In a Fiber-to-the-Home (FTTH) network, the
1. Core Functions of the ONU
(1) Optical-Electrical (O/E) Signal Conversion
1490nm (GPON) / 1310nm (EPON)
Converts user-generated electrical signals back into 1310nm (GPON) / 1490nm (EPON)
(2) PON Protocol Processing
MPCP (Multi-Point Control Protocol)
Collaborates with the OLT to dynamically assign upstream timeslots, preventing collisions in shared fiber networks (TDMA-based).
(3) User Access & Service Distribution
Multi-Service Interfaces:
Ethernet (RJ45):
Supports SIP-based telephony.
Wi-Fi (Optional):
802.1Q VLAN tags
2. ONU's Position in the FTTH Architecture
OLT-ONU Relationship:
Configuration (TR-069, OMCI)
User-Side Role:
, converting PON-specific signals into standard Ethernet/IP traffic.
3. Key Technical Features
(1) Standards Compliance
GPON (ITU-T G.984) / EPON (IEEE 802.3ah)
(2) Security Mechanisms
AES-128 Encryption (GPON)
(3) Power & Thermal Design
IEEE 802.3az (Energy-Efficient Ethernet) for low-power operation.
Industrial-grade ONUs support -40 degree to +75 degree
4. ONU Deployment Scenarios
| Integrated router/Wi-Fi | Residential FTTH (e.g., Huawei HG8245) | |
| Enterprise CPE (e.g., Nokia G-010G-A) | ||
| MDU (Multi-Dwelling Unit) | Multi-user aggregation | Apartment buildings (e.g., ZTE F601) |
5. ONU Management & Troubleshooting
TR-069
- Enables remote ISP control (TR-069/OMCI).
- A
