WO2021223050A1

WO2021223050A1 - Techniques for prioritizing selection of a radio access technology in wireless communications

Info

Publication number: WO2021223050A1
Application number: PCT/CN2020/088570
Authority: WO
Inventors: Yuankun ZHU; Qi Wang; Chaofeng HUI; Fojian ZHANG
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-04
Filing date: 2020-05-04
Publication date: 2021-11-11

Abstract

Aspects described herein relate to detecting a channel release from a circuit- switched (CS) call, and prioritizing, based on detecting the channel release, cell selection for a cell that supports fifth generation (5G) radio access technology communications over a cell that supports fourth generation (4G) radio access technology communications.

Description

TECHNIQUES FOR PRIORITIZING SELECTION OF A RADIO ACCESS TECHNOLOGY IN WIRELESS COMMUNICATIONS

FIELD OF THE DISCLOSURE

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to techniques for performing cell selection from one radio access technology to another.

DESCRIPTION OF RELATED ART

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems, and single-carrier frequency division multiple access (SC-FDMA) systems.

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. For example, a fifth generation (5G) wireless communications technology (which can be referred to as 5G new radio (5G NR) ) is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations. In an aspect, 5G communications technology can include: enhanced mobile broadband addressing human-centric use cases for access to multimedia content, services and data; ultra-reliable-low latency communications (URLLC) with certain specifications for latency and reliability; and massive machine type communications, which can allow a very large number of connected devices and transmission of a relatively low volume of non-delay-sensitive information.

In some radio access technologies (RATs) , such as long term evolution (LTE) and 5G NR, circuit switch (CS) fallback is provided where a user equipment (UE) can perform a CS call using a fallback RAT (e.g., a second generation (2G) or third generation (3G) RAT) , which may occur where LTE or 5G NR service is not of sufficient quality to perform the call.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

According to an example, a method for wireless communication is provided. The method includes detecting a channel release from a circuit-switched (CS) call, and prioritizing, based on detecting the channel release, cell selection for a cell that supports fifth generation (5G) radio access technology (RAT) communications over a cell that supports fourth generation (4G) RAT communications.

One or more of the above examples can further include wherein prioritizing the cell selection for the cell that supports 5G communications includes performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications, where the first cell that supports 5G RAT communications is detected within the period of time, connecting to the first cell, and where the first cell that supports 5G RAT communications is not detected within the period of time, performing the second search for the second cell that supports 4G RAT communications.

One or more of the above examples can further include wherein performing the first search includes attempting to detect one or more signals from the first cell based on an acquisition procedure defined for the 5G RAT communications.

One or more of the above examples can further include wherein the one or more signals include a synchronization signal block (SSB) .

One or more of the above examples can further include wherein connecting to the first cell includes establishing idle mode communications with the first cell.

One or more of the above examples can further include, where the second cell that supports 4G communications is detected, connecting to the second cell.

One or more of the above examples can further include wherein connecting to the second cell includes establishing idle mode communications with the second cell.

One or more of the above examples can further include obtaining, from the second cell, a list of one or more neighboring cells that support 5G RAT communications, and measuring the one or more neighboring cells for reselection based on 5G RAT communications.

In another example, an apparatus for wireless communication is provided that includes a transceiver, a memory configured to store instructions, and one or more processors communicatively coupled with the transceiver and the memory. The one or more processors are configured to detect a channel release from a circuit-switched (CS) call, and prioritize, based on detecting the channel release, cell selection for a cell that supports 5G RAT communications over a cell that supports 4G RAT communications.

One or more of the above examples can further include wherein the one or more processors are configured to prioritize the cell selection for the cell that supports 5G communications at least in part by performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications, where the first cell that supports 5G RAT communications is detected within the period of time, connecting to the first cell, and where the first cell that supports 5G RAT communications is not detected within the period of time, performing the second search for the second cell that supports 4G RAT communications.

One or more of the above examples can further include wherein the one or more signals include a SSB.

One or more of the above examples can further include wherein the one or more processors are configured to connect to the first cell at least in part by establishing idle mode communications with the first cell.

One or more of the above examples can further include wherein the one or more processors are configured to, where the second cell that supports 4G communications is detected, connect to the second cell.

