Tag Archives: GPON

Comparison Between EPON and GPON

PON is the abbreviation of passive optical network, which only uses fiber and passive components like splitters and combiners. EPON (Ethernet PON) and GPON (Gigabit PON) are the most important versions of passive optical networks, widely used for Internet access, voice over Internet protocol (VoIP), and digital TV delivery in metropolitan areas. Today we are going to talk about the differences between them.

PON network

Technology Comparison

EPON is based on the Ethernet standard 802.3 that can support the speed of 1.25 Gbit/s in both the downstream and upstream directions. It is well-known as the solution for the “first mile” optical access network. While GPON, based on Gigabit technology, is designated as ITU-T G.983 which can provide for 622 Mbit/s downstream and 155 Mbit/s upstream. GPON is an important approach to enable full service access network. Its requirements were set force by the Full Service Access Network (FASN) group, which was later adopted by ITU-T as the G.984.x standards–an addition to ITU-T recommendation, G.983, which details broadband PON (BPON).

As the parts of PON, they have something in common. For example, they both can be accepted as international standards, cover the same network topology methods and FTTx applications, and use WDM (wavelength-division multiplexing) with the same optical frequencies as each other with a third party wavelength; and provide triple-play, Internet Protocol TV (IPTV) and cable TV (CATV) video services.

Costs Comparison

No matter in a GPON or in an EPON, the optical line terminal (OLT), optical network unit (ONU) and optical distribution network (ODN) are the indispensable parts, which are the decisive factor of the costs of GPON and EPON deployments.

The cost of OLT and ONT is influenced by the ASIC (application specific integrated circuit) and optic module. Recently, the chipsets of GPON are mostly based on FPGA (field-programmable gate array), which is more expensive than the EPON MAC layer ASIC. On the other hand, the optic module’s price of GPON is also higher than EPON’s. When GPON reaches deployment stage, the estimated cost of a GPON OLT is 1.5 to 2 times higher than an EPON OLT, and the estimated cost of a GPON ONT will be 1.2 to 1.5 times higher than an EPON ONT.

We all know that the ODN is made up of fiber cable, cabinet, optical splitter, connector, and etc. In the case of transmitting signals to the same number of users, the cost of EPON and GPON would be the same.

Summary

Nowadays, since many experts have different opinions on GPON and EPON. Thus, there is no absolute answer to determine which is better. But one thing is clear: PON, which possesses the low cost of passive components, has made great strides driven by the growing demand for faster Internet service and more video. Also, fiber deployments will continue expanding at the expense of copper, as consumer demands for “triple-play” (video, voice and data) grow.

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

Mobile Internet strategy – Increase broadband

As the use of mobile applications and services that require increasingly more bandwidth continues to grow, wireless service providers must find cost-effective and efficient methods for meeting the bandwidth demand. Legacy transport networks are no longer capable of adequately serving today’s cell sites. Newer technologies such as GPON, WDM-PON, and Ethernet over CWDM/DWDM are all well-suited to cost-effectively address the growing bandwidth needs of wireless service providers. Regardless of the technology used, Fiberstore product is an integral part of the solution.

GPON

While GPON has been adopted as a technology of choice in high-speed access networks for inexpensive residential service delivery, more recently, it has begun to spread into business access.  With the ability to deliver up to 10Gbps per GPON OLT port, it can also be a cost-effective technology for delivering higher bandwidth to cell towers.
GPON

Figure 1: GPON Network

Whether the GPON splitters are collocated with the OLT or distributed in the field, it is likely that a multiple of splitter modules would be needed to handle each serving area.  To aid with this, the SplitLight HD can provide up to 16 GPON splitters in a single, 1RU chassis, while traditional solutions can only provide a single GPON splitter in the same footprint. In addition, legacy LGX solutions would require at least 4RU to deliver the same density.

