Dual-SIM Call Handover Across VoLTE, VoNR, and VoWiFi
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Solution Overview
Problem
Multi-SIM wireless communication devices face challenges in maintaining simultaneous active calls due to the exclusive use of radio frequency resources, leading to suspended or dropped calls when a new call request occurs during an ongoing call.
Innovation Solution
The wireless communication device implements a method to perform a handover from one radio access technology to another, allowing simultaneous active calls by managing radio access technologies like VoLTE, VoNR, and VoWiFi, and utilizing a radio frequency integrated circuit to control SIMs for concurrent call handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dual SIM dual standby (DSDS) device performs a wireless call connection through a first SIM, then the first SIM occupies the radio frequency resource, but when a new wireless call request for a second SIM occurs, the device must terminate the existing call or reject the new call connection
Solution Approach 1:
The patent implements dynamic radio access technology selection and handover mechanisms that allow the system to adapt its resource allocation in real-time. When a call is active on the first SIM, the system can dynamically switch the second SIM to use alternative access technologies (such as Wi-Fi for voice calls) instead of being restricted to cellular networks only, enabling simultaneous call handling without terminating existing calls
Solution Approach 2:
The system changes the operational parameters of SIM cards by allowing them to operate on different radio access technologies simultaneously. The first SIM may use traditional cellular networks (4G/5G) while the second SIM uses Wi-Fi-based voice services, effectively changing the network parameter from exclusively cellular to a multi-network configuration that supports concurrent calls
2Reliability
If the first SIM occupies the radio frequency resource for an active call, then the radio frequency resource is dedicated to the first call, but the second SIM cannot simultaneously access the same resource for a new call
Solution Approach 1:
The patent segments the radio access resources by dividing them into different technology domains - cellular network resources for the first SIM and Wi-Fi network resources for the second SIM. This segmentation allows each SIM to access dedicated resources appropriate to its selected access technology, enabling simultaneous call operations without resource conflicts
Solution Approach 2:
The system introduces an intermediary layer (the radio access technology selection mechanism) that mediates between the SIM cards and the available network resources. This intermediary intelligently routes the second SIM's call requests to alternative networks (Wi-Fi) when cellular resources are occupied, enabling concurrent call handling while maintaining call stability
Data Source
AI summary
Wireless communication device including one or more SIMs and operating method thereof are provided. The operating method includes performing a first call with a first device using a first SIM, the first call being based on a first RAT, receiving a connection request for a second call from a second device using a second SIM, the connection request for the second call being based on the first RAT, determining whether the first SIM is to perform a handover to a second RAT for the first call, performing the handover of the first call to the second RAT in response to determining the first SIM is to perform the handover to the second RAT, and contemporaneously performing the second call and the first call after the performing the handover of the first call to the second RAT, the first call being performed using the first SIM, the first RAT including at least one of VoLTE or VoNR, and the second RAT including VoWiFi.