WO2021232264A1

WO2021232264A1 - Multi-subscription out-of-service scan

Info

Publication number: WO2021232264A1
Application number: PCT/CN2020/091164
Authority: WO
Inventors: Xiuqiu XIA; Hao Zhang; Jian Li; Tianya LIN; Quanling ZHANG
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-20
Filing date: 2020-05-20
Publication date: 2021-11-25

Abstract

Certain aspects of the present disclosure provide techniques for multi-subscription out-of-service scanning. A method that may be performed by a user equipment (UE) includes identifying that a plurality of subscriptions are out-of-service with a radio access network (RAN) and searching, with a first subscription of the subscriptions, for service with the RAN based on the identification. The method also includes receiving, from a network entity in the RAN in response to the search for service, an indication that service is available for the first subscription. The method further includes transmitting, in response to the indication that service is available for the first subscription, one or more requests to connect to the RAN for the other one or more subscriptions of the subscriptions.

Description

MULTI-SUBSCRIPTION OUT-OF-SERVICE SCAN

BACKGROUND

Field of the Disclosure

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for scanning for service under multiple subscriptions.

Description of Related Art

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, etc. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc. ) . Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE Advanced (LTE-A) systems, code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems, to name a few.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. New radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is a set of enhancements to the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using OFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL) . To these ends, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in NR and LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

The systems, methods, and devices of the disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of this disclosure as expressed by the claims which follow, some features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description” one will understand how the features of this disclosure provide advantages that include a desirable level of power consumption when performing an out-of-service scan for multiple subscriptions.

Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a user equipment (UE) . The method generally includes identifying that a plurality of subscriptions are out-of-service with a radio access network (RAN) and searching, with a first subscription of the subscriptions, for service with the RAN based on the identification. The method also includes receiving, from a network entity in the RAN in response to the search for service, an indication that service is available for the first subscription. The method further includes transmitting, in response to the indication that service is available for the first subscription, one or more requests to connect to the RAN for the other one or more subscriptions of the subscriptions.

Aspects of the present disclosure provide means for, apparatus, processors, and computer-readable mediums for performing the methods described herein.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the appended drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

FIG. 1 is a block diagram conceptually illustrating an example wireless communication network, in accordance with certain aspects of the present disclosure.

FIG. 2 is a block diagram conceptually illustrating a design of an example a base station (BS) and user equipment (UE) , in accordance with certain aspects of the present disclosure.

FIG. 3 is an example frame format for certain wireless communication systems (e.g., new radio (NR) ) , in accordance with certain aspects of the present disclosure.

FIG. 4 is a flow diagram illustrating example operations for wireless communication by a UE, in accordance with certain aspects of the present disclosure.

FIG. 5 is a signaling flow diagram illustrating example operations for a multi-subscription out-of-service scan, in accordance with aspects of the present disclosure.

FIG. 6 illustrates a communications device (e.g., a UE) that may include various components configured to perform operations for the techniques disclosed herein in accordance with aspects of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for multi-subscription out-of-service scanning. For example, after identifying that multiple subscriptions are out of service with a Radio Access Network (RAN) , the user equipment (UE) may search for service with the RAN using a limited number of the subscriptions, such as only one subscription or fewer than all of the subscriptions. When the UE detects service with the subscription, the UE may then attempt to reconnect with the RAN using the other subscriptions. Performing the out-of-service scan with a limited number of the subscriptions (e.g., fewer than all of the subscriptions) may provide a desirable level of power consumption for the UE. In aspects, the techniques for scanning described herein may facilitate desirable battery life for portable wireless communication devices (e.g., cell phones, tablets, smartphones, smart devices, etc. ) when multiple subscriptions are out-of-service.

The following description provides examples of out-of-service scanning in communication systems, and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to, or other than, the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim. 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.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, etc. A frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, a subband, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs.

The techniques described herein may be used for various wireless networks and radio technologies. While aspects may be described herein using terminology commonly associated with 3G, 4G, and/or new radio (e.g., 5G NR) wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems.

FIG. 1 illustrates an example wireless communication network 100 in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network) , an Evolved Universal Terrestrial Radio Access (E-UTRA) system, a Universal Mobile Telecommunications System (UMTS) , a CDMA2000 system, or the like. In aspects, the UE 120a includes a service manager 122 that performs an out-of-service scan for multiple subscriptions, in accordance with aspects of the present disclosure.