WDM-PON

Building on the advantages of GPON, shared infrastructure and a single OLT transponder, WDM-PON provides the added advantage of delivering a dedicated wavelength to each GPON ONT. WDM-PON does not use a splitter. Instead, an Arrayed Waveguide Grating (AWG) is used to multiplex and de-multiplex wavelengths between the feeder fibers and distribution fibers. The result is dedicated bandwidth and a more secure network for each subscriber, or in this case, cell tower. Another advantage of WDM-PON is the ability to add/drop wavelengths at intermediate cell towers that lie between mobile switching centers.
WDM-PON

Figure 2: WDM-PON Network
As with GPON splitters, it is likely that multiple AWGs would be required at both ends of the WDM-PON network. The SplitLight HD can also house up to 12 AWGs in a single, 1RU chassis. In addition, the SplitLight HD has the flexibility to also house passive OADMs for the intermediate add/drops.

How does wdm-pon optical access ?

PON technology developed with two directions, one is single wavelength higher transmission rate, such as 10G EPON and XG – PON; Another is the single fiber transmission multiple wavelengths, namely the WDM – PON technology industry high attention. And WDM-PON is a combination of WDM technology and the advantages of PON topology structure, developed into a high performance access way.

Since the emergence of PON and years of development, it formed the BPON, EPON, GPON, WDM – PON and a series of concepts. WDM – PON EPON and GPON has many advantages: saving the cost of optical fiber and OSP, transmission distance is longer, the fiber optic network is simpler; It combines the advantages of WDM technology and PON topology, developed into a high performance access way. Though the WDM – PON production chain is not mature, and the price is not high, its future prospects is bright.

Along with the national broadband strategy, the “broadband China” and “three net fusions” further develop. PON access technology plays an increasingly important role. Compared with and the mainstream EPON/GPON comparison, WDM – PON PON has many advantages

1.Cost saving
(1) EPON/GPON each optical fiber carrying two wavelength (1490nm and 1490nm);
(2) WPON two-way carrying 16 ~ 64 C + L band wavelength, save fiber resources between 16 to 64 times.

2. The fiber transmission distance is longer
(1) 27 db EPON/GPON optical power fiber transmission distance is about 20 km;
(2) the WDM – PON 27 db fiber transmission distance of optical power budget is up to 63 km.

3. Compared to EPON/GPON networks, the WDM – PON is simpler, completely transparent in speed, business, and the expandability, safer and easier to maintain.

However, the development of WDM – PON Splitters also has difficulties: standard, the industry chain and cost performance.

1. The standard has not been formed: slow development of WDM – PON is a major cause of failure to form a standard. Currently, standard organizations and manufacturers only on WDM – PON reached consensus on the two functions, one is to introduce the principle of wavelength division fiber access system, the second is to use of point to multi-point network topology. And for the formation of the WDM – PON standards also need a period of time.

2. Industrial chain is not yet mature: WDM PON technical basically has two factors, one is the complicated environment on the WDM-PON AWG strict requirements, the second is how to meet the demands of fiber transceivers,such as DWDM SFP transceiver and CWDM GBIC.(Related products in: CWDM compatible SFP)
3. The price has no advantages: because the manufacturer of the WDM-PON equipment is less, the device manufacturer also less, the lack of competition mechanism, the price is on the high side. From the point of new economy analysis, WDM-PON cost per user is still now about three times of EPON/GPON technology.
From WDM-PON market development situation at present, internationally, so far most of the WDM – PON network deployment in South Korea. Korea telecom (KT) is the most active operators deploy WDM-PON.

WDM – PON technology in the practical application has shown good performance and application prospects, including NTT, KDDI, Verizon and some operators in Europe also expressed a keen interest in WDM-PON, and plan to choose WDM-PON as candidates for the next generation access fiber optic network technology solutions, including the Netherlands UNET FTTB commercial network, already deployed using WDM-PON for high-end business users provide better service. WDM-PON commercial process will produce a great impetus, make its future application more clear.

 

Related products: http://www.fs.com/c/pon-splitters_1017