Unlicensed Carrier Sub-Frame Occupation Strategy for LTE

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing data transmission methods for LTE systems using unlicensed carriers face challenges in efficiently managing frame structures, leading to high interference and resource wastage, particularly due to limitations in Frame-Based Equipment (FBE) and Load-Based Equipment (LBE) frame structures, which affect spectrum efficiency and compliance with regional control requirements.

Innovation Solution

A data transmission method that determines a sub-frame occupation strategy after successfully preempting an unlicensed carrier through Clear Channel Assessment (CCA) or Extended Clear Channel Assessment (eCCA), optimizing the number and timing of sub-frames occupied, and integrating uplink and downlink designs to maximize resource utilization and compliance with regional regulations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If FBE frame structure is used, then implementation simplicity is achieved, but resource wastage increases due to fixed time occupation and idle sub-frame preemption

Engineering Contradiction:
Improveimplementation simplicityVSAvoidresource wastage
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent introduces a dynamic frame structure that combines elements of both FBE and LBE. The frame structure can adaptively switch between fixed-duration occupation (FBE-like) and variable-duration occupation (LBE-like) based on channel conditions and data transmission needs, thereby reducing resource wastage while maintaining implementation feasibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent modifies the frame structure parameters by introducing flexible frame durations and variable sub-frame allocations. Instead of fixed time slots, the system can adjust frame lengths and sub-frame positions dynamically, allowing better resource utilization and reducing idle time wastage.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If FBE frame structure is used, then fixed time occupation is achieved, but preemption success probability decreases due to single CCA opportunity

Engineering Contradiction:
Improvefixed time occupationVSAvoidpreemption success probability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent implements multiple CCA opportunities within each frame structure, allowing data transmission sites to perform channel assessments at multiple predetermined points. This preliminary repeated action increases the probability of successful preemption while maintaining structured time occupation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces periodic CCA opportunities at regular intervals within the frame structure. This periodic assessment mechanism ensures that multiple chances are provided for successful channel preemption while maintaining the structured and predictable nature of frame-based operation.

Inventive Principle:
Principle #19Periodic action

3Productivity

If LBE frame structure is used, then resource utilization is improved, but system complexity increases due to timing mechanism modifications

Engineering Contradiction:
Improveresource utilizationVSAvoidtiming mechanism modification
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the LBE frame structure into standardized sub-frames with defined functions. By dividing the variable frame into consistent modular units, the system achieves flexible resource allocation while reducing the complexity of timing mechanisms through repetition of standardized patterns.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent designs a universal frame structure that can serve multiple purposes - supporting both fixed and variable duration transmissions, accommodating different CCA opportunities, and maintaining compatibility with existing LTE timing mechanisms. This multi-functionality reduces the need for separate specialized mechanisms.

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

4Productivity

If LBE frame structure is used, then variable frame length is achieved, but interference risk increases when adjacent sites simultaneously preempt

Engineering Contradiction:
Improvevariable frame lengthVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements feedback mechanisms where data transmission sites monitor channel conditions and adjust their preemption behavior based on observations of other sites. This feedback loop allows variable frame lengths to be utilized while coordinating transmissions to avoid simultaneous interference.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces preliminary channel assessment and coordination mechanisms that prevent adjacent sites from simultaneously preempting the same resource. By performing preliminary checks and establishing coordination protocols before variable-duration transmissions, the system avoids the harmful interference that would result from simultaneous preemptions.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP3253146B1Data transmission method and data transmission site
Publication Date: 2022.10.12 ZTE CORP
  • EP3253146B1 patent drawingFigure 1~2
  • EP3253146B1 patent drawingFigure 3~4
  • EP3253146B1 patent drawingFigure 5~6

AI summary

Some embodiments provide a data transmission method and a data transmission site. In the method, a sub-frame occupation strategy is determined after a data transmission site successfully preempts an unlicensed carrier by executing Clear Channel Assessment or Extended Clear Channel Assessment (CCA/eCCA); and data transmission is performed according to the sub-frame occupation strategy. According to the solution, a constraint of a frame of Frame-Based Equipment (FBE) is taken into consideration, so that a parameter related to a timeslot in the frame may continue adopting a design of Long Term Evolution (LTE) system, and simplicity for implementation is further ensured. In addition, by the solution, the problem of boundary constraint of the frame of the FBE is also solved, and characteristics of Load-Based Equipment (LBE) are maximally supported, so that related advantages of the LBE are achieved, and few resources are wasted. Some embodiments also provide a computer storage medium.