Tag - power over fiber

Fiber Optic | Maximizing Speed and Distance in PoE Networking

In a previous article, Versa discussed hybrid fiber-and-copper blended cabling and the power-over-fiber cabling options that are in development. These solutions have their place in network deployments, but like anything that is specialized can be costly to purchase. In this article, we will look at reasons for deploying fiber in segments of an installation, and why this less expensive approach makes sense. For other parts of an installation, copper is king. It’s a green alternative. It’s also pre-existing and thereby much less costly, which causes less friction for approval within organizations trying to stretch a dollar. Pre-existing coaxial, too, has found a place in the geography of Power over Ethernet (PoE). There remains a position within the illustrious cabling stratosphere, though, that only fiber optic can fill. Because of its speed and resistance to harsh environments, it is especially well suited to ultra-long distances and high-noise industrial deployments. To begin this discussion, it’s useful to recap some of the main points in Power over Ethernet (PoE) copper cabling and understand its limitations.

Power over Ethernet Using Copper

Electrical signals over copper [PoE] need a refresh at a distance of 100 meters. That means without the use of extenders and other long reach technologies that’s the limit of power and data on a single cable.
IEEE 802.3bt (PoE ++, or Type 3) provides up to 80 watts of power by using all four twisted copper pairs to transmit data and power at a maximum supported distance of 100 meters. Copper is able to transmit power over longer distances; transmitting data over copper, without the use of boosting devices, is limited to ranges of 100 meters.
  Happily, there are plenty of networking devices allow IT administrators and installers the luxury of sending signals for much longer distances and combining multi-cable networks with ease.
  • Extenders - can be used to extend an Ethernet network up to distances of 6,000 meters. The VX-VEB160G4 (V2) can achieve 300Mbps [downstream up to 190Mbps and upstream up to 110Mbps.]. Extenders also work for wireless and coax networks.
  • Injectors may be used to inject power at midspan for legacy equipment deployments where power needs to be combined with data.
  • Fiber media converters are used to combine segments of a network where fiber and twisted pair cabling appear in the same network stream.
Extenders, Injectors, Media Converters Each of these technologies can add considerable distance to the reach of a LAN. But they aren’t able to span ultra-long distance like fiber can.

Some of the Benefits of Fiber

The optical fiber transmits up to 100 Terabits per second and can easily surpass 100-meter distances. Singlemode fiber can reach distances over 120 km but it’s more expensive than multimode. The primary reason for this is the tightness of the single mode connection required. Connectors have to be ceramic. That makes labor more expensive as installers must finely polish and splice connections. Multimode is less expensive to install but single mode has a higher capacity. In either case, fiber outdistances copper and coax dramatically. And they offer speeds that are much faster because they travel over light pulses.

A Side-by-Side Comparison of Features

There are good reasons why single mode and multimode cabling types are so popular. The glass in fiber optic cable is less susceptible to harsh temperatures than copper which can expand or contract significantly. And though glass tends to be brittle, it can also handle loud noise and electrostatic emissions found in industrial environments. Let’s take a closer look at how they work.
Single Mode FiberSingle mode fiber uses the 9/125 ratio in its construction. The core to cladding diameter is 9 microns to 125 microns.

Single mode Fiber

The reason single mode is called “single” is that it carries a single ray of light. At the center of this fiber optic cable is a small diametral core. The core will only allow one mode of light to propagate. As the light transmit down the core, the number of reflections decreases. This also lowers the rate in which a signal attenuates or weakens. The narrowing action propels the signal further. This is what makes single mode ideal for long distance deployments.
Multimode FiberMultimode fiber uses the 62.5/125 ratio in its construction. The core to cladding diameter is approximately 62.5 microns to 125 microns.

Multimode Fiber

The reason multimode is called “multi” is because it carries multiple rays of light. At its center, as you probably guessed by process of elimination, is a large diametric core. This allows light to propagate in both directions. The number of light reflections that this additional space allows increases as the signal passes through the core. More data is able to transmit at a time. For the same reason, though, the wider core can also lead to a high rate of dispersion reducing signal quality over long distances. Radio frequencies don’t transmit over multimode fiber.

Power Over Fiber and Copper / Fiber Hybrids

Manufacturers have been busy. Besides copper, coax and fiber there are other options availablehybrid and composite cables. They are nothing new but in a discussion about network cabling, they definitely need to be mentioned.

Hybrid cables

The hybrid factor is based upon the type of fiber being usedusually multimode and single mode. Installers deploy them in contained areas like a campus or premises backbone where single mode may be used in future deployments.

Hybrid cable vs Composite cable

Composite cables

The composite factor refers to cables that contain both fiber and electrical conductors. This variety is referred to as a powered fiber cable system (PFCS). These cables are grounded for safety. Note: These cables may be used for underwater tethered vehicles, remote wireless antennas, and CCTV cameras.

