PON Principles:
[bodyads]
(Almost) all PON types obey the same basic principles
OLT and ONU consist of
- Layer 2 (Ethernet MAC, ATM adapter, etc.)
- optical transceiver using different ls for transmit and receive
- optionally: Wavelength Division Multiplexer
Downstream transmission
- OLT broadcasts data downstream to all ONUs in ODN
- ONU captures data destined for its address, discards all other data
- encryption needed to ensure privacy
Upstream transmission
- ONUs share bandwidth using Time Division Multiple Access
- OLT manages the ONU timeslots
- ranging is performed to determine ONU-OLT propagation time
Additional functionality
- Physical Layer OAM
- Autodiscovery
- Dynamic Bandwidth Allocation