One or more of the above examples can further include wherein the one or more processors are configured to connect to the second cell at least in part by establishing idle mode communications with the second cell.

One or more of the above examples can further include wherein the one or more processors are further configured to obtain, from the second cell, a list of one or more neighboring cells that support 5G RAT communications, and measure the one or more neighboring cells for reselection based on 5G RAT communications.

In another example, an apparatus for wireless communication is provided that includes means for detecting a channel release from a circuit-switched (CS) call, and means for prioritizing, based on detecting the channel release, cell selection for a cell that supports 5G RAT communications over a cell that supports 4G RAT communications.

One or more of the above examples can further include wherein the means for prioritizing the cell selection for the cell that supports 5G communications includes means for performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications, where the first cell that supports 5G RAT communications is detected within the period of time, means for connecting to the first cell, and where the first cell that supports 5G RAT communications is not detected within the period of time, means for performing the second search for the second cell that supports 4G RAT communications.

One or more of the above examples can further include wherein the means for performing the first search attempts to detect one or more signals from the first cell based on an acquisition procedure defined for the 5G RAT communications.

One or more of the above examples can further include wherein the means for connecting to the first cell establishes idle mode communications with the first cell.

One or more of the above examples can further include, where the second cell that supports 4G communications is detected, means for connecting to the second cell.

One or more of the above examples can further include wherein the means for connecting to the second cell establishes idle mode communications with the second cell.

One or more of the above examples can further include means for obtaining, from the second cell, a list of one or more neighboring cells that support 5G RAT communications, and means for measuring the one or more neighboring cells for reselection based on 5G RAT communications.

In another example, a computer-readable medium is provided that includes code executable by one or more processors for wireless communications. The code includes code for detecting a channel release from a CS call, and prioritizing, based on detecting the channel release, cell selection for a cell that supports 5G RAT communications over a cell that supports 4G RAT communications.

One or more of the above examples can further include wherein the code for prioritizing the cell selection for the cell that supports 5G communications includes code for performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications, where the first cell that supports 5G RAT communications is detected within the period of time, code for connecting to the first cell, and where the first cell that supports 5G RAT communications is not detected within the period of time, code for performing the second search for the second cell that supports 4G RAT communications.

One or more of the above examples can further include wherein the code for performing the first search attempts to detect one or more signals from the first cell based on an acquisition procedure defined for the 5G RAT communications.

One or more of the above examples can further include wherein the code for connecting to the first cell establishes idle mode communications with the first cell.

One or more of the above examples can further include, where the second cell that supports 4G communications is detected, code for connecting to the second cell.

One or more of the above examples can further include wherein the code for connecting to the second cell establishes idle mode communications with the second cell.

One or more of the above examples can further include code for obtaining, from the second cell, a list of one or more neighboring cells that support 5G RAT communications, and code for measuring the one or more neighboring cells for reselection based on 5G RAT communications.

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 annexed 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, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction with the appended drawings, provided to illustrate and not to limit the disclosed aspects, wherein like designations denote like elements, and in which:

FIG. 1 illustrates an example of a wireless communication system, in accordance with various aspects of the present disclosure;

FIG. 2 is a block diagram illustrating an example of a UE, in accordance with various aspects of the present disclosure;

FIG. 3 is a flow chart illustrating an example of a method for selecting a cell of a first RAT following a circuit-switched CS call with a fallback RAT, in accordance with various aspects of the present disclosure;

FIG. 4 illustrates an example of a wireless communication system for executing at least a fifth generation (5G) cell search following a CS call, in accordance with various aspects of the present disclosure; and

FIG. 5 is a block diagram illustrating an example of a MIMO communication system including a base station and a UE, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect (s) may be practiced without these specific details.

The described features generally relate to performing cell selection to a radio access technology (RAT) following a circuit switched (CS) call in a fallback RAT. In long term evolution (LTE) and fifth generation (5G) new radio (NR) , a user equipment (UE) can perform a CS fallback (CSFB) call (or other CS call) using a fallback RAT (e.g., a second generation (2G) or third generation (3G) RAT) , which may occur where LTE or 5G NR service is not of sufficient quality to perform the call. Following the call, the UE operating according to a third generation partnership project (3GPP) RAT, can detect release of the channel with the fallback RAT and perform cell search in LTE in an attempt to connect to an LTE cell for further communications. After the UE acquires an LTE cell, the UE can obtain information from the LTE cell to measure and perform reselection to a 5G cell.

