MBS Downlink HARQ Combining for Reliable Data Decoding

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Solution Overview

Problem

The existing Long Term Evolution (LTE) technology does not support Hybrid Automatic Repeat Request (HARQ) transmission for Multicast and Broadcast Service (MBS), leading to decreased decoding success rates and increased packet loss rates due to repeated data transmissions that cannot be combined or decoded.

Innovation Solution

Implementing a Hybrid Automatic Repeat Request (HARQ) process for MBS services, allowing terminals to combine and decode repeatedly sent data, thereby improving decoding success rates and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If MBS service uses one-time sending without HARQ transmission, then the system complexity is low, but the decoding success rate decreases and packet loss rate increases

Engineering Contradiction:

Improvesystem complexityVSAvoiddecoding success rate

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces dynamic HARQ processes for MBS service, allowing the system to adaptively combine repeated data transmissions. The terminal device maintains multiple HARQ processes and dynamically combines received data packets, transforming the static one-time sending into a dynamic retransmission mechanism that improves decoding success rate while managing system complexity through standardized procedures

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission parameter from single-send to multi-send with HARQ combining. By modifying the transmission mode to support repeated sending and combining at the terminal, the system achieves improved reliability without proportionally increasing complexity, as the combining operation follows defined protocols

Inventive Principle:

Principle #35Parameter changes

2Reliability

If MBS service implements repeated sending without HARQ combination, then the data transmission coverage is improved, but the packet loss rate increases due to inability to combine data

Engineering Contradiction:

Improvesending reliabilityVSAvoidpacket loss rate

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent implements HARQ combination at the terminal device, where multiple repeated data transmissions are merged together. The terminal maintains HARQ buffer and combines received packets using defined combining rules, transforming separate transmissions into a unified decoded result, thereby reducing packet loss rate while maintaining sending reliability

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent enables continuous data transmission through HARQ retransmission mechanism. Instead of single-send followed by stop, the system continuously transmits and combines data packets until successful decoding or maximum retries, ensuring continuous useful action and reducing overall packet loss through persistent transmission attempts with combining

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS12425136B2Downlink data receiving method, downlink data sending method, and device

Publication Date: 2025.09.23 VIVO MOBILE COMM CO LTD

AI summary

A downlink data receiving method, a downlink data sending method, and a device are provided. The downlink data receiving method includes: obtaining a Hybrid Automatic Repeat Request (HARQ) process of an Multicast and Broadcast Service (MBS) service; and receiving downlink data of the MBS service according to the HARQ process. In the embodiments of the present disclosure, a specific MBS service can be sent and retransmitted through a corresponding HARQ process, so that a terminal can combine and decode data repeatedly sent by a network side for a plurality of times.