WO2021237698A1

WO2021237698A1 - Stable service with multiple data subscriptions

Info

Publication number: WO2021237698A1
Application number: PCT/CN2020/093367
Authority: WO
Inventors: Guojing LIU; Chaofeng HUI; Dongsheng Wang; Dunfa SHI; Fojian ZHANG; Xiaomeng Lu; Xuesong Chen
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-12-02

Abstract

A user equipment (UE) may work in a first data subscription (DS) (e.g., non-default data subscription (non-DDS) in a first radio access technology (e.g., 4G LTE) and also in a second DS (e.g., DDS) in a second RAT (e.g., 5G NR). In high mobility scenarios, much power can be consumed due to frequent cell reselection in both RATS. Also, services in one or both RATs may be less reliable when radio hardware of the UE is not usable by both DDSes at the same time. To address this issue, when the first DS is in idle mode, unconditional call forwarding may be set on first DS to the second DS, and the first DS can be deactivated. In this way, power consumption is reduced by deactivation of first DS, and the UE is still capable of receiving mobile calls due to setting of the call forwarding.

Description

STABLE SERVICE WITH MULTIPLE DATA SUBSCRIPTIONS

TECHNICAL FIELD

Various aspects described herein generally relate to wireless communication systems, and more particularly, to receiving stable service in user equipment with multiple data subscriptions (e.g., multiple subscriber identity modules (SIMs) ) .

BACKGROUND

Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G) , a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks) , a third-generation (3G) high speed data, Internet-capable wireless service and a fourth-generation (4G) service (e.g., Long-Term Evolution (LTE) or WiMax) . There are presently many different types of wireless communication systems in use, including Cellular and Personal Communications Service (PCS) systems. Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS) , and digital cellular systems based on Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , the Global System for Mobile access (GSM) variation of TDMA, etc.

A fifth generation (5G) mobile standard calls for higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. The 5G standard, according to the Next Generation Mobile Networks Alliance, is designed to provide data rates of several tens of megabits per second to each of tens of thousands of users, with 1 gigabit per second to tens of workers on an office floor. Several hundreds of thousands of simultaneous connections should be supported in order to support large sensor deployments. Consequently, the spectral efficiency of 5G mobile communications should be significantly enhanced compared to the current 4G standard. Furthermore, signaling efficiencies should be enhanced and latency should be substantially reduced compared to current standards.

5G New Radio (NR) connectivity, or simply NR connectivity, has gained significant commercial traction in recent time. Thus, to attract more users to their network, network operators would like to show NR connectivity to users most of the time on the user interface (UI) of the mobile device such as the user equipment (UE) .

SUMMARY

This summary identifies features of some example aspects, and is not an exclusive or exhaustive description of the disclosed subject matter. Whether features or aspects are included in, or omitted from this summary is not intended as indicative of relative importance of such features. Additional features and aspects are described, and will become apparent to persons skilled in the art upon reading the following detailed description and viewing the drawings that form a part thereof.

An exemplary user equipment (UE) configured to operate in first and second radio access technologies (RATs) is disclosed. The UE may comprise a processor, a memory, and a transceiver. The processor, the memory, and/or the transceiver may be configured to determine whether a first data subscription (DS) is camped on the first RAT in idle mode. The processor, the memory, and/or the transceiver may also be configured to set the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode. The LACF state may be a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT. The processor, the memory, and/or the transceiver may further be configured to determine whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state. Each LAFC undo event may be an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding. The processor, the memory, and/or the transceiver may yet be configured to determine whether the first DS is back in the idle mode in the first RAT when it is determined that the one or more LACF events have been triggered. The processor, the memory, and/or the transceiver may yet further be configured to repeat setting the first DS to the LACF state when it is determined that the first DS is back in the idle mode in the first RAT.

An exemplary method performed by a user equipment (UE) configured to operate in first and second radio access technologies (RATs) is disclosed. The method may comprise determining whether a first data subscription (DS) is camped on the first RAT in idle mode. The method may also comprise setting the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode. The LACF state may be a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT. The method may further comprise determining whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state. Each LAFC undo event may be an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding. The method may yet comprise determining whether the first DS is back in the idle mode in the first RAT when it is determined that the one or more LACF events have been triggered. The method may yet further comprise repeating setting the first DS to the LACF state when it is determined that the first DS is back in the idle mode in the first RAT.

Another exemplary user equipment (UE) configured to operate in first and second radio access technologies (RATs) is disclosed. The UE may comprise means for determining whether a first data subscription (DS) is camped on the first RAT in idle mode. The UE may comprise also means for setting the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode. The LACF state may be a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT. The UE may comprise further means for determining whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state. Each LAFC undo event may be an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding. The means for setting the first DS to the LACF may repeat when it is determined that the first DS is back in the idle mode in the first RAT.

