Low-Cost UE Initial Access with Capability Signaling and Reject Handling

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently handling low-cost, low-complexity user equipment (MTC UEs) due to their limited radio frequency capabilities, particularly in performing initial access procedures within wideband system bandwidth networks.

Innovation Solution

A method and apparatus for low-cost UEs to transmit a list of capabilities to the network and receive reject messages when unsupported, utilizing separate control channels and resource allocations, and employing time/frequency division multiplexing for PRACH to facilitate initial access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If low-cost UEs use reduced RF/baseband complexity and smaller operating frequency bandwidth, then cost and battery consumption are reduced, but initial access procedure efficiency in wideband networks deteriorates

Engineering Contradiction:

Improvebattery consumptionVSAvoidinitial access procedure efficiency

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent segments the initial access procedure into multiple steps: capability transmission, network rejection message reception, and fallback to standard procedures. This allows low-cost UEs to efficiently indicate their limitations without requiring the network to process full wideband capabilities, thus maintaining access efficiency while accommodating reduced UE complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of capability indication by introducing a rejection message mechanism. Instead of requiring low-cost UEs to support all wideband parameters, the system allows parameter mismatch handling through explicit rejection signaling, enabling efficient initial access despite parameter differences between UE and network

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If low-cost UEs transmit capability lists to the network, then network compatibility is improved, but signaling overhead and access latency increase

Engineering Contradiction:

Improvenetwork compatibilityVSAvoidaccess latency

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having low-cost UEs transmit their capability lists during the initial access procedure before actual data transmission. This allows the network to pre-evaluate compatibility and send rejection messages if needed, preventing wasted transmission resources and reducing overall access latency despite the additional capability signaling

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12568008B2Method and apparatus for performing initial access procedure for low cost user equipment in wireless communication system

Publication Date: 2026.03.03 LG ELECTRONICS INC

AI summary

A method and apparatus for performing an initial access procedure in a wireless communication system is provided. A low cost user equipment (UE) transmits a list of capabilities to a network, and receives a reject message from the network when at least one of the capabilities is not supported by the network. The list of capabilities may be transmitted during a random access procedure via a random access preamble on a physical random access channel (PRACH) or a message 3 on a physical uplink shared channel (PUSCH). The reject message may be received during the random access procedure a random access response or an acknowledge message for the message 3.