Back in September 2018 Apple's SVP of Worldwide Marketing introduced eSIM and Dual SIM with iPhone XS and XS Max. The video below presents that part of the keynote outlining these new technologies. The video is set up to start at the 1:17:30 mark of the keynote. You could stop it 2 minutes later when that segment is over. 

In January of this year Patently Apple posted a report titled "Apple's Patent covering iPhone eSIM and Dual SIM Reveals that it was first filed in China." 

Today the US Patent & Trademark Office published a patent application from Apple that generally relate to wireless communications, and more particularly, to methods and apparatus to support access to services for multiple subscriber identity modules (SIMs) simultaneously by a single-radio, multiple SIM (multi-SIM) wireless device. It's a much deeper patent than the one that we covered back in January.

Apple notes in their patent filing that users of wireless devices can seek to access services provided by a common cellular wireless network service provider for different cellular service account subscriptions or provided by different cellular wireless network service providers through different cellular wireless networks.

A user can obtain and use a variety of UICCs, also referred to as SIM cards, and/or install multiple electronic SIMs (eSIMs) on an eUICC of the wireless device, where the SIMs/eSIMs provide access to services for one or more service providers. Use of multiple SIMs/eSIMs allows for flexibility and convenience to access a broader variety of services by the wireless device. A user can seek to access services provided by multiple SIMs/eSIMs without having to use a wireless device that can connect to multiple associated radio access networks of the cellular wireless networks associated with the multiple SIMs/eSIMs at the same time.

The wireless device includes a first SIM/eSIM that provides for access to wireless services of a first wireless service provider via a first cellular wireless network that includes a first radio access network using a first radio access technology and a first core network.

The wireless device also includes a second SIM/eSIM that provides for access to additional wireless services, which may be for the same first wireless service provider, e.g., using a common, serving public land mobile network (PLMN), or for a second wireless service provider via a second cellular wireless network that includes a second radio access network using a second (possibly distinct) radio access technology and a second core network, e.g., using distinct serving PLMNs. In some embodiments, the wireless device includes multiple SIMs/eSIMs that provide for access to wireless services of one or more wireless service providers.

In a first mechanism, the wireless device establishes parallel, linked protocol data unit (PDU) sessions, one PDU session for a first SIM and a second, tunneled PDU session using a second SIM, on behalf of the first SIM, where only one PDU session is active at a time. A SIM of the wireless device can have access to subscription information for one or more other SIMs and can provide information regarding at least one of the one or more other SIMs during an Internet Protocol Multimedia Subsystem (IMS) registration process, during a non-access stratum (NAS) registration procedure with a cellular wireless core network, and/or when requesting establishment of parallel PDU sessions. The first and second SIMs can be associated with a common PLMN or with different PLMNs. Accumulated data usage and/or time accounting for tunneled access carried via the tunneled PDU session using the second SIM, on behalf of the first SIM, can be applied for billing purposes to the first SIM.

In a second mechanism, the wireless device includes subscriber identification information, e.g., a 5G globally unique temporary identity (GUTI) of a subscription that originates data traffic, within a protocol header field to allow cellular wireless access network element, e.g., a gNodeB, to determine from which of multiple SIMs a data packet originated. The cellular wireless access network element separates the multiplexed traffic from multiple SIMs and appropriately routes the traffic via distinct parallel tunnels to one or more cellular wireless core networks.

In a third mechanism, the wireless device creates, using a first, active SIM, an additional dedicated bearer for each data network name (DNN) over which to route traffic for a second, suspended SIM. In some embodiments, a cellular wireless network initiates creation of the additional dedicated bearer in response to a first SIM informing the cellular wireless network that the first SIM will be suspended, e.g., due to a tune-away of cellular wireless circuitry to another cellular wireless network associated with a second SIM. Data traffic for the first SIM can be routed through the dedicated bearer based on subscription information, e.g., international mobile subscriber identity (IMSI), fifth-generation globally unique temporary identity (5G-GUTI), mobile station international subscriber directory number (MSISDN), subscription permanent identifier (SUPI), or subscription concealed identifier (SUCI) values, as well as network node identifiers, e.g., access point name (APN) or data network name (DNN) values. When the first SIM is resumed, the dedicated bearer for the first SIM via the second SIM can be released.

Apple's patent FIG. 1 below illustrates an example of a multiple subscriber identity module (SIM)/electronic SIM (eSIM) wireless device communicating with two wireless networks.

Apple's patent FIG. 2 above illustrates diagrams of exemplary multi-SIM/eSIM wireless devices that support multiple subscriber identities using removable UICCs and/or embedded UICCs (eUICCs) with SIMs and/or eSIMs implemented thereon. Three different configurations are noted above in color coded boxes.

To dive deeper into Apple's patent application number 20210136849, click here.