Summary | Why Use Different Cables

Connecting together an enterprise network, whether business, governmental, or academic, can be like piecing together a puzzle. The wisdom as to why an installer chooses a particular cable not only rests on its function but also how much it costs to deploy. Keeping costs down has allowed organizations the ability to afford frequent upgrades. One of the most exciting solutions of the present day has definitely been PoE and its satellite components. Along with much repurposing of Cat 5e, Cat 6, and Cat 6a, though, there seems to be a resurge in coax and a steady proportionate deployment of fiber. If you’re piecing together a network of diverse cabling and would like some help in understanding the best option for your deployment, please feel free to reach out.
Powered Fiber Cable Systems

Exploring Powered Fiber Cable Systems (PFCS)— Is it time for PoE to Divorce Power and Data?

Power over Ethernet (PoE) is known for its simultaneous transmission of power and data using twisted pair copper, but will the search for faster speed rates influence the separation of data and power? New Powered Fiber Cable System (PFCS) solutions introduce a new breed of PoE extension. The solution utilizes a powered fiber cable that insulates fiber and copper separately and assigns copper with one sole purpose—to transmit power.

Understanding PoE's 100 Meter Limitation

Each new 802.3 PoE standard tends to introduce higher power outputs. IEEE’s initial 802.3af PoE standard introduced compliance for 15 watts of power (12.95 with power dissipation). The standard was followed by 802.3at, also known as PoE+, and introduced compliance for 30 watts of power (25.4 watts of power). IEEE is currently studying 802.3bt, also known as PoE ++, a new standard that aims to provide up to 80 watts of power by using all four twisted copper pairs to transmit data and power. But though new standards seem to be improving upon output power, each new standard fails to improve the maximum supported distance of 100 meters—the standard Ethernet limitation. Receive a Complementary Consultation   Copper has the ability to transmit power to longer distances; however, the range of PoE is limited by copper’s inability to transmit data to ranges that exceed 100 meters. Optical fiber can transmit up to 100 Terabits per seconds.  Copper cables are able to transmit gigabit speeds and up to 10 Gbps with newer networking cables such as Cat6 and Cat7.  For the time being, 10 Gbps transfer speeds are sufficient for even the most data-hungry Internet users. Nonetheless, optical fiber easily surpasses 100 meter distances. Fiber cable systems with new powered fiber cables can achieve up to 3,000 meters.

Approximating Power over Fiber

Commscope has designed a new powered fiber cable that insulates the optical fiber cable and copper wire within their own separate jackets. The new design deviates from traditional hybrid optical fiber cables that insulate both types of mediums within the same jacket. Network installers can easily peel the cables apart for quick access. The new cabling requires no other special tools besides a wire stripper. These new types of powered fiber cables are quite flexible in comparison to traditional hybrid fiber cables. powered fiber cable system Though the solution can’t exactly be described as Power over Fiber, the optical fiber and copper cabling run alongside each other and leverages the same benefit that PoE provides—the ability to deploy powered devices at any location without having to rely on local power supplies. The ability to install devices without relying on local power supplies, along with its simple ‘plug-and-play’ installation, makes PoE an essential component of networking topologies. But PoE faces a standard 100 meter limitation which forces network administrators to rely on additional equipment such as PoE extenders and media converters to extend network connections beyond Ethernet’s standard 100 meter limitation. This new breed of PoE extenders will eliminate the need for additional extender kits and simplify network connections.

Leveraging the Power of Copper and Fiber—Separately

Electrical Engineer Bill Schweber observes that the effectiveness of powered fiber systems stems from separating optical fiber and copper. He remarks that the simultaneous transmission of power and data in standard networking cables “require significant "negotiation" and confirmation between the source and load, between intervening ICs and, in order to assure that power is available and acceptable by a peripheral, that there are no conflicts in hardware or software.” Powered fiber cable systems eliminate power negotiations and reserves optical fiber for data transmission and copper wiring for power transmission. The electrical engineer comments that “PFCS [Powered Fiber Cable Systems] seems to me to be a clever scheme, since it leverages the advantages of each medium (optical+copper, PoE) without either one getting in the way of the other one, and the associated complexity.” Schweber concludes “that by using the long run of copper just for power and not for data, the technical difficulties will be reduced while the performance will be more consistent and easier to manage”. Separating data and power allows copper to deliver power output ranges that exceed the current 802.3at standard of 30 watts. And optical fiber speeds will be able to deliver transmission speeds that surpass 10Gbps to future powered devices.

Additional Benefits of Powered Fiber Cable Systems

powered-fiber-cable-systems-use-cases-compressor According to Aruba Networks, Powered Fiber Cable Systems “Greatly speed up planning by eliminating DC electrical calculations for voltage/power drop over varying distances”. These devices can support up to 32 devices from a centrally located USPs. Powered Fiber Cable Systems essentially operate similar to long extension cords. It’s highly unlikely that IEEE will divorce Power from Data when it comes to PoE. PoE is ideal for home and enterprise networks, even with a 100 meter Ethernet limitation. And in the cases where powered devices need to be installed beyond 100 meters, there are a myriad of PoE extender options such as fiber media extenders, UTP Ethernet Extenders, and coaxial cable extenders for example, that effectively bypass the limited distance and preserve speed. Click here to view our interactive infographic explaining the top methods used to extend Ethernet. Related Posts:
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