Hello, everyone!
Today, I will explain EPON and 10G EPON technology. This is the third article about PON technology.
EPON or 1G-EPON is an abbreviation from Ethernet Passive Optical Network. This technology is based on the IEEE 802.3ah. All data packets are encapsulated in Ethernet frames. EPON uses Ethernet frames instead of ATM cells. It also uses IP to carry video data, voice and data. This system can have CATV service – DVB standard and the wavelength for this purpose is 1550nm.
In the next figure, we can see the architecture of the EPON.
EPON is composed of OLT (Optical Line Terminal), ODN (Optical Distribution Network) and ONUs (Optical Network Unit). This technology uses one fiber for both directions (SM fiber IEC 60793-2-50 B1.1 or B1.3 (ITU-T G.652)). Maximum distance between OLT and ONU is 20 km and the maximum PON splits is 64, but the typical split ratio is 16 or 32.
EPON supported triple services (data, voice and video). EPON uses a similar wavelength plan to BPON. For downstream, the system uses 1490 nm for all services (without CATV), and for upstream 1310nm for all services.
The downstream and upstream speed is symmetrical and the maximum is 1 Gbps (1 Gpbs prior to 8B/10B coding).
In next table show us the main features of EPON technology.
Standard | IEEE 802.3ah |
Protocol | Ethernet |
Downstream wavelength | 1490 nm for data, voice and iptv, 1550nm for CATV |
Upstream wavelength | 1310 nm |
Max speed | 1 Gbps for downstream 1 Gbps for upstream |
Voice support | TDM over packet |
Video support | IP video + CATV |
Number of fibers | 1 |
Split Ratio | typical 16 or 32, max 64 |
Max Reach | 20 km |
Fiber Type | G.652 |
Maximum attenuation | 1000Base-PX10-U: 20 dB 1000Base-PX10-D: 19.5 dB 1000Base-PX20-U: 24 dB 1000Base-PX20-D: 23.5 dB |
Minimum attenuation | 1000Base-PX10-U: 5 dB 1000Base-PX10-D: 5 dB 1000Base-PX20-U: 10 dB 1000Base-PX20-D: 10 dB |
EPON offers triple services, low cost of devices and low cost of maintaining the network. This technology offers high speed downstream and upstream for customers. The main strength of EPON is that it supports natively all Ethernet applications. Therefore it is a very suitable technology. The IP applications are: internet, IP telephone or VoIP, IPTV, VoD (Video On Demand), etc.
The next generation of EPON is 10G-EPON. This technology is defined by IEEE 802.3av standard. It offers asymmetrical (10/1Gbps) and symmetrical (10/10 Gbps) rates for downstream and upstream. The architecture of the 10G-EPON is the same as EPON (OLT, ODN and ONU).
The 10G-EPON uses one fiber, the maximum distance between OLT and ONUs is 20km, with a max split of 64. The standard defines three optical power budgets, therefore, minimum attenuation is from 5 to 15 dBm and maximum attenuation is from 20 to 29 dB. For downstream, the system uses 1578 nm, and for upstream 1310nm and 1270nm. 10G-EPON is technology from 2009, and it is compatible with EPON.
Thank you!