In aspects described herein, the UE can determine to perform cell search and selection of the 5G cell following channel release of the CS call without first acquiring the LTE cell. In this example, the UE can perform 5G cell search, for at least a period of time, after channel release of the CS call, and where a 5G cell is located, the UE can acquire the 5G cell. If a 5G cell is not located during the 5G cell search, the UE can perform cell search and/or selection of a LTE cell. Thus, cell search for 5G cells can be prioritized over cell search for LTE cells for at least a period of time following CS call termination. In this example, a more efficient acquisition of a 5G cell following a CS call is provided over first acquiring and LTE cell and then moving from the LTE cell to the 5G cell.

The described features will be presented in more detail below with reference to FIGS. 1-5.

As used in this application, the terms “component, ” “module, ” “system” and the like are intended to include a computer-related entity, such as but not limited to hardware, software, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets, such as data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” may often be used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM ^TM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new 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) . The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies, including cellular (e.g., LTE) communications over a shared radio frequency spectrum band. The description below, however, describes an LTE/LTE-A system for purposes of example, and LTE terminology is used in much of the description below, although the techniques are applicable beyond LTE/LTE-Aapplications (e.g., to fifth generation (5G) new radio (NR) networks or other next generation communication systems) .

The following description provides examples, 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 other examples.

Various aspects or features will be presented in terms of systems that can include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems can include additional devices, components, modules, etc. and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. A combination of these approaches can also be used.

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) can include base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and/or a 5G Core (5GC) 190. The base stations 102 may include macro cells (high power cellular base station) and/or small cells (low power cellular base station) . The macro cells can include base stations. The small cells can include femtocells, picocells, and microcells. In an example, the base stations 102 may also include gNBs 180, as described further herein. In one example, some nodes of the wireless communication system may have a modem 240 and communicating component 242 for performing cell selection following a CS call, as described herein. Though a UE 104 is shown as having the modem 240 and communicating component 242, this is one illustrative example, and substantially any node or type of node may include a modem 240 and communicating component 242 for providing corresponding functionalities described herein.

The base stations 102 configured for 4G LTE (which can collectively be referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through backhaul links 132 (e.g., using an S1 interface) . The base stations 102 configured for 5G NR (which can collectively be referred to as Next Generation RAN (NG-RAN) ) may interface with 5GC 190 through backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of 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, radio access network (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 directly or indirectly (e.g., through the EPC 160 or 5GC 190) with each other over backhaul links 134 (e.g., using an X2 interface) . The backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with one or more UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group, which can be referred to 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 and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 /UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (e.g., for x component carriers) used for transmission in the DL and/or the UL direction. The carriers may or may not be adjacent to each other. 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 component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

In another example, certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102' , employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

A base station 102, whether a small cell 102' or a large cell (e.g., macro base station) , may include an eNB, gNodeB (gNB) , or other type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF 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 the 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 has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. A base station 102 referred to herein can include a gNB 180.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The 5GC 190 may include an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 can be a control node that processes the signaling between the UEs 104 and the 5GC 190. Generally, the AMF 192 can provide QoS flow and session management. User Internet protocol (IP) packets (e.g., from one or more UEs 104) can be transferred through the UPF 195. The UPF 195 can provide UE IP address allocation for one or more UEs, as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services.

The base station may also be referred to as a gNB, Node B, evolved Node B (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or 5GC 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a positioning system (e.g., satellite, terrestrial) , a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, robots, drones, an industrial/manufacturing device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, virtual reality goggles, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet) ) , a vehicle/avehicular device, a meter (e.g., parking meter, electric meter, gas meter, water meter, flow meter) , a gas pump, a large or small kitchen appliance, a medical/healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., meters, pumps, monitors, cameras, industrial/manufacturing devices, appliances, vehicles, robots, drones, etc. ) . IoT UEs may include MTC/enhanced MTC (eMTC, also referred to as CAT-M, Cat M1) UEs, NB-IoT (also referred to as CAT NB1) UEs, as well as other types of UEs. In the present disclosure, eMTC and NB-IoT may refer to future technologies that may evolve from or may be based on these technologies. For example, eMTC may include FeMTC (further eMTC) , eFeMTC (enhanced further eMTC) , mMTC (massive MTC) , etc., and NB-IoT may include eNB-IoT (enhanced NB-IoT) , FeNB-IoT (further enhanced NB-IoT) , etc. The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

