The cost savings, positive employee impact and public persona benefits of healthy, green and smart buildings can be significant, and many organizations are aggressively implementing policies to make their buildings healthier, energy efficient and sustainable. For businesses, schools, hotels, hospitals, government agencies and other organizations to maintain healthy, green and smart buildings, IT management must play its part. The IT staff is responsible for evaluating the performance of network systems to determine if a better, more socially conscious alternative exists.
Most organizations run either a copper-based point-to-point LAN or a fiber-based point-to-multipoint Passive Optical LAN. But which one is the better choice for high-performing buildings? This document will compare the two LAN technologies and explain why fiber Optical LAN, based on Passive Optical Network (PON) technology, is the lower-cost, energy-efficient, healthy, smart and modern choice. Optical LANs deliver the cost-effective, low-energy, small form-factor infrastructure that directly impacts healthy adaptations and cradle-to-grave lifecycle analysis of smart building design.
Passive Optical LAN delivers tangible benefits to healthy, green and smart building design, such as:
- Lower Space Requirements and Smaller Footprint
- Less Equipment, and Less Natural Material
- Reduced Energy Consumption and Heat Dissipation
- Improved Longevity and Product Lifecycle
- Contribute to Healthy, Green, and Smart Building Certifications
Lower Space Requirements and Smaller Footprint
Fiber-based Optical LAN leverages the inherent benefits of PON with a centrally located Optical Line Terminal (OLT) at the core, and passive optical splitters for distribution, Optical Network Terminals (ONT) positioned as close to the connected endpoints as possible, and single pane of glass software defined management. Optical LAN uses a Singlemode Fiber (SMF) for in-building and across-campus cabling that converges all user connections, smart building and Internet of Things (IoT) services, such as voice, video, data, wireless access, security, surveillance and building automation, over a single infrastructure.
All of these benefits of Optical LAN and SMF affect the design of high-performance buildings, such as:
- Smaller Main Data Center – In the main data center room, Optical LAN offers 4x better Ethernet density from a smaller footprint. By occupying less rack area you save physical space, and with OLAN great aggregation capabilities, you also save ports at the core router which saves money too.
- Reduced Telecom Room Impact – OLAN design gives you the opportunity to reduce or eliminate the telecom rooms. When you eliminate the telecommunications rooms you gain a rippling effect of reducing air conditioning, fire suppression systems, security surveillance and other building materials needed.
- Shrink the Pathway Footprint – Within the cabling pathways, the single mode fiber (SMF) can carry as many as 128 gigabit Ethernet connections across a single cable with OLAN. Furthermore, with OLAN deep fiber design, every 4-port ONT provides a 4 to 1 reduction in cabling between the telecom closet and the connected devices. Because of the reduced amount of cabling J-Hooks can be used in the horizontal pathways instead of more substantial cable trays .
Figure 1: Comparison of CAT6A serving eight gigabit Ethernet connections, versus an Optical LAN’s singlemode fiber serving eight gigabit Ethernet connections via two 4-port ONTs
In general, the gains in building floor space from Optical LAN enable real estate square footage to be repurposed for revenue generation, building amenities and building aesthetics. Such efficiency makes Optical LAN an excellent choice for buildings that have restricted space. For example, Optical LAN is ideal for buildings with challenging cable access points, especially retrofit projects and historic preservation projects.
Less Equipment, and Less Natural Material
Again, Optical LAN provides superior density, with over 4,000 Ethernet endpoints connected and powered (i.e. PoE) from one 5-inch high OLT occupying three rack units. In comparison, a copper-based Ethernet switch that serves 2,016 Ethernet endpoints occupies 90 rack units or 157½ inches. Plus, optical splitters eliminate the need for active electronics used in the distribution/aggregation sector of this LAN, thus eliminating telecom closets/IDFs. Eliminating active electronics reduces additional equipment, space, power, thermals and construction material in the main data center/MDF and throughout the building (i.e. no closets/IDFs). Relative to cabling impact, SMF is smaller, lighter and stronger; it has a tighter bend radius; offers higher bandwidth, longer reach, better EMI/RFI, faster connectors, longer life and is less expensive than copper cabling. Concerning Optical LAN, a single SMF strand can carry services to 128 IP/Ethernet endpoints, while CATx copper cable carries to only one.
Designing an enterprise network using Optical LAN and SMF offers the following green results:
- Less Cabling – Since Optical LAN prioritizes the use of fiber cabling and minimizes the use of copper cabling, far less copper is introduced into the buildings – in fact, miles less! This is a very good thing, since copper is a precious metal with a horrible environment track record for their destructive mining activities. Silicon (i.e. glass) is the 2nd most abundant material in the earth’s crust. Plus, copper cables consume 100x to 200x more natural resources than glass-based cables to manufacture. Less cabling also translates into smaller/fewer floor and wall penetrations, which helps lower fire hazards and reduces the addition of firestopping material around those holes.
