False NACK Signaling for Dual-SIM Tune-Away Throughput
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Solution Overview
Problem
In dual-subscriber identity module (SIM) devices, the need to periodically tune away from an active data session to receive control data from a secondary subscription leads to reduced data throughput due to the transceiver being occupied for extended periods, especially during base station registration, and cannot be completely avoided as essential messages must be received.
Innovation Solution
The method involves sending 'false' or 'fake' NACK/Tx messages prior to the tune-away period to keep the eNB busy with retransmissions, allowing the UE to recover after tune-away by acknowledging already received messages, thus minimizing disruption to the active data session.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the transceiver tunes away to the second subscription to receive control data, then the second subscription can receive essential paging messages, but the data throughput on the first subscription is reduced
Solution Approach 1:
The system performs preliminary actions by sending false NACK messages before the tune-away period begins. This triggers the eNB to prepare and queue retransmissions in advance, so that when the UE returns from tune-away, the retransmissions are already available and can be immediately acknowledged, minimizing data loss and throughput reduction.
Solution Approach 2:
The system applies preliminary anti-action by proactively sending false negative acknowledgments to prevent the harmful effect of data loss during tune-away. By anticipating the upcoming tune-away period, the UE triggers retransmissions beforehand, counteracting the potential data loss that would occur if the UE were to tune away before receiving and acknowledging the data.
2Reliability
If the transceiver holds radio resources for base station registration, then the second subscription can complete software processing, but the data session on the first subscription is interrupted for longer periods
Solution Approach 1:
The system performs preliminary actions by triggering retransmissions before the extended tune-away period for base station registration. The eNB queues these retransmissions and makes them available when the UE returns, ensuring that data transfer can resume immediately without prolonged interruption to the data session.
3Productivity
If false NACK messages are sent prior to tune-away, then data throughput is maintained by keeping eNB busy with retransmissions, but additional signaling overhead is introduced
Solution Approach 1:
The system changes parameters by selectively sending false NACK messages only when specific conditions are met, such as when the upcoming tune-away period exceeds a threshold duration or when the data session is in a particular state. This conditional approach minimizes unnecessary signaling overhead while maintaining data throughput during critical tune-away periods.
Data Source
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AI summary
A method, device and system provide improved throughput for network subscriptions in multi-SIM, multi-standby wireless devices by triggering false or fake NAK/Tx messages prior to the tune-away. The technique includes receiving and decoding communications from a node at a user equipment during a first subscription communication mode; in response to a communication from the node to the user equipment after a certain time period prior to a tune away period in which the user equipment communicates in a second subscription communication mode, communicating a fake NACK message from the user equipment to the node; and after the tune away period ends, receiving communications at the user equipment from the node and responding with an ACK message.