NTS uses (or will use) at least five fiber standards. Sadly, fiber standards are not uniquely identified by connector types.
|10 FL||10 Mb/s||850 nm||mm||-12||-20||-32.5||12.5||2000 M|
|100 FX||100 Mb/s||1300 nm||mm||-14||-20||-31||11||2000 M|
|1000 SX||1 Gb/s||815 nm||mm||-3.2||-9.5||-17||7.5||220 M||$1,000|
|1000 LX||1 Gb/s||1310 nm||mm||-9||-11.5||-19||7.5||550 M **||$2,000|
|1000 LX||1 Gb/s||1310 nm||sm||-9||-11||-19||8.0||5 KM||$2,000|
|1000 ZX||1 Gb/s||1550 nm||sm||5.2||0.0||-24||8 to 24||70 KM||$12,000|
|mm = multimode ; these numbers are for FDDI grade 62.5 micron fiber core|
|sm = singlemode ; 9 micron fiber core|
|optics costs are Cisco full list price for a pair of GBICs|
|ZX has a minimum loss requirement to avoid saturating the receiver. Other types will not saturate even with short low loss jumper cables.|
10 and 100 Mb/s use diode emitters; 1 Gb/s uses class I laser emitters
** A special mode conditioning cable is required to achieve more than
200 meters with multimode fiber.
Emerging standards for 10 G/s LAN fiber interconnect.
|10GbaseLR||10 Gb/s||1310 nm||sm||10 KM|
|10GbaseER||10 Gb/s||1550 nm||sm||40 KM|
|10GbaseSR||10 Gb/s||850 nm||mm **||65 M|
|10GbaseLX4||10 Gb/s||1310 nm WDM||mm **||300 M|
** The multimode fiber contemplated here is "laser enhanced" 50 micron core diameter. 65 meters may be a soft limit depending on the detailed bandwidth specification of the fiber. LX4 encodes the data over four separate wavelengths.
dBm is a measure of power, like watts. 0 dBm = 0.001 Watt 10 dBm = 0.010 Watt -10 dBm = 0.0001 Watt Loss budget = Min_Transmit_Power - Rcvr_Sensitivity If you attach a power meter with a 62.5 micron jumper to one of the mm sources above, you expect to see a power level between Min and Max. Rcvr sensitivity means with at least this much power delivered to the receiver the design error rate can be achieved. 1:1,000,000,000 At 10 and 100 Mb/s, the distance limit for full duplex systems is due to loss of light. At 1 Gb/s over multimode fiber, the limit is due to fiber bandwidth. If too much power is delivered to the receiver it is possible to overload it. With long range ZX optics, if the fiber link provides less than 8 dB of loss, additional attenuation should be added. It is technically permissible to use LX for short range fiber applications because the fiber path is not required to have attenuation to prevent overload. Rules of thumb At Gig speeds, most of our light losses come from the connectors and only a very small amount from the fiber. The faster we go, the lower the loss budget we get to work with. The more important it is to treat connectors with great respect and minimize patch cables. Using ZX to make up for connector losses is a very expensive proposition. Over its useful life, an ordinary light bulb loses about half its brightness before it burns out. The same is true for fiber optic light sources. The loss budget numbers allow for expected lower output over the useful life of the fiber transceiver. The aging process "settles down" after a few thousand hours. Fiber light sources don't have a "burn out" mechanism that is similar to light bulb filaments. Version of Dec 15, 2002