Why need to add pcm equipment to the machine room?

First of all, you have to understand what a PCM device is and what is an optical transceiver. Then will know why the PCM equipment is added to the equipment room.

The role of PCM device in a communication system is to transmit various 64k services over an E1 (2M) line, which is a digital signal generated by sampling, quantizing, and encoding a continuously varying analog signal. Mainly used to transmit voice telephone interface, two-wire audio interface, four-wire audio interface, two-wire EM interface, four-wire EM interface, asynchronous RS232, synchronous RS232, RS422 interface, RS485 interface, hotline, magnet phone interface, 10Base_T Ethernet interface etc.

However, due to the limitation of the transmission distance, the coaxial cable connected by the PCM device can only support the distance within 300 meters, and the attenuation is too large, which affects the transmission quality.

Therefore now the communication system is a combination of the optical transceiver and the PCM device. The PCM is to multiplex the multi-channel user service data into one 2M signal, and the optical transceiver extends the one channel or multi-channel 2M signal to the opposite end through the optical cable.

The essential function of the optical transceiver is to extend the transmission distance of the data signal, which is an optical fiber communication device that prolongs data transmission.

Due to the limited transmission capacity of PCM devices, the 1 channel E1 channel can only carry 30 channels of various 64k services. The optical transceiver only needs one optical cable to transmit dozens or hundreds of E1 channels, which greatly improves the performance of the whole communication system. Therefore, the optical transceiver and the PCM equipment are the preferred networking solutions for most private network users.

So this is why the machine room has to add pcm equipment. This is the difference between a PCM device and an optical transceiver.