A non-transitory computer-readable medium storing computer-executable instructions for a user equipment (UE) configured to operate in first and second radio access technologies (RATs) is disclosed. The executable instructions may comprise one or more instructions instructing the UE to determine whether a first data subscription (DS) is camped on the first RAT in idle mode. The executable instructions may also comprise one or more instructions instructing the UE to set the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode. The LACF state may be a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT. The executable instructions may further comprise one or more instructions instructing the UE to determine whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state. Each LAFC undo event may be an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding. The executable instructions may yet comprise one or more instructions instructing the UE to determine whether the first DS is back in the idle mode in the first RAT when it is determined that the one or more LACF events have been triggered. The executable instructions may yet further comprise one or more instructions instructing the UE to repeat setting the first DS to the LACF state when it is determined that the first DS is back in the idle mode in the first RAT.

Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description of examples of one or more aspects of the disclosed subject matter and are provided solely for illustration of the examples and not limitation thereof:

FIG. 1 illustrates an exemplary wireless communications system in accordance with one or more aspects of the disclosure;

FIG. 2 is a simplified block diagram of several sample aspects of components that may be employed in wireless communication nodes and configured to support communication in accordance with one or more aspects of the disclosure;

FIG. 3 illustrates a flow of an example scenario that shows a technique implemented by a user equipment to provide a working mode over multiple data subscriptions in accordance with one or more aspects of the disclosure;

FIGs. 4-6 illustrate flow charts of an exemplary method performed by a user equipment to to provide a working mode over multiple data subscriptions in accordance with one or more aspects of the disclosure;

FIG. 7 illustrates a simplified block diagram of several sample aspects of a user equipment apparatus configured to provide a working mode over multiple data subscriptions in accordance with one or more aspects of the disclosure.

DETAILED DESCRIPTION

Aspects of the subject matter are provided in the following description and related drawings directed to specific examples of the disclosed subject matter. Alternates may be devised without departing from the scope of the disclosed subject matter. Additionally, well-known elements will not be described in detail or will be omitted so as not to obscure the relevant details.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term “aspects” does not require that all aspects include the discussed feature, advantage, or mode of operation.

The terminology used herein describes particular aspects only and should not be construed to limit any aspects disclosed herein. As used herein, the singular forms “a, ” “an, ” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Those skilled in the art will further understand that the terms “comprises, ” “comprising, ” “includes, ” and/or “including, ” as used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Further, various aspects may be described in terms of sequences of actions to be performed by, for example, elements of a computing device. Those skilled in the art will recognize that various actions described herein can be performed by specific circuits (e.g., an application specific integrated circuit (ASIC) ) , by program instructions being executed by one or more processors, or by a combination of both. Additionally, these sequences of actions described herein can be considered to be embodied entirely within any form of non-transitory computer-readable medium having stored thereon a corresponding set of computer instructions that upon execution would cause an associated processor to perform the functionality described herein. Thus, the various aspects described herein may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspects may be described herein as, for example, “logic configured to” and/or other structural components configured to perform the described action.

As used herein, the terms “user equipment” (UE) and “base station” are not intended to be specific or otherwise limited to any particular Radio Access Technology (RAT) , unless otherwise noted. In general, such UEs may be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, Internet of Things (IoT) device, etc. ) used by a user to communicate over a wireless communications network. A UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a Radio Access Network (RAN) . As used herein, the term “UE” may be referred to interchangeably as an “access terminal” or “AT, ” a “client device, ” a “wireless device, ” a “subscriber device, ” a “subscriber terminal, ” a “subscriber station, ” a “user terminal” or UT, a “mobile terminal, ” a “mobile station, ” or variations thereof. Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and/or the Internet are also possible for the UEs, such as over wired access networks, WiFi networks (e.g., based on Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc. ) and so on.

A base station may operate according to one of several RATs in communication with UEs depending on the network in which it is deployed, and may be alternatively referred to as an Access Point (AP) , a Network Node, a NodeB, an evolved NodeB (eNB) , a general Node B (gNodeB, gNB) , etc. In addition, in some systems a base station may provide edge node signaling functions while in other systems it may provide additional control and/or network management functions.

UEs can be embodied by any of a number of types of devices including but not limited to printed circuit (PC) cards, compact flash devices, external or internal modems, wireless or wireline phones, smartphones, tablets, tracking devices, asset tags, and so on. A communication link through which UEs can send signals to a RAN is called an uplink channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc. ) . A communication link through which the RAN can send signals to UEs is called a downlink or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc. ) . As used herein the term traffic channel (TCH) can refer to either an uplink /reverse or downlink /forward traffic channel.

