RedCap UE Identification via LCID Segmentation

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Solution Overview

Problem

Current technologies face challenges in identifying and managing reduced capability user equipment (RedCap UE) during RRC idle or inactive states, particularly in efficiently enabling network access control and ensuring compatibility with existing NR specifications.

Innovation Solution

The solution involves using a logical channel identifier (LCID) field in the MAC service data unit or MAC control element to convey an indication of RedCap UE during MsgA or Msg3 of the Random Access procedure, allowing network operators to identify and restrict access to RedCap devices without extending the size of RRC messages or using spare bits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing NR specifications are used for UE identification, then compatibility with legacy systems is maintained, but RedCap UE cannot be identified in RRC idle or inactive states

Engineering Contradiction:

Improveidentification accuracyVSAvoidstate coverage

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the LCID field into multiple values to represent different UE types. Specific LCID values are assigned to indicate RedCap UEs, while other values represent legacy UEs. This segmentation allows the system to distinguish between different UE categories without creating a new identification field, thereby maintaining backward compatibility while enabling RedCap UE identification in all RRC states.

Inventive Principle:

Principle #1Segmentation

2Reliability

If new identification fields are added to RRC messages, then RedCap UE identification capability is improved, but signaling overhead increases

Engineering Contradiction:

Improveidentification capabilityVSAvoidsignaling overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent makes the existing LCID field universal by assigning it multiple functions. The same LCID field that traditionally identified logical channels now also serves to identify UE types (RedCap vs. legacy). This multi-functionality eliminates the need for separate identification fields, thereby improving RedCap UE identification capability without increasing signaling overhead.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Quantity of substance

If LCID field values are reused for RedCap indication, then signaling overhead is reduced, but ambiguity in field interpretation may occur

Engineering Contradiction:

Improvesignaling overheadVSAvoidfield interpretation clarity

Core Design Contradiction:

Quantity of substanceVSLoss of information

Solution Approach 1:

The patent applies local quality by assigning specific LCID values with specific meanings in specific contexts. Certain reserved LCID values are designated exclusively for RedCap UE indication, while other values maintain their traditional logical channel identification function. This localized assignment of meanings to different LCID values eliminates ambiguity in field interpretation while maintaining efficient signaling.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP4115694B1Redcap UE identification

Publication Date: 2024.11.06 NOKIA TECHNOLOGIES OY

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AI summary

During an RRC Connection setup or resume procedure, a user equipment may explicitly identify itself to the network using Msg3. Rather than using the spare bit or including additional bits in Msg3, one or more values of the LCID field of the MAC sub-header of the MAC PDU may be used to identify a reduced capability user equipment. The one or more LCID field values that can identify a reduced capability user equipment may also be configured to identify a common control channel service data unit size. A plurality of LCID field values may be defined to identify varies types of RedCap UEs.