MBSFN Subframe Allocation Signaling for Mixed Carrier Networks

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Solution Overview

Problem

Current multimedia broadcast/multicast service (MBMS) solutions, such as 3GPP MBMS, face challenges in efficiently signaling MBSFN subframe allocation to user equipment (UEs), which affects decoding efficiency and power saving, particularly due to limited reference symbols in MBSFN subframes and interference with unicast transmissions.

Innovation Solution

A method and apparatus for efficiently signaling MBSFN subframe allocation using a two-level allocation scheme, where MBSFN radio frames are allocated on a macro level and subframes within these frames are assigned on a micro level, utilizing a bitmap and allocation order to indicate MBSFN subframes, allowing flexible and power-efficient signaling while minimizing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If MBSFN subframes are allocated with reduced reference symbols to enable efficient broadcasting, then channel capacity is improved, but terminal measurement capability deteriorates

Engineering Contradiction:
Improvechannel capacityVSAvoidterminal measurement capability
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the radio frame into different subframe types (MBSFN subframes with reduced reference symbols for broadcasting and regular subframes with full reference symbols for measurements). This allows the system to optimize each subframe type for its specific function, achieving high channel capacity for MBSFN while preserving measurement capability in regular subframes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic subframe allocation where the eNodeB can flexibly configure which subframes are MBSFN subframes and which are regular subframes based on traffic conditions and measurement needs. This dynamic configuration allows the system to adaptively balance between broadcasting efficiency and measurement capability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If MBSFN subframe allocation is signaled in system information, then terminal awareness is improved, but signaling overhead increases

Engineering Contradiction:
Improveterminal awarenessVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the signaling information into two parts: a compact bitmap indicating which radio frames contain MBSFN subframes, and an allocation pattern that defines the subframe structure. This segmentation reduces the total signaling overhead compared to transmitting complete allocation details for every subframe.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses preliminary signaling in system information to provide terminals with advance knowledge of MBSFN subframe allocation patterns. This allows terminals to prepare for efficient decoding and measurement in upcoming subframes without requiring continuous signaling updates.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If MBSFN and unicast transmissions share the same carrier, then spectrum utilization is improved, but interference between transmission types increases

Engineering Contradiction:
Improvespectrum utilizationVSAvoidinterference between transmission types
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the time domain by alternating MBSFN subframes and unicast subframes within the same carrier. This temporal segmentation allows both MBSFN broadcasting and unicast transmissions to share the frequency spectrum without mutual interference, as each subframe type is dedicated to its specific transmission mode.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different transmission characteristics to different subframes within the same carrier. MBSFN subframes use broadcast-specific parameters (reduced reference symbols, synchronized transmission) while unicast subframes use unicast parameters, allowing each transmission type to optimize its performance locally without affecting the other.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2258121B1Apparatus and method for allocation of subframes on a mixed carrier
Publication Date: 2016.10.26 NOKIA TECHNOLOGIES OY
  • EP2258121B1 patent drawingFigure 1
  • EP2258121B1 patent drawingFigure 2
  • EP2258121B1 patent drawingFigure 3

AI summary

Methods and apparatus, including computer program products, are provided for allocating subframes of a mixed carrier. In one aspect, there is provided a method. The method may include allocating subframes within radio frames transmitted to a user element. Moreover, the method may include transmitting, to the user element, a message comprising an indication of the allocation. The indication may be representative of the allocation within the subframes of consecutive radio frames, without the indication identifying the radio frames including the allocated subframes. Related apparatus, systems, methods, and articles are also described.