As illustrated in FIG. 1, the wireless communication network 100 may include a number of BSs 110a-z (each also individually referred to herein as BS 110 or collectively as BSs 110) and other network entities. A BS 110 may provide communication coverage for a particular geographic area, sometimes referred to as a “cell” , which may be stationary or may move according to the location of a mobile BS 110. In some examples, the BSs 110 may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces (e.g., a direct physical connection, a wireless connection, a virtual network, or the like) using any suitable transport network. In the example shown in FIG. 1, the

BSs

110a, 110b and 110c may be macro BSs for the

macro cells

102a, 102b and 102c, respectively. The BS 110x may be a pico BS for a pico cell 102x. The BSs 110y and 110z may be femto BSs for the

femto cells

102y and 102z, respectively. A BS may support one or multiple cells.

The BSs 110 communicate with UEs 120a-y (each also individually referred to herein as UE 120 or collectively as UEs 120) in the wireless communication network 100. The UEs 120 (e.g., 120x, 120y, etc. ) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. Wireless communication network 100 may also include relay stations (e.g., relay station 110r) , also referred to as relays or the like, that receive a transmission of data and/or other information from an upstream station (e.g., a BS 110a or a UE 120r) and sends a transmission of the data and/or other information to a downstream station (e.g., a UE 120 or a BS 110) , or that relays transmissions between UEs 120, to facilitate communication between devices.

A network controller 130 may be in communication with a set of BSs 110 and provide coordination and control for these BSs 110 (e.g., via a backhaul) . In aspects, the network controller 130 may be in communication with a core network 132 (e.g., a 5G Core Network (5GC) ) , which provides various network functions such as Access and Mobility Management, Session Management, User Plane Function, Policy Control Function, Authentication Server Function, Unified Data Management, Application Function, Network Exposure Function, Network Repository Function, Network Slice Selection Function, etc.

FIG. 2 illustrates example components of BS 110a and UE 120a (e.g., the wireless communication network 100 of FIG. 1) , which may be used to implement aspects of the present disclosure.

At the BS 110a, a transmit processor 220 may receive data from a data source 212 and control information from a controller/processor 240. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid ARQ indicator channel (PHICH) , physical downlink control channel (PDCCH) , group common PDCCH (GC PDCCH) , etc. The data may be for the physical downlink shared channel (PDSCH) , etc. A medium access control (MAC) -control element (MAC-CE) is a MAC layer communication structure that may be used for control command exchange between wireless nodes. The MAC-CE may be carried in a shared channel such as a physical downlink shared channel (PDSCH) , a physical uplink shared channel (PUSCH) , or a physical sidelink shared channel (PSSCH) .

The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, such as for the primary synchronization signal (PSS) , secondary synchronization signal (SSS) , PBCH demodulation reference signal (DMRS) , and channel state information reference signal (CSI-RS) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 232a-232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a-232t may be transmitted via the antennas 234a-234t, respectively.

At the UE 120a, the antennas 252a-252r may receive the downlink signals from the BS 110a and may provide received signals to the demodulators (DEMODs) in transceivers 254a-254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all the demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120a to a data sink 260, and provide decoded control information to a controller/processor 280.

On the uplink, at UE 120a, a transmit processor 264 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from a data source 262 and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor 280. The transmit processor 264 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS) ) . The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by the modulators in transceivers 254a-254r (e.g., for SC-FDM, etc. ) , and transmitted to the BS 110a. At the BS 110a, the uplink signals from the UE 120a may be received by the antennas 234, processed by the modulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 120a. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to the controller/processor 240.

The

memories

242 and 282 may store data and program codes for BS 110a and UE 120a, respectively. A scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

Antennas 252,

processors

266, 258, 264, and/or controller/processor 280 of the UE 120a and/or antennas 234,

processors

220, 230, 238, and/or controller/processor 240 of the BS 110a may be used to perform the various techniques and methods described herein. As shown in FIG. 2, the controller/processor 280 of the UE 120a has a service manager 281 that performs an out-of-service scan for multiple subscriptions, according to aspects described herein. Although shown at the controller/processor, other components of the UE 120a and BS 110a may be used to perform the operations described herein.