In an example, communicating component 242 of a UE 104 can perform a CS call with a cell of a fallback RAT, such as 2G or 3G. After channel release from the CS call, communicating component 242 can prioritize cell search for a 5G cell (e.g., a cell that supports 5G RAT communications) over cell search for a 4G cell (e.g., a cell that supports 4G RAT communications) . For example, communicating component 242 can perform, after channel release from the CS call and for at least a period of time, the cell search for the 5G cell before performing cell search for a 4G cell. If a 5G cell is located during the search, communicating component 242 can establish communications with the 5G cell, which may include performing idle mode selection to the 5G cell. If a 5G cell is not located during the search after the period of time, communicating component 242 can then perform cell search for a 4G cell for establishing communications therewith.

Turning now to FIGS. 2-5, aspects are depicted with reference to one or more components and one or more methods that may perform the actions or operations described herein, where aspects in dashed line may be optional. Although the operations described below in FIGS. 3-4 are presented in a particular order and/or as being performed by an example component, it should be understood that the ordering of the actions and the components performing the actions may be varied, depending on the implementation. Moreover, it should be understood that the following actions, functions, and/or described components may be performed by a specially-programmed processor, a processor executing specially-programmed software or computer-readable media, or by any other combination of a hardware component and/or a software component capable of performing the described actions or functions.

Referring to FIG. 2, one example of an implementation of UE 104 may include a variety of components, some of which have already been described above and are described further herein, including components such as one or more processors 212 and memory 216 and transceiver 202 in communication via one or more buses 244, which may operate in conjunction with modem 240 and/or communicating component 242 for performing cell selection following a CS call, as described herein.

In an aspect, the one or more processors 212 can include a modem 240 and/or can be part of the modem 240 that uses one or more modem processors. Thus, the various functions related to communicating component 242 may be included in modem 240 and/or processors 212 and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors 212 may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or a transceiver processor associated with transceiver 202. In other aspects, some of the features of the one or more processors 212 and/or modem 240 associated with communicating component 242 may be performed by transceiver 202.

Also, memory 216 may be configured to store data used herein and/or local versions of applications 275 or communicating component 242 and/or one or more of its subcomponents being executed by at least one processor 212. Memory 216 can include any type of computer-readable medium usable by a computer or at least one processor 212, such as random access memory (RAM) , read only memory (ROM) , tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory 216 may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining communicating component 242 and/or one or more of its subcomponents, and/or data associated therewith, when UE 104 is operating at least one processor 212 to execute communicating component 242 and/or one or more of its subcomponents.

Transceiver 202 may include at least one receiver 206 and at least one transmitter 208. Receiver 206 may include hardware and/or software executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium) . Receiver 206 may be, for example, a radio frequency (RF) receiver. In an aspect, receiver 206 may receive signals transmitted by at least one base station 102. Additionally, receiver 206 may process such received signals, and also may obtain measurements of the signals, such as, but not limited to, Ec/Io, signal-to-noise ratio (SNR) , reference signal received power (RSRP) , received signal strength indicator (RSSI) , etc. Transmitter 208 may include hardware and/or software executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium) . A suitable example of transmitter 208 may including, but is not limited to, an RF transmitter.

Moreover, in an aspect, UE 104 may include RF front end 288, which may operate in communication with one or more antennas 265 and transceiver 202 for receiving and transmitting radio transmissions, for example, wireless communications transmitted by at least one base station 102 or wireless transmissions transmitted by UE 104. RF front end 288 may be connected to one or more antennas 265 and can include one or more low-noise amplifiers (LNAs) 290, one or more switches 292, one or more power amplifiers (PAs) 298, and one or more filters 296 for transmitting and receiving RF signals.

