RRC Inactive Data Transmission Resource Allocation

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Solution Overview

Problem

In the NR system, inactive UEs face challenges with small data transmission due to unknown channel conditions and limited bandwidth allocation, leading to increased overhead, delay, and reduced coverage when transmitting larger messages, as the scheduler must use a low coding rate and limited transport block size, and the network cannot allocate physical resource blocks outside the minimum bandwidth for synchronization signal block transmission.

Innovation Solution

The method involves determining a desired resource for message 3 transmission based on the terminal device's capability and message size, allowing for multiple-slot scheduling or bandwidth allocation, which is requested via message 1 transmission, enabling the network to perform enhanced scheduling for small data transmission and supporting larger data size transmission in the RRC inactive state, thereby reducing overhead and delay and increasing coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the network uses a low coding rate for scheduling inactive UEs due to unknown channel conditions, then transmission reliability is improved, but the transport block size is limited and overhead increases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidtransport block size
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by having the UE indicate its capability and preferred scheduling parameters in advance through message 1 transmission. The UE provides information about its buffer status, channel conditions, and scheduling preferences before the actual data transmission, allowing the network to make informed scheduling decisions without relying on low coding rates. This preliminary information exchange enables the network to allocate appropriate resources and select optimal coding rates, thereby increasing transport block size while maintaining transmission reliability.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If the network allocates resources within the minimum bandwidth for synchronization signal block transmission, then device complexity is reduced, but coverage and data transmission efficiency are limited

Engineering Contradiction:
Improvebandwidth allocation complexityVSAvoidcoverage area
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent applies dynamics by enabling flexible and adaptive bandwidth allocation based on UE capabilities and transmission requirements. Instead of being constrained to a fixed minimum bandwidth, the network can dynamically allocate broader bandwidth resources when needed for larger data transmissions. The UE indicates its capability to handle different bandwidth allocations, and the network adapts its resource allocation accordingly, allowing coverage and transmission efficiency to be enhanced without permanently increasing device complexity.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the network performs enhanced scheduling with multiple-slot allocation and bandwidth adaptation, then data transmission efficiency is improved, but scheduling complexity increases

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidscheduling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies self-service by having the UE actively participate in the scheduling process by indicating its own capabilities, buffer status, and preferred scheduling parameters. The UE essentially serves itself by providing the network with the information needed to make optimal scheduling decisions, reducing the burden on the network to perform complex scheduling algorithms. This self-service approach enables enhanced scheduling with multiple-slot allocation and bandwidth adaptation while keeping scheduling complexity manageable, as the UE has already performed much of the analysis and provided recommendations.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3498017B1Method and device for data transmission
Publication Date: 2022.08.10 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3498017B1 patent drawingFigure 1~2
  • EP3498017B1 patent drawingFigure 3~5
  • EP3498017B1 patent drawingFigure 6~7

AI summary

A method and device for data transmission. A terminal device determines a desired resource for transmitting message 3 according to the capability of the terminal device and the size of message 3; and transmits a request for the desired resource via message 1 transmission. With the method and the device, overhead and delay of small data transmission may be reduced, larger data size transmission in RRC inactive state may be supported, and coverage may be increased.