the development of technology, the network PON type shifting its focus from residential connections to the commercial market. Especially, it performs well in healthcare, sports venues, college campuses, hotels, and office buildings. The PON eliminates the need for switches and a wiring closet, which means a lower chance of failure.
References:
This articles is a mash up of several other articles assembled to tell a different story.
Crosby, T. (2018). How Fiber-to-the-Home works. Howstuffworks.com. Retrieved on December 25, 2018 from, https://computer.howstuffworks.com/fiber-to-the-home2.htm
SaskTel. (2018). SaskTel History. SaskTel. Retrieved on December 25, 2018 from, https://www.sasktel.com/about-us/company-info/vision-mission-and-values/history-site/history#y1980s
Wikipedia. (2018). 1980 Winter Olympics. Retrieved on December 25, 2018 from, https://en.wikipedia.org/wiki/1980_Winter_Olympics
Wikipedia. (2018). Avalanche Photodiode. Retrieved on December 25, 2018 from, https://en.wikipedia.org/wiki/Avalanche_photodiode
Wikipedia. (2018). Fiber-Optic Communication. Retrieved on December 25, 2018 from, https://en.wikipedia.org/wiki/Fiber-optic_communication
Wikipedia. (2018). Grass Valley, California. Retrieved on December 25, 2018 from, https://en.wikipedia.org/wiki/Grass_Valley,_California
Zhu, A, (2016). Introduction to Passive Optical Networks (PON). fiber-optic-solutions,com. Retrieved on December 25, 2018 from, http://www.fiber-optic-solutions.com/intro-optical-network-pon.html
About the Author:
Michael Martin has more than 35 years of experience in systems design for broadband networks, optical fibre, wireless and digital communications technologies.
He is a Senior Executive with IBM Canada’s Office of the CTO, Global Services. Over the past 14 years with IBM, he has worked in the GBS Global Center of Competency for Energy and Utilities and the GTS Global Center of Excellence for Energy and Utilities. He was previously a founding partner and President of MICAN Communications and before that was President of Comlink Systems Limited and Ensat Broadcast Services, Inc., both divisions of Cygnal Technologies Corporation (CYN: TSX).
Martin currently serves on the Board of Directors for TeraGo Inc (TGO: TSX) and previously served on the Board of Directors for Avante Logixx Inc. (XX: TSX.V).
He serves as a Member, SCC ISO-IEC JTC 1/SC-41 – Internet of Things and related technologies, ISO – International Organization for Standardization, and as a member of the NIST SP 500-325 Fog Computing Conceptual Model, National Institute of Standards and Technology.
He served on the Board of Governors of the University of Ontario Institute of Technology (UOIT) and on the Board of Advisers of five different Colleges in Ontario. For 16 years he served on the Board of the Society of Motion Picture and Television Engineers (SMPTE), Toronto Section.
He holds three master’s degrees, in business (MBA), communication (MA), and education (MEd). As well, he has diplomas and certifications in business, computer programming, internetworking, project management, media, photography, and communication technology.