NR may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. NR may support half-duplex operation using time division duplexing (TDD) . OFDM and single-carrier frequency division multiplexing (SC-FDM) partition the system bandwidth into multiple orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. Modulation symbols may be sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers may be dependent on the system bandwidth. The minimum resource allocation, called a resource block (RB) , may be 12 consecutive subcarriers. The system bandwidth may also be partitioned into subbands. For example, a subband may cover multiple RBs. NR may support a base subcarrier spacing (SCS) of 15 KHz and other SCS may be defined with respect to the base SCS (e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc. ) .

FIG. 3 is a diagram showing an example of a frame format 300 for NR. The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms) and may be partitioned into 10 subframes, each of 1 ms, with indices of 0 through 9. Each subframe may include a variable number of slots (e.g., 1, 2, 4, 8, 16, …slots) depending on the SCS. Each slot may include a variable number of symbol periods (e.g., 7, 12, or 14 symbols) depending on the SCS. The symbol periods in each slot may be assigned indices. A mini-slot, which may be referred to as a sub-slot structure, refers to a transmit time interval having a duration less than a slot (e.g., 2, 3, or 4 symbols) . Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission and the link direction for each subframe may be dynamically switched. The link directions may be based on the slot format. Each slot may include DL/UL data as well as DL/UL control information.

In NR, a synchronization signal block (SSB) is transmitted. In certain aspects, SSBs may be transmitted in a burst where each SSB in the burst corresponds to a different beam direction for UE-side beam management (e.g., including beam selection and/or beam refinement) . The SSB includes a PSS, a SSS, and a two symbol PBCH. The SSB can be transmitted in a fixed slot location, such as the symbols 0-3 as shown in FIG. 3. The PSS and SSS may be used by UEs for cell search and acquisition. The PSS may provide half-frame timing, the SS may provide the CP length and frame timing. The PSS and SSS may provide the cell identity. The PBCH carries some basic system information, such as downlink system bandwidth, timing information within radio frame, SS burst set periodicity, system frame number, etc. The SSBs may be organized into SS bursts to support beam sweeping. Further system information such as, remaining minimum system information (RMSI) , system information blocks (SIBs) , other system information (OSI) can be transmitted on a physical downlink shared channel (PDSCH) in certain subframes. The SSB can be transmitted up to sixty-four times, for example, with up to sixty-four different beam directions for mmWave. The multiple transmissions of the SSB are referred to as a SS burst set. SSBs in an SS burst set may be transmitted in the same frequency region, while SSBs in different SS bursts sets can be transmitted at different frequency regions.

Example Multi-Subscription Out-of-Service Scan

In certain wireless communication networks (such as CDMA2000, UMTS, E-UTRA, and/or 5G NR) , a UE may support a plurality of subscriptions (e.g., via a plurality of subscriber identity modules (SIMs) or universal SIMs (USIMs) ) with one or more wireless networks. A UE with multiple subscription capabilities (e.g., multiple SIMs) may be able to access various services or functions associated with each of the subscriptions, such as a different subscriber account, a different network (e.g., a RAN) , and/or a different radio access technology (RAT) (e.g., E-UTRA or 5G NR) . In certain cases, the UE may have a SIM for business use and another SIM for private use, where each SIM provides a separate number and/or data services (e.g., 5G NR and/or E-UTRA data services) . In other cases, an additional SIM may be employed when the UE is taken to a different country with a different RAN or RAT. Some multiple subscription configurations enable each subscription to be active simultaneously, allowing communications at any given time (e.g., Dual SIM Single Standby (DSSS) , Dual SIM Dual Standby (DSDS) , Dual SIM Dual Active (DSDA) , Triple SIM Triple Standby (TSTS) , etc. ) .

In certain cases, the UE may have multiple subscriptions with the same wireless service provider (i.e., a wireless network operator or carrier) . When the UE enters a weak coverage area of the RAN, the UE may be out of service for all of the subscriptions with the same wireless service provider. For example, as a DSDS UE, both of the subscriptions may be out of service with the same wireless service provider. For both of the subscriptions, the UE may initiate independent searches for service with the RAN. In other words, the UE may perform separate and concurrent scans for service with the subscriptions. Performing the independent and concurrent searches for the network under the same wireless service provider may consume an undesirable amount of power, when the subscriptions may encounter similar coverage areas (e.g., channel conditions) and network loads with the same wireless service provider.

