On Thursday the US Patent & Trademark Office published a patent application from Apple that relates to the field of wireless communication, and more particularly to a user equipment (UE) having multiple subscriber identity modules which performs improved network notification during SIM suspend/resume operations. The iPhone XS, and XS Max were the first iPhones to use Apple's eSIM for most of the world while iPhones in China came with a Dual SIM.
To ensure that the iPhone would be adequately protected for this feature in China, Apple first filed this patent in China on July 10, 2019 as noted in the partial graphic of patent docket below. Their US filing, revealed on Thursday by USPTO, was originally filed on June 29, 2020, almost a year after their Chinese filing.
Apple also noted in their patent that "Dual SIM or multi-SIM UE devices have been especially popular in more recently developing economies such as China."
Apple's invention covers devices and associated methods for operating a dual-subscriber identity module (SIM) dual-standby (DSDS) user equipment device (UE) configured with a first SIM and a second SIM. The UE performs communications with a first cellular network using the first SIM and a first radio resource control (RRC) connection, and receives a request to perform a higher priority communication using the second SIM. In response to the request to perform the higher priority communication, the UE transmits a request to the first network to suspend the first RRC connection. After transmission of the request to suspend the first RRC connection, the UE receives a message from the first network to place the first RRC connection in an inactive state, and initiates a timer, wherein the timer is used to determine whether the first RRC connection remains in the inactive state or transitions to an idle state.
As shown in Apple's patent FIG. 4 below the iPhone (UE #106) may also include two or more subscriber identity modules (SIMs) 360 and 362. One or both of SIMs 360 and 362 may be implemented as an embedded SIM (eSIM).
As one example, a SIM #360 may be an application which executes on a Universal Integrated Circuit Card (UICC). Alternatively, or in addition, one or both of SIMs 360 and 362 may be implemented as removeable SIM cards.
Each SIM (#360 or #362) may include a number of types of information, including personalized information specific to a user and/or device (e.g., personalized information), and information that is not specific to a user and/or device (e.g., common information). The personalized information may include user/unit specific data, for example information identifying the user/unit to their carrier's network, personalized authorization and/or security information, etc. Some or all of the personalized information may be used as a subscriber identity for an iPhone, for example in order to identify an iPhone to a carrier's network and to obtain cellular service from the carrier.
Apple introduced dual SIM, eSIM and more during their 2018 iPhone event. The video below is set to start exactly when Phil Schiller introduces these new features for iPhone. We can't set the end of that segment, so stop the video when that segment is done.
Wireless buffs and engineers could review Apple's patent application number 20210014934 here for more details. It would appear that this is now a patent fulfilled.
For those unfamiliar with Dual-SIM and eSIM for iPhones, you could check out C/Net's article titled "Dual-SIM and eSIM on Apple's 2018 iPhones: Everything you need to know," here.