Optimizing cellular wireless network search by multiple SIM / ESIM wireless devices

Abstract

The present application relates to optimizing cellular wireless network searches by a wireless device supporting multiple subscriber identity modules (SIMs) and / or electronic SIMs (eSIMs). The wireless device includes at least two active SIM / eSIMs, each SIM / eSIM being associated with a different modem. A first modem performs a PLMN search and provides PLMN search results to a second modem that abandons or delays its own PLMN search. Once the first modem detects a PLMN, PLMN search results are provided, and the second modem may reside (or reselect) a higher / highest priority PLMN detected and reported by the first modem without waiting for additional PLMN search results. When a first modem of the wireless device is in a restricted or normal service mode, the second modem ignores a system information block (SIB) message for an emergency alert, and monitors the SIB message and provides access to emergency services in dependence on the first modem.

Description

Technical Field

[0001] The described embodiments relate to wireless communications, including methods and apparatus for optimizing cellular wireless network searches on a wireless device that supports multiple subscriber identity modules (SIMs) and / or electronic SIMs (eSIMs). Background Art

[0002] Many wireless devices are configured to use removable Universal Integrated Circuit Cards (UICCs) that enable the wireless device to access services provided by mobile network operators (MNOs), also known as carriers. Each UICC includes a microprocessor and read-only memory (ROM), where the ROM is configured to store a Subscriber Identity Module (SIM) profile, which the wireless device uses to register with the MNO and interact with the MNO to obtain wireless service via a cellular wireless network. Typically, a UICC takes the form of a small, removable card (often referred to as a SIM card) that is inserted into a UICC receiving area of the wireless device. In recent implementations, the UICC is embedded directly into the system board of the wireless device as an embedded UICC (eUICC), which can offer advantages over traditional removable UICCs. The eUICC may include rewritable memory that can facilitate the installation, modification, and / or deletion of one or more electronic SIMs (eSIMs) on the eUICC, where the eSIMs can provide access to new and / or different services and / or updates for extended features offered by the MNO. An eUICC can store multiple MNO profiles (also referred to herein as eSIMs) and eliminate the need to include a UICC reception area in a wireless device. A wireless device may include multiple SIMs and / or eSIMs to provide access to different cellular wireless service subscriptions. The wireless device may maintain a different modem software stack to support communications via each SIM and / or eSIM. When performing a public land mobile network (PLMN) search, such as when roaming, searching for a higher-priority PLMN, during an out-of-service (OOS) recovery process, or when in limited service mode, repeated PLMN searches across multiple SIMs / eSIMs waste computing resources and drain the mobile wireless device's limited battery power. Similarly, each software stack independently monitoring system information (SI) from each SIM and / or eSIM in the same cell is inefficient. Therefore, there is a need to optimize wireless network searches and SI monitoring, and to share search results across multiple software stacks associated with different SIMs and / or eSIMs in a wireless device that supports multiple SIMs and / or eSIMs. Summary of the Invention

[0003] The present application relates to wireless communications, including methods and apparatus for optimizing cellular wireless network searches on a wireless device that supports multiple subscriber identity modules (SIMs) and / or electronic SIMs (eSIMs), which may be referred to as a multi-SIM / eSIM wireless device. A multi-SIM / eSIM wireless device may include multiple different SIMs and / or eSIMs, each associated with a different subscription, to access cellular wireless services from various mobile operators (MNOs). In some cases, a multi-SIM / eSIM wireless device may include common cellular wireless circuitry that allows communication with only one cellular wireless network at a time. The multi-SIM / eSIM wireless device may efficiently perform public land mobile network (PLMN) searches, for example, to find suitable service for the multi-SIM / eSIM wireless device, switch to a higher-priority PLMN, or perform out-of-service (OOS) recovery procedures. The multi-SIM / eSIM wireless device may share information about PLMNs via a first modem (e.g., a first software stack associated with the first SIM / eSIM and configured to communicate via the wireless circuitry of the multi-SIM / eSIM wireless device) and a second modem (e.g., a second software stack associated with a second SIM / eSIM and configured to communicate via the same wireless circuitry). Sharing detected PLMN information across multiple searched radio access technologies (RATs) and associated radio frequency (RF) bands can reduce power consumption and focus searches for repeated searches, and accelerate PLMN detection through focused searches by a second modem. In some embodiments, a first modem of a multi-SIM / eSIM wireless device performs a high-priority (HP) PLMN (HPPLMN) search and indicates the HPPLMN search results to a second modem of the multi-SIM / eSIM wireless device. When the first modem does not detect an HPPLMN for the second modem and the first modem has searched all configured RATs and RF bands for the second modem, the second modem can stop and subsequently restart the HPPLMN timer to avoid performing a separate HPPLMN search. In some embodiments, the first modem reports detected PLMNs during the PLMN search, for example, upon each PLMN detection or upon completion of a RAT and / or RF band search, and the second modem can receive the reported PLMNs and act accordingly. In some embodiments, the second modem initiates an immediate search for the highest-priority PLMN reported by the first modem without waiting for the first modem's PLMN search to complete. In some embodiments, upon receiving an indication that the first modem detected a higher priority PLMN that is not the highest priority PLMN for the second modem, the second modem awaits further PLMN search results.In some embodiments, when a wireless network search (e.g., a PLMN search, a HPPLMN search, or a restricted service camp-on search) conducted by the first modem terminates before completing the wireless network search, the first modem provides an indication of the termination of the wireless network search, and the second modem determines whether to initiate a separate wireless network search.

[0004] In some embodiments, when a first modem of a multi-SIM / eSIM wireless device is camped on a cellular wireless network in limited service mode, for example, to provide access to emergency service information, or camped in normal service mode, a second modem of the multi-SIM / eSIM wireless device avoids camping in limited service mode (when camping in normal service mode is not possible) and performs periodic cellular wireless network searches on any available PLMNs for normal service based on wireless network search information provided by the first modem. In some embodiments, the second modem does not monitor for selected broadcast system information block (SIB) messages, such as SIB type 1 (SIB-1) and SIB type 2 (SIB-2) messages, and relies on the first modem to receive the same SIB messages and monitor for emergency alerts accordingly. If the first modem enters an OOS state, the second modem can resume PLMN search and camp on the wireless network in limited service mode if normal service is unavailable.

[0005] Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example the principles of the described embodiments.

[0006] This summary is provided for the purpose of summarizing some example embodiments only, in order to provide a basic understanding of some aspects of the subject matter described herein. Therefore, it should be understood that the above-mentioned features are merely examples and should not be construed as narrowing the scope or essence of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present disclosure will be more readily understood through the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals designate like structural elements.

[0008] Figure 1 Illustrated is a block diagram of various components of an exemplary system configured to implement cellular service provisioning to a wireless device in accordance with some embodiments.

[0009] Figure 2 Illustrated according to some embodiments Figure 1 A block diagram of a more detailed view of exemplary components of a system.

[0010] Figure 3A An example of a multiple Subscriber Identity Module (SIM) / electronic SIM (eSIM) wireless device communicating with two wireless networks is illustrated in accordance with some embodiments.

[0011] Figure 3B An example of a wireless device supporting multiple user identities according to some embodiments is illustrated.

[0012] Figure 4 A diagram illustrating an exemplary optimization of a High Priority Public Land Mobile Network (HPPLMN) search for a multi-SIM / eSIM wireless device in accordance with some embodiments.

[0013] Figure 5 A diagram illustrating exemplary optimization of PLMN searches by a multi-SIM / eSIM wireless device in limited service mode, according to some embodiments.

[0014] Figure 6 A flow chart illustrating an exemplary optimization of PLMN searches through early PLMN search result reporting by a multi-SIM / eSIM wireless device in accordance with some embodiments is illustrated.

[0015] Figure 7 A flow chart illustrating an exemplary optimization of HPPLMN search when one or both modems of a multi-SIM / eSIM wireless device are in Radio Resource Control (RRC) Connected mode while roaming is provided, in accordance with some embodiments.

[0016] Figure 8 A flow chart illustrating an exemplary optimization of HPPLMN search while multiple modems of a multi-SIM / eSIM wireless device are in radio resource control (RRC) idle mode, according to some embodiments.

[0017] Figure 9 A flow chart illustrating another exemplary optimization of HPPLMN search while multiple modems of a multi-SIM / eSIM wireless device are in RRC idle mode according to some embodiments.

[0018] Figure 10 A flow chart illustrating an exemplary optimization of a PLMN search in the event of an interruption in a PLMN search by a multi-SIM / eSIM wireless device, according to some embodiments.

[0019] Figure 11 A flow chart illustrating an example method for optimizing PLMN searches by a multi-SIM / eSIM wireless device according to some embodiments is illustrated.

[0020] Figure 12A A flow chart illustrating an example method for optimizing PLMN searches by a multi-SIM / eSIM wireless device while in limited service mode is provided in accordance with some embodiments.

[0021] Figure 12B A flow chart illustrating an example method for optimizing PLMN searches performed by a multi-SIM / eSIM wireless device while in normal service mode is illustrated in accordance with some embodiments.

[0022] Figure 13 A block diagram illustrating exemplary elements of a wireless device according to some embodiments is illustrated. DETAILED DESCRIPTION

[0023] This section describes representative applications of the methods and apparatus according to the present application. These examples are provided solely to add context and aid in understanding the described embodiments. Therefore, it will be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other cases, well-known processing steps have not been described in detail to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be considered limiting.