Aspects of the present disclosure provide an apparatus and various techniques for managing out-of-service scans for multiple subscriptions. For example, after identifying that multiple subscriptions are out of service with a RAN, the UE may search for service with the RAN using a limited number of the subscriptions, such as only one subscription or fewer than all of the subscriptions. When the UE detects service with the subscription, the UE may then attempt to reconnect with the RAN using the other subscriptions. Performing the out-of-service scan with a limited number of the subscriptions (e.g., fewer than all of the subscriptions) may provide a desirable level of power consumption for the UE. In aspects, the techniques for scanning described herein may facilitate desirable battery life for certain wireless communication devices (e.g., cell phones, tablets, smartphones, smart devices, etc. ) when multiple subscriptions are out-of-service.

FIG. 4 is a flow diagram illustrating example operations 400 for wireless communication, in accordance with certain aspects of the present disclosure. The operations 400 may be performed, for example, by a UE (e.g., the UE 120a in the wireless communication network 100) . The operations 400 may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor 280 of FIG. 2) . Further, the transmission and reception of signals by the UE in operations 400 may be enabled, for example, by one or more antennas (e.g., antennas 252 of FIG. 2) . In certain aspects, the transmission and/or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor 280) obtaining and/or outputting signals.

The operations 400 may begin, at 402, where the UE may identify that a plurality of subscriptions are out-of-service with a radio access network (RAN) . At 404, the UE may search, with a first subscription of the subscriptions and without one or more second subscriptions of the subscriptions, for service with the RAN based on the identification. At 406, the UE may receive, from a network entity (e.g., BS 110a) in the RAN in response to the search for service, an indication that service is available for the first subscription. At 408, the UE may transmit, in response to the indication that service is available for the first subscription, one or more requests to connect to the RAN for the one or more second subscriptions.

In aspects, identifying that the subscriptions are out-of-service at 402 may involve the UE receiving, from the RAN, various indications that the subscriptions are out-of-service or detecting no responses from the RAN. For example, identifying that the plurality of subscriptions are out-of-service may include the UE receiving indications that the subscriptions are out-of-service. As an example, the indication that a subscription is out-of-service may be received via radio resource control (RRC) signaling, such as a RRC connection release message. In certain cases, the UE may identify that a subscription is out-of-service due to a radio link failure or detecting no response from the RAN, for example, during a Random Access Channel (RACH) procedure. For example, if the UE fails to receive a response to a RACH preamble message for a certain subscription, the UE may identify that the subscription is out-of-service. In certain cases, the UE may be out-of-service due to poor channel conditions with the RAN, such that the UE is unable to communicate with the RAN via over-the-air resources (e.g., time-frequency resources) . In other cases, the UE may be out-of-service with the RAN due to the RAN being overloaded with traffic and/or users, such that the RAN releases an active connection that UE has with the RAN or blocks subsequent connection requests from the UE.

In aspects, the out-of-service scan at 404 may be triggered when all of the subscriptions are identified as being out-of-service with the RAN, or when a subset of the subscriptions are identified as being out of service with the RAN. In certain cases, the out-of-service scan may be triggered by the identification of a single subscription being out-of-service, and the UE may block separate out-of-service scans from being initiated for other subscriptions as the other subscriptions are identified as being out-of-service. In other words, searching for service at 404 may involve performing an out-of-service scan with a subscription and blocking separate out-of-service scans from being initiated for other subscriptions after it is identified that multiple subscriptions are out-of-service.

In certain aspects, searching for service at 404 may involve the UE monitoring for various reference signals (e.g., synchronization signals as described herein with respect to FIG. 3) and system information from the RAN, and the UE transmitting a request to connect to the RAN based on the reference signals and system information. For example, the UE may transmit, to the network entity in the RAN, a network acquisition request for the first subscription. In certain aspects, the UE may monitor for synchronization signals (e.g., the SSBs of FIG. 3) and system information (e.g., a system information block (SIB) providing RACH resources) from the RAN and transmit a RACH preamble as the network acquisition request based on the received system information. That is, searching for service at 404 may include the UE performing part of a RACH procedure to connect to the RAN.