In an aspect, LNA 290 can amplify a received signal at a desired output level. In an aspect, each LNA 290 may have a specified minimum and maximum gain values. In an aspect, RF front end 288 may use one or more switches 292 to select a particular LNA 290 and its specified gain value based on a desired gain value for a particular application.

Further, for example, one or more PA (s) 298 may be used by RF front end 288 to amplify a signal for an RF output at a desired output power level. In an aspect, each PA 298 may have specified minimum and maximum gain values. In an aspect, RF front end 288 may use one or more switches 292 to select a particular PA 298 and its specified gain value based on a desired gain value for a particular application.

Also, for example, one or more filters 296 can be used by RF front end 288 to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter 296 can be used to filter an output from a respective PA 298 to produce an output signal for transmission. In an aspect, each filter 296 can be connected to a specific LNA 290 and/or PA 298. In an aspect, RF front end 288 can use one or more switches 292 to select a transmit or receive path using a specified filter 296, LNA 290, and/or PA 298, based on a configuration as specified by transceiver 202 and/or processor 212.

As such, transceiver 202 may be configured to transmit and receive wireless signals through one or more antennas 265 via RF front end 288. In an aspect, transceiver may be tuned to operate at specified frequencies such that UE 104 can communicate with, for example, one or more base stations 102 or one or more cells associated with one or more base stations 102. In an aspect, for example, modem 240 can configure transceiver 202 to operate at a specified frequency and power level based on the UE configuration of the UE 104 and the communication protocol used by modem 240.

In an aspect, modem 240 can be a multiband-multimode modem, which can process digital data and communicate with transceiver 202 such that the digital data is sent and received using transceiver 202. In an aspect, modem 240 can be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, modem 240 can be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, modem 240 can control one or more components of UE 104 (e.g., RF front end 288, transceiver 202) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration can be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration can be based on UE configuration information associated with UE 104 as provided by the network during cell selection and/or cell reselection.

In an aspect, communicating component 242 can optionally include a CS call component 252 for performing a CS call using a fallback RAT and/or a cell selecting component 254 for selecting a cell of another RAT for communications following the CS call, as described herein.

In an aspect, the processor (s) 212 may correspond to one or more of the processors described in connection with the UE in FIG. 5. Similarly, the memory 216 may correspond to the memory described in connection with the UE in FIG. 5.

FIG. 3 illustrates a flow chart of an example of a method 300 for selecting a cell of a first RAT following a CS call with a fallback RAT, in accordance with aspects described herein. In one example, a UE 104 can perform the functions described in method 300 using one or more of the components described in FIGS. 1 and 2.

In method 300, at Block 302, a channel release from a CS call can be detected. In an aspect, CS call component 252, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, communicating component 242, etc., can detect the channel release from the CS call. For example, CS call component 252 can perform a CS call using a fallback RAT, such as 2G or 3G. In this example, the UE 104 can communicate with a cell using a first RAT, such as LTE, 5G, etc., and can fallback to the fallback RAT to perform a CS call. The UE 104 may perform CSFB based on determining not to perform the call on the first RAT (e.g., as a packet-switched (PS) call) . This determination may be based on one or more characteristics of a cell providing the first RAT to which the UE 104 is connected, one or more characteristics of the UE 104, radio conditions experienced by the UE 104 in communicating with the cell, etc. In any case, CS call component 252 can establish communications with a cell providing the fallback RAT, which may be the same or different cell providing the first RAT, for performing the CS call. Following the CS call, whether terminated by the UE 104 or terminated based on loss of connection, etc., CS call component 252 detects the channel release with the cell providing the fallback RAT as part of the CS call procedure. For example, CS call component 252 can receive instructions from the cell to release the channel or can otherwise detect that the channel has been released or no longer exists, etc.

In method 300, at Block 304, based on detecting the channel release, cell selection for a first cell that supports 5G RAT communications can be prioritized over a second cell that supports 4G RAT communications. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can prioritize, based on detecting the channel release, cell selection for the first cell that supports 5G RAT communications over the second cell that supports 4G RAT communications. In this regard, for example, where the first cell that supports 5G RAT communications is detected, this first cell can be selected to provide a more efficient process for establish 5G communications following a CS call than where a 4G cell is searched and selected allowing subsequent reselection to a 5G cell.

