OLT Fragmentation Allocation for ONU Upstream Bandwidth Use
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical line terminals (OLTs) face inefficiencies in bandwidth utilization due to misalignment of data unit sizes with allocated time slots, leading to unnecessary fragmentation and high memory and computing resource requirements, especially in high-speed networks.
Innovation Solution
An OLT dynamically allocates fragmentation based on available resources and traffic characteristics, enabling or disabling fragmentation for individual optical network units (ONUs) to optimize bandwidth use and reduce memory and computing demands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If every ONU fragments the last data unit to fully utilize the transmission time slot, then bandwidth utilization is improved, but memory and computing resources at the OLT increase significantly
Solution Approach 1:
The patent applies local quality by enabling fragmentation selectively for specific ONUs or specific data units rather than universally. The OLT controller determines which ONUs should fragment their data units based on local conditions such as time slot utilization efficiency and OLT resource availability, thereby achieving bandwidth optimization only where necessary while limiting memory and computing resource consumption at the OLT.
2Reliability
If the OLT stores and defragments all fragmented data units, then complete data transmission is ensured, but device complexity and cost increase
Solution Approach 1:
The patent extracts the fragmentation and defragmentation functionality from the OLT and relocates it to the ONUs. The OLT controller only manages the fragmentation allocation and receives already-defragmented complete data units from ONUs. This extraction significantly simplifies the OLT structure and reduces its cost while ensuring complete data transmission through coordinated ONU defragmentation.
Solution Approach 2:
The OLT controller acts as an intermediary that coordinates fragmentation without performing defragmentation itself. It sends fragmentation allocation information to ONUs and receives status reports, mediating between the need for bandwidth optimization and the desire to simplify OLT complexity. The ONUs serve as intermediaries that actually perform the defragmentation operation locally.
3Speed
If time slot duration is reduced to match data unit size, then transmission efficiency is improved, but bandwidth utilization decreases due to unutilized remaining duration
Solution Approach 1:
The patent applies dynamics by making the fragmentation allocation adaptive and changeable over time. The OLT controller dynamically adjusts fragmentation allocation for different ONUs and different time slots based on current network conditions, traffic patterns, and resource availability. This dynamic approach allows the system to optimize both transmission efficiency and bandwidth utilization under varying conditions rather than using a fixed configuration.
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
Example embodiments describe an optical line terminal, OLT, configured to perform: determining a fragmentation allocation for respective ONUs; and notifying, the respective ONUs, of the fragmentation allocation. Other example embodiments relate to an optical network unit, ONU, configured to perform: receiving, from the OLT, fragmentation allocation for fragmenting one or more packets; processing the packets in accordance with the fragmentation allocation, thereby obtaining fragmented and unfragmented packets; and forwarding, to the OLT, the fragmented and unfragmented packets in accordance with the dynamic upstream allocation map.