Buffer Status Report Coordination in Carrier Aggregation

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Solution Overview

Problem

In scenarios where a small cell and a macro base station jointly provide data services to a user equipment, they struggle to accurately learn buffer status reports (BSRs) due to existing technologies' inability to coordinate BSRs across multiple base stations, leading to inefficient scheduling.

Innovation Solution

A method is introduced where a macro base station sends indication information to the user equipment (UE) to request and receive BSRs, using traffic distribution ratio information or logical channel priority parameters to determine and send BSRs to both the macro base station and small cells, ensuring accurate and timely scheduling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple base stations (small cell and macro base station) jointly serve a UE, then service coverage and capacity are improved, but the base stations cannot accurately learn the buffer status report (BSR) reported by the UE

Engineering Contradiction:
Improveservice capacityVSAvoidbuffer status report accuracy
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent segments the BSR information by introducing separate logical channel groups (LCGs) for different base stations. The UE maintains separate LCGs for macro base station and small cell, allowing independent BSR reporting for each base station's buffered data. This segmentation enables accurate BSR reporting while maintaining multi-base station service capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism through the macro base station that collects and forwards BSR information to the small cell. The macro base station acts as a mediator that receives BSR from UE, determines which small cell should receive the BSR based on configured relationships, and forwards the appropriate BSR information, ensuring all base stations obtain accurate buffer status information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If BSRs are sent separately to each base station, then scheduling accuracy for each base station is improved, but the complexity of BSR management and coordination increases

Engineering Contradiction:
Improvescheduling accuracyVSAvoidBSR management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a universal BSR reporting framework where a single BSR message from the UE can serve multiple base stations. The macro base station receives the BSR and distributes it to appropriate small cells based on pre-configured relationships. This multi-functional approach allows one BSR to fulfill scheduling needs for multiple base stations without requiring separate BSR messages for each.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements preliminary action by pre-configuring the relationships between macro base station and small cells before BSR reporting occurs. The network configures LCG mappings and base station relationships in advance, so when BSR needs to be reported, the UE and base stations already have the necessary mapping information ready, eliminating the need for complex real-time coordination and reducing management overhead.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the UE sends uplink data to multiple base stations separately, then data transmission reliability is improved, but the base stations cannot perform scheduling in a timely manner

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidscheduling delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent enables continuous scheduling by ensuring all base stations have access to BSR information simultaneously. The macro base station receives BSR from UE and immediately forwards it to relevant small cells without delay. This continuous information flow allows all base stations to perform scheduling decisions concurrently rather than waiting for separate BSR arrivals, eliminating scheduling delays while maintaining reliable multi-base station data transmission.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2905992B1Methods for transmitting and receiving buffer status report, user equipments and base stations
Publication Date: 2018.08.29 HUAWEI TECH CO LTD
  • EP2905992B1 patent drawingFigure 1~2
  • EP2905992B1 patent drawingFigure 3~4
  • EP2905992B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention provide a method for sending and receiving a buffer status report, a user equipment, and a base station. The method includes: receiving indication information that is sent by a macro base station and that is used to request a user equipment UE to send a buffer status report, and sending a buffer status report BSR to the macro base station and/or at least one small cell according to the indication information, where the macro base station and the at least one small cell jointly serve the UE, and a service area of the macro base station is larger than a service area of each small cell of the at least one small cell.