FIG. 1 illustrates an exemplary wireless communications system 100 according to one or more aspects. The wireless communications system 100, which may also be referred to as a wireless wide area network (WWAN) , may include various base stations 102 and various UEs 104. The base stations 102 may include macro cells (high power cellular base stations) and/or small cells (low power cellular base stations) . The macro cells may include Evolved NodeBs (eNBs) where the wireless communications system 100 corresponds to an Long-Term Evolution (LTE) network, gNodeBs (gNBs) where the wireless communications system 100 corresponds to a 5G network, and/or a combination thereof, and the small cells may include femtocells, picocells, microcells, etc.

The base stations 102 may collectively form a Radio Access Network (RAN) and interface with an Evolved Packet Core (EPC) or Next Generation Core (NGC) through backhaul links. In addition to other functions, the base stations 102 may perform functions that relate to one or more of transferring user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC /NGC) over backhaul links 134, which may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, although not shown in FIG. 1, coverage areas 110 may be subdivided into a plurality of cells (e.g., three) , or sectors, each cell corresponding to a single antenna or array of antennas of a base station 102. As used herein, the term “cell” or “sector” may correspond to one of a plurality of cells of a base station 102, or to the base station 102 itself, depending on the context.

While neighbor macro cell geographic coverage areas 110 may partially overlap (e.g., in a handover region) , some of the geographic coverage areas 110 may be substantially overlapped by a larger geographic coverage area 110. For example, a small cell base station 102′may have a coverage area 110′that substantially overlaps with the coverage area 110 of one or more macro cell base stations 102. A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home eNBs (HeNBs) and/or Home gNodeBs, which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple input multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL) .

The wireless communications system 100 may further include a wireless local area network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152 via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz) . When communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell base station 102′may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base station 102′may employ LTE or 5G technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150. The small cell base station 102′, employing LTE /5G in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. LTE in an unlicensed spectrum may be referred to as LTE-unlicensed (LTE-U) , licensed assisted access (LAA) , or MulteFire.

The wireless communications system 100 may further include a mmW base station 180 that may operate in mmW frequencies and/or near mmW frequencies in communication with a UE 182. Extremely high frequency (EHF) is part of the radio frequency (RF) range in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band have high path loss and a relatively short range. The mmW base station 180 may utilize beamforming 184 with the UE 182 to compensate for the extremely high path loss and short range. Further, it will be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it will be appreciated that the foregoing illustrations are merely examples and should not be construed to limit the various aspects disclosed herein.

The wireless communications system 100 may further include one or more UEs, such as UE 190, that connects indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. In the embodiment of FIG. 1, UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which UE 190 may indirectly obtain WLAN-based Internet connectivity) . In an example, the D2D P2P links 192-194 may be supported with any well-known D2D radio access technology (RAT) , such as LTE Direct (LTE-D) , WiFi Direct (WiFi-D) , Bluetooth, and so on. Any of the

base stations

102, 102’, 180 may send measurement requests (e.g., measurement control order (MCO) ) to the

UEs

104, 182, 190, and the UE’s 104, 182, 190 may respond with measurement reports accordingly.

FIG. 2 illustrates several sample components (represented by corresponding blocks) that may be incorporated into an apparatus 202 and an apparatus 204 (corresponding to, for example, a UE and a base station (e.g., eNB, gNB) , respectively, to support the operations as disclosed herein. As an example, the apparatus 202 may correspond to a UE, and the apparatus 204 may correspond to a network node such as a gNB and/or an eNB. It will be appreciated that the components may be implemented in different types of apparatuses in different implementations (e.g., in an ASIC, in a System-on-Chip (SoC) , etc. ) . The illustrated components may also be incorporated into other apparatuses in a communication system. For example, other apparatuses in a system may include components similar to those described to provide similar functionality. Also, a given apparatus may contain one or more of the components. For example, an apparatus may include multiple transceiver components that enable the apparatus to operate on multiple carriers and/or communicate via different technologies.

The apparatus 202 and the apparatus 204 each may include at least one wireless communication device (represented by the communication devices 208 and 214) for communicating with other nodes via at least one designated RAT (e.g., LTE, New Radio (NR) ) . Each communication device 208 may include at least one transmitter (represented by the transmitter 210) for transmitting and encoding signals (e.g., messages, indications, information, and so on) and at least one receiver (represented by the receiver 212) for receiving and decoding signals (e.g., messages, indications, information, pilots, and so on) . Each communication device 214 may include at least one transmitter (represented by the transmitter 216) for transmitting signals (e.g., messages, indications, information, pilots, and so on) and at least one receiver (represented by the receiver 218) for receiving signals (e.g., messages, indications, information, and so on) .