[0024] The present application relates to wireless communications, including methods and apparatus for optimizing cellular wireless network searches on wireless devices that support multiple subscriber identity modules (SIMs) and / or electronic SIMs (eSIMs), which may be referred to as multi-SIM / eSIM wireless devices. A multi-SIM / eSIM wireless device may include multiple different SIMs and / or eSIMs, each associated with a different subscription, to access cellular wireless services from various mobile operators (MNOs). In some cases, a multi-SIM / eSIM wireless device may include common cellular wireless circuitry that allows communication with only one cellular wireless network at a time. The multi-SIM / eSIM wireless device may efficiently perform public land mobile network (PLMN) searches, such as finding suitable services, such as voice or data services, for the multi-SIM / eSIM wireless device or switching to a higher-priority PLMN. This may reduce roaming costs for users of the multi-SIM / eSIM wireless device (and, in some cases, the home PLMN). For example, the multi-SIM / eSIM wireless device may select an initial PLMN when roaming and later change PLMNs based on a higher-priority PLMN search. Multi-SIM / eSIM wireless devices can also perform an out-of-service (OOS) recovery procedure to locate a PLMN to camp on for normal service, or in some cases, a PLMN to camp on in limited service mode when normal service is otherwise unavailable. The mechanism for performing a PLMN search is not standardized by cellular wireless standards organizations such as 3GPP, and the specific implementation may vary for different wireless devices. Optimizing PLMN search for multi-SIM / eSIM wireless devices can reduce the duplication of PLMN search efforts performed by different modems associated with different SIMs / eSIMs, thereby reducing battery power consumption for PLMN searches. Battery performance is an important performance metric for users of multi-SIM / eSIM wireless devices.

[0025] A multi-SIM / eSIM wireless device can share information about PLMNs via a first modem (e.g., a first software stack associated with the first SIM / eSIM and configured to communicate via wireless circuitry of the multi-SIM / eSIM wireless device) and a second modem (e.g., a second software stack associated with the second SIM / eSIM and configured to communicate via the same (or separate) wireless circuitry). Sharing detected PLMN information across multiple searched radio access technologies (RATs) and associated radio frequency (RF) bands can reduce power consumption and focus searches for repeated searches, and accelerate PLMN detection through focused searches by the second modem. Sharing PLMN search results across multiple active SIMs / eSIMs in the multi-SIM / eSIM wireless device enables faster service restoration and improves service restoration performance for the multi-SIM / eSIM wireless device by avoiding repeated searches for PLMNs that have already been located or determined to be unavailable. In addition, when a multi-SIM / eSIM wireless device cannot establish normal service for any active SIM / eSIM, only one active SIM / eSIM needs to camp on the cellular wireless network in limited service mode to allow monitoring of broadcast system information (SI) messages, such as SI Block Type 1 (SIB-1) and SI Block Type 2 (SIB-2) messages, which may provide information on the presence of additional broadcast emergency alert messages (e.g., Earthquake and Tsunami Warning System (ETWS) and Commercial Mobile Alert System (CMAS) messages). The SIM / eSIM camped on the cellular wireless network in limited service mode can be relied upon to receive ETWS / CMAS alert messages, and thus, the other active SIM / eSIMs do not need to camp on the cellular wireless network in limited service mode and wake up from a reduced power state to monitor SIB and alert messages in parallel with the other SIM / eSIMs already camped in limited service mode.

[0026] In some embodiments, a first modem of a multi-SIM / eSIM wireless device performs a high-priority (HP) PLMN (HPPLMN) search and indicates the HPPLMN search results to a second modem of the multi-SIM / eSIM wireless device. When the first modem does not detect an HPPLMN for the second modem and the first modem has searched all configured RATs and RF bands for the second modem, the second modem may stop and subsequently restart the HPPLMN timer to avoid performing a separate HPPLMN search. In some embodiments, the first modem reports detected PLMNs during the PLMN search, for example, upon each PLMN detection or upon completion of a RAT and / or RF band search, and the second modem may receive the reported PLMNs and immediately proceed accordingly. In some embodiments, the second modem initiates an immediate search for the highest-priority PLMN reported by the first modem without waiting for the first modem's PLMN search to complete. In some embodiments, upon receiving an indication that the first modem has detected a higher-priority PLMN that is not the highest-priority PLMN for the second modem, the second modem awaits further PLMN search results. In some embodiments, when a wireless network search (e.g., a PLMN search, a HPPLMN search, or a restricted service camp-on search) conducted by a first modem terminates before the first modem completes the wireless network search, the first modem provides an indication that the wireless network search terminated prematurely, and a second modem determines whether to initiate a separate wireless network search. In some embodiments, when providing PLMN search results to a second modem of a multi-SIM / eSIM wireless device, the first modem indicates which radio access technologies (RATs) were searched, which radio frequency (RF) bands were searched, and whether the search was complete or incomplete (e.g., ongoing or prematurely terminated).

[0027] In some embodiments, when a first modem of a multi-SIM / eSIM wireless device is camped on a cellular wireless network in limited service mode, for example, to provide access to emergency service information, or camped in normal service mode, a second modem of the multi-SIM / eSIM wireless device avoids camping in limited service mode (when camping in normal service mode is not possible) and performs periodic cellular wireless network searches on any available PLMNs for normal service based on wireless network search information provided by the first modem. In some embodiments, the second modem does not monitor for selected broadcast system information block (SIB) messages, such as SIB type 1 (SIB-1) and SIB type 2 (SIB-2) messages, and relies on the first modem to receive the same SIB messages and monitor for emergency alerts accordingly. If the first modem enters an OOS state, the second modem can resume PLMN search and camp on the wireless network in limited service mode if normal service is unavailable.

[0028] In the following detailed description, reference is made to the accompanying drawings which form a part of the specification and in which are shown by way of illustration specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable those skilled in the art to practice the described embodiments, it is to be understood that these examples are not limiting; other embodiments may be used and modifications may be made without departing from the spirit and scope of the described embodiments.

[0029] These and other embodiments are referenced below. Figures 1 to 13 however, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for illustrative purposes only and should not be construed as limiting.

[0030] Figure 1 A block diagram illustrating various components of a system 100 is shown, including: i) a wireless device 102 (which may also be referred to as a mobile wireless device, a wireless communication device, a mobile device, a user equipment (UE), a device, etc.); ii) a set of base stations 112-1 through 112-N managed by different mobile network operators (MNOs) 114; and iii) a set of configuration servers 116 in communication with the MNOs 114. The wireless device 102 may represent a mobile computing device (e.g., Production or ) or wearable devices with cellular capabilities (e.g., Apple ). Base stations 112-1 to 112-N may represent cellular wireless network entities that include fourth generation (4G) long term evolution (LTE) evolved Node Bs (eNodeBs or eNBs) and / or fifth generation (5G) Node Bs (gNodeBs or gNBs) configured to communicate with wireless device 102. MNO 114 may represent different wireless service providers that provide specific services (e.g., voice and data) to which a user of wireless device 102 may subscribe to access these services via wireless device 102. Applications resident on mobile wireless device 102 may advantageously access services using 4G LTE connections and / or 5G connections via base stations 112. Mobile wireless device 102 may include processing circuitry, an embedded universal integrated circuit card (eUICC) 108, and a baseband component 110, wherein the processing circuitry may include memory 106 and one or more processors 104. In some embodiments, in addition to eUICC 108, wireless device 102 also includes one or more physical UICCs 118 (also known as subscriber identity modules (SIM) cards). The components of the wireless device 102 work together to enable the wireless device 102 to provide useful features to the user of the wireless device 102, such as cellular wireless network access, non-cellular wireless network access, localized computing, location-based services, and internet connectivity. The eUICC 108 can be configured to store multiple electronic SIMs (eSIMs) for accessing services provided by one or more different MNOs 114 via communications through base stations 112-1 to 112-N. Similarly, one or more UICCs 118 can include a universal SIM (USIM) for accessing the services of the associated MNO 114. To enable access to services provided by the MNO, one or more eSIMs can be configured into the eUICC 108 of the wireless device 102 (or into one or more UICCs 118 installed in the wireless device 102).

[0031] Figure 2 Illustrated Figure 11. Block diagram 200 of a more detailed view of a wireless device 102. One or more processors 104, in conjunction with memory 106, may implement a main operating system (OS) 202 that is configured to execute applications 204 (e.g., native OS applications and user applications). One or more processors 104 may include application processing circuitry and, in some embodiments, wireless communication control circuitry. The application processing circuitry may monitor application requirements and usage to determine recommendations regarding communication connection attributes (such as bandwidth and / or latency) and provide information to the communication control circuitry to determine an appropriate wireless connection for use by a particular application. The communication control circuitry may process information from the application processing circuitry and from additional circuitry (such as baseband component 110 and other sensors (not shown)) to determine the state of components of the wireless device 102 (e.g., reduced power mode) and the state of the wireless device 102 as a whole (e.g., mobility state). The wireless device 102 includes an eUICC 108, which may be configured to implement an eUICC OS 206 for managing the hardware resources of the eUICC 108 (e.g., a processor and memory embedded in the eUICC 108). The eUICC OS 206 may also be configured to manage the eSIM 208 stored by the eUICC 108, for example, by enabling, disabling, modifying, updating, or otherwise performing management of the eSIM 208 within the eUICC 108 and providing access to the eSIM 208 to the baseband component 110 to provide access to wireless services for the wireless device 102. The eUICC OS 206 may include an eSIM manager 210 that may perform management functions for the various eSIMs 208. Each eSIM 208 may include a plurality of applets 212 that define how the eSIM 208 operates. For example, one or more of the applets 212 , when implemented by the baseband component 110 and the eUICC 108 , may be configured to enable the wireless device 102 to communicate with the MNO 114 and provide useful features (eg, phone calls and the internet) to a user of the wireless device 102 .

[0032] The baseband component 110 of the wireless device 102 may include a baseband OS 214 configured to manage the hardware resources (e.g., processor, memory, various radio components, etc.) of the baseband component 110. According to some embodiments, the baseband component 110 may implement a baseband manager 216 configured to interact with the eUICC 108 to establish a secure channel with the provisioning server 116 and obtain information (such as eSIM data) from the provisioning server 116 for managing the eSIM 208. The baseband manager 216 may be configured to implement services 218, which represent a collection of software modules that are instantiated by the various applets 212 of the enabled eSIMs 208 included in the eUICC 108. For example, the services 218 may be configured to manage different connections between the wireless device 102 and the MNO 114 depending on the different eSIMs 208 enabled within the eUICC 108.

