Part I. What is PON?
PON stands for Passive Optical Network. A PON is a telecommunications network that transmits data over fiber-optic lines. It is “passive” since it uses passive optical splitter to route data sent from a central location to multiple destinations.
PONs are used by ISPs and NSPs as a cost-effective way to provide Internet access for customers. Since PON is a point-to-multipoint (P2MP) system, which provides a more efficient way to transmit data than a point-to-point network.
The main transmission line can split off into 32 separate lines, which requires far less infrastructure than building direct lines to each destination with fiber optical cabling.
The central location of a PON is also called OLT (optical line terminal), while the individual destination is called ONU (optical network unit).
Part II. What is the benefit of PON?
As the technology of access network, PON has been deployed for over 15 years. Compared to traditional Ethernet, PON performs better in medium, medium and cost, resource utilization, space occupation, etc.
● Relatively low cost
What PON can bring are relatively low cost, simple maintenance, easy expansion, and easy upgrade. The PON structure does not require a power supply in transmission. There is no electronic component, which makes it easy to deploy. Basically, it doesn’t require maintenance, which saves a lot in long-term operating costs and management costs.
● Prefect-dielectric network
The passive optical network is a prefect-dielectric network, which completely avoids electromagnetic interference and lightning effects. It’s extremely suitable for applying in areas with harsh natural conditions.
● Little resource utilization
The PON system occupies few resources at the local end. The initial investment of the system is low. The expansion is easy and the return on investment is high.
● High bandwidth
EPON/GPON is upgraded to 1G/2.5G-10G-25/50G with the development rate of Ethernet technology.
● Wide range of services
Since PON adopts the point-to-multipoint access mode, the infrastructure cost of laying optical fibers between the central office and the users is shared by the users, which can improve the return on investment in network construction. Compared with the method of configuring end-to-end optical fibers for each user, the PON equipment that improves services for the same number of customers is smaller and occupies less space in the central office.
Part III. Types of PON
While all PONs use optical fibers and unpowered splitters, there are several different versions. Below is a list of different types of PON.
APON: It refers to ATM PON. ATM is a transmission protocol based on cells. It can provide dynamic bandwidth allocation for the access network, which helps better meet the demands of broadband data services.
BPON: It means Broadband PON. It’s developed based on APON, which supports transmission rates of 622Mbps. More functions like dynamic bandwidth allocation and protection are provided. It supports services such as Ethernet access, video transmission, and high-speed leased lines.
EPON: It refers to Ethernet PON. EPON standard is published by IEEE802.3 EFM. It combines Ethernet with PON technologically, adopting PON at the physical layer and Ethernet protocol at the data link layer, and achieving Ethernet access with the topology of PON.
GPON: The full form is Gigabit PON. It’s the latest standard of PON access, which is of high bandwidth, high efficiency, large coverage, and abundant interfaces. GPON is considered the ideal technology for achieving access networks.
Part IV. Application of PON
Lines that terminate outside buildings are called fiber-to-the-neighborhood (FTTN) or fiber-to-the-curb (FTTC). Lines that extend all the way to buildings are called fiber-to-the-building (FTTB) or fiber-to-the-home (FTTH).
