Upstream Bandwidth Allocation in Passive Optical Networks
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Solution Overview
Problem
The complexity of processing FEC-encoded data in existing upstream bandwidth allocation processes in Passive Optical Networks (PONs) is increased due to the need for adding and removing '0' padding bytes to ensure data blocks match a fixed size for Reed-Solomon encoding.
Innovation Solution
The method involves allocating upstream bandwidth by an Optical Line Terminal (OLT) through a US BWmap, ensuring the total length of payloads transmitted by consecutive Transmission Containers (T-CONTs) is a product of the byte length of FEC-encoded data and a positive integer, minus the byte length of data not protected by FEC, allowing the Optical Network Unit (ONU) to encapsulate and transmit data without additional padding, thus simplifying FEC processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Reed-Solomon FEC encoding is applied to upstream data in GPON systems, then error correction capability is improved, but processing complexity increases due to adding and removing padding bytes
Solution Approach 1:
The patent changes the bandwidth allocation parameter from arbitrary values to specific values that are multiples of the FEC code block size (232 bytes). This parameter change ensures that the data length before FEC encoding is always an integral multiple of the code block size, eliminating the need for padding bytes and reducing processing complexity while maintaining error correction capability
2Productivity
If data blocks are padded to match fixed size for FEC encoding, then encoding efficiency is improved, but processing time increases
Solution Approach 1:
The patent performs preliminary bandwidth allocation planning to ensure that the allocated bandwidth corresponds to data lengths that are integral multiples of the FEC code block size. This preliminary action prevents the need for subsequent padding operations, thereby reducing processing time while maintaining encoding efficiency
3Adaptability or versatility
If padding bytes are added to ensure fixed data block size, then FEC encoding compatibility is improved, but data transmission overhead increases
Solution Approach 1:
The patent changes the bandwidth allocation parameter to specific values that are multiples of the FEC code block size (232 bytes). This parameter change ensures that data blocks are naturally aligned with FEC encoding requirements without needing additional padding bytes, thereby maintaining FEC encoding compatibility while eliminating data transmission overhead associated with padding
Data Source
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AI summary
A method for upstream bandwidth allocation in a passive optical network is provided by the disclosure. The method includes the following steps: an Optical Line Terminal (OLT) allocates an upstream bandwidth for an Optical Network Unit (ONU) through an upstream bandwidth mapping (US BWmap) domain, wherein the total length B of payloads transmitted by consecutive Transmission Containers (T-CONTs) allocated for the ONU is: the product of the positive integer n and the data byte length L contained in a code word when the ONU uses Forward Error Correction (FEC) encoding, minus the byte length R of the contents protected by FEC, except the payloads, in an upstream burst slot transmitted by the ONU, i.e. B=Lxn-R bytes (401); and the ONU encapsulates the upstream data according to the size of the T-CONT total bandwidth allocated by the OLT and transmits it to the OLT (402). A system for upstream bandwidth allocation in a passive optical network is also provided by the disclosure. Application of the disclosure reduces the complexity of processing FEC-encoded data by the ONU and the OLT, and improves the encoding efficiency of the ONU and the decoding efficiency of the OLT.