OLT Slot Allocation for Low-Delay PON Field Bus Communication
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Solution Overview
Problem
Field bus networks experience long delays, exceeding millisecond levels, which are inadequate for low-delay scenarios such as machine vision, motion control, virtual reality, and augmented reality.
Innovation Solution
An optical head-end allocates a first slot for periodic data transmission and a second slot for windowing in an optical bus network system, reducing delays and jitter by optimizing slot allocation based on cycle period and data amount, allowing online optical terminals to get online without disrupting normal service data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional field bus network is used, then network compatibility is maintained, but communication delay exceeds millisecond level which is inadequate for low-delay scenarios
Solution Approach 1:
The uplink transmission time is segmented into multiple slots within each cycle period. The first slot is dedicated to periodic data from online terminals, while the second slot handles windowing for offline terminals. This segmentation ensures that periodic data transmission is not blocked by offline terminal registration processes, reducing communication delay and delay jitter to meet low-delay scenario requirements.
2Adaptability or versatility
If windowing is performed for offline optical terminal to get online, then new terminal registration is enabled, but delay of service data transmission by online optical terminal increases
Solution Approach 1:
The uplink transmission time is divided into multiple slots within each cycle period. The first slot is dedicated to periodic data from online terminals, while the second slot handles windowing for offline terminals. This segmentation ensures that periodic data transmission is not blocked by offline terminal registration processes, reducing communication delay and delay jitter to meet low-delay scenario requirements.
Solution Approach 2:
The system pre-allocates specific time slots for different purposes before transmission occurs. By predetermined allocating the first slot for periodic data and the second slot for windowing, the system avoids dynamic conflicts during transmission, ensuring that online terminal data transmission delays are minimized while still allowing offline terminals to register.
3Device complexity
If uniform slot allocation is used, then system simplicity is maintained, but delay jitter increases and low-delay requirements cannot be met
Solution Approach 1:
The uplink transmission time is segmented into multiple slots within each cycle period. The first slot is dedicated to periodic data from online terminals, while the second slot handles windowing for offline terminals. This segmentation ensures that periodic data transmission is not blocked by offline terminal registration processes, reducing communication delay and delay jitter to meet low-delay scenario requirements.
Solution Approach 2:
Different slots are assigned different functions based on local requirements. The first slot is optimized for periodic data transmission with guaranteed timing, while the second slot is dedicated to windowing operations. This local differentiation of slot qualities allows the system to meet strict delay requirements for periodic data while still handling terminal registration, reducing delay jitter without excessive complexity.
Data Source
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AI summary
A communication method and a communication apparatus are provided, and are applicable to the field of optical communication technologies, to resolve a problem of how an ONT gets online and problems of a large delay and large delay jitter of sending uplink service data by an online ONT when a field bus performs communication by using a PON system. The method includes: An optical line terminal OLT may obtain a cycle period and a data amount of periodic data, and allocate a first slot and a second slot based on the data amount of the periodic data and the cycle period, where the first slot is used to transmit the periodic data, the second slot is used for windowing, and the second slot is a part or all of slots other than the first slot in the cycle period. The OLT uniformly allocates the first slot used to transmit the periodic data and the second slot used for windowing. In this way, a delay, of transmitting service data by an online ONT, caused by windowing performed for an off-line ONT to get online can be reduced, and delay jitter can be reduced.