In aspects, the UE may loop through (i.e., repeat) the search for service until the UE receives an indication that service is available for the subscription. For example, the UE may receive, in response to the network acquisition request, an indication that no cell is available for service, and the UE may continue to perform the search for service in response to the indication. In certain cases, the UE may not receive a response to the network acquisition request from the RAN within a certain time window (e.g., a Random Access Response Window such as the parameter ra-ResponseWindow in 4G and 5G RATs) , and the UE may continue the search for service after expiration of the time window without a response from the RAN. That is, the UE may transmit subsequent network acquisition requests after the expiration of the time window for receiving a response from the RAN. In aspects, the UE may adjust (e.g., increase) the transmit power for the subsequent transmissions of the network acquisition request.

In certain aspects, the UE may conduct the search for service with a limited number of subscriptions (e.g., fewer than all the subscriptions) . In aspects, the UE may transmit the network acquisition request via a limited number of the subscriptions (e.g., fewer than all the subscriptions) . In certain cases, searching for service at 404 may include the UE searching only with the first subscription for service with the RAN. For example, the UE may transmit the network acquisition request only through the first subscription. That is, a single subscription may be used to scan for service with the RAN. Searching for service with only a single subscription may enable the UE to conserve power consumption compared to searching for service with all of the subscriptions. In aspects, searching for service with only a single subscription may facilitate a desirable battery life for the UE.

In aspects, the UE may select the subscription to use for the out-of-service scan (e.g., searching at 404) based on various criteria. For example, the UE may use a default subscription for the out-of-service scan or a subscription that may use less power consumption, such as a subscription to 4G services compared to a subscription for 5G services. In certain cases, the UE may select the subscription, which is first detected as being out-of-service, for the out-of-service scan. As an example, the UE may select the first subscription among the subscriptions for searching based on receiving the indication that the first subscription is out of service before the indications for the other one or more subscriptions of the subscriptions, and the UE may search for service with the first subscription based on the selection.

According to certain aspects, receiving the indication that service is available at 406 may involve the UE receiving a network camp indication. That is, the indication that service is available for the first subscription includes a network camp indication. In certain cases, the indication that service is available at 406 may include a Random Access Response (RAR) message, which may provide an uplink grant and temporary identifier for the UE. The UE may proceed to attach to the RAN via the first subscription, for example, through RRC connection establishment. For example, the UE may transmit an RRC setup request message (or RRC connection request message under a 4G RAT) in accordance with the uplink grant in the RAR message.

In aspects, after successfully establishing a connection to the RAN with the first subscription, the UE may attempt to establish a connection to the RAN with the remaining subscriptions. For example, at 408, the UE may transmit RACH preambles for the other subscriptions after successfully establishing a connection to the RAN with the first subscription at 406.

According to certain aspects, after successfully establishing connections to the RAN with the subscriptions, the UE may communicate with the RAN via the plurality of subscriptions after transmitting the one or more requests to connect to the RAN. For example, the UE may receive data traffic from the RAN via the subscriptions and/or transmit data traffic to the RAN via the subscriptions.

In aspects, the subscriptions may be associated with a same wireless service provider. That is, the subscriptions for the UE may be under the same wireless carrier or wireless network operator. In aspects, the UE may encounter similar channel conditions and/or traffic loads for the subscriptions due to the subscriptions being under the same wireless service provider. In certain cases, searching at 404 may be dependent on the subscriptions being with the same wireless service provider. That is, searching at 404 may be based on the subscriptions being with the same wireless service provider and the identification that the subscriptions are out-of-service. A wireless service provider may be referred to as a wireless network operator or carrier in which the subscriptions are registered. The UE may be capable of communicating with the RAN (s) of the wireless service provider through the subscriptions.

In aspects, a Radio Access Network (RAN) may be part of a wireless communication network (such as the wireless communication network 100) that provides UEs with connections to a core network (e.g., the core network 132) and/or data network (e.g., the internet) . In certain cases, the RAN may include base stations (e.g., the BSs 110) and/or a network controller (e.g., the network controller 130) . In aspects, the network entity in the RAN of the operations 400 may be a base station and/or a network controller.

