The first step in many audio and video optical fiber projects is to replace the transceiver with a cable. Only after the connection is completed, it is discovered that there is not enough margin left. Cross-building transmission actually involves three steps: first measure the distance, then calculate the link budget, and finally determine the specifications.
First measure the actual trace distance, not the straight line distance.
Climbing weak current wells, bypassing bridges, and reserving fiber optics will all add to the actual fiber length. The straight-line distance of 60 meters between two floors often exceeds 100 meters after routing. It is recommended to measure section by section during the survey and mark a 10 to 15 percent reservation on the drawing. It is also advisable to take photos in the shaft to record the position of the fiber coils to facilitate future maintenance.
Link budget counts three items: attenuation, joints, and margin.
The attenuation of single-mode optical fiber in the 1310 nm window is about 0.35 dB per kilometer, and at 1550 nm is about 0.25 dB per kilometer. Each pair of movable connectors is estimated to be 0.5 dB, and each splice point is estimated to be 0.1 dB. After totaling, an engineering margin of 3 dB is left to deal with jumper contamination and temperature drift. Audio and video optical transceivers are usually divided into 10, 20, and 40 kilometers. For links within 200 meters across buildings, the 10-kilometer dual-fiber grade has the largest margin.
- Short distance in the same computer room: Just connect the original factory jumper directly
- Within 300 meters across the building: Ten kilometers of single mode is enough
- Multiple buildings in the park exceed one kilometer: use the 20-kilometer range and centralize wiring management
After determining the distance, look at the fiber core and protection.
When the fiber core is tight, you can choose a single-fiber bidirectional solution to save half the fiber core. The specifications of the transmit and receive wavelengths are generally slightly less than those of dual-fiber. Please confirm with the technology in advance. It is recommended to use armored jumpers or rodent-proof optical cables for outdoor overhead and pipe sections, and to ground the entrance to the room. like2-way HDMI+network+2-way independent two-way audio optical transceiverFor this type of multi-interface equipment, reporting the distance and fiber core conditions to technical support for verification before placing an order can avoid most of the rework.
By writing these three steps into the survey form, the probability of a black screen across floors will be significantly reduced. If you are unsure about the budget, you can send the drawings to EB-LINK technical support 0755-83179002 for accounting.