Is a GPON coming to a hotel near you? In NTI’s Autumn 2011 Newsletter, our lead article posed thia question. At that time, the answer was, ‘not yet’, at least for the U.S. At that time, Passive Optical Networks (PON) had been implemented in Asian, and some European markets but here in the United States was a different story.
In recent months, the dynamics surrounding a PON solution have changed and, as a result, the implementation of a PON has become a more viable option for Owners and Developers.
A PON is a fiber based alternative to a traditional copper cable plant which can provide far more bandwidth capacity than a Category 6 copper cable, and, in theory, can reduce operational costs and reduce or even eliminate telecom/IDF room space requirements. GPONs (the G stands for Gigabit) are the type of PON most often considered as the option to replace Category 6 cable.
Historically, the major issue that prevented PONS from gaining traction in the U.S. has been the initial cost comparison of the GPON relative to the Category 6 solution. Secondarily, Category 6 copper cable provided sufficient bandwidth for future projected needs of a property. And a final consideration was potential integration challenges for the vendors that must rely on the GPON to transport their data.
PON Acceptance Growing Globally
NTI has been tracking the GPON marketplace for a long while, even before writing the lead article for our 2011 newsletter. During the past several years, GPON implementation pricing has continued to become more competitive with the traditional copper infrastructure. Additionally, bandwidth requirement projections provide insight that suggests that bandwidth demand may surpass copper cable capacity within the next decade or so.
Bandwidth Projections and Demand
Nielsen’s Law of Bandwidth growth projections, first published in 1998. Using date from 1983, the law projected a 50% per year increase in high end user’s demand.
If bandwidth demand continues at the same pace as it has for the past 30 years, then it is possible that Category 6 bandwidth capacity could be reached sometime within the next 10 years!
An important point regarding the Nielsen projections is that it predicts ‘high end user’s bandwidth’, so typical demand may be less than these projections, which would extend Cat 6’s useful life beyond 2023.
Even with a traditional Category 6 copper cabling infrastructure, the “choke point” for bandwidth delivery is often at the service provider Demarcation point. The implementation of a GPON will not alter that scenario, however, as many high-speed bandwidth service providers currently offer burstable bandwidth via their fiber networks at continually decreasing costs, the GPON architecture within the building prevents the “choke point” from shifting back to the cabling infrastructure within the building.
A combination of bandwidth demand doubling every 18 months (approximate) along with a general increase in GPON acceptance worldwide has brought GPON consideration to the United States. However, as the concept is still somewhat new for the U.S. market, and many data systems vendors are not yet comfortable with the approach, there can remain a perceived risk associated with choosing a GPON approach over a more traditional Category 6 cabling infrastructure.
The Hotel Market
To evaluate how they work and the cost/benefit of implementing a GPON versus traditional copper, let’s look at the hotel market, as we are currently evaluating GPON implementation in numerous new hotel projects.
Evaluating the merits of implementing a GPON begins with the cost differential relative to the traditional copper infrastructure. The data regarding ongoing operational savings remains sparse and inconclusive. However the GPON initial costs have fallen over the past few years. Even so, GPON installed costs currently remain higher (typically 20% or so) than for a traditional copper infrastructure implementation. But with more hoteliers actively considering GPONs, an evaluation of costs and benefits is becoming more common.
In addition to initial construction costs, to properly evaluate the GPON implementation, there are other factors to consider, beginning with the design.
The GPON Design
The primary reason for considering GPONs is their ability to deliver more bandwidth than copper. However, owners are not likely to incur the expense of delivering surplus bandwidth, which may not be needed for 5 or 10 years. The inherent scalability of a good GPON design provides the means to increase the system capacity, as needed, to address growing bandwidth demand.
A GPON design is different than copper based design. GPONs are based on deploying splitters, which effectively split the light waves and associated fixed bandwidth within a single fiber strand to serve multiple end points. As multiple end point users share the bandwidth from their single source fiber, the “split ratio” becomes an important system design factor. The higher the split ratio, the lower the end point bandwidth availability, and overall cost. When designed properly, a GPON can be scalable over time, by reducing the split ratio (via changing out the splitters) to increase bandwidth availability at the end point, such as in a hotel guestroom.
Another design consideration is the need for telecom/IDF rooms. The MDF room (Main Distribution Frame) is the main technology room for the building, the telecom/IDF (Intermediate Distribution Frame) room is located near the guestrooms. This room houses emergency power and technology cabling cross connects and network equipment-including network switches that connect the guest room Category 6 copper cabling to the fiber optics backbone cabling.
For a pure GPON, network switches are not required in the telecom/IDF rooms. The Fiber backbone cable is connected through the passive splitters directly to the guest room where the fiber is terminated onto a device known as an Optical Network Terminator (ONT). Via the multiple types of ports available on an ONT, the TV, phone and internet devices can plug directly into the ONT. The ONT does require power but as splitters are passive devices and can be located in any accessible area, if a GPON is implemented, the telecom/IDF room is theoretically unnecessary.
However, in hotels, in particular, it is critical to keep the phone live for a specified amount of time during a power outage. If the ONT is not connected to an emergency power outlet (which is costly), batteries within the ONT or some other means of powering the ONT is necessary to assure the phone remains powered during an outage. One means of powering the ONT is via copper from the telecom/IDF room. Thus the decision to eliminate the telecom/IDF rooms needs to be fully vetted with consideration given to the phone power requirements.
A final consideration of GPON planning is the reality that it is brand new to many systems vendors. The GPON serves as the convergence medium for the network. While “triple play” (phone, internet and TV services from a common carrier) systems are common for residential market, in the hotel world, full convergence of the disparate data, TV, AV, phone, PMS, POS, etc. systems is difficult to achieve. A decision to implement a GPON for a hotel project requires “buy in” from all of the vendors that may ultimately rely on the GPON system to transport their data.
The global acceptance of the GPON is a rather good indication that GPONs are here to stay. The timing of when GPONs begin to displace copper infrastructures remains a question, but as the cost of implementation continues to decrease and the individual’s thirst for bandwidth continues to increase, the GPON shall continue to improve as a viable alternative to copper.
by Jeff Cook RCDD