A transmitter and a receiver may comprise an integrated device (e.g., embodied as a transmitter circuit and a receiver circuit of a single communication device) in some implementations, may comprise a separate transmitter device and a separate receiver device in some implementations, or may be embodied in other ways in other implementations. In an aspect, a transmitter may include a plurality of antennas, such as an antenna array, that permits the respective apparatus to perform transmit “beamforming, ” as described further herein. Similarly, a receiver may include a plurality of antennas, such as an antenna array, that permits the respective apparatus to perform receive beamforming, as described further herein. In an aspect, the transmitter and receiver may share the same plurality of antennas, such that the respective apparatus can only receive or transmit at a given time, not both at the same time. A wireless communication device (e.g., one of multiple wireless communication devices) of the apparatus 204 may also comprise a Network Listen Module (NLM) or the like for performing various measurements.

The apparatus 204 may include at least one communication device (represented by the communication device 220) for communicating with other nodes. For example, the communication device 220 may comprise a network interface (e.g., one or more network access ports) configured to communicate with one or more network entities via a wire-based or wireless backhaul connection. In some aspects, the communication device 220 may be implemented as a transceiver configured to support wire-based or wireless signal communication. This communication may involve, for example, sending and receiving messages, parameters, or other types of information. Accordingly, in the example of FIG. 2, the communication device 220 is shown as comprising a transmitter 222 and a receiver 224 (e.g., network access ports for transmitting and receiving) .

The

apparatuses

202 and 204 may also include other components used in conjunction with the operations as disclosed herein. The apparatus 202 may include a processing system 232 for providing functionality relating to, for example, communication with the network. The apparatus 204 may include a processing system 234 for providing functionality relating to, for example, communication with the UEs. In an aspect, the

processing systems

232 and 234 may include, for example, one or more general purpose processors, multi-core processors, ASICs, digital signal processors (DSPs) , field programmable gate arrays (FPGA) , or other programmable logic devices or processing circuitry.

The apparatus 202 may include first and second data subscriptions (e.g., subscriber identify modules (SIMs) ) 252 and 256 that may be associated with providing services in different radio access technologies (e.g., 4G LTE, 5G NR) .

The

apparatuses

202 and 204 may include memory components 238 and 240 (e.g., each including a memory device) , respectively, for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and so on) . In various implementations, memory 238 can comprise a computer-readable medium storing one or more computer-executable instructions for a user equipment (UE) where the one or more instructions instruct apparatus 202 (e.g., processing system 232 in combination with communications device 208 and/or other aspects of apparatus 202) to perform any of the functions of FIGs. 3, 4, and 5. In addition, the

apparatuses

202 and 204 may include

user interface devices

244 and 246, respectively, for providing indications (e.g., audible and/or visual indications) to a user and/or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on) .

For convenience, the

apparatuses

202 and 204 are shown in FIG. 2 as including various components that may be configured according to the various examples described herein. It will be appreciated, however, that the illustrated blocks may have different functionality in different designs. The components of FIG. 2 may be implemented in various ways. In some implementations, the components of FIG. 2 may be implemented in one or more circuits such as, for example, one or more processors and/or one or more ASICs (which may include one or more processors) . Here, each circuit may use and/or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by

blocks

208, 232, 238, and 244 may be implemented by processor and memory component (s) of the apparatus 202 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) . Similarly, some or all of the functionality represented by

blocks

214, 220, 234, 240, and 246 may be implemented by processor and memory component (s) of the apparatus 204 (e.g., by execution of appropriate code and/or by appropriate configuration of processor components) .

In an aspect, the apparatus 204 may correspond to a “small cell” or a Home gNodeB. The apparatus 202 may transmit and receive messages via a wireless link 260 with the apparatus 204, the messages including information related to various types of communication (e.g., voice, data, multimedia services, associated control signaling, etc. ) . The wireless link 260 may operate over a communication medium of interest, shown by way of example in FIG. 2 as the medium 262, which may be shared with other communications as well as other RATs. A medium of this type may be composed of one or more frequency, time, and/or space communication resources (e.g., encompassing one or more channels across one or more carriers) associated with communication between one or more transmitter /receiver pairs, such as the apparatus 204 and the apparatus 202 for the medium 262.

In general, the apparatus 202 and the apparatus 204 may operate via the wireless link 260 according to one or more radio access types, such as LTE, LTE-U, or NR, depending on the network in which they are deployed. These networks may include, for example, different variants of CDMA networks (e.g., LTE networks, NR networks, etc. ) , TDMA networks, FDMA networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, and so on.