[0033] Figure 3A Diagram 300 illustrates a multi-SIM / eSIM wireless device 302, which may be in the form of wireless device 102 and includes one or more processors 104 and wireless circuitry 304 that provides wireless radio frequency (RF) connectivity between the multi-SIM / eSIM wireless device 302 and a first cellular wireless network 310A and a second cellular wireless network 310B. In some embodiments, wireless circuitry 304 includes one or more baseband processors and a set of RF analog front-end circuits. In some embodiments, wireless circuitry 304 and / or portions thereof may include or be referred to as a wireless transmitter / receiver, transceiver, or radio. The terms "circuitry," "component," and "component block" are used interchangeably herein and, in some embodiments, refer to one or more operating units of a wireless device that process and / or manipulate digital signals, analog signals, or digital data units for wireless communication. For example, representative circuitry may perform various functions, such as converting digital data units into transmitted RF analog waveforms and / or converting received analog waveforms into digital data units (including intermediate analog and digital forms). The wireless circuitry 304 may include components of RF analog front-end circuitry, such as a set of one or more antennas that may be interconnected with additional supporting RF circuitry that may include filters and other analog components that may be “configured” to transmit and / or receive analog signals to one of the first cellular wireless network 310A and the second cellular wireless network 310B via the one or more corresponding antennas.

[0034] In some embodiments, the multi-SIM / eSIM wireless device 302 may include hardware restrictions that limit the multi-SIM / eSIM wireless device 302 to connecting to only one of the first and second cellular wireless networks at a time via their respective access network equipment 312A / 312B. For example, the wireless circuitry 304 may include a single transmitter and one or more receivers for cellular wireless communication, such that only one active two-way cellular radio frequency connection to a cellular access network may be used at a time. While the multi-SIM / eSIM wireless device 302 has an active connection via the access network equipment 312A of the first cellular wireless network 310A, the multi-SIM / eSIM wireless device 302 may be prevented from establishing another active connection via the access network equipment 312B of the second cellular wireless network 310B (or from establishing a second active connection to the first cellular wireless network 310A). In some embodiments, the multi-SIM / eSIM wireless device 302 may be simultaneously registered with multiple subscriptions corresponding to different SIMs / eSIMs.

[0035] The multi-SIM / eSIM wireless device 302 can simultaneously register with multiple wireless networks (e.g., a first cellular wireless network 310A and a second cellular wireless network 310B). The wireless circuitry 304 of the multi-SIM / eSIM wireless device 302 can be configured to register with and / or establish a connection with the first cellular wireless network 310A via access network equipment 312A interfacing with a core network 314A. The wireless circuitry 304 of the multi-SIM / eSIM wireless device 302 can also be configured to register with and / or establish a connection with the second cellular wireless network 310B via access network equipment 312B interfacing with a core network 314B. The wireless circuitry 304 of the multi-SIM / eSIM wireless device 302 can support transmission and reception to only one of the first and second wireless networks 310A, 310B at a time via their respective access networks 312A / B. Because the multi-SIM / eSIM wireless device 302 can be registered with two different wireless networks simultaneously via two different subscriptions, the multi-SIM / eSIM wireless device 302 may appear to be two different devices (each associated with a different number, user, and / or subscription). A multi-SIM / eSIM wireless device that can connect to only one wireless network at a time but can monitor and / or receive communications from multiple wireless networks with which the multi-SIM / eSIM wireless device 302 is registered may be referred to as a multi-SIM multi-standby (MSMS) wireless device (or a dual-SIM dual-standby (DSDS) wireless device in the case of a wireless device with two SIM / eSIMs). In a 5G NR cellular wireless network that includes shared access network equipment with separate core networks, the multi-SIM / eSIM wireless device 302 can connect to the same access network equipment for accessing services of two different cellular wireless networks. Although Figure 3A The multi-SIM / eSIM wireless device 302 includes the UICC 118 and the eUICC 108 , but other configurations of the multi-SIM / eSIM wireless device 302 are possible.

[0036] Figure 3BDiagrams illustrating exemplary multi-SIM / eSIM wireless devices that support multiple user identities using a removable UICC 118 having a SIM implemented thereon and / or an eUICC 108 having an eSIM 208 implemented thereon. As illustrated in diagram 330, a multi-SIM wireless device 332 includes multiple UICCs 118 that can be inserted and removed individually or collectively and communicate with one or more processors 104 connected to wireless circuitry 304, which provides wireless communication with one or more wireless networks 310. Because the physical size and design of a multi-SIM wireless device 332 may limit the number of UICCs 118 that can be supported, a multi-eSIM wireless device 342 may alternatively include an eUICC 108 connected to a processor 104 and to a wireless network 310 via wireless circuitry 304, as illustrated in diagram 340. The eUICC 108 may store multiple eSIMs 208, each of which may be associated with a different user identity and / or provide different services or subscriptions to a user of the multi-eSIM wireless device 342. Diagram 350 illustrates an exemplary multi-SIM / eSIM wireless device 352 that includes a removable UICC 118 on which one or more SIMs may be installed, and an eUICC 108 on which one or more eSIMs 208 may be installed. The multi-SIM / eSIM wireless device 352 may represent Figure 1 Diagram 360 illustrates another multi-SIM / eSIM wireless device 362 that includes multiple UICCs 118 on which one or more SIMs may be installed, and an eUICC 108 on which one or more eSIMs 208 may be installed. The combination of the SIMs on the UICCs 118 and / or the eSIMs 208 on the eUICCs 108 may provide connectivity to one or more wireless networks 310 using wireless circuitry 304 under the control of the processor 104 of the multi-SIM / eSIM wireless device 362.

[0037] Generally speaking, a multi-SIM / eSIM wireless device that supports multiple subscriber identities may include (i) at least one UICC 118 that supports multiple SIMs, (ii) an eUICC 108 that supports multiple eSIMs 208, or (iii) a combination of a UICC 118 and an eUICC 108. Each UICC 118 may support one or more SIMs, and each eUICC 108 may support one or more eSIMs 208. A multi-SIM / eSIM wireless device that supports multiple subscriber identities (e.g., 102, 332, 342, 352, 362) may include a combination of SIMs and / or eSIMs 208 to support communications with one or more wireless networks 310.

[0038] Figure 4 Diagrams 400, 410 illustrate exemplary optimizations of a high priority PLMN (HPPLMN) search for a multi-SIM / eSIM wireless device. The multi-SIM / eSIM wireless device includes multiple SIM / eSIMs, two of which are active simultaneously. Each SIM / eSIM is associated with an MNO 114, which need not be the same MNO 114. Each SIM / eSIM may include information regarding the priority of the PLMN search, for example, a list of previously prioritized PLMNs, a set of RATs, a set of RF bands, etc., for the multi-SIM / eSIM wireless device when searching for PLMNs (such as during an OOS recovery procedure or when selecting a PLMN while roaming). Figure 4In an example, the multi-SIM / eSIM wireless device is also in a roaming state, for example, in a geographic area where a Home PLMN (HPLMN) is not available for use by the multi-SIM / eSIM wireless device. One parameter specified by MNO 114 and included in the SIM / eSIM is an Elementary File (EF) that specifies a time interval between HPPLMN searches, i.e., an EFHPPLMN parameter that indicates the amount of time (time interval) between HPPLMN searches. A modem for a SIM / eSIM of the multi-SIM / eSIM wireless device, when roaming and camping on a visited PLMN that is not the highest priority PLMN for the SIM / eSIM, may set a timer value based on the EFHPPLMN value for the SIM / eSIM, start the timer, and begin the next HPPLMN search after the timer expires. As shown in diagram 400, consecutive HPPLMN searches for a first modem-0 associated with a first SIM / eSIM can be separated by a time interval, T0, specified by the EFHPPLMN value for the first SIM / eSIM. Similarly, consecutive HPPLMN searches for a second modem-1 associated with a second SIM / eSIM can be separated by a time interval, T1, specified by the EFHPPLMN value for the second SIM / eSIM. By utilizing shared wireless circuitry, HPPLMN searches for different modems can be spaced apart to occur at non-overlapping times. Without HPPLMN search optimization, as shown in diagram 400, each modem performs a parallel HPPLMN search, which can result in higher-than-desirable power consumption of the limited battery power of a multi-SIM / eSIM wireless device, particularly when the highest priority PLMN is not detected, because each modem performs the same (or overlapping) search of RATs and RF bands. Diagram 410 illustrates an example of optimizing HPPLMN searches for a multi-SIM / eSIM device, where the first modem (Modem-0) performs an HPPLMN search and provides the results of the HPPLMN search to the second modem (Modem-1). The results may include an indication of the detected PLMNs, which radio access technologies (RATs) were searched, and which RF bands were searched. The second modem (Modem-1) may stop the HPPLMN timer (if running) based on an indication from the HPPLMN search results of the first modem (Modem-0), wherein the HPPLMN search results indicate that the HPPLMN search performed by the first modem (Modem-0) did not find an HPPLMN for the second modem (Modem-1), and that the first modem (Modem-0) searched all configured RATs and RF bands for the second modem (Modem-1).The second modem (Modem-1) may forgo performing its own parallel HPPLMN search due to the HPPLMN search results from the first modem (Modem-0) and restart the HPPLMN timer at an appropriate time, for example, to allow the first modem (Modem-0) sufficient time to perform subsequent HPPLMN search results. Eliminating the HPPLMN search by the second modem (Modem-1) can conserve limited battery power that would otherwise be used to perform redundant (at least partial) PLMN searches. In some embodiments, the time interval T0 for the first modem (Modem-0) and the time interval T1 for the second modem are the same. In some embodiments, the time intervals T0 and T1 are different for each modem. In some embodiments, the first modem (Modem-0) reports detected PLMNs to the second modem (Modem-1) during the HPPLMN search without waiting for the HPPLMN search across all RATs and all RF bands to complete. In some embodiments, the second modem (Modem-1) may initiate an immediate search for the highest-priority PLMN for the second modem (Modem-1) upon receiving an indication from the first modem (Modem-0) that the highest-priority PLMN was detected. When the PLMN detected by the first modem (Modem-0) and reported to the second modem (Modem-1) is not the highest priority PLMN for the second modem (Modem-1), the second modem (Modem-1) may wait for further PLMN search results from the first modem (Modem-0) because the first modem (Modem-0) may still detect the highest priority PLMN.

