PDCP RLC Data Traffic Management for Wireless Receivers

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Solution Overview

Problem

Conventional wireless communication systems face inefficiencies in managing out-of-order Protocol Data Units (PDUs), leading to wastage of network resources and increased power consumption due to unnecessary retransmissions and discarding of PDUs after the expiry of the PDCP reordering timer, especially in scenarios involving multiple Subscriber Identity Modules (MUSIMs) and RF tune-aways.

Innovation Solution

Implementing methods and systems that detect and recover out-of-order PDUs by initiating a RLC packet recovery timer and sending RLC status reports before the PDCP reordering timer expires, and enabling the delivery of old PDUs to higher layers if sequence number thresholds are met, thereby preventing unnecessary retransmissions and resource wastage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the PDCP layer initiates a reordering timer and waits for missing PDUs, then in-order delivery is achieved, but network resources are wasted due to continuous RLC ARQ retransmissions

Engineering Contradiction:

Improvein-order deliveryVSAvoidnetwork resource wastage

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements feedback mechanisms where the PDCP layer informs the RLC layer about the reordering timer status. When the reordering timer expires, the PDCP layer sends feedback to the RLC layer to stop ARQ retransmissions for missing PDUs, preventing continuous resource wastage while maintaining in-order delivery through the timer-based approach

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The PDCP layer performs preliminary action by starting the reordering timer before the RLC layer completes ARQ retransmissions. This preliminary timing mechanism allows the system to proactively stop unnecessary retransmissions once the timer expires, avoiding waste of network resources while ensuring in-order delivery is achieved

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the RLC layer continuously sends ARQ requests for missing PDUs, then recovery of out-of-order PDUs is attempted, but power consumption increases at the receiver

Engineering Contradiction:

ImprovePDU recoveryVSAvoidreceiver power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The PDCP layer provides feedback to the RLC layer about timer expiration status, enabling the RLC layer to stop ARQ retransmissions and avoid continuous power-consuming operations at the receiver while maintaining the ability to recover PDUs that arrive within the timer window

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the ARQ retransmission behavior based on the reordering timer status. The RLC layer transitions from active retransmission mode to idle mode when the timer expires, optimizing power consumption by adapting its operation to the actual delivery requirements

Inventive Principle:

Principle #15Dynamics

3Productivity

If the PDCP layer updates state variables after timer expiry, then progress is made, but old PDUs received later are discarded unnecessarily

Engineering Contradiction:

Improvestate variable updateVSAvoidPDU delivery

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The PDCP layer performs preliminary state variable updates only after confirming the reordering timer has expired and no more PDUs are expected. This preliminary check prevents premature updates that would cause legitimate old PDUs to be discarded, while still enabling progress when appropriate

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the reordering timer mechanism to control state variable updates. The timer expiration serves as a feedback signal that determines whether updating state variables is appropriate, preventing premature updates and ensuring reliable PDU delivery

Inventive Principle:

Principle #23Feedback

4Adaptability or versatility

If RF tune-away is performed for MUSIM operations, then multiple network support is enabled, but PDCP reordering timer behavior becomes problematic

Engineering Contradiction:

ImproveMUSIM supportVSAvoidreordering timer behavior

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adapts the reordering timer behavior based on RF tune-away events. When MUSIM operations require RF tuning, the timer mechanism is adjusted to account for the temporary unavailability, preventing premature expiration and maintaining reliable PDU delivery across multiple networks

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20240237116A9Methods and devices for managing data traffic in a wireless communication system

Publication Date: 2024.07.11 SAMSUNG ELECTRONICS CO LTD

AI summary

Embodiments herein disclose methods and devices for managing data traffic on a receiver. A method disclosed herein includes detecting, by a receiver, at least one out of order radio link control (RLC) protocol data unit (PDU) in a plurality of RLC PDUs received from a transmitter, performing, by the receiver, a recovery action based on a Packet Data Convergence Protocol (PDCP) reordering time to recover the at least one out of order RLC PDU; and causing, by the receiver, an RLC layer to send a plurality of RLC service data units (SDUs) to a higher layer after the performing the recovery action, the plurality of RLC SDUs corresponding to the plurality of RLC PDUs.