In prioritizing cell selection for the first cell that supports 5G RAT communications at Block 304, optionally at Block 306, a first search for the first cell that supports 5G RAT communications can be performed for a period of time without first performing a second cell search for the second cell that supports 4G RAT communications. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can perform, for the period of time, the first search for the first cell that supports 5G RAT communications without first performing the second search for the second cell that supports 4G RAT communications. For example, cell selecting component 254 can determine the period of time during which to perform the cell search for 5G cells based on a configuration that can be stored in memory 216 of the UE 104 (e.g., based on a configuration defined for 5G communications, based on a configuration received in signaling from a base station or other network component, etc. ) . As described above and further herein, cell selecting component 254 can first attempt to find a 5G cell for at least the period of time before searching for 4G cell.

In performing the first search for the first cell that supports 5G RAT communications at Block 306, optionally at Block 308, detection of one or more signals can be attempted based on an acquisition procedure defined for the 5G RAT communications. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, communicating component 242, etc., can attempt to detect the one or more signals based on the acquisition procedure defined for the 5G RAT communications. For example, cell selecting component 254 can, at least for the period of time, attempt to receive and/or detect synchronization signal block (SSB) signals from 5G cells over frequency channels defined for the acquisition procedure in 5G RAT communications. Where the one or more signals are detected from a 5G cell (e.g., based on the acquisition procedure defined for 5G RAT communications) , cell selecting component 254 can determine that the first cell that supports 5G RAT communications is detected, and/or can determine an identifier of the 5G cell to continue attempting to establish connection with or otherwise acquire the 5G cell.

In prioritizing cell selection for the first cell that supports 5G RAT communications at Block 304, optionally at Block 310, it can be determined whether the first cell is detected within a period of time. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can determine whether the first cell is detected within the period of time. In one example, cell selecting component 254 can initialize a timer when detecting the channel release from the CS call (or otherwise based on detecting the channel release from the CS call) according to the configured period of time. In this regard, for example, determining whether the first cell is detected within the period of time at Block 310 may include determining that the first cell is detected before the timer expires or determining that the timer expired before detecting the first cell, where determining that the timer expired can be an indication that the first cell is not detected within the period of time.

Where the first cell is detected within the period of time at Block 310, optionally at Block 312, the first cell can be connected to. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can connect to the first cell in this case. For example, cell selecting component 254 can perform a random access channel (RACH) procedure defined for 5G RAT communications to establish connection with the first cell. In an example, this may include completing an acquisition procedure defined for 5G RAT communications. If the connection succeeds, the UE 104 can be connected to the 5G cell for communications. If the connection fails, for example, the UE 104 can return to performing the first search at Block 306 at least for the remainder of the period of time.

In one example, in connecting to the first cell at Block 312, optionally at Block 314, idle mode communications can be established with the first cell. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can establish the idle mode communications with the first cell to initially camp on the first cell in the idle mode. Idle mode communications can relate to operating in a radio resource control (RRC) idle mode or state as defined for 5G RAT communications where the UE 104 can suspend or otherwise decrease power to transceiver resources during certain time periods while providing or otherwise indicating power to the transceiver resources during paging intervals to potentially receive paging messages indicating to switch to a more active state to communicate with the 5G cell.

Where the first cell is not detected within the period of time at Block 310, optionally at Block 316, the second search for the second cell that supports 4G RAT communications can be performed. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can perform the second search for the second cell that supports 4G RAT communications. For example, performing the 4G cell search can include attempting to detect one or more signals from a 4G cell based on an acquisition procedure defined for the 4G RAT communications, such as a primary synchronization signal (PSS) , secondary synchronization signal (SSS) , etc. of a certain 4G cell (e.g., a previous 4G cell to which the UE 104 was connected before the CS call) or any 4G cell. Once detected, cell selecting component 254 can perform a RACH procedure with the 4G cell to establish a connection therewith. Once connected, cell selecting component 254 can receive a neighbor cell list of 5G cells and can measure the 5G cells for cell reselection, etc. In an example, cell selecting component 254 can perform the second search according to another period of time, after which cell selecting component 254 can determine to remain on the fallback RAT for a period of time before again attempting to perform the second search for the second cell that supports 4G RAT communications.