- Less Plastic – Reducing the amount of plastics and PVCs burdening a building is another excellent green benefit. SMF cabling has 60% less plastic jacketing based on its smaller circumference. As previously referenced, every 4-port ONT provides a 4 to 1 reduction in cabling. These factors also reduce the smoke load of a building which is a very important safety aspect.
- Less Infrastructure – Finally, all this reduction of infrastructure (i.e. less cable, fewer racks, reduced cable trays) has a far-reaching rippling effect that can significantly lower the weight impact on the buildings shell . Architects and engineers will value the substantial new space available to them, and they can start thinking about how to reuse all this recaptured space for revenue generating business purposes, or the building occupant’s health needs, or even visually appealing building aesthetics.
Figure 2: Multiple racks of point-to-point switches (left) serving 2,000 gigabit Ethernet connections, versus one rack of point-to-multipoint Optical LAN (right) serving 4,000 gigabit Ethernet connections
Dematerializing building infrastructure improves sustainability goals, since less material being used in a building can lead to the best possible cradle-to-grave lifecycle analysis.
Reduced Energy Consumption and Heat Dissipation
Customer-generated business cases have shown that Optical LAN can reduce energy consumption by up to 20-50% using OLT and ONTs instead of a traditional copper-based active Ethernet LAN . With a fully meshed hierarchy of active Ethernet switches, energy is consumed every time an optical-to-electrical conversion or electrical-to-optical conversion occurs. With fewer O-to-E and E-to-O conversions, a network based on PON architecture will consume less energy.
Figure 3: Energy use analysis of traditional LAN (188 48-port switches serving 9,000 endpoints) versus Optical LAN (2,250 4-port ONTs serving 9,000 connections) that shows 60% in savings for OLAN. You can read our blog “Optical LAN Energy Usage Comparison Unveils Rippling Effect for Building Power and Cooling Savings” that explains this Optical LAN energy usage comparison in more details.
When the energy savings of Optical LAN is reviewed, it is easy to see the compounded effect of the savings relative to the electrical (plug load) and thermal (HVAC) load design of the total building. For example, one (1) watt of electricity consumption saved in a data center results in 2x savings throughout the entire building. This is a direct result of needing less DC/DC, AC/DC power distribution, and transformer, generator and battery backup. From a thermal standpoint, the Optical LAN’s lower energy consumption requires less HVAC capacity. Forward-looking building design could even use extended temperature range OLTs in data centers/telecom closets and use only fresh air ventilation, eliminating any need for forced air conditioning. Better yet, an OLT located beyond the building footprint, and coupled with solar powering can provide a true net-zero network.
Summarizing the potential energy and thermal savings for Optical LAN, the gains can be contributed to:
- Network Power Lowered – The energy use analysis presented above compares a traditional LAN built with 188 48-port switches that serves 9,000 endpoints to an Optical LAN with 2,250 4-port ONTs serving 9,000 connections . This comparison shows 60% in savings for PON. This is consistent with real-world Optical LAN deployments, like Department of Energy Sandia National Laboratory, which has experienced savings of as much as 65% in power consumption as a result of OLAN (e.g. 1 million kwh saved per year at Sandia).
- Reduced Air Conditioning – Another reduction in energy can be gained by lower air conditioning. This is possible because of reduced or eliminated telecom rooms, and because the ONTs and OLTs can operate at extended temperature ranges. The energy comparison provided in Figure 3 calculates a 60% dollar savings in cooling impact alone for PON and 60% savings in kilowatts per hour .
- More Efficient Power over Ethernet (PoE) – Finally, we have been seeing that Power over Ethernet (PoE) can be delivered more efficiently over an Optical LAN architecture – as much as 13% power savings with PoE over OLAN! This is simple physics, as the closer you can position the powered devices (i.e. VoIP phone, IP camera, Wi-Fi access point) to the PoE source (i.e. ONT), the shorter the distance the PoE needs to travel, and the lower the power loss through inefficiencies will be.
With all the great energy savings that Optical LAN offers, it is easy to extrapolate the corresponding reductions in carbon emissions of 332 metric tons of carbon dioxide (CO2) emissions avoided per year . Based on the kwh savings shown in Figure 3 for Optical LAN and 332 metric tons CO2 for OLAN real life equivalence . You can click here to learn about Tellabs’ Optical LAN carbon reduction calculator for enterprise networks
(https://hub.tellabs.com/optical-lan-carbon-reduction-calculator-contact-request).
Figure 4: In the energy use analysis above, Optical LAN removes 332 metric tons of CO2 per year per EPA Greenhouse Gas Equivalencies Calculator
Improved Longevity and Product Lifecycle
Healthy, green and smart buildings with Optical LAN connectivity are well positioned to hold their value since technology upgrades are independent of fiber infrastructure. Optical LAN and SMF represent the best choice for future-proof LANs. For example, the migration from 2.4 gigabit Passive Network (G-PON) to symmetrical 10 gigabit XGS-PON is accomplished by adding new 10G PON wavelengths across existing infrastructure – with no rip-and-replace disruption of business. This allows Optical LAN owners to utilize the same SMF cable, fiber management, raisers, pathways and optical splitters. Looking further into the future, the PON and SMF supports even more wavelengths – currently eight additional symmetrical 10G wavelength are defined in PON industry standards .
