DSDS UE Synchronization Recovery via Uplink Control Channel

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Solution Overview

Problem

Dual SIM Dual Standby (DSDS) user equipment (UE) experiences synchronization loss and increased signaling response round trip time due to RF gaps, leading to false network transmission cessation and delayed data link layer recovery, as the network decodes noise as actual information during RF pauses.

Innovation Solution

The DSDS UE independently maintains transmission by detecting RF resume events and transmitting uplink dedicated physical control channels irrespective of downlink DPCCH signal-to-interference ratio quality, and initiates data link layer recovery without waiting for a poll timer expiration, allowing for faster bursty data receptions and reducing signaling response delays by differentiating between time-critical and non-time-critical pause requests.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If RF gaps are created for stack-1 to maintain paging reception and measurements on stack-2, then paging reception and measurements are maintained, but physical layer synchronization is lost and noise is transmitted during RF void intervals

Engineering Contradiction:

Improvepaging reception capabilityVSAvoidphysical layer synchronization

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by having the DSDS UE transmit padding bits during RF gaps before actual data transmission resumes. This preliminary transmission of known padding sequences allows the network to maintain synchronization expectations, so when real data arrives, the network is already prepared to correctly interpret the signal, preventing synchronization loss due to RF gaps

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses padding bits as an intermediary element between the RF gap and actual data transmission. These padding bits act as a bridge that maintains the expected signal structure during gaps, allowing the network to transition smoothly from gap state to data reception state without experiencing synchronization disruption

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the network decodes noise as actual information during RF pauses, then continuous transmission attempt is maintained, but false network transmission cessation occurs and synchronization is lost

Engineering Contradiction:

Improvetransmission continuityVSAvoidsynchronization accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent converts the harmful noise transmitted during RF gaps into a beneficial synchronization mechanism. By transmitting known padding bits during gaps, the noise that would normally cause synchronization loss is transformed into a predictable signal pattern that actually helps maintain synchronization expectations at the network side, turning a harmful effect into a useful one

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If the DSDS UE waits for poll timer expiration to detect missed PDUs, then network retransmission is triggered, but signaling response round trip time is increased

Engineering Contradiction:

ImprovePDU delivery assuranceVSAvoidsignaling response round trip time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the DSDS UE immediately detect and report missed PDUs upon RF resumption, before the network's poll timer expires. The UE proactively identifies the missing PDUs by comparing expected versus received packets and sends NACK signals immediately, eliminating the need to wait for the network's periodic polling and significantly reducing round trip time

Inventive Principle:

Principle #10Preliminary action

4Adaptability or versatility

If RF gaps are created temporarily for stack-1, then paging reception on stack-2 is maintained, but data link layer recovery is delayed

Engineering Contradiction:

Improvedual stack operation capabilityVSAvoiddata link layer recovery time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the DSDS UE immediately initiate data link layer recovery procedures upon RF resumption, before normal data transmission resumes. The UE proactively detects RF resumption events, identifies any missed PDUs, and triggers retransmission requests immediately, eliminating delays that would occur if recovery waited for network-initiated polling cycles

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10757667B2Method and user equipment for managing synchronization with network

Publication Date: 2020.08.25 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided is a method for managing synchronization with a network. The method includes detecting, by a dual SIM dual standby user equipment (a DSDS UE), a radio frequency resume event (an RF resume event); transmitting, by the DSDS UE, at least one uplink dedicated physical control channel (at least one UL-DPCCH) to the network in response to the RF resume event being detected, wherein the at least one UL-DPCCH is transmitted irrespective of a signal to interference ratio quality (an SIR quality) on a downlink dedicated physical control channel (a DL-DPCCH) of the network being below a first quality threshold; and managing, by the DSDS UE, a downlink (a DL) synchronization with the network.