[0039] Figure 5Diagrams 500 and 510 illustrate exemplary optimizations for PLMN searches performed by a multi-SIM / eSIM wireless device in limited service mode. The multi-SIM / eSIM wireless device includes multiple SIMs / eSIMs, two of which are simultaneously active. Each SIM / eSIM is associated with an MNO 114, which need not be the same MNO 114. When unable to camp on a cellular wireless network in normal service mode via an active SIM / eSIM, the multi-SIM / eSIM wireless device can locate and camp on the cellular wireless network in limited service mode, for example, to provide access to emergency service calls and receive system information regarding emergency alerts, such as monitoring broadcast SI Block Type 1 (SIB-1) and SI Block Type 2 (SIB-2) messages, which can provide information about the presence of additional broadcast emergency alert messages, such as Earthquake and Tsunami Warning System (ETWS) and Commercial Mobile Alert System (CMAS) messages. Because broadcast emergency alert messages are applicable to multi-SIM / eSIM wireless devices as a whole (and may not require repeated monitoring across multiple active SIMs / eSIMs in a multi-SIM / eSIM wireless device), one modem (e.g., the first modem (Modem-0)) can provide limited service mode residency, SIB monitoring, and PLMN search for normal service, while the second modem (Modem-1) can perform a shortened PLMN search without having to reside in limited service mode in parallel with the first modem (Modem-0) and rely on the first modem (Modem-0) to monitor for emergency alert information. As shown in diagram 500, without PLMN search optimization, both the first modem (Modem-0) and the second modem (Modem-1) reside in limited service mode and monitor broadcast SIB-1 messages to determine whether to read additional broadcast SIB-6, SIB-7, and / or SIB-8 messages to determine whether there are indications of upcoming or existing ETWS / CMAS alert messages. The first modem (Modem-0) can perform PLMN searches at regular intervals to locate a PLMN on which the first modem (Modem-0) can reside for normal service. The results of the PLMN search for normal service can be provided by the first modem (Modem-0) to the second modem (Modem-1), wherein the second modem (Modem-1) can use the PLMN search results from the PLMN search performed by the first modem (Modem-0) to shorten the time for the second modem (Modem-1) to perform a corresponding PLMN search for normal service.However, without further optimization, both the first modem (Modem-0) and the second modem (Modem-1) can independently wake up from a reduced power state while camped in limited service mode to receive and process broadcast SIB-1 messages, thereby detecting any SIB-6, SIB-7, and / or SIB-8 messages used for ETWS / CMAS communications. Concurrent monitoring of broadcast SIB-1 messages is not necessary, as ETWS / CMAS communications will work for multi-SIM / eSIM wireless devices regardless of which SIM / eSIM is active. As shown in diagram 510, the second modem (Modem-1) can remain in an uncamped state (when unable to camp in normal service mode) and forgo receiving and processing broadcast SIB-1 messages, relying instead on the first modem (Modem-0) to meet limited service mode requirements. Both Modem-0 and Modem-1 can attempt to camp on a PLMN to obtain normal service while in uncamped or limited service mode. If Modem-0 loses limited service coverage, Modem-1 can fall back to its own PLMN search and use the shared search results provided by Modem-0. If an emergency services call is triggered while Modem-0 (or Modem-1) is in limited service state, the emergency services call will be routed via the modem with limited service state and the normal process for searching for emergency services may proceed.

[0040] Figure 6 A flowchart 600 illustrating an exemplary optimization of PLMN search for a multi-SIM / eSIM wireless device, wherein early PLMN search results are reported between respective modems. At 602, a first modem (Modem-0) and a second modem (Modem-1) are each in a Radio Resource Control (RRC) idle mode and are performing periodic PLMN searches based on their own PLMN search timers. In some embodiments, Modem-0 and Modem-1 are roaming in a geographic area without access to a home PLMN. In some embodiments, Modem-0 and Modem-1 are performing an Out of Service (OOS) recovery procedure, searching for a PLMN to reside on. Figure 6In the example shown, a PLMN search timer for modem-0 may expire during a PLMN search conducted by modem-1. At 604, modem-1 initiates a PLMN search, which may occur due to the expiration of a PLMN search timer (e.g., associated with a HPPLMN search while roaming, or associated with a PLMN search following a loss of service and performing a service recovery procedure), and provides an indication to modem-0 that the PLMN search has begun. In some embodiments, modem-1 indicates the type of PLMN search initiated, e.g., a HPPLMN search while roaming or a general PLMN search for an OOS recovery procedure. Modem-1 performs a PLMN search across one or more radio access technologies (RATs) applicable to the capabilities of a multi-SIM / eSIM wireless device. In some embodiments, the RATs selected for the PLMN search are prioritized, e.g., searching newer standardized RATs for cellular wireless communications over older cellular RATs. In Figure 6In the example shown, Modem-1 first searches for fifth-generation (5G) New Radio (NR) RATs, then fourth-generation (4G) Long Term Evolution (LTE) RATs, then third-generation (3G) Universal Mobile Telecommunications System (UMTS) RATs, and finally second-generation (2G / 2.5G) Global System for Mobile Communications (GSM) RATs. In some embodiments, Modem-1 considers the applicability of various RATs to the active SIM / eSIM associated with Modem-1 and searches only for those RATs applicable to the active SIM / eSIM. In some embodiments, Modem-1 considers the applicability of various RATs to one or more active SIM / eSIMs (e.g., the SIM / eSIM associated with Modem-1 and the SIM / eSIM associated with Modem-0) and searches only for those RATs applicable to the one or more active SIM / eSIMs of a multi-SIM / eSIM wireless device. Modem-1 also performs a PLMN search across different RF bands applicable to the searched RATs. In some embodiments, Modem-1 may also prioritize and select which RF bands to search for a given RAT, for example, based on the capabilities of the multi-SIM / eSIM wireless device, based on the availability of one or more active SIMs / eSIMs in the multi-SIM / eSIM wireless device, and / or based on the geographic region in which the multi-SIM / eSIM wireless device is operating. At 606, Modem-1 performs a search for available PLMNs that provide cellular wireless service using the 5G NR RAT. In some embodiments, Modem-1 reports to Modem-0 when one or more PLMNs for a given RAT are detected. In some embodiments, Modem-1 reports to Modem-0 each PLMN detected for a given RAT. Modem-1 may report detected PLMNs from the PLMN search to Modem-0 regardless of Modem-0's operating mode, including, for example, when Modem-0 is in RRC connected mode. In addition to the detected PLMNs, Modem-1 may also report the status of the PLMN search, e.g., whether the PLMN search for a given RAT is complete or in progress, an indication of the RATs searched so far for the PLMN search as a whole, and an indication of the RF bands searched for a particular RAT (or for all searched RATs). In some embodiments, Modem-1 reports measured parameters and / or metrics of the detected PLMNs, such as carrier frequency, signal strength (e.g., reference signal received power (RSRP) level), signal quality (e.g., reference signal received quality (RSRQ) or signal to interference plus noise (SINR) level), etc.), for Modem-0 to evaluate the suitability of the detected PLMN for use by Modem-0.At 608, Modem-0 processes the information received from Modem-1 regarding each detected and reported PLMN and, based on this information (and, in some cases, additional measurements performed by Modem-0), determines whether the detected PLMN is suitable for Modem-0 to attempt camping on. If a suitable PLMN for Modem-0's service is detected, Modem-0 may stop the PLMN search timer for Modem-0 (if running) and attempt to camp on the detected PLMN. It is important to note that each SIM / eSIM in a multi-SIM / eSIM is associated with its own MNO 114, which may vary for each SIM / eSIM and has associated standards for connection provided by MNO 114. Therefore, a PLMN detected by Modem-1 may be suitable for Modem-0, Modem-1, both Modem-0 and Modem-1, or neither Modem-0 nor Modem-1. Modem-1 may continue searching for a 5G NR RAT while Modem-0 determines the suitability of the previously reported PLMN. When Modem-1 has not reported any suitable PLMNs to Modem-0, Modem-0 continues to wait for reported PLMN information from Modem-1, including while Modem-0's own PLMN search timer is running. At 610, Modem-0's PLMN search timer expires (if running); however, Modem-0 will not perform a parallel PLMN search while a PLMN search by Modem-1 is still ongoing, or if Modem-1 previously detected a suitable PLMN, reported it to Modem-0, and Modem-0 can obtain service via that suitable PLMN. Instead, Modem-0 waits for additional PLMN search results from Modem-1.