Furthermore, Optical LAN and SMF is ideal for efficiently and economically supporting the migration to multi-gigabit Ethernet (i.e. 1G, 2.5G, 5G and 10G Ethernet), especially in response to the evolution to Wi-Fi 6. Today’s 10G XGS-PON ONTs already support multi-gigabit Ethernet connectivity and these deep fiber ONTs are already positioned as close to the wireless access points as possible – thus, minimizing the impact of the transition to multi-gigabit Ethernet.
So, when analyzing improved longevity, and cradle-to-grave product lifecycle, Optical LAN clearly provides:
- Fewer Cable Refreshes – This is the holy grail for green, sustainability and environment initiatives! Simply stated, there are fewer cable refreshes when investing in a fiber-based enterprise LAN infrastructure. Fiber often has a warrantee that lasts 25-30 years, while copper cabling is historically ripped out of buildings every 7-10 years – this has a huge negative impact on landfills.
- Fewer Equipment Refreshes – Next, there is fewer equipment refreshes with Optical LAN. As already stated, we have already witnessed G-PON be upgraded by 10 gigabit XGS-PON while keeping the same fiber cabling and passive optical splitters – the same will hold true for 40G or 100G NG-PON too! Furthermore, OLAN design does an excellent job at decoupling technology upgrades, like IEEE 802.11ax Wi-Fi 6. If you already have an OLAN installed in your building or campus, the upgrade to Wi-Fi 6 only means adding 10G XGS-PON XFPs pluggable optics at the OLT, and 10G XGS-PON ONTs, and then equipping those ONTs with multi-gigabit Ethernet SFP+ pluggable optics to connect the Wi-Fi 6 wireless access point.
- Decouple Technology Updates – Last, OLAN’s support of multiwavelength is a game changer! This because it allows you to stack multiple 10 gigabit XGS-PON wavelengths over the same fiber infrastructure you originally invested in – that means you can grow this network to 40 gigabit capacity or greater!
Figure 5: Eight additional symmetrical 10G wavelength are defined in by PON industry standards bodies
With this near futureproof LAN infrastructure, the number of technology refreshes is drastically reduced, resulting in significantly less waste (e.g., money, time, natural resources), and less impacts on landfills, over the long run. Thus, truly PON technology has the industry best cradle-to-grave lifecycle results.
Contribute to Healthy, Green, and Smart Building Certifications
Standards that govern the creation of high-performance buildings have been developed and managed by many organizations (i.e. USGBC LEED, TIA SPIRE, GreenGlobe, WELL Building Standard, Living Building Challenge) These healthy, green and smart initiatives set industry standards and certifications. They aim to cover new construction (including new development, major renovations, the core and shell of the building) and existing buildings (e.g., quantify and compare building operations, improvements and maintenance). Their goal is often to maximize building operational efficiencies while minimizing environmental impact. They typically work on a rating system that awards points based on sustainability, water efficiency, energy and atmosphere, material and resources, indoor environmental quality, innovation in operations and regional priority. The desired outcome is that these certified buildings are designed to lower operating costs, increase asset value, reduce waste sent to landfills, conserve energy and water, be healthier and safer for occupants and reduce harmful greenhouse gas emissions. Finally, it is possible for these certified buildings to qualify for tax rebates, zoning allowances and other incentives.
Optical LAN can assist with healthy, green and smart building certification by:
- Increasing asset value
- Lowering operating costs
- Reducing waste sent to landfills
- Directly contributing to energy savings
- Indirectly lowering thermal loads for HVAC
- Reducing harmful greenhouse gas emissions
Engineering and designing a building with Optical LAN can even result in additional innovation bonus points within some of these certification programs.
The ultimate goals of Optical LAN are to directly contribute to a high-performance building certification, increase the building’s value and improve the quality of the user experience. Studies have shown that buildings with fiber connections sell with a 5% to 10% premium, and Optical LAN seeks to achieve that same value gain inside buildings. An Optical LAN design can differentiate a building to attract and retain tenants/employees. Once building certification is achieved, building owners, IT managers and tenants can reap the rewards of the measurable high-performance building (e.g., federal, state and local tax incentives and rebate/reimbursement/grant programs). There might even be rebates to be gained through local utility companies. On average, certified new construction buildings achieve 30% better energy performance compared to similar noncertified buildings .
Figure 6: Studies have shown that buildings with fiber connections sell with a 5% to 10% premium
Optical LAN helps IT staff make tangible contributions to healthy, green and smart corporate goals
Passive Optical LAN is the smart enterprise network option for high-performance buildings and campuses. Fiber-based LANs are more energy-efficient, healthier, and environmentally friendly. Organizations implementing healthy, green and smart building certification can achieve greater results and success by switching to an Optical LAN design. IT professionals now have the means to make tangible contributions to the greater company goals by leveraging an Optical LAN design.
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