A UE may be capable of operating in multiple radio access technologies (RATs) . For example, a UE may be capable of operating in a first RAT (e.g., NR) and in a second RAT (e.g., LTE) . These are merely examples, and first and second RATs may be any of the RATs currently known (e.g., WiMax, CDMA, WCDMA, UTRA, Evolved Universal Terrestrial Radio Access (E-UTRA) , GSM, FDMA, GSM, TDMA, etc. ) .

Also, a UE may be may be capable of operating in multiple RATs at the same time. For example, a UE that can operate in both LTE and NR simultaneously is an E-UTRA-NR Dual Connectivity (ENDC) capable UE. Note that ENDC is an example of Multi-RAT DC (MRDC) capability. In general, when an MRDC capable UE is operating in two RATs, it may be communicating with a base station (e.g., eNB) of a first RAT (e.g., LTE) and with a base station (e.g., gNB) of a second RAT (e.g., NR) . When the UE operates in the first RAT, it may communicate with a network node (e.g., base station, gNB, etc. ) of the first RAT. Similarly, when the UE operates in the second RAT, it may communicate with a network node (e.g., base station, eNB, etc. ) of the second RAT.

The UE may be capable of operating in a standalone (SA) or in a non-standalone (NSA) mode within a given RAT. When operating in the SA mode, the UE is able to exchange both control and data plane (also referred to as user plane) information with the network node and/or the core network of the given RAT (e.g., NR) . When operating in the NSA mode, the UE is communicating with network nodes of the first and second RATs. In the NSA mode, the UE can exchange data plane information with the network nodes of both the first RAT (e.g., NR) and the second RAT (e.g., LTE) . However, the control plane information is exchanged only with the network node of the second RAT (e.g., LTE) .

A UE may be configured such that it can be equipped with multiple subscriptions -e.g., default data subscription (DDS) and non-DDS. The UE may also be capable of operating in multiple radio access technologies (RATS) . The DDS may be configured for operation in one RAT (e.g., 5G NR) and the non-DDS may be configured for operation in another RAT (e.g., 4G LTE) .

When both DDSes are in operation, the UE may consume much power. This can be particularly true in high mobility scenarios, i.e., when the UE is moving fast. For example, the UE may be in a vehicle or in a train. In such high mobility scenarios, there can be frequent cell reselection and frequent over-the-air (OTA) messages in both RATs, which can cause high power consumption.

Also when both DDSes are in operation, service unreliability can result. When there is frequent cell reselection and OTA messages, both DDSes may compete for radio resources -e.g., transceiver resources -to perform the cell reselection and send/receive OTA messages. For example, if the UE’s transceiver is being used for cell reselection in 4G LTE, then it may not be available to provide 5G NR services. In high mobility scenarios, this may result in the NR services being dropped.

To address such issues, it is proposed to provide a working mode to reduce power consumption and enhance service reliability while allowing both DDSes to operate. In particular, when one of the DDSes is in idle mode, calls made to that DDS may be unconditionally forwarded to the other DDS. Also, the DDS may be deactivated.

FIG. 3 an example flow of a scenario 300 in which a proposed technique is implemented. In FIG. 3, it is assumed that the default data subscription is a 5G SIM and the non-default is a 4G SIM. However, these are just examples, and the proposed technique is not so limited.

The proposed technique may proceed when the non-DDS is camped on 4G LTE in idle mode, and the DDS is camped on 5G NR in connected. In FIG. 3, elements with rounded corners may be viewed as external events and/or conditions. Elements with sharp corners may be viewed as actions taken to implement the proposed technique. When the non-DDS is camped on 4G in idle mode, then the following actions may be taken:

1. Set unconditional call forwarding on non-DDS to DDS;

2. Deactivate non-DDS.

Thereafter, if an application (AP) triggers data, voice call, SMS, etc. over non-DDS, the UE will activate the non-DDS and also will undo the call forwarding. When the non-DDS is active, it may then perform procedures that use the radio resources (e.g., transceiver) such as monitor paging, cell reselection, OTA messages, and so on. When the non-DDS is back in 4G idle mode, then actions 1 and 2 may be repeated.

The proposed technique has at least the following benefits. First, deactivating the non-DDS saves power. Second, deactivating the non-DDS also enables the 5G services to be more reliable since the non-DDS need not occupy radio resources for paging, reselection, OTA messages, etc. in idle mode. Third, due to call forwarding, the UE will still be able to receive mobile terminated calls.

