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1. What is GPON?

GPON (Gigabit-CapablePON) technology is the latest generation broadband passive optical integrated access standard based on the ITU-TG.984.x (ITU TG.984.x) standard, with the advantages of high bandwidth, high efficiency, large coverage area, and rich user interfaces. It is regarded by most operators as an ideal technology for realizing broadband and comprehensive transformation of access network services.

2. The Principle of GPON

GPON downlink - broadcast transmission

GPONS uplink - TDMA mode

The network topology of passive optical fiber transmission is mainly composed of OLT (Optical Line Terminal), ODN (Optical Distribution Network), and ONU (Optical Network Unit).

ODN provides optical transmission means for OLT and ONU. It is composed of passive optical splitter and passive optical combiner. It is a passive device connecting OLT and ONU.

3. The Principle of GPON - Uplink

1). The transmission of uplink data is uniformly controlled by the OLT.

2). The ONU transmits user data according to the time slot allocated by the OLT to avoid data transmission conflicts generated by the ONU.

3). The ONU inserts uplink data into its own time slot according to the time slot allocation frame, realizing the sharing of uplink channel bandwidth between multiple ONUs.

4. GPON Networking Mode

The main networking methods used by GPON are FTTH/O, FTTB+LAN and FTTB+DSL.

1). FTTH/O is fiber to the home/office. After the optical fiber enters the optical splitter, it is directly connected to the user ONU. One ONU is only used by one user, with high bandwidth and high cost. It is generally aimed at high-end users and business users.

2). FTTB+LAN is fiber to the building, and then different services are connected to multiple users through a large-capacity ONU (called MDU). Therefore, multiple users share the bandwidth resources of one ONU, and each person occupies a lower bandwidth and lower cost. , generally aimed at low-end residential and low-end commercial users.

3). FTTB+ADSL is fiber to the building, and then the business is connected to multiple users in the form of ADSL, and multiple users share one ONU. The bandwidth, cost and customer base are similar to FTTB+LAN.