[0041] The PLMN search continues, with Modem-1 searching for one or more additional RATs and reporting the detected PLMN results to Modem-0. At 612, Modem-1 searches for available PLMNs using the 4G LTE RAT. At 614, Modem-1 searches for available PLMNs using the 3G UMTS RAT. At 616, Modem-1 searches for available PLMNs using the 2G (or 2.5G) GSM RAT. Once a PLMN has been detected and information has been processed for that PLMN, Modem-1 may report the detected PLMN results to Modem-0. At 618, Modem-0 receives and processes the PLMN results received from Modem-1, including relevant parameters and metrics for the different detected PLMNs, an updated PLMN search status for each report, an indication of the searched RAT, and an indication of the searched RF band. At 618, Modem-0 may use the reported PLMN search received from Modem-1 to determine whether there are suitable PLMNs available for Modem-0. Modem-0 may also use the PLMN search results to prioritize its own separate PLMN search (if performed after the PLMN search performed by Modem-1 has concluded). In some embodiments, when a home PLMN for Modem-0 or a top-priority PLMN for Modem-0 is detected and reported to Modem-0, Modem-0 may attempt to locate and camp on the detected home PLMN or top-priority PLMN without waiting for additional PLMN search results from Modem-1. The PLMN (or PLMNs) considered the top-priority PLMN for Modem-0 may be the same as or different from the top-priority PLMN for Modem-1. Whether a PLMN is the top-priority PLMN for a modem may also depend on the geographic region in which the multi-SIM / eSIM wireless device is operating. After the PLMN search performed by Modem-1 is completed, if Modem-1 does not detect a suitable PLMN for Modem-1, Modem-1 restarts its own PLMN search timer at 626. At 620, after the PLMN search performed by Modem-1 is completed, Modem-0 performs a prioritized PLMN search based on the RAT and RF band discovered and reported by Modem-1. Thus, Modem-0 may perform a target PLMN search using the knowledge of the RAT and RF band detected by Modem- 1 to expedite its own PLMN search. If Modem-0 detects a suitable PLMN, Modem-0 may attempt to camp on the detected PLMN.In some cases, the PLMN search performed by Modem-1 may not be complete, for example, if Modem-1 does not search all required RATs or RF bands for Modem-0, or if Modem-1 prematurely terminates its PLMN search before completing all RATs or RF bands. It should be noted that the required RATs and / or RF bands for each modem may be the same or different, and therefore Modem-1 may perform a PLMN search applicable to its own active SIM / eSIM, which may have different requirements than the active SIM / eSIM associated with Modem-0. In some embodiments, Modem-0 uses the PLMN search results, including information about the RAT and RF band searches performed by Modem-1, to determine whether Modem-1 has searched all required RATs and / or RF bands for Modem-0. In some embodiments, when Modem-1's PLMN search is incomplete, Modem-1 reports any unsearched RATs and / or RF bands to Modem-0. At 622, when Modem-1's PLMN search is incomplete, Modem-0 may perform a partial or complete PLMN search. Modem-0 may perform a partial PLMN search for RATs and / or RF bands that are required by Modem-0 and that have not been searched by Modem-1, and may not search RATs and / or RF bands that Modem-1 has already searched. In some embodiments, when the PLMN search by Modem-1 is prematurely terminated, Modem-0 performs a full PLMN search for the geographic area in which the multi-SIM / eSIM wireless device is operating on supported RATs and / or RF bands applicable to Modem-0. At 624, if no suitable PLMN is found after searching all required RATs and RF bands for Modem-0, Modem-0 may restart its own PLMN search timer.

[0042] Figure 7A flowchart 700 illustrates an exemplary optimization of a high-priority PLMN (HPPLMN) search when one modem of a multi-SIM / eSIM wireless device is in radio resource control (RRC) connected mode while roaming. At 702, modem-0 is in RRC connected mode while roaming with a cellular wireless network using a first SIM / eSIM and, in response to the expiration of the HPPLMN timer for modem-0, moves to RRC idle mode and performs a periodic HPPLMN search for modem-0. At 704, modem-1 either i) uses a second SIM / eSIM to search for a suitable PLMN with which to register for normal service, or ii) is in RRC idle mode and, in response to the expiration of the HPPLMN timer for modem-1, performs a periodic HPPLMN search for modem-1. While each modem's HPPLMN timer can run in parallel, the results of an HPPLMN search conducted by one modem can be used by another modem, thereby eliminating the need for multiple modems of the multi-SIM / eSIM wireless device to conduct parallel, concurrent searches for PLMNs and avoiding unnecessary waste of limited battery power. At 706, Modem-1 initiates a HPPLMN search (or is initiated to recover from a no-service condition) in response to the expiration of its own HPPLMN timer, wherein the HPPLMN search is performed across all supported RF bands and all supported RATs in the geographic area in which the multi-SIM / eSIM wireless device is operating. The RATs and RF bands searched by Modem-1 are prioritized, e.g., attempting to locate a suitable PLMN with a higher priority RAT and / or an RF band suitable for the geographic area. The HPPLMN search performed by Modem-1 may be performed across all supported RF bands and supported RATs in the current geographic area in which the multi-SIM / eSIM wireless device is operating. The HPPLMN search performed by Modem-1 may occur while Modem-0 is in RRC connected mode. In some embodiments, the HPPLMN search performed by Modem-1 is customized according to the requirements of Modem-1, e.g., according to the second SIM / eSIM used by Modem-1 to camp on the cellular wireless network when Modem-1 is in RRC connected mode. In some embodiments, the HPPLMN search performed by Modem-1 is based on the requirements of the SIM / eSIM associated with Modem-0 and Modem-1. Additionally, at 706, Modem-1 provides an indication to Modem-0 that a PLMN search has begun. In some embodiments, Modem-1 indicates the type of PLMN search initiated, e.g., a HPPLMN search when roaming or a general PLMN search for an OOS recovery procedure.At 708, the HPPLMN search timer for Modem-0 expires. While a PLMN search by Modem-1 is ongoing (e.g., based on receiving a PLMN search initiation indication from Modem-0 and the absence of a corresponding PLMN search termination from Modem-1), Modem-0 may abandon performing a parallel PLMN search. At 710, Modem-1 searches the RF band associated with a first RAT (e.g., a 5G NR RAT) for a PLMN and provides PLMN search results to Modem-0, including an indication of the detected PLMN, the PLMN search status (e.g., ongoing, completed, terminated and completed, terminated and not completed), an indication of the searched RAT, and an indication of the searched RF band. At 712, Modem-1 continues the PLMN search by searching for PLMNs in an RF band associated with a second RAT (e.g., a 4G LTE RAT) and provides additional PLMN search results to Modem-0. At 714, Modem-1 further continues the PLMN search across RF bands associated with a third RAT (e.g., 3G UMTS RAT) and provides further PLMN results to Modem-0. Finally, at 716, Modem-1 performs a PLMN search across RF bands associated with a fourth RAT (e.g., 2G / 2.5G GSM RAT) and provides the final PLMN results to Modem-0. At 718, Modem-0 prioritizes future PLMN searches performed after the connection is released based on the PLMN search results provided by Modem-1. When the reported PLMN from Modem-1 is a HPPLMN for Modem-0, Modem-0 may prioritize searching the RF band and RAT used by the reported HPPLMN during its own HPPLMN search performed after the connection is released. When none of the PLMNs reported by Modem-1 is a HPPLMN for Modem-0, and when all required RF bands and supported RATs for Modem-0, as well as the geographic area in which the multi-SIM / eSIM wireless device is operating, are searched by Modem-1, then Modem-0 may consider the PLMN search performed by Modem-1 to be complete for Modem-0 and forgo performing a separate PLMN search. At 720, Modem-0 transitions from RRC connected mode to RRC idle mode. Note that the RRC connection may be released while the PLMN search performed by Modem-1 is ongoing or after the PLMN search performed by Modem-1 is complete.If an RRC connection is active at Modem-0 when Modem-1 completes the PLMN search, Modem-0 may continue to wait until the active RRC connection is released and Modem-0 returns to RRC idle mode before performing its own targeted, prioritized, partial, or full PLMN search. At 724, when the PLMN reported by Modem-1 to Modem-0 is the highest priority PLMN for Modem-0, Modem-0 may immediately search for the highest priority PLMN. When Modem-1 does not report or Modem-0 does not locate the highest priority PLMN, at 726, Modem-0 performs a prioritized search for PLMNs based on the PLMN search results from Modem-1 (e.g., based on one or more RATs and / or one or more RF bands associated with the PLMN found and reported to Modem-0 by Modem-1). In some cases, the PLMN search by Modem-1 may end without searching all desired RATs and / or RF bands applicable to Modem-0, in which case, at 728, Modem-0 performs its own partial or full PLMN search. At 730, when either Modem-1 or Modem-0 does not find the highest priority PLMN, and after searching all required RATs and RF bands for Modem-0, Modem-0 may restart its own PLMN search timer. Similarly, at 722, when Modem-1 does not find the highest priority PLMN applicable to Modem-1 during its PLMN search, Modem-1 restarts the corresponding high priority PLMN search timer.