FIG. 4 illustrates a flow chart of an exemplary recovery method performed by a UE, e.g., to provide stable services when there are multiple data subscriptions (e.g., multiple SIMs) in operation in the UE. FIG. 4 may be viewed as a generalization of the flow of FIG. 3. Here, the UE (such as the UE 202) may be capable of operating in multiple radio access technologies (RATs) such as 4G LTE and 5G NR. The memory component 238 may be viewed as an example of a non-transitory computer-readable medium that stores computer-executable instructions to operate components of the UE 202 such as the transceiver 208 (including transmitter 210 and receiver 212) , the processing system 232 (including one or more processors) , memory component 238, etc.

In block 410, the UE may determine whether a first data subscription (DS) is camped on the first RAT in idle mode. For example, the first DS may be a 4G SIM and the first RAT may be 4G LTE. Means for performing block 510 may include the processing system 232, the memory component 238 and/or the transceiver 208 of the UE 202.

If it is not determined that the first DS is camped on the first RAT in idle mode (N branch from block 410) , then the method may simply refer back to block 410. On the other hand, when it is determined that the first DS is camped on the first RAT in idle mode (Y branch from block 410) , then in block 420, the UE may set the first DS in a state referred to as low-activity-call-forward (LACF) state for convenience. The LACF state may be viewed as a state in which:

· The UE refrains from performing one or more idle mode procedures in the first RAT; and

· Calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT.

Means for performing block 420 may include the processing system 232 and/or the memory component 238 of the UE 202. The second DS may be a 5G SIM and the second RAT may be 5G NR. The idle mode procedures in the first RAT that the UE may refrain from performing may include any one or more of page monitoring, cell search, cell measurement, cell reselection, and over-the-air (OTA) messaging. In general, the UE may refrain from performing those procedures, if performed, may result in the transceiver not being available for the second DS. By refraining from performing such idle mode procedures, radio resources will be available to the second DS, which is in connected mode, to provide second RAT services.

FIG. 5 illustrates a flow chart of an example process that may be performed by the UE to implement block 420. In block 510, the UE may set an unconditional call forwarding on the first DS to the second DS camped on the second RAT. In an aspect, the second DS may be camped on the second RAT in connected mode. In this way, the UE will still be able to receive mobile terminated calls. Means for performing block 510 may include the processing system 232, the memory component 238 and/or the transceiver 208 of the UE 202.

In block 520, the UE may deactivate the first DS. In so doing, power consumption may be reduced. Also, the first RAT idle mode procedures need not be performed. Means for performing block 520 may include the processing system 232, the memory component 238 and/or the transceiver 208 of the UE 202.

Referring back to FIG. 4, after setting the first DS to the LACF state, in block 430, the UE may determine whether one or more LAFC undo events have been triggered. Each LAFC undo event may be viewed as an event that enables or otherwise triggers the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding. Means for performing block 430 may include the processing system 232, the memory component 238 and/or the transceiver 208 of the UE 202.

FIG. 6 illustrates a flow chart of an example process that may be performed by the UE to implement block 430. In particular, three examples of LACF undo events are shown, which for convenience are referred to as first, second, and third LACF undo events. In block 610, the UE may determine whether a first LACF undo event -of a first application triggering data over the first DS -has occurred. In block 620, the UE may determine whether a second LACF undo event -of a second application triggering a voice call over the first DS -has occurred. In block 630, the UE may determine whether a third LACF undo event -of a third application triggering a short messaging service (SMS) over the first DS -has occurred. It should be noted that the first, second, and third LACF undo events are merely examples. There can be others. For example, any event that causes the UE to undo the call forwarding and activating the first DS may be included. Means for performing

blocks

610, 620, 630 may include the processing system 232, the memory component 238 and/or the transceiver 208 of the UE 202.

If any of the LACF undo events occur (Y branch from any of the

blocks

610, 620, 630) , then in block 640, the UE may determine that one or more LACF undo events have been triggered. On the other hand, if none of the LACF undo events have occurred (N branch from all of the

blocks

610, 620, 630) , then in block 650, the UE may determine that no LACF undo events have been triggered. Means for performing

blocks

640, 650 may include the processing system 232 and/or the memory component 238 of the UE 202.

Referring back to FIG. 4, if it is not determined that the LACF undo events have occurred (N branch from block 430) , this implies that the first DS remains in the LACF state, and the method may simply proceed back to block 430.

On the other hand, when it is determined that one or more LACF undo events have occurred (Y branch from block 430) , then in block 440, the UE may determine whether the first DS is back in the idle mode in the first RAT. Means for performing block 440 may include the processing system 232, the memory component 238 and/or the transceiver 208 of the UE 202.

If it is not determined that the first DS is back in the idle mode in the first RAT (N branch from block 440) , the method may simply proceed back to block 440. On the other hand, when it is determined that first DS is back in the idle mode in the first RAT (Y branch from block 440) , the UE may repeat block 420.

