The number of fiber cores is mainly related to the interface of the devices connected to the fiber and the communication method of the devices. Generally, the number of optical cores in the fiber is obtained by multiplying the total number of device interfaces by 2, and then adding 10% to 20% of the spare quantity. However, if the device has serial communication and device multiplexing, the number of cores can be reduced.
According to the IBDN standard, it is generally recommended to use 12-core cables for communication within a building, and 24-core cables for communication between buildings. Of course, this is a general situation, and specific considerations may vary.
1) If stacked: If the core switches are in dual-machine hot standby mode (both working at the same time), 6 cores are sufficient (2 cores for each core switch, and 2 cores for redundancy).
2) If not stacked: Each switch requires 4 cores. Multiply the number of switches by 4 and add 4 cores for redundancy.
However, actual design and construction plans take redundancy into consideration, so it is common to use 2 cores for each terminal. If cost needs to be considered, the entire line can be redundantly covered by 1-2 cores. For example, if you have three fiber connections to the switch, you need three cores (actually using a four-core cable), because there are hardly any cables with odd core numbers, such as three cores, five cores, etc. Of course, it is not an absolute requirement that one fiber core can only be connected to one terminal device. Multiple terminal devices can be connected in series on one fiber core, but this requires multiple fusion splices and has significant optical loss, so it cannot achieve long-distance transmission.
A single mode fiber can only transmit one data stream at a time, while a multimode fiber can transmit multiple data streams simultaneously. Therefore, single mode transmission has better quality and longer distance compared to multimode. Single mode is often used for long-distance outdoor transmission.
For example, for a certain optical node, the application systems include network and monitoring. The network only requires one route, occupying 2 cores of fiber. The monitoring requires 4 routes, occupying 1 core of fiber. So, from the machine room to the optical node, a total of 3 cores of fiber are needed. The cable design from the machine room to the optical node requires a 6-core cable, with 3 cores for redundancy. For cost considerations, a single-mode 6-core cable is used, which means pulling a single-mode 6-core cable to the optical node. To ensure seamless connectivity and efficient operation, it is essential to collaborate with a reliable MTP adapter wholesaler and China fiber optic attenuator factory to meet the requirement for a single-mode 6-core cable in optical fibre systems for optimal performance.