[0043] Figure 8A flowchart 800 illustrates an exemplary optimization of a high-priority PLMN (HPPLMN) search when both modems of a multi-SIM / eSIM wireless device are in radio resource control (RRC) idle mode while roaming. At 802, Modem-0 is in RRC idle mode and performs a periodic HPPLMN search while the multi-SIM / eSIM wireless device is roaming. At 804, Modem-1 either i) searches for a suitable PLMN with which to register for normal service using a second SIM / eSIM, or ii) is in RRC idle mode and performs a periodic HPPLMN search for Modem-1 in response to the expiration of Modem-1's HPPLMN timer. The periodic searches performed by each of Modem-0 and Modem-1 may be performed based on the expiration of separate HPPLMN timers maintained by Modem-0 and Modem-1, respectively. To reduce power consumption due to parallel searches of the same or overlapping PLMN search spaces, a multi-SIM / eSIM wireless device can provide the results of a HPPLMN search from one modem to another modem to help the second modem locate a PLMN (if recovering from an OOS condition) or a higher priority PLMN (if already camped on a PLMN). One modem's HPPLMN search can also cause the second modem to learn of its highest priority PLMN sooner than if it were to wait to perform its own HPPLMN search. At 806, Modem-1 initiates a HPPLMN search (or initiates a PLMN search to recover from an out-of-service condition) in response to expiration of the HPPLMN search timer, wherein the HPPLMN search spans all supported RF bands and RATs in the geographic area in which the multi-SIM / eSIM wireless device is operating. Modem-1 provides an indication to Modem-0 regarding the start of the HPPLMN search by Modem-1. Modem-1 provides PLMN search results, including the detected PLMNs, an indication of the status of the HPPLMN search (e.g., ongoing, completed, terminated and completed, or terminated and incomplete), an indication of the searched RAT, and an indication of the searched RF band. The PLMN search results are provided by Modem-1 to Modem-0 throughout the HPPLMN search process, rather than being collected and provided at the end of the HPPLMN search. Incremental PLMN search results from Modem-1 can more quickly provide information about which action Modem-0 can take. At 808, Modem-1 performs an HPPLMN search across the RF bands of the 5G NR RAT and, when a 5G NR RAT PLMN is detected, provides the PLMN search results to Modem-0.When Modem-1 detects and reports the highest-priority PLMN for Modem-0, Modem-0 may stop its own HPPLMN timer (if running) and attempt to camp on the detected highest-priority PLMN. Modem-1's detection and reporting of the highest-priority PLMN for Modem-0 may occur at any time during Modem-1's complete HPPLMN search. At 812, the running HPPLMN search timer for Modem-0 expires; however, Modem-0 will not perform a parallel PLMN search while Modem-1's HPPLMN search is ongoing. Instead, Modem-0 awaits the results of Modem-1's HPPLMN search, which may inform future PLMN searches performed by Modem-0. At 814, Modem-1 performs an HPPLMN search across the RF band of the 4G LTE RAT and, upon detecting a 4G LTE RAT PLMN, provides the PLMN search results to Modem-0. At 816, Modem-1 performs an HPPLMN search across the RF band of the 3G UMTS RAT and, upon detecting a 3G UMTS RAT PLMN, provides the PLMN search results to Modem-0. At 818, Modem-1 performs a HPPLMN search across the RF bands of the 2G / 2.5G GSM RAT and, upon detecting a 2G / 2.5G GSM RAT PLMN, provides the PLMN search results to Modem-0. At 820, Modem-0 uses the PLMN search results provided by Modem-1 to prioritize future HPPLMN (or general PLMN) searches. When the PLMN reported by Modem-1 to Modem-0 is a higher priority PLMN than the PLMN for Modem-0 already in use, Modem-0 may, after the PLMN search by Modem-1 is complete, perform a prioritized PLMN search on those RF bands and RATs where the corresponding higher priority PLMN was detected, at 826. If any PLMN detected and reported to Modem-0 by Modem-1 is the highest priority PLMN for Modem-0, Modem-0 may immediately attempt to camp on that highest priority PLMN without waiting for additional PLMN search results from Modem-1. When Modem-1 has not searched all desired RATs and / or RF bands for Modem-0, then at 828, Modem-0 may perform a partial or full PLMN search, where Modem-0 may use the PLMN search results provided by Modem-1 to prioritize, focus, and / or prune the PLMN search.Specifically, Modem-0 should avoid re-searching RATs and / or RF bands that Modem-1 has already fully searched. When none of the detected PLMNs reported to Modem-0 by Modem-1 is a higher priority PLMN than a PLMN already used by Modem-0, and Modem-1 (or Modem-0 in the partial or complete PLMN search at 828) has searched all required RATs and RF bands for Modem-0 applicable to the geographic area in which the multi-SIM / eSIM wireless device is roaming, then at 830, Modem-0 may restart its own HPPLMN timer without performing an additional HPPLMN search. As previously discussed, each SIM / eSIM in a multi-SIM / eSIM may have its own associated RAT and associated RF band to search, and thus Modem-0 and Modem-1 may each be configured to use different RAT and / or RF band search spaces. In some embodiments, Modem-0 searches only those RF bands and / or RATs that have not been searched, and the PLMN search results are provided by Modem-1.

[0044] Figure 9A flowchart 900 illustrates another exemplary optimization of a high-priority PLMN search performed by a multi-SIM / eSIM wireless device with multiple modems in an RRC Idle state. At 902, Modem-0 is in an RRC Idle state and configured for a periodic high-priority PLMN search, e.g., based on the expiration of a HPPLMN search timer having a value determined by an EFHPPLMN parameter specified by the SIM / eSIM associated with Modem-0. At 903, Modem-1 either i) searches for a suitable PLMN with which to register for normal service using a second SIM / eSIM, or ii) is in RRC Idle mode and performs a periodic HPPLMN search for Modem-1 in response to the expiration of Modem-1's HPPLMN timer. At 904, Modem-1 initiates a PLMN search, which may be in response to the expiration of Modem-1's HPPLMN timer or may be initiated to recover from a loss of service (e.g., an OOS condition). The PLMN search may be performed across all supported RATs and corresponding RF bands in the geographic area in which the multi-SIM / eSIM wireless device is operating. In some cases, a multi-SIM / eSIM wireless device is roaming, and each modem camps on a PLMN based on its corresponding SIM / eSIM. Modem-1 may perform a HPPLMN search to determine if there is a higher priority PLMN to camp on. Modem-1 provides an indication to Modem-0 when initiating the PLMN search, which may include an indication of whether the PLMN search is a HPPLMN search or a more general PLMN search (e.g., for OOS recovery). At 906, Modem-1 performs a PLMN search across RF bands associated with the 5G NR RAT and provides PLMN results to Modem-0, which may include the detected PLMNs, the status of the PLMN search (e.g., in progress, completed, terminated and fully searched, terminated and only partially searched), an indication of the searched RAT, and an indication of the associated RF bands searched. In some embodiments, Modem-1 detects a PLMN suitable for Modem-1, e.g., when performing a recovery from OOS procedure, and attempts to camp on that PLMN before reporting the detected PLMN to Modem-0. In some embodiments, Modem-1 detects a higher priority PLMN for Modem-1 than the PLMN on which Modem-1 is already camped, and attempts to reselect to the higher priority PLMN before reporting the detection of the higher priority PLMN to Modem-0. The higher priority PLMN for Modem-1 may not necessarily be the higher priority PLMN for Modem-0.For example, if Modem-0 and Modem-1 are associated with different SIMs / eSIMs, each SIM / eSIM may have a different prioritized list of PLMNs. At 908, Modem-0 determines whether the PLMN reported by Modem-1 is the highest priority PLMN for Modem-0's service. If the reported PLMN is the highest priority PLMN, Modem-0 stops the high priority PLMN timer (if running) and attempts to camp on the highest detected priority PLMN. If the PLMN reported by Modem-1 to Modem-0 is not the highest priority PLMN, Modem-0 may use the PLMN results to prioritize future PLMN searches performed by Modem-0. At 910, Modem-1 continues the PLMN search across RF bands associated with the 4G LTE RAT and provides Modem-0 with updated PLMN search results, including an indication of the detected PLMN, the search status, the cumulative searched RATs, and the associated searched RF bands. At 912, Modem-1 further continues the PLMN search across the RF bands associated with the 3G UMTS RAT and provides additional PLMN search results to Modem-0. Finally, at 914, Modem-1 performs a PLMN search across the RF bands associated with the 2G / 2.5G RAT and provides the PLMN search results to Modem-0. With each PLMN result provided by Modem-1, Modem-0 may determine whether a highest priority PLMN for Modem-0 is detected and immediately attempt to camp on the highest priority PLMN after stopping the high priority PLMN search timer (if running). At 918, if the PLMN reported by Modem-1 is a higher priority PLMN for Modem-0 (compared to the PLMN on which Modem-0 is currently camped), Modem-0 may attempt to reselect to the higher priority PLMN and stop the HPPLMN timer (if running). At 922, if Modem-1 has not yet exhausted all RATs and RF bands required by Modem-0 and Modem-1 has not detected and reported a higher priority PLMN to Modem-0, Modem-0 may discard the PLMN search results provided by Modem-1 and maintain the HPPLMN timer running. Later, upon expiration of the HPPLMN timer, Modem-0 may perform its own PLMN search across all RATs and RF bands required by Modem-0 or across those RATs and RF bands not previously searched by Modem-1.After completing the PLMN search, at 920, Modem-1 may restart the HPPLMN search timer if the PLMN search did not find a suitable higher priority PLMN, or start a dormancy timer and initiate a new PLMN search when the dormancy timer expires.

[0045] Figure 10A flowchart 1000 illustrates an exemplary optimization of a PLMN search in the event of an interruption in a PLMN search performed by a multi-SIM / eSIM wireless device. While the multi-SIM / eSIM wireless device is performing a PLMN search, which may be a high-priority PLMN search to locate the highest or higher priority PLMN while roaming, a PLMN search for a wireless network camped on for restricted access services, or a PLMN search to locate a suitable PLMN when recovering from a no-service situation, the multi-SIM / eSIM wireless device may encounter a scenario in which the ongoing PLMN search may be aborted. At the start of the PLMN search, Modem-1 provides an indication of the PLMN search to Modem-0, and during the PLMN search, Modem-1 provides PLMN search results. When the PLMN search is interrupted, Modem-1 may also immediately provide an indication of the interruption to Modem-0. In some cases, Modem-0 may initiate a separate PLMN search in response to an indication that Modem-1's PLMN search was prematurely interrupted and terminated before completing the search of all RATs and associated RF bands. At 1002, Modem-0 is in an RRC Idle state and configured for a periodic high-priority PLMN search, e.g., based on the expiration of a HPPLMN search timer having a value determined by the EFHPPLMN parameter specified by the SIM / eSIM associated with Modem-0. At 1003, Modem-1 either i) searches for a suitable PLMN with which to register for normal service using a second SIM / eSIM, or ii) is in RRC Idle mode and performs a periodic HPPLMN search for Modem-1 in response to the expiration of Modem-1's HPPLMN timer. At 1004, Modem-1 initiates a PLMN search, which may be in response to the expiration of Modem-1's HPPLMN timer or to recover from a server loss (e.g., an OOS condition). The PLMN search may be performed across all supported RATs and corresponding RF bands in the geographic area in which the multi-SIM / eSIM wireless device is operating. In some cases, the multi-SIM / eSIM wireless device is roaming, and each modem is camped on a PLMN based on its respective SIM / eSIM. Modem-1 may perform a HPPLMN search to determine if there is a higher priority PLMN to camp on. Modem-1 provides an indication to Modem-0 when to initiate a PLMN search, which may include an indication of whether the PLMN search is a HPPLMN search or a more general PLMN search (e.g., for OOS recovery).At 1006, Modem-1 begins a PLMN search by searching the RF bands of the 5G NR RAT and provides the PLMN search results to Modem-0 during the PLMN search. The PLMN search results may include an indication of the detected PLMN, the search status, which RATs were searched, and which RF bands of the RATs were searched. Modem-0 processes the PLMN search results received from Modem-1 and, upon detecting the highest priority PLMN for Modem-0's service, at 1008, Modem-0 stops the HPPLMN search timer for Modem-0 and attempts to camp on the detected PLMN. For detected PLMNs, except for the highest priority PLMN, Modem-0 uses this information to inform its own future PLMN searches. Figure 10In the illustrated scenario, a PLMN search performed by Modem-1 is interrupted at 1010 due to one or more triggering criteria, such as Modem-1 initiating an outgoing voice call, Modem-1 receiving an incoming voice call, Modem-1 registering due to a Tracking Area Identifier (TAI) change, or Modem-1's highest priority PLMN being detected, causing Modem-1's PLMN search to be suspended. Modem-1 provides an indication to Modem-0 that the PLMN search has been aborted, which may be included in a recent set of PLMN search results (e.g., as a search status value). At 1012, Modem-0 determines whether Modem-1 reported a highest priority PLMN for Modem-0's service in the PLMN search results. Upon detecting a highest priority PLMN for Modem-0, Modem-0 may stop the HPPLMN search timer and attempt to camp on the detected highest priority PLMN. At 1014, when Modem-1 has not searched for all required RATs or RF bands for Modem-0 (e.g., due to an interruption in the PLMN search performed by Modem-1), and no higher priority PLMN than the one already used by Modem-0 is detected, Modem-0 may allow the existing HPPLMN search timer to continue running (or restart Modem-0's HPPLMN search timer). At 1016, Modem-0 initiates its own PLMN search in response to the expiration of Modem-0's HPPLMN search timer and provides an indication of the initiation of the HPPLMN search to Modem-1. At 1018, Modem-1 restarts its own HPPLMN search timer upon completion of the activity that interrupted the PLMN search (e.g., voice call termination, registration completion, etc.). When the previous PLMN search did not detect a suitable highest priority PLMN for Modem-1 (and was not performed by Modem-1 prior to the interruption of the PLMN search), Modem-1 may restart its own HPPLMN search timer, or start a dormant timer and, upon expiration, initiate a new PLMN search (when Modem-0's PLMN search was not in progress). At 1020, Modem-0 begins a PLMN search by searching for PLMNs in the RF band of the 5G NR RAT and provides the PLMN search results to Modem- 1. As described herein with respect to Modem- 1 performing a PLMN search, additional searches by Modem-0 over additional RATs may occur.

