DRX Measurement in CELL_FACH State via Common Pattern

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Solution Overview

Problem

In the CELL_FACH state of wireless communications, WTRUs face challenges in performing inter-frequency and inter-RAT measurements due to overlapping E-DCH resource allocation and DRX periods, leading to potential downlink channel unavailability and inefficient data transmission, as well as unsynchronized DRX patterns among WTRUs, resulting in wasted capacity and delayed data rates.

Innovation Solution

The method involves modifying FACH measurement occasions for WTRUs with allocated E-DCH resources, allowing them to ignore or terminate E-DCH transmissions during measurement occasions, and enabling inter-frequency and inter-RAT measurements during DRX periods, using a common DRX pattern for all WTRUs to synchronize wake-up times for receiving common traffic.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If WTRUs perform inter-frequency and inter-RAT measurements during FACH measurement occasions, then measurement capability is improved, but downlink channel availability deteriorates due to E-DCH resource allocation conflicts

Engineering Contradiction:

Improveinter-frequency and inter-RAT measurement capabilityVSAvoiddownlink channel availability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies dynamics by making the DRX pattern configurable and adaptable. The network can dynamically adjust the DRX pattern parameters (cycle length, on-duration, offset) based on traffic conditions and measurement requirements, allowing the system to optimize between measurement performance and downlink availability rather than using fixed patterns

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements preliminary action by performing inter-frequency and inter-RAT measurements during the DRX on-duration when the WTRU is already awake and receiving downlink traffic. This eliminates the need for separate measurement gaps that would cause channel unavailability, as measurements are conducted in advance during the natural wake period

Inventive Principle:

Principle #10Preliminary action

2Use of energy by moving object

If WTRUs use individual DRX patterns, then battery consumption is reduced through discontinuous reception, but network capacity is wasted due to unsynchronized wake-up times for common traffic

Engineering Contradiction:

ImproveWTRU battery consumptionVSAvoidnetwork capacity utilization

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent applies universality by designing a common DRX pattern that serves multiple WTRUs simultaneously. The standardized pattern structure allows different WTRUs to share the same wake-up schedule for common traffic while still permitting individual optimizations, making the DRX mechanism universally applicable across multiple users with coordinated behavior

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges individual DRX operations with common traffic reception by aligning wake-up times. Multiple WTRUs combine their reception activities during synchronized on-durations, allowing the network to deliver common traffic to multiple users simultaneously rather than requiring separate transmissions, thus improving capacity utilization

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If WTRUs synchronize DRX patterns for common traffic reception, then network capacity efficiency is improved, but measurement flexibility deteriorates due to constrained wake-up scheduling

Engineering Contradiction:

Improvenetwork capacity efficiencyVSAvoidmeasurement scheduling flexibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent segments the DRX operation into two independent components: a common synchronized pattern for coordinate reception and individual measurement opportunities during the on-duration. This segmentation allows the system to maintain synchronization benefits while preserving measurement flexibility, as each component operates independently within the overall framework

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10560852B2Method and apparatus for performing discontinuous reception and downlink inter-frequency and inter-radio access technology measurements in CELL_FACH state

Publication Date: 2020.02.11 INTERDIGITAL PATENT HOLDINGS INC

AI summary

A method and apparatus of performing discontinuous reception (DRX) and downlink inter-frequency and inter-radio access technology (RAT) measurements in CELL_FACH state are disclosed. While in DRX mode, a wireless transmit/receive unite (WTRU) may perform inter-frequency and inter-RAT measurements in a measurement occasion that fall into a DRX period. The WTRU may take the measurements on first predetermined number of frame in which a DRX frame would coincide after a last reception frame if DRX operation was ongoing. The WTRU may periodically wake up for downlink reception in CELL_FACH state in accordance with common DRX pattern that is common to all WTRUs in a cell or may wake up from DRX upon reception of the order and receiving a common traffic.