Classification of Fiber Optic Transceivers

With the diversified development of optical fiber transceiver products, their classification methods are also different, but there is a certain correlation between various classification methods.

1. Optical transceivers are divided by rate

It can be divided into single 10M, 100M, 1000M fiber optic transceivers, 10/100M adaptive, 10/100/1000M adaptive fiber optic transceivers. Most of the single 10M, 100M and 1000M transceiver products work at the physical layer, and the transceiver products that work at this layer forward data in bits.

This forwarding method has the advantages of fast forwarding speed and low delay, and is suitable for use on links with a fixed rate. The 10/100M and 10/100/1000M fiber optic transceivers work at the data link layer and use a store-and-forward mechanism, so that the forwarding mechanism must read its source MAC address and destination MAC address for each received data packet. address and data payload, and the data packet is forwarded only after the CRC cyclic redundancy check is completed.

The benefits of store-and-forward can prevent some erroneous frames from being propagated in the network, occupying valuable network resources, and can also prevent packet loss caused by network congestion. When the data link is saturated, store-and-forward can be unable to The forwarded data is first placed in the transceiver's buffer, and then forwarded when the network is idle. This not only reduces the possibility of data conflict but also ensures the reliability of data transmission, so 10/100m, 10/100/1000m fiber optic transceivers are suitable for working on links with variable rates.

2. Optical transceivers are divided by structure

It can be divided into desktop (stand-alone) fiber optic transceivers and rack-mounted fiber optic transceivers. The desktop fiber optic transceiver is suitable for a single user, such as the uplink of a single switch in the corridor. Rack-type fiber optic transceivers are suitable for multi-user aggregation. For example, the central computer room of a community must meet the uplink of all switches in the community. The use of racks is convenient for unified management and unified power supply of all modular fiber optic transceivers. 

3. Optical transceivers are divided by optical fibers

It can be divided into multi-mode optical transceivers and single-mode optical fiber transceivers. Due to the different optical fibers used, the distances that the transceivers can transmit are also different. The general transmission distance of multi-mode transceivers is within 2km, while the range covered by single-mode transceivers can range from 3km to 120km. It should be pointed out that due to the different transmission distances, the transmitting power, receiving sensitivity and wavelength of the optical fiber transceiver itself will also be different. For example, the transmit power of a 2km fiber optic transceiver is generally between -20 and -14db, the receiving sensitivity is -30db, and the wavelength of 1310nm is used; while the transmit power of a 120km fiber optic transceiver is mostly between -3 and 0dB, and the receiving sensitivity is less than - 36dB, using a wavelength of 1550nm.

4. Optical transceivers are divided according to the number of optical fibers

It can be divided into single-fiber optical fiber transceivers and dual-fiber optical fiber transceivers. As the name implies, single-fiber equipment can save half of the optical fiber, that is, data reception and transmission can be realized on one optical fiber, which is very suitable in places where optical fiber resources are scarce. This kind of product adopts the technology of wavelength division multiplexing. With the increasing use of single-fiber optical transceivers, the products have become mature and stable.

5. Optical transceivers are divided according to power supply

It can be divided into built-in power supply and external power supply. Among them, the built-in switching power supply is a carrier-grade power supply, while the external transformer power supply is mostly used in civil equipment. The advantage of the former is that it can support an ultra-wide power supply voltage, better achieve voltage regulation, filtering and equipment power protection, and reduce external failure points caused by mechanical contact; the latter has the advantage of small size and cheap equipment.