FIG. 7 illustrates an example user equipment apparatus 700 represented as a series of interrelated functional modules connected by a common bus. Each of the modules may be implemented in hardware or as a combination of hardware and software. For example, the modules may be implemented as any combination of the modules of the apparatus 202 of FIG. 2. A module for determining whether the first DS is camped on the first RAT in idle mode 710 may correspond at least in some aspects to a communication device (e.g., communication device 208) , a processing system (e.g., processing system 232) , and/or a memory component (e.g., memory component 238) . A module for setting the first DS to the LACF state establishing first packet session 720 may correspond at least in some aspects to a communication device (e.g., communication device 208) , a processing system (e.g., processing system 232) , and/or a memory component (e.g., memory component 238) . A module for determining whether one or more LACF undo events have occurred 730 may correspond at least in some aspects to to a communication device (e.g., communication device 208) , a processing system (e.g., processing system 232) , and/or a memory component (e.g., memory component 238) . A module for determining whether the first DS is back in idle mode in the first RAT 740 may correspond at least in some aspects to a communication device (e.g., communication device 208) , a processing system (e.g., processing system 232) , and/or a memory component (e.g., memory component 238) .

The functionality of the modules of FIG. 7 may be implemented in various ways consistent with the teachings herein. In some designs, the functionality of these modules may be implemented as one or more electrical components. In some designs, the functionality of these blocks may be implemented as a processing system including one or more processor components. In some designs, the functionality of these modules may be implemented using, for example, at least a portion of one or more integrated circuits (e.g., an ASIC) . As discussed herein, an integrated circuit may include a processor, software, other related components, or some combination thereof. Thus, the functionality of different modules may be implemented, for example, as different subsets of an integrated circuit, as different subsets of a set of software modules, or a combination thereof. Also, it will be appreciated that a given subset (e.g., of an integrated circuit and/or of a set of software modules) may provide at least a portion of the functionality for more than one module.

In addition, the components and functions represented by FIG. 7, as well as other components and functions described herein, may be implemented using any suitable means. Such means also may be implemented, at least in part, using corresponding structure as taught herein. For example, the components described above in conjunction with the “module for” components of FIG. 7 also may correspond to similarly designated “means for” functionality. Thus, in some aspects one or more of such means may be implemented using one or more of processor components, integrated circuits, or other suitable structure as taught herein.

Those of skill in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in random access memory (RAM) , flash memory, read-only memory (ROM) , erasable programmable ROM (EPROM) , electrically erasable programmable ROM (EEPROM) , registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., UE) . In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Furthermore, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.

Claims

A user equipment (UE) configured to operate in first and second radio access technologies (RATs) , comprising:

a processor;

a memory; and

a transceiver,

wherein the processor, the memory, and/or the transceiver are configured to:

determine whether a first data subscription (DS) is camped on the first RAT in idle mode;

set the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode, the LACF state being a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT;

determine whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state, each LAFC undo event being an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding; and

determine whether the first DS is back in the idle mode in the first RAT when it is determined that the one or more LACF undo events have been triggered; and

repeat setting the first DS to the LACF state when it is determined that the first DS is back in the idle mode in the first RAT.
The UE of claim 1, wherein the first and second DSes are first and second subscriber identity modules (SIMs) .
The UE of claim 1, wherein the first RAT is 4G Long Term Evolution (LTE) and the second RAT is 5G New Radio (NR) .
The UE of claim 1, wherein in the LACF state, the one or more idle mode procedures in the first RAT the UE refrains from performing comprise any one or more of page monitoring, cell search, cell measurement, cell reselection, and over-the-air (OTA) messaging.
The UE of claim 4, wherein the one or more idle mode procedures in the first RAT are such that when they are performed, the transceiver is not available for the second DS.
The UE of claim 1, wherein in setting the first DS to the LACF state, the processor, the memory, and/or the transceiver are configured to:

set an unconditional call forwarding on the first DS to the second DS camped on the second RAT; and

deactivate the first DS.
The UE of claim 6, wherein the second DS is camped on the second RAT in connected mode when the unconditional call forwarding on the first DS to the second DS is set.
The UE of claim 1, wherein in determining whether one or more LACF undo events have been triggered, the processor, the memory, and/or the transceiver are configured to:

determine whether any one or more of first, second, and third LACF undo events have occurred,

the first LACF undo event being a first application triggering data over the first DS,

the second LACF undo event being a second application triggering a voice call over the first DS, and

the third LACF undo event being a third application triggering a short messaging service (SMS) over the first DS;

determine that the one or more LACF undo events have been triggered when it is determined that any one or more of first, second, and third LACF undo events have occurred; and

