Multi-Rate PON Downstream Frames Using Interleaved Rate-Specific Subframes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional OLTs in PONs are limited to transmitting data downstream at a single data rate, despite being capable of supporting multiple rates, lacking a protocol to efficiently transmit at varying rates to multiple ONUs.
Innovation Solution
Implementing a multi-rate downstream frame structure with subframes, each associated with a different data rate, and including headers with indicators to manage and transmit these subframes efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional OLTs transmit data at a single data rate, then the system is simple to operate, but the data transfer efficiency is limited and cannot be optimized for different ONUs
Solution Approach 1:
The downstream frame is segmented into multiple subframes, where each subframe is associated with a specific data rate. This allows the OLT to transmit different subframes at different data rates to different ONUs within a single frame structure, thereby optimizing data transfer efficiency for each ONU while maintaining overall system organization.
Solution Approach 2:
The frame structure is made dynamic by allowing each subframe to have variable length and be associated with different data rates. The OLT can dynamically adjust which subframes are included in each downstream frame based on the capabilities and requirements of different ONUs, enabling flexible and efficient multi-rate transmission.
2Adaptability or versatility
If the OLT supports multiple data rates, then the adaptability to different ONUs is improved, but the complexity of managing and transmitting varying rates increases
Solution Approach 1:
By dividing the transmission into rate-specific subframes, each subframe can be independently managed with its own length indicator and data rate association. This segmentation simplifies the management of multiple data rates by providing clear delimiters and metadata for each subframe, reducing the overall protocol complexity despite supporting multiple rates.
Solution Approach 2:
The downstream frame structure is designed to be universal by incorporating multiple subframes that can accommodate different data rates within a single frame format. This multi-functional frame structure can serve multiple ONUs with different capabilities using the same frame template, reducing the need for multiple specialized protocols.
3Productivity
If subframes are transmitted at different data rates, then the bandwidth utilization is optimized, but the synchronization and timing management becomes more difficult
Solution Approach 1:
Each subframe is pre-marked with a length indicator that specifies its duration before transmission begins. This preliminary information allows ONUs to预先 know how long to wait for each subframe, enabling accurate synchronization and timing management despite the varying data rates of different subframes.
Solution Approach 2:
The frame structure includes explicit length indicators for each subframe that provide feedback information to receiving ONUs about the timing and duration of each subframe. This feedback mechanism enables ONUs to synchronize their reception and processing of subframes transmitted at different data rates, maintaining timing accuracy throughout the frame.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method implemented at an optical line terminal (OLT) comprising a memory storage comprising instructions, a processor in communication with the memory, wherein the processor executes the instructions to generate a multi-rate downstream frame having a pre-defined length, the multi-rate downstream frame comprising a plurality of subframes that are each associated with a respective data rate, and a transmitter coupled to the processor and configured to transmit each of the plurality of subframes of the multi-rate downstream frame at the respective data rate.