FIG. 5 is a signaling flow diagram illustrating example operations 500 for performing an out-of-service scan, in accordance with certain aspects of the present disclosure. In aspects, the UE 120 may have a first subscription and a second subscription with the same wireless service provider, such that the UE 120 may communicate with the same RAN through the first and second subscriptions. As shown, at 502, the UE 120 may receive, from the RAN 140, an out-of-service indication for the first subscription (e.g., an RRC connection release message) , and at 504, the UE 120 may receive, from the RAN 140, an out-of-service indication for the second subscription. In certain cases, the UE 120 may identify that first and second subscriptions are out-of-services due to a radio link failure or detecting no response from the RAN 140.

After identifying that the subscriptions are out-of-service, the UE 120 may initiate a search for service with one of the subscriptions. For example, the UE 120 may scan for service with only the first subscription. As shown, the UE 120 may transmit a network acquisition request (e.g., a RACH preamble message) at 506. In certain cases, at 508, the UE 120 may receive an indication that no service is available for the first subscription. In other cases, the UE 120 may determine that there is no service available for the subscription due to the UE 120 not receiving a response from the RAN within a certain time window (e.g., the window set according to the parameter ra-ResponseWindow) .

The UE 120 may continue to search for service until the UE 120 receives an indication that service is available for the first subscription. For example, at 510, the UE 120 may transmit a subsequent network acquisition request (e.g., a RACH preamble message) , and at 512, the UE 120 may receive an indication that service is available for the first subscription (e.g., a RAR message) .

After successfully establishing a connection to the RAN 140 via the first subscription, the UE 120 may attempt to establish a connection to the RAN 140 via the second subscription. For example, at 514, the UE 120 may transmit a network acquisition request (e.g., a RACH preamble message) for the second subscription, and at 512, the UE 120 may receive an indication that service is available for the second subscription (e.g., a RAR message) .

After successfully establishing connections to the RAN 140 for the first and second subscriptions, the UE 120 may communicate with the RAN 140 through the first and second subscriptions. For example, the UE 120 may communicate with the RAN 140 via the first subscription at 518 (such as voice call traffic) , and the UE 120 may communicate with the RAN 140 via the second subscription at 520 (such as 4G/5G data traffic) .

While the example depicted in FIG. 5 is described herein with respect to the UE 120 communicating with a single RAN 140 to facilitate understanding, aspects of the present disclosure may also be applied to the UE having multiple subscriptions and communicating with multiple RANs supporting one or more RATs.

FIG. 6 illustrates a communications device 600 (e.g., the UE 120) that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operations illustrated in FIG. 4. The communications device 600 includes a processing system 602 coupled to a transceiver 608 (e.g., a transmitter and/or a receiver) . The transceiver 608 is configured to transmit and receive signals for the communications device 600 via an antenna 610, such as the various signals as described herein. The processing system 602 may be configured to perform processing functions for the communications device 600, including processing signals received and/or to be transmitted by the communications device 600.

The processing system 602 includes a processor 604 coupled to a computer-readable medium/memory 612 via a bus 606. In certain aspects, the computer-readable medium/memory 612 is configured to store instructions (e.g., computer-executable code) that when executed by the processor 604, cause the processor 604 to perform the operations illustrated in FIG. 4, or other operations for performing the various techniques discussed herein for multi-subscription out-of-service scanning. In certain aspects, computer-readable medium/memory 612 stores code for receiving 614, code for transmitting 616, code for identifying 618, and/or code for searching 620. In certain aspects, the processor 604 has circuitry configured to implement the code stored in the computer-readable medium/memory 612. The processor 604 includes circuitry for receiving 624, circuitry for transmitting 626, circuitry for identifying 628, and/or circuitry for searching 630.

The techniques described herein may be used for various wireless communication technologies, such as NR (e.g., 5G NR) , 3GPP Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single-carrier frequency division multiple access (SC-FDMA) , time division synchronous code division multiple access (TD-SCDMA) , and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA) , cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA network may implement a radio technology such as NR (e.g. 5G RA) , Evolved UTRA (E-UTRA) , Ultra Mobile Broadband (UMB) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . LTE and LTE-A are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . cdma2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . NR is an emerging wireless communications technology under development.

