PON Optical Transceiver is a high-performance Optical Transceiver for PON system, also known as PON module, which complies with ITU-T G.984.2 standard and Multi-Source Agreement (MSA), and it uses different wavelengths to send and receive signals between OLTs (Optical Line Terminals) and ONTs (Optical Network Terminals).PON Optical Transceivers are indispensable for the wide application of PON Ethernet Passive Optical Networks, as it is an important part of the PON system.
A. PON Optical Transceiver classification
1, SFF/SFP/SFP+ and XFP Optical Transceivers
According to the different types of packaging, PON Optical Transceivers can be divided into SFF (small size), SFP (small size pluggable, 4G), SFP + (enhanced small size pluggable, Ethernet 10G) or XFP (standard small size pluggable, serial 10G) types.
SFP+ has gradually replaced XFP as the mainstream of 10G market by virtue of its miniaturization, low cost and other advantages to meet the demand for high-density Optical Transceivers for equipment.
2, OLT Optical Transceiver and ONU Optical Transceiver
According to the different plug-in devices, PON Optical Transceivers have two types of OLT Optical Transceivers and ONU (optical network unit) Optical Transceivers, and their encapsulation types are SFP.
OLT Optical Transceivers are more complex than ONU Optical Transceivers because each OLT Optical Transceiver must signal with 64 ONU Optical Transceivers.
3, APON Optical Transceiver, GPON Optical Transceiver, and EPON Optical Transceiver
According to the different technical standards (i.e., transmission protocols), PON Optical Transceivers can be divided into four types: APON (ATM PON), BPON (Broadband Passive Optical Network), EPON (Ethernet Passive Optical Network) and GPON (Gigabit Passive Optical Network).
Currently, the latter two are more widely used. EPON Optical Transceivers are available in SFP, XFP and SFP+ packages with transmission distances of up to 20km, and the receiver portion has a sealed preamplifier and a limiting amplifier with LVPECL-compatible differential outputs. GPON Optical Transceivers are high-performance and cost-effective Optical Transceivers used for 2.5Gpbs serial optical data communication applications. The advantage of this Optical Transceiver is that it is guaranteed to be free from eye damage in case of any failure.
GPON Optical Transceivers have better performance than EPON Optical Transceivers, but EPON Optical Transceivers have more advantages in terms of cost, which have their own advantages and disadvantages and can coexist and complement each other. If customers have higher requirements for bandwidth, multi-service, QoS and security as well as ATM technology as the backbone network, it is recommended to choose GPON Optical Transceiver; if you want to save costs and do not have high requirements for QoS and security, EPON Optical Transceiver may be more suitable.
4, PON Optical Transceiver and Traditional Optical Transceiver
According to the different development time, there are two types of Optical Transceivers: PON Optical Transceiver and traditional Optical Transceiver.
When using traditional Optical Transceivers, the optical signal transmission mode is point-to-point (P2P), where the modules are used in pairs, and one or two fibers are used for transmission (duplex or simplex). Fiber optic link loss including attenuation, dispersion, fiber connection insertion loss, etc.; has a long transmission distance, up to 200km; due to cost factors less used in the access network, mainly used in the backbone network.
When using PON Optical Transceivers, the optical signal transmission mode is point-to-multipoint (P2MP), and the modules are not used in pairs. Fiber optic link loss including attenuation, dispersion, crossover ratio loss, fiber optic connection insertion loss, etc.; transmission distance is shorter than the traditional module, the distance is only 20km; mainly used in access networks.
5, SFP Optical Transceiver and GBIC Optical Transceiver
The volume of SFP Optical Transceiver is reduced by half compared with GBIC Optical Transceiver, and the number of SFP ports on the same panel will be twice as many as GBIC Optical Transceiver.
The same SFP Optical Transceiver has a plug-and-play mini fiber slot, in line with the high-density requirements of the data center, the future SFP Optical Transceiver will replace the GBIC Optical Transceiver in the data center.
B.PON Optical Transceiver applications
Video conferencing, cable TV and other applications of the growing demand for Internet access, resulting in the popularity of fiber-to-the-home deployment, PON as a leading technology in the field of fiber-to-the-home applications, is also widely used in the PDH SONET, ATM/SDH, data communications, telecommunications network access network.
C. PON Optical Transceiver shortcomings
Although PON Optical Transceivers provide satisfactory performance in FTTH applications, there are still some challenges in the following areas:
Burst mode optical transmission technology for uplink;
High output optical power and high sensitivity OLTs at the CO (central office) are required for connecting user premises to the optical splitting:
Burst mode optical transmission technology for uplinks;
The need for high output optical power and high sensitivity OLTs at the CO (central office) for connecting the user premises to the optical splitter and the loss introduced by the fiber;
The need for optical line terminal (OLT) RXs to be able to receive packets with large differences in optical power and phase alignment;
Fast rise/fall times to minimize protection time during transmission.
Energy Consumption
DAC cables typically save more energy than AOC fiber optic cables that require 1-2 watts. Active DAC cables consume less than 1 watt, while passive DAC cables are very energy efficient at less than 0.15 watts due to the thermal design of the directly connected copper cables. As a result, operating costs associated with power consumption can be reduced by choosing a DAC solution.
