Dynamic Bandwidth Allocation for Mixed 1G and 10G Passive Optical Networks
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Solution Overview
Problem
Current dynamic bandwidth allocation (DBA) algorithms in passive optical networks (PONs) face challenges in efficiently managing upstream data transmission for both 1G and 10G ONUs, due to dual-mode transceiver overhead and fairness issues, leading to significant CPU processing time and potential utilization losses from unutilized frame sizes.
Innovation Solution
Implementing a method that prioritizes transmission speed over ONU type for scheduling and bandwidth allocation, using a shuffler module and bandwidth allocation module to assign transmission ranks and allocate bandwidth based on requested guaranteed and best-effort bandwidths, with hardware acceleration to reduce CPU burden and minimize processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the OLT optical transceiver switches between 1G receive mode and 10G receive mode to handle mixed-rate ONUs, then the system can support both transmission speeds, but switching overhead increases processing time and reduces efficiency
Solution Approach 1:
The patent segments the upstream transmission timeline into separate 1G and 10G transmission periods. The OLT allocates specific time slots for 1G ONUs and 10G ONUs to transmit upstream data. By segmenting the transmission opportunities by rate, the OLT can configure its optical transceiver for one rate during its corresponding transmission period without needing to switch modes frequently, thereby reducing switching overhead while maintaining support for both transmission speeds.
2Reliability
If the DBA algorithm monitors and sorts all ONUs by fairness criterion to ensure fair bandwidth allocation, then fairness among ONUs is enforced, but CPU processing time increases considerably
Solution Approach 1:
The patent segments the set of ONUs into two separate groups: 1G ONUs and 10G ONUs. The DBA algorithm applies different fairness criteria and sorting mechanisms to each group independently. By segmenting the ONU population, the algorithm reduces the computational complexity of sorting and monitoring, as it processes smaller subsets separately rather than all ONUs together, thereby reducing CPU processing time while maintaining fairness within each rate group.
Solution Approach 2:
The patent applies different fairness criteria and allocation strategies locally to each ONU rate group. Instead of using a single uniform fairness criterion for all ONUs, the system tailors the fairness approach to the specific characteristics of 1G and 10G ONUs. This local customization allows the DBA algorithm to optimize processing for each group's specific needs while ensuring fair allocation within each group, reducing overall computational burden.
3Ease of manufacture
If the EPON standard prohibits fragmentation of frames during ONU upstream transmission to simplify protocol, then implementation is simpler, but utilization loss occurs due to unutilized frame sizes up to MTU
Solution Approach 1:
The patent introduces dynamic frame segmentation and reassembly mechanisms that adapt to the available bandwidth and ONU transmission rate. While maintaining the no-fragmentation rule at the ONU level, the system dynamically adjusts the allocated bandwidth and frame timing to better match actual data sizes. The OLT dynamically configures transmission parameters based on real-time bandwidth requests and traffic conditions, optimizing utilization without requiring ONUs to fragment frames, thus balancing protocol simplicity with efficient bandwidth usage.
Data Source
AI summary
An OLT allocates a bandwidth budget and assigns upstream transmission order by receiving upstream transmission requests from a plurality of ONUs. Each ONU's request includes a requested guaranteed bandwidth and a requested best effort bandwidth. Each ONU has respective first and second attribute values. One attribute is given allocation priority over the other attribute. One attribute is given scheduling priority over the other attribute. Within each attribute, an allocation rank and a transmission rank is assigned to the possible attribute values. The bandwidth budget is allocated in accordance with the allocation priority and ranks. The upstream transmissions are scheduled in accordance with the scheduling priority and ranks.