[0046] Figure 11A flowchart 1100 illustrates an example method for optimizing a PLMN search performed by a multi-SIM / eSIM wireless device. At 1102, a first modem of the multi-SIM / eSIM wireless device initiates a PLMN search. At 1104, the first modem provides an indication of the initiated PLMN search to a second modem of the multi-SIM / eSIM wireless device. At 1106, the first modem performs a PLMN search on one or more RATs and associated RF bands. At 1108, the first modem provides PLMN search results, including an indication of detected PLMNs, to a second modem, where the second modem may delay or abandon the second PLMN search until the PLMN search performed by the first modem is complete or until the highest priority PLMN for the second modem is reported by the first modem during a PLMN search while the second modem is in an RRC idle state.

[0047] In some embodiments, a first modem includes a first SIM or eSIM 208 enabled on a multi-SIM / eSIM wireless device and associated with a first MNO 114, and a second modem includes a second SIM or eSIM 208 enabled on the multi-SIM / eSIM wireless device and associated with a second MNO different from the first MNO. In some embodiments, the first modem performs a PLMN search on RATs and associated RF bands applicable to the first SIM or eSIM and the first MNO. In some embodiments, the second PLMN search performed by the second modem includes one or more unsearched RATs or associated RF bands applicable to the second SIM or eSIM and the second MNO. In some embodiments, when the multi-SIM / eSIM wireless device is in a roaming geographic area, the first modem and the second modem each perform a service recovery from an out of service (OSS) state. In some embodiments, the first modem provides an indication of each PLMN detected during the PLMN search to the second modem as part of the PLMN search results. In some embodiments, a second modem is in an RRC idle state in a no-service recovery mode, and the second modem is configured to: i) determine whether a PLMN detected by the first modem is suitable for the second modem, and ii) if the PLMN detected by the first modem is suitable for the second modem, stop the second modem's PLMN search timer while it is running and attempt to camp on the PLMN without waiting for the first modem to complete the PLMN search. The suitability of a PLMN for a modem may depend on the requirements of a SIM / eSIM associated with the modem. In some embodiments, in response to the PLMN search timer for the second modem expiring during a PLMN search conducted by the first modem, the second modem delays or abandons the second PLMN search. In some embodiments, the second modem is configured to: i) after the first modem completes the PLMN search, determine that none of the PLMNs detected by the first modem are suitable for the second modem, and ii) perform a second PLMN search that prioritizes the RATs and associated RF bands detected by the first modem in the second PLMN search. In some embodiments, the first modem provides an indication to the second modem of RATs and / or associated RF bands that the first modem did not search in the PLMN search, and the second PLMN search performed by the second modem includes one or more of the RATs and / or associated RF bands that the first modem did not search in the PLMN search.In some embodiments, one or more of the RATs and / or associated RF bands are applicable to the second eSIM of the second modem and to the geographic area in which the multi-SIM / eSIM wireless device is operating. In some embodiments, the PLMN search results provided by the first modem to the second modem include an indication of one or more of: the detected PLMN, whether the PLMN search was partial or complete, the cumulative RATs searched, or the cumulative RF bands searched. In some embodiments, the PLMN search performed by the first modem is a high-priority PLMN search; the second PLMN search performed by the second modem is a second-highest-priority PLMN search; the second modem is in an RRC Connected state during at least a portion of the high-priority PLMN search performed by the first modem; and the second modem delays performing the second-highest-priority PLMN search until the connection is released and the transition to the RRC Idle state is made. In some embodiments, the PLMN search results from the first modem include a highest-priority PLMN for the second modem, and the second modem prioritizes searching the highest-priority PLMN upon initiation of the second high-priority PLMN search. In some embodiments, the PLMN search results from the first modem do not include a highest priority PLMN for the second modem, and the second modem waits until the high priority PLMN search performed by the first modem is complete before performing a second high priority PLMN search. In some embodiments, the PLMN search performed by the first modem is a high priority PLMN search; during the PLMN search performed by the first modem, a high priority PLMN search timer for the second modem expires; and the second modem is configured to perform the second PLMN search after the first modem completes the PLMN search, and restart the high priority PLMN search timer when no suitable highest priority PLMN for the second modem is detected during the second PLMN search. In some embodiments, the PLMN search performed by the first modem is a high priority PLMN search; the PLMN search includes all RATs and RF bands applicable to the second modem; the PLMN search results include a PLMN with a higher priority for the second modem; and the second modem is configured to stop the high priority PLMN timer for the second modem and attempt to camp on the PLMN with the higher priority.In some embodiments, when a PLMN search by the first modem terminates without searching all RATs or RF bands applicable to the second modem and the PLMN search does not detect a higher priority PLMN, the second modem is configured to discard the PLMN search results from the first modem and initiate a separate PLMN search in response to expiration of a high priority PLMN timer for the second modem.

[0048] Figure 12A A flowchart 1200 illustrates an exemplary method for optimizing PLMN searches performed by a multi-SIM / eSIM wireless device in limited service mode. At 1202, a first modem of the multi-SIM / eSIM wireless device performs a periodic search for normal service. At 1204, the first modem reports the results of the periodic PLMN search to a second modem. At 1206, while the first modem is camped on a cellular wireless network in limited service mode, the second modem avoids camping on any cellular wireless network in limited service mode. At 1208, the second modem ignores system information (SI) messages, such as SI block type 1 (SIB1) messages, broadcast by the cellular wireless network on which the first modem is camped. The second modem relies on the first modem to receive any emergency alert messages, such as Earthquake Tsunami Warning System (ETWS) or Commercial Mobile Alert System (CMAS) emergency alert messages. At 1210, the second modem performs a limited search for normal service based on the results of the periodic search reported by the first modem.

[0049] Figure 12B A flowchart 1250 illustrates another exemplary method for optimizing a PLMN search performed by a multi-SIM / eSIM wireless device when a first modem of the multi-SIM / eSIM wireless device is camped on a cellular wireless network in normal service mode. At 1252, a second modem of the multi-SIM / eSIM wireless device performs a periodic search for a suitable PLMN to camp on for normal service. At 1254, the second modem avoids camping on a cellular wireless network in limited service mode or any other cellular wireless network. At 1256, the second modem of the multi-SIM / eSIM wireless device ignores system information messages broadcast by cellular wireless networks, including the cellular wireless network on which the first modem is camped. The second modem relies on the first modem to receive any emergency alert messages, such as Earthquake Tsunami Warning System (ETWS) or Commercial Mobile Alert System (CMAS) emergency alert messages.

[0050] Representative exemplary devices

[0051] Figure 13 An example computing device 1300 that can be used to implement the various components and techniques described herein according to some embodiments is illustrated in a block diagram format. In particular, the detailed view of the example computing device 1300 illustrates various components that may be included in a multi-SIM / eSIM wireless device. Figure 13 As shown, computing device 1300 may include one or more processors 1302, representing microprocessors or controllers for controlling the overall operation of computing device 1300. In some embodiments, computing device 1300 may also include user input devices 1308 that allow a user of computing device 1300 to interact with computing device 1300. For example, in some embodiments, user input devices 1308 may take a variety of forms, such as buttons, a keypad, a dial, a touch screen, an audio input interface, a visual / image capture input interface, input in the form of sensor data, and the like. In some embodiments, computing device 1300 may include a display 1310 (screen display) that may be controlled by processor 1302 to display information to the user (e.g., information related to incoming, outgoing, or active communication sessions). A data bus 1316 may facilitate data transfer between at least storage device 1340, processor 1302, and controller 1313. Controller 1313 may be used to interact with and control various devices via device control bus 1314. The computing device 1300 may also include a network / bus interface 1311 coupled to the data link 1312. In the case of a wireless connection, the network / bus interface 1311 may include wireless circuitry such as a wireless transceiver and / or a baseband processor. The computing device 1300 may also include a secure element 1324. The secure element 1324 may include the eUICC 108.

[0052] The computing device 1300 also includes a storage device 1340, which may include a single storage device or multiple storage devices (e.g., hard drives), and a storage management module that manages one or more partitions within the storage device 1340. In some embodiments, the storage device 1340 may include flash memory, semiconductor (solid-state) memory, etc. The computing device 1300 may also include random access memory (RAM) 1320 and read-only memory (ROM) 1322. ROM 1322 may store programs, utilities, or processes to be executed in a non-volatile manner. RAM 1320 may provide volatile data storage and store instructions related to the operation of the computing device 1300.

