Tag Archives: PON

Comparison Between Active and Passive Optical Network

As time goes by, in order to meet the need for higher bandwidth, faster speed and better utilization of fiber optics, FTTH access networks designs have developed rapidly. And there are two basic paths of FTTH networks: active optical network (AON) and passive optical network (PON). However, how much do you know about the them? Do you know what’s the differences between the two systems? Now, this article will give a detailed comparison between them.

Active Optical Network (AON)

Active optical network, also called point-to-point network, usually uses electrically powered switching equipment such as a router or switch aggregator, to manage signal distribution and direct signals to specific customers. This switch opens and closes in various ways to direct incoming and outgoing signals to the proper place. Customers can have a dedicate fiber running to his or her home, but it needs many fibers.

aon

Passive Optical Network (PON)

Different from AON, PON doesn’t contain electrically powered switching equipment, instead it uses fiber optic splitters to guide traffic signals contained in specific wavelengths. The optical splitters can separate and collect optical signals when they run through the network. And powered equipment is needed only at the signal source and the receiving ends of the signals. Usually, the PON network can distribute signals into 16, 32 and 64 customers.

pon

AON vs. PON

As data travel across the fiber connection, it needs a way to be directed so that the correct information can arrive at its intended destination. And AON and PON offer a way to separate data and set it upon its intended route to arrive at the proper place. Therefore, these two networks are widely applied in FTTH systems. However, each system has their own merits and shortcomings. Here is a simple comparison between them.

Signal Distribution

In AON networks, subscribers have a dedicated fiber optic strand. In another word, each subscriber gets the same bandwidth that doesn’t be shared. While the users share the fiber optic strands for a portion of the network. These different network structures also lead to different results. For example, if something goes wrong in a PON network, it will be difficult to find the source of the problem. But this problem does not exist in AON.

Equipment

As we have noted above, AON directs optical signals mainly by powered equipment while PON has no powered equipment in guiding signals except for two ends of the system.

Cost

When running an existing network, it’s known to us that the main source of cost is the maintenance and powering equipment. However, PON uses passive components that only need less maintenance and do not need power, which contributes to that PON building is cheaper than that of AON.

Coverage Distance

AON networks can cover a range to about 100 km, a PON is typically limited to fiber cable runs of up to 20 km. That is to say, subscribers must be geographically closer to the central source of the data.

Of course, apart from what have been listed above, there are other differences between these two networks. For instance, AON network is currently the industry standard. It’s simple to add new devices to the network. And there are numbers of similar products on the market, which are convenient for users to select. Besides, AON is a powered network, which decides it’s less reliable than PON. However, since the bandwidth in PON is not dedicated to individual users, people who use a passive optical network may find that their system slows down during peak usage times.

Conclusion

In summary, AON and PON have their own advantages and disadvantages, but both of them provide practical solutions for FTTH network connection. There is no right or wrong answers when it comes to choose which one of them. FS.COM provides several kinds of PON equipment such as PON splitters and OLT/ONT Units. If you want to find out more, please visit Fiberstore website.

A Guide for PON

Nowadays, there is a growing popularity of Video-on-Demand (VoD), VoIP and increased IPTV deployment. Providers aim to offering fiber-to-the-home (FTTH), (fiber-to-the-building) FTTB and fiber-to-the-curb (FTTC) solutions through advancing passive optical network (PON) technology. The term “PON” may confuse you for its complexity and extensiveness. Details are as followed.

PON is a single, shared optical fiber that uses inexpensive optical splitters to divide the single fiber into separate strands. It can build up a point-to-point topology supporting 1Gbps transmission to home and business typically within 20km. PON system is called “passive” because that there are no active electronics within the access network. It uses optical splitters to separate and collect signals rather than electrically powered switching equipment.

PON consists of an Optical Line Terminal (OLT) connected to multiple Optical Network Units (ONUs) via an Optical Distribution Network (ODN).

OLT: it is a device at the service provider’s central office, performing conversion between the electrical signals used by the service provider’s equipment and the fiber optic signals used by the passive optical network and coordinating the multiplexing between the conversion devices on the other end of that network.

ODN: it is used for distributing signals to users in a telecommunications network by optical fiber. ODN has been made up entirely of passive optical components particularly singlemode optical fibers and optical splitters.

ONUs: they are devices near end users, delivering traffic-load information provided by OLTs to each end user.

PON System

PON system has achieved significant deployment in today’s FTTx networks especially in FTTH networks as the development of Gigabit passive optical network (GPON) and Ethernet passive optical network (EPON). Nowadays, GPON and EPON are the mostly widely used types of PON for their low cost, high bandwidth, great flexibility and easy management, etc.

GPON: it is defined by ITU-T recommendation series G.984.1 through G.984.6. It can transport not only Ethernet, but also ATM and TDM (PSTN, ISDN, E1 and E3) traffic. It supports services like carrying video and delivering video on single fiber distribution, allowing low-consuming transmission, more efficient maintenance, cabling and overall performance.

EPON: it is defined by the Ethernet standard rather than by the ATM standard, making you utilize the economies-of-scale of Ethernet. It can provide simple and easy-to-manage connectivity to Ethernet-based, IP equipment both at the customer premises and at the central office. It is perfect for voice and video traffic solution as with other Gigabit Ethernet media.

GPON and EPON

 For more information about OLTs, Optical Splitters and ONUs, please visit www.fs.com.

Originally published at: www.fiber-optic-equipment.com/a-guide-for-pon.html