NR access may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or beyond) , millimeter wave (mmWave) targeting high carrier frequency (e.g., e.g., 24 GHz to 53 GHz or beyond) , massive machine type communications MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low-latency communications (URLLC) . These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTI) to meet respective quality of service (QoS) requirements. In addition, these services may co-exist in the same subframe. NR supports beamforming and beam direction may be dynamically configured. MIMO transmissions with precoding may also be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.

In 3GPP, the term “cell” can refer to a coverage area of a Node B (NB) and/or a NB subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term “cell” and BS, next generation NodeB (gNB or gNodeB) , access point (AP) , distributed unit (DU) , carrier, or transmission reception point (TRP) may be used interchangeably. A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cells. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG) , UEs for users in the home, etc. ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS.

A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE) , a cellular phone, a smart phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, a smart bracelet, etc. ) , an entertainment device (e.g., a music device, a video device, a satellite radio, etc. ) , a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. Some UEs may be considered machine-type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a BS, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities utilize resources allocated by the scheduling entity. Base stations are not the only entities that may function as a scheduling entity. In some examples, a UE may function as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs) , and the other UEs may utilize the resources scheduled by the UE for wireless communication. In some examples, a UE may function as a scheduling entity in a peer-to-peer (P2P) network, and/or in a mesh network. In a mesh network example, UEs may communicate directly with one another in addition to communicating with a scheduling entity.

The methods disclosed herein comprise one or more steps or actions for achieving the methods. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information) , accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the term “some” refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112 (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for. ”

The various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component (s) and/or module (s) , including, but not limited to a circuit, an application specific integrated circuit (ASIC) , or processor. Generally, where there are operations illustrated in figures, those operations may have corresponding counterpart means-plus-function components with similar numbering.

The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , 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 commercially available 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.

If implemented in hardware, an example hardware configuration may comprise a processing system in a wireless node. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including a processor, machine-readable media, and a bus interface. The bus interface may be used to connect a network adapter, among other things, to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of a user terminal (see FIG. 1) , a user interface (e.g., keypad, display, mouse, joystick, etc. ) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further. The processor may be implemented with one or more general-purpose and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry that can execute software. Those skilled in the art will recognize how best to implement the described functionality for the processing system depending on the particular application and the overall design constraints imposed on the overall system.

If implemented in software, the functions may be stored or transmitted over as one or more instructions or code on a computer readable medium. Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on the machine-readable storage media. A computer-readable storage medium may be coupled to a 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. By way of example, the machine-readable media may include a transmission line, a carrier wave modulated by data, and/or a computer readable storage medium with instructions stored thereon separate from the wireless node, all of which may be accessed by the processor through the bus interface. Alternatively, or in addition, the machine-readable media, or any portion thereof, may be integrated into the processor, such as the case may be with cache and/or general register files. Examples of machine-readable storage media may include, by way of example, RAM (Random Access Memory) , flash memory, ROM (Read Only Memory) , PROM (Programmable Read-Only Memory) , EPROM (Erasable Programmable Read-Only Memory) , EEPROM (Electrically Erasable Programmable Read-Only Memory) , registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. The machine-readable media may be embodied in a computer-program product.

A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. The computer-readable media may comprise a number of software modules. The software modules include instructions that, when executed by an apparatus such as a processor, cause the processing system to perform various functions. The software modules may include a transmission module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. By way of example, a software module may be loaded into RAM from a hard drive when a triggering event occurs. During execution of the software module, the processor may load some of the instructions into cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When referring to the functionality of a software module below, it will be understood that such functionality is implemented by the processor when executing instructions from that software module.

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 (IR) , 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, include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk, and

disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Thus, in some aspects computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media) . In addition, for other aspects computer-readable media may comprise transitory computer-readable media (e.g., a signal) . Combinations of the above should also be included within the scope of computer-readable media.

Thus, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may comprise a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein, for example, instructions for performing the operations described herein and illustrated in FIG. 4.