[0053] Wireless Terminology

[0054] According to various embodiments described herein, the terms "wireless communication device," "wireless device," "mobile device," "mobile station," and "user equipment (UE)" may be used interchangeably herein to describe one or more common consumer electronic devices that may be capable of performing the processes associated with various embodiments of the present disclosure. According to various specific implementations, any of these consumer electronic devices may relate to: a cellular telephone or smartphone, a tablet computer, a laptop computer, a notebook computer, a personal computer, a netbook computer, a media player device, an e-reader device, Devices, wearable computing devices, and any other type of electronic computing device with wireless communication capabilities, which may include communication via one or more wireless communication protocols, such as protocols for communicating over the following networks: wireless wide area networks (WWANs), wireless metropolitan area networks (WMANs), wireless local area networks (WLANs), wireless personal area networks (WPANs), near field communication (NFC), cellular wireless networks, fourth generation (4G) LTE, LTE-Advanced (LTE-A), and / or 5G or other currently or future developed advanced cellular wireless networks.

[0055] In some embodiments, the wireless communication device may also operate as part of a wireless communication system, which may include a group of client devices, which may also be referred to as stations, client wireless devices, or client wireless communication devices, interconnected to an access point (AP) (e.g., as part of a WLAN) and / or interconnected with each other (e.g., as part of a WPAN and / or "ad hoc" wireless network). In some embodiments, the client device may be any wireless communication device capable of communicating via WLAN technology (e.g., according to a wireless local area network communication protocol). In some embodiments, the WLAN technology may include a Wi-Fi (or more generally, WLAN) wireless communication subsystem or radio component, which may implement the Institute of Electrical and Electronics Engineers (IEEE) 802.11 technology, such as one or more of the following: IEEE 802.11a; IEEE 802.11b; IEEE 802.11g; IEEE 802.11-2007; IEEE 802.11n; IEEE 802.11-2012; IEEE 802.11ac; or other currently or future developed IEEE 802.11 technologies.

[0056] In addition, it should be understood that the UE described herein can be configured as a multimode wireless communication device that is also capable of communicating via different third generation (3G) and / or second generation (2G) RATs. In these cases, the multimode user equipment (UE) can be configured to prefer attaching to an LTE network that provides a faster data rate throughput over other 3G legacy networks that provide a lower data rate throughput. For example, in some implementations, the multimode UE can be configured to fall back to a 3G legacy network, such as an evolved High Speed Packet Access (HSPA+) network, or a Code Division Multiple Access (CDMA) 2000 Evolution-Data Only (EV-DO) network, when LTE and LTE-A networks are otherwise unavailable.

[0057] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0058] The various aspects, embodiments, implementations, or features of the described embodiments may be used individually or in any combination. Various aspects of the described embodiments may be implemented by software, hardware, or a combination of hardware and software. The described embodiments may also be implemented as computer-readable code on a non-transitory computer-readable medium. A non-transitory computer-readable medium is any data storage device that can store data that can then be read by a computer system. Examples of non-transitory computer-readable media include read-only memory, random access memory, CD-ROM, HDD, DVD, magnetic tape, and optical data storage devices. Non-transitory computer-readable media may also be distributed on network-coupled computer systems so that the computer-readable code is stored and executed in a distributed manner.

[0059] For illustrative purposes, the foregoing description uses specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to those skilled in the art that specific details are not required in order to practice the described embodiments. Therefore, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. The foregoing descriptions are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to those skilled in the art that, in light of the above teachings, many modifications and variations are possible.

Claims

1. A method for public land mobile network (PLMN) search on a wireless device, the method comprising: By the wireless device: Initiating a PLMN search by a first modem of the wireless device; providing, by the first modem to a second modem of the wireless device, an indication of initiation of the PLMN search; performing, by the first modem, the PLMN search on one or more radio access technologies (RATs) and associated radio frequency (RF) bands; providing, by the first modem to the second modem, PLMN search results including an indication of a detected PLMN; as well as prioritizing, by the second modem, a second PLMN search based on the PLMN search results, wherein the second modem delays or abandons the second PLMN search until: The PLMN search performed by the first modem is completed, or A highest priority PLMN for the second modem is reported by the first modem during the PLMN search when the second modem is in a radio resource control (RRC) idle state.

2. The method according to claim 1, wherein: The first modem includes a first SIM or eSIM enabled on the wireless device and associated with a first mobile network operator (MNO); and The second modem includes a second SIM or eSIM enabled on the wireless device and associated with a second MNO different from the first MNO.

3. The method according to claim 2, wherein: The first modem performs the PLMN search on a RAT and associated RF band applicable to the first SIM or eSIM and the first MNO.

4. The method according to claim 3, wherein: The second PLMN search includes one or more unsearched RATs or associated RF bands applicable to the second SIM or eSIM and the second MNO.

5. The method of claim 1, wherein the first modem and the second modem each perform a service recovery procedure from an out of service (OOS) state when the wireless device is in a roaming geographic area.

6. The method of claim 1, wherein the providing PLMN search results comprises providing an indication of each PLMN detected during the PLMN search.

7. The method according to claim 6, wherein: The second modem is in a radio resource control (RRC) idle state in a no service recovery mode; and The method further includes, by the second modem: determining whether the PLMN detected by the first modem is suitable for the second modem; and When the PLMN detected by the first modem is suitable for the second modem: When a PLMN search timer for the second modem is running, stopping the PLMN search timer; and Attempting to camp on the PLMN without waiting for the first modem to complete the PLMN search.

8. The method of claim 1, wherein in response to a PLMN search timer for the second modem expiring during the PLMN search by the first modem, the second modem delays or abandons the second PLMN search.

9. The method according to claim 1, further comprising: determining, by the second modem after the first modem completes the PLMN search, that none of the PLMNs detected by the first modem is suitable for the second modem; as well as The second PLMN search is performed by the second modem, prioritizing RATs and associated RF bands detected by the first modem.

10. The method according to claim 1, further comprising: providing, by the first modem to the second modem, an indication of RATs and / or associated RF bands that the first modem did not search for in the PLMN search; and The second PLMN search includes one or more of the RATs and / or associated RF bands not searched by the first modem in the PLMN search.

11. The method of claim 10, wherein the one or more of the RATs and / or associated RF bands are applicable to a second eSIM of the second modem and to a geographic region in which the wireless device is operating.

12. The method of claim 1, wherein the PLMN search results include an indication of one or more of: a detected PLMN, whether the PLMN search is partial or complete, cumulative RATs searched, or cumulative RF bands searched.

13. The method of claim 1, wherein: the PLMN search performed by the first modem is a high priority PLMN search; the second PLMN search performed by the second modem being a second highest priority PLMN search; the second modem being in an RRC connected state during at least a portion of the high priority PLMN search performed by the first modem; and The second modem delays performing the second high priority PLMN search until the connection is released and transitions to the RRC idle state.

14. The method according to claim 13, wherein: The PLMN search results from the first modem include the highest priority PLMN for the second modem; and The second modem preferentially searches for the highest priority PLMN upon initiation of the second high priority PLMN search.

15. The method of claim 13, wherein: The PLMN search results from the first modem do not include the highest priority PLMN for the second modem; and The second modem waits until the high priority PLMN search by the first modem is completed before performing the second high priority PLMN search.

16. The method of claim 1, wherein: the PLMN search performed by the first modem is a high priority PLMN search; During the PLMN search by the first modem, a high priority PLMN search timer for the second modem expires; and The method further includes: the second modem: performing the second PLMN search after the first modem completes the PLMN search; as well as When a suitable highest priority PLMN for the second modem is not detected during the second PLMN search, the high priority PLMN search timer is restarted.

17. The method of claim 1, wherein: the PLMN search performed by the first modem is a high priority PLMN search; The PLMN search includes all RATs and RF bands applicable to the second modem; The PLMN search results include a PLMN with a higher priority for the second modem; and The method further includes: the second modem: stopping a high priority PLMN timer for the second modem; as well as An attempt is made to camp on the PLMN having the higher priority.

18. The method of claim 1 , wherein when the PLMN search by the first modem is terminated without searching all RATs or RF bands applicable to the second modem and the PLMN search does not detect a higher priority PLMN, the method further comprises: The second modem: discarding the PLMN search result from the first modem; as well as A separate PLMN search is initiated in response to expiration of a high priority PLMN timer for the second modem.

19. A method for reducing monitoring of system information broadcast (SIB) messages by a wireless device while a first modem of the wireless device is camped on a cellular wireless network in a limited service mode: performing, by the first modem, a periodic PLMN search for normal service; reporting, by the first modem, a result of the periodic PLMN search to a second modem of the wireless device; avoiding, by the second modem, camping on the cellular wireless network or another cellular wireless network in the restricted service mode; ignoring, by the second modem, SIB type one (SIB-1) messages broadcast by the cellular wireless network; as well as A restricted search for normal services is performed by the second modem based on the result of the periodic PLMN search reported by the first modem.

20. A method for reducing monitoring of system information broadcast (SIB) messages by a wireless device while a first modem of the wireless device is camped on a cellular wireless network in a normal service mode: performing, by the second modem, a periodic PLMN search for a suitable PLMN for normal service; when the first modem is camped on the cellular wireless network in the normal service mode, refraining, by the second modem, from camping on the cellular wireless network or another cellular wireless network in the restricted service mode; as well as System information (SI) messages broadcast by any cellular wireless network are ignored by the second modem.

21. An apparatus configurable for operation in a wireless device, the apparatus comprising one or more processors coupled to a memory storing instructions that, when executed by the one or more processors, configure the wireless device to perform the actions of any one of claims 1 to 20.

22. A wireless device, comprising: wireless circuitry including one or more antennas; and At least one processor communicatively coupled to the wireless circuitry and to a memory storing instructions that, when executed by the at least one processor, cause the wireless device to perform actions according to any one of claims 1 to 20.

23. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors of a wireless device, configure the wireless device to perform the actions of any one of claims 1 to 20.

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