determine that no LACF undo events have been triggered when it is determined that none of the first, second, and third LACF undo events have occurred.
The UE of claim 8, wherein the memory, and/or the transceiver are further configured to:

repeat determining whether one or more LAFC undo events has been triggered when it is determined that no LAFC undo events has been triggered subsequent to setting the first DS to the LACF state.
The UE of claim 1, wherein the memory, and/or the transceiver are further configured to:

repeat determining whether the first DS is back in the idle mode in the first RAT when it is determined that the first DS is not back in the idle mode in the first RAT subsequent to determining that the one or more LACF undo events have been triggered.
A method of a user equipment (UE) configured to operate in first and second radio access technologies (RATs) , comprising:

determining whether a first data subscription (DS) is camped on the first RAT in idle mode;

setting the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode, the LACF state being a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT;

determining whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state, each LAFC undo event being an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding;

determining whether the first DS is back in the idle mode in the first RAT when it is determined that the one or more LACF undo events have been triggered; and

repeating setting the first DS to the LACF state when it is determined that the first DS is back in the idle mode in the first RAT.
The method of claim 11, wherein the first and second DSes are first and second subscriber identity modules (SIMs) .
The method of claim 11, wherein the first RAT is 4G Long Term Evolution (LTE) and the second RAT is 5G New Radio (NR) .
The method of claim 11, wherein in the LACF state, the one or more idle mode procedures in the first RAT the UE refrains from performing comprise any one or more of page monitoring, cell search, cell measurement, cell reselection, and over-the-air (OTA) messaging.
The method of claim 14,

wherein the UE comprises a transceiver, and

wherein the one or more idle mode procedures in the first RAT are such that when they are performed, the transceiver is not available for the second DS.
The method of claim 11, wherein setting the first DS to the LACF state comprises:

setting an unconditional call forwarding on the first DS to the second DS camped on the second RAT; and

deactivating the first DS.
The method of claim 16, wherein the second DS is camped on the second RAT in connected mode when the unconditional call forwarding on the first DS to the second DS is set.
The method of claim 11, wherein determining whether one or more LACF undo events have been triggered comprises:

determining whether any one or more of first, second, and third LACF undo events have occurred,

the first LACF undo event being a first application triggering data over the first DS,

the second LACF undo event being a second application triggering a voice call over the first DS, and

the third LACF undo event being a third application triggering a short messaging service (SMS) over the first DS;

determining that the one or more LACF undo events have been triggered when it is determined that any one or more of first, second, and third LACF undo events have occurred; and

determining that no LACF undo events have been triggered when it is determined that none of the first, second, and third LACF undo events have occurred.
The method of claim 18, further comprising:

repeating determining whether one or more LAFC undo events has been triggered when it is determined that no LAFC undo events has been triggered subsequent to setting the first DS to the LACF state.
The method of claim 11, further comprising:

repeating determining whether the first DS is back in the idle mode in the first RAT when it is determined that the first DS is not back in the idle mode in the first RAT subsequent to determining that the one or more LACF undo events have been triggered.
A user equipment (UE) configured to operate in first and second radio access technologies (RATs) , comprising:

means for determining whether a first data subscription (DS) is camped on the first RAT in idle mode;

means for setting the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode, the LACF state being a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT;

means for determining whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state, each LAFC undo event being an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding; and

means for determining whether the first DS is back in the idle mode in the first RAT when it is determined that the one or more LACF undo events have been triggered,

wherein the means for setting the first DS to the LACF state repeats when it is determined that the first DS is back in the idle mode in the first RAT.
A non-transitory computer-readable medium storing computer-executable instructions for a user equipment (UE) , the computer-executable instructions comprising:

one or more instructions instructing the UE to determine whether a first data subscription (DS) is camped on the first RAT in idle mode;

one or more instructions instructing the UE to set the first DS to a low-activity-call-forward (LACF) state when it is determined that the first DS is camped on the first RAT in idle mode, the LACF state being a state in which the UE refrains from performing one or more idle mode procedures in the first RAT and in which calls on the first DS are unconditionally forwarded to a second DS camped on the second RAT;

one or more instructions instructing the UE to determine whether one or more LAFC undo events have been triggered subsequent to setting the first DS to the LACF state, each LAFC undo event being an event that enables the UE to perform the one or more idle mode procedures in the first RAT and/or undo the unconditional call forwarding;

one or more instructions instructing the UE to determine whether the first DS is back in the idle mode in the first RAT when it is determined that the one or more LACF undo events have been triggered; and

one or more instructions instructing the UE to repeat setting the first DS to the LACF state when it is determined that the first DS is back in the idle mode in the first RAT.