Mode Conditioning Patch cord (MCP), also known as Gigabit Launch Patch cord, is used in longwave/ long haul (LX/LH) Gigabit Interface Converter (GBICs) with multimode fiber. Without using MCP, multiple signals are generated when a singlemode laser launch into the center of a multimode fiber. This would result in pulse broadening or Differential Model Delay (DMD) effects which degrade the modal bandwidth of fiber cable and limit the link span (the distance between the transmitter and receiver) for operating Gigabit Application. MCP provides an offset single mode to multimode fiber connector point that eliminates the effect of DMD by launching the single mode laser into multimode core at a specified offset.
Kewei fiber manufactures and supplies standard and custom length 50/125,62.5/125 and OEM equivalent mode conditioning fiber optic patch cords for 1000BASE-LX/LH Gigabit Ethernet (1300nm long wavelength) applications installed into existing multimode cable plants. These specialized cords help avoid Differential Mode Delay(DMD)effects that can occur when long wave transceiver modules operate at both single-mode and multimode wavelengths. And they are available with FC, ST, SC, LC and MT-RJ connectors.
How the Mode Conditioning Cable Works
The need for this conditioning fiber optic patch cord is due to the single-mode launch nature of the-LX or long-wave(1300nm) transceiver modules used for Gigabit Ethernet. Launching a single-mode laser into the center of a multimode fiber can cause multiple signals to be generated that confuse the receiver at the other end of the fiber. In that case, a mode conditioning patch cord eliminates these multiple signals by allowing the single-mode launch to be offset away from the center of a multimode fiber. This offset point creates a launch that is similar to typical multimode LED launches. (see diagram below)
In some cases, customers might experience that a link would be operating properly over FDDI-grade,OM1 or OM2 fiber types without MCP.However please note there is no guarantee link will be operating properly over time, and the recommendation remains to use the MCP.There is a risk associated to this type of nonstandard deployment without MCP,especially when the jumper cable is an FDDI-grade or OM1 type.In such case the power coupled directly into a 62.5-micron fiber could be as high as a few dBm and the adjacent receiver will be saturated.This can cause high bit error rate,link flaps,link down status and eventually irreversible damaged to the device.Mode conditioning patch cords can only convert single-mode to multimode.If you want to convert multimode to single-mode,then a media converter will be required.Another alternative for short reaches within the same location is to use a single-mode patch cable.There will be no saturation over single-mode fiber.
How to Install the Mode Conditioning Cable
If your gigabit LX switch is equipped with SC or LC connectors,please be sure to connect the yellow leg(Singlemode)of the cable to the transmit side,and the orange leg(multimode)to the receive side of the equipment.It is imperative that this configuration be maintained on both ends.The swap of transmit and receive can only be done at the cable plant side.(see diagram below)
Things to Know When Using Mode Conditioning Cables
Mode conditioning patch cords are usually used in pairs.Which means that you will need a mode conditioning patch cord at each end to connect the equipment to the cable plant.Generally,Mode Conditioning patch cords are required for link distances greater than 984 feet(300 meters).
Features and Application of OMC’s MCP (Mode Conditioning Patch Cable)
Increased transmission bandwidth up to 4 times
PC,UPC,APC polish types
Fits existing cabling scheme
Low insertion loss
Reduced modal noise
Removes effects form DMD
OFNR rated jacket complies with strict building codes
Permanent, low-profile offset closure
Compliant with IEEE 802.3 applications
With above excellent characteristics, mode conditioning patch cables can be used to deploy new high-speed 1000BASE-LX routers, switches, or transceivers within existing multimode system backbones. These cables can be applied in Local Area Networks and Metropolitan Area Systems.
Specifications of Mode Conditioning Patch Cable
Light Source Transmission Direction
|Testing Wavelength||Insertion Loss|
|D→B||850nm, 1,300nm||Max .≤ 0.30dB|
|B→D||850nm, 1,300nm||Max .≤ 0.30dB|
|C→A||850nm, 1,300nm||≤ 15.0dB(50/125um);|
≤ 18.0dB(62.5/125um)A→C850nm, 1,300nmMax .≤ 0.30dB
SM APC≥60.0dB; SM UPC≥50.0dB
1,000 mating, typical≤0.20dB
-20℃ to ＋70℃
-40℃ to ＋85℃
Notes: A B C and Corresponding to A B C and D on Fig.2.
Connector for Equipment Side
Connector for Plant Side
Mode Conditioning Patch cord(MCP)
62.5/125 ( OM2)
For example: MCP-FC-SC-OM1-2.0- 1.0