Further, it should be appreciated that modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc. ) , such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage means to the device. Moreover, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

A method of wireless communication by a user equipment, comprising:

identifying that a plurality of subscriptions are out-of-service with a radio access network (RAN) ;

searching, with a first subscription of the subscriptions and without one or more second subscriptions of the subscriptions, for service with the RAN based on the identification;

receiving, from a network entity in the RAN in response to the search for service, an indication that service is available for the first subscription; and

transmitting, in response to the indication that service is available for the first subscription, one or more requests to connect to the RAN for the one or more second subscriptions.
The method of claim 1, wherein searching comprises transmitting, to the network entity in the RAN, a network acquisition request for the first subscription.
The method of claim 2, wherein searching comprises receiving, in response to the network acquisition request, an indication that no cell is available for service.
The method of claim 3, wherein searching comprises continuing to transmit, in response to receiving the indication that no cell is available, the network acquisition request for the first subscription.
The method of claim 1, wherein searching comprises searching only with the first subscription for service with the RAN.
The method of claim 1, wherein identifying that the plurality of subscriptions are out-of-service comprises receiving indications that the subscriptions are out-of-service.
The method of claim 6, wherein searching comprises:

selecting the first subscription among the subscriptions for searching based on receiving the indication that the first subscription is out of service before the indications for the other one or more subscriptions of the subscriptions; and

searching for service with the first subscription based on the selection.
The method of claim 1, wherein the indication that service is available for the first subscription includes a network camp indication.
The method of claim 1, further comprising communicating with the RAN via the plurality of subscriptions after transmitting the one or more requests to connect to the RAN.
The method of claim 1, wherein the subscriptions are associated with a same wireless service provider.
An apparatus for wireless communication, comprising:

a processing system configured to identify that a plurality of subscriptions are out-of-service with a radio access network (RAN) ; and

a transceiver configured to:

search, with a first subscription of the subscriptions and without one or more second subscriptions of the subscriptions, for service with the RAN based on the identification,

receive, from a network entity in the RAN in response to the search for service, an indication that service is available for the first subscription, and

transmit, in response to the indication that service is available for the first subscription, one or more requests to connect to the RAN for the one or more second subscriptions.
The apparatus of claim 11, wherein the transceiver is configured to transmit, to the network entity in the RAN, a network acquisition request for the first subscription.
The apparatus of claim 12, wherein the transceiver is configured to receive, in response to the network acquisition request, an indication that no cell is available for service.
The apparatus of claim 13, wherein the transceiver is configured to continue to transmit, in response to receiving the indication that no cell is available, the network acquisition request for the first subscription.
The apparatus of claim 11, wherein the transceiver is configured to search only with the first subscription for service with the RAN.
The apparatus of claim 11, wherein:

the transceiver is configured to receive indications that the subscriptions are out-of-service; and

the processing system is configured to identify that the plurality of subscriptions are out-of-service based on the indications that the subscriptions are out-of-service.
The apparatus of claim 16, wherein:

the processing system is configured to select the first subscription among the subscriptions for searching based on receiving the indication that the first subscription is out of service before the indications for the other one or more subscriptions of the subscriptions; and

the transceiver is configured to search for service with the first subscription based on the selection.
The apparatus of claim 11, wherein the indication that service is available for the first subscription includes a network camp indication.
The apparatus of claim 11, wherein the transceiver is configured to communicate with the RAN via the plurality of subscriptions after transmitting the one or more requests to connect to the RAN.
The apparatus of claim 11, wherein the subscriptions are associated with a same wireless service provider.
An apparatus for wireless communication, comprising:

means for identifying that a plurality of subscriptions are out-of-service with a radio access network (RAN) ;

means for searching, with a first subscription of the subscriptions and without one or more second subscriptions of the subscriptions, for service with the RAN based on the identification;

means for receiving, from a network entity in the RAN in response to the search for service, an indication that service is available for the first subscription; and

means for transmitting, in response to the indication that service is available for the first subscription, one or more requests to connect to the RAN for the one or more second subscriptions.
A computer readable medium having instructions stored thereon for:

identifying that a plurality of subscriptions are out-of-service with a radio access network (RAN) ;

searching, with a first subscription of the subscriptions and without one or more second subscriptions of the subscriptions, for service with the RAN based on the identification;

receiving, from a network entity in the RAN in response to the search for service, an indication that service is available for the first subscription; and

transmitting, in response to the indication that service is available for the first subscription, one or more requests to connect to the RAN for the one or more second subscription.