TSF Rollover Flag for Wireless Beacon Synchronization

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Solution Overview

Problem

Existing wireless communication systems face challenges in handling time synchronization function (TSF) timer rollover issues, particularly in frames like S1G Beacons, where the separation of least significant bytes (LSBs) and most significant bytes (MSBs) of the TSF timer can lead to synchronization errors due to generation and processing delays.

Innovation Solution

The solution involves generating a frame with a first field containing the time stamp and a second field with one or more bits representing the TSF Rollover Flag, which is included in the Capability Information field of the Short Beacon Compatibility element, allowing the receiving device to determine if a rollover has occurred by comparing the TSF Rollover Flag with the adjusted Timestamp field, and updating the TSF timer accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the TSF timer is separated into LSBs and MSBs for transmission in different fields, then the frame size is reduced and processing efficiency is improved, but synchronization errors occur due to generation and processing delays

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidsynchronization accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A TSF Rollover Flag is introduced as an intermediary element to detect and indicate timer rollover conditions. The flag is set based on comparing the current TSF timer value with the previous value, allowing the receiving device to identify whether a rollover has occurred between the transmission of LSBs and MSBs, thereby resolving the synchronization error problem while maintaining the separated field structure

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The TSF Rollover Flag is preliminarily set before transmitting the TSF timer values in the frame. By pre-calculating and indicating the rollover status in advance, the receiving device can correctly interpret the TSF timer values even when processing delays cause temporal separation between receiving different parts of the timer information

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If the TSF timer rollover is not properly detected, then the system complexity is reduced, but synchronization errors and communication reliability deteriorate

Engineering Contradiction:
Improvesystem complexityVSAvoidcommunication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The TSF Rollover Flag serves as a simple intermediary mechanism that adds minimal complexity to the system. Instead of implementing complex rollover detection algorithms, the flag provides a straightforward indication that can be easily processed by both transmitting and receiving devices, maintaining low system complexity while significantly improving communication reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The TSF Rollover Flag implements a feedback mechanism where the transmitting device monitors its own TSF timer for rollover conditions and feeds back this information in the frame. The receiving device uses this feedback to adjust its synchronization, creating a closed-loop system that maintains reliability without requiring complex error correction protocols

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3087788B1Time synchronization function timer rollover solutions
Publication Date: 2017.09.13 QUALCOMM INC
  • EP3087788B1 patent drawingFigure 1
  • EP3087788B1 patent drawingFigure 2
  • EP3087788B1 patent drawingFigure 3

AI summary

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer program products for time synchronization function (TSF) rollover solutions for short beacons. Aspects of the present disclosure provide an apparatus for wireless communications. The apparatus generally includes a processing system configured to generate a time stamp with a first value of a first portion of a counter and generate a frame including a first field with the time stamp and a second field having one or more bits with a second value of the first portion of the counter, and an interface configured to output the frame for transmission to a receiving device.