Based on locating the second cell that supports 4G RAT communications at Block 316, optionally at Block 318, the second cell can be connected to. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can connect to the second cell in this case. For example, cell selecting component 254 can perform a random access channel (RACH) procedure defined for 4G RAT communications to establish connection with the second cell. In an example, this may include completing an acquisition procedure defined for 4G RAT communications. If the connection succeeds, the UE 104 can be connected to the 4G cell for communications. If the connection fails, for example, the UE 104 can return to performing the second search at Block 316, can remain on the fallback RAT, for a period of time before attempting the second search (or the first search) , etc.

In one example, in connecting to the second cell at Block 318, optionally at Block 320, idle mode communications can be established with the second cell. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can establish the idle mode communications with the second cell to initially camp on the second cell in the idle mode as defined for 4G RAT communications.

Where the UE 104 is connected to the 4G cell, optionally at Block 322, a list of one or more neighboring cells that support 5G RAT communications can be obtained from the second cell. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can obtain, from the second cell, the list of one or more neighboring cells that support 5G RAT communications. For example, cell selecting component 254 can obtain the neighboring list in system information block (SIB) or other broadcast or dedicated signaling received from the 4G cell. The neighbor list may include a list of cell identifiers of 5G cells, corresponding operating frequencies, and/or the like.

Where the UE 104 is connected to the 4G cell, optionally at Block 324, one or more neighboring cells can be measured for reselection based on 5G RAT communications. In an aspect, cell selecting component 254, e.g., in conjunction with processor (s) 212, memory 216, transceiver 202, etc., can measure the one or more neighboring cells for reselection based on 5G RAT communications. For example, cell selecting component 254 can measure signals received from the one or more neighboring cells (e.g., SSB or other signals defined for 5G acquisition procedure) based on the neighbor list. In an example, cell selecting component 352 can possibly determine to reselect from the 4G cell to a 5G cell for 5G RAT communications where one of the one or more neighboring cells is determined to have a threshold measurement.

FIG. 4 illustrates an example of a wireless communication system 400 for performing a 5G cell search following a CS call. The wireless communication system 400 includes a UE 402, a 2G/3G cell 404 providing a fallback RAT, potentially a 4G LTE cell 406, and a 5G standalone (SA) cell 408. In this example, the UE 402 can perform a CS call 410 with the 2G/3G cell 404 based on the 2G/3G fallback RAT. The 2G/3G cell 404 can send a channel release 412 to the UE 402 to release the channel after the CS call 410 terminates. In some systems, the UE 402 can first attempt 4G cell search following CS call channel release, and then can reselect a 5G cell after connected to a 4G cell. In examples described herein, however, the UE 414 can execute 5G cell search 414 for at least a period of time T_period 416 after channel release 412. The UE 402 can determine if a 5G cell is found at 418, which can occur based on expiration of T_period 416, based on detecting a 5G cell before expiration of T_period 416, etc.

If a 5G cell is found at 418, the UE 402 can camp to the 5G SA cell 408 at 420, which can include establishing an idle mode connection with the 5G SA cell 408, as described. If a 5G cell is not found at 420, the UE 402 can then perform the 4G cell search to fast return to LTE 422. Once a 4G LTE cell 406 is located, the UE 402 can camp the 4G LTE cell 406 at 424, which can include establishing an idle mode connection with the 4G cell 406. While the UE 402 is connected with the 4G LTE cell 406, it can attempt to reselect to the 5G cell 408 based on reading system information block (SIB) from the 4G LTE cell 406 to get a 5G neighbor cell (NC) list 426. Based on the NC list, the UE 402 can measure 5G SA neighbor cells and may locate a 5G SA cell 408 suitable for establishing 5G RAT communications. The UE 402 can then reselect to the 5G SA cell 408 at 430.

FIG. 5 is a block diagram of a MIMO communication system 500 including a base station 102 and a UE 104, in accordance with various aspects of the present disclosure. The MIMO communication system 500 may illustrate aspects of the wireless communication access network 100 described with reference to FIG. 1. The base station 102 may be an example of aspects of the base station 102 described with reference to FIG. 1. The base station 102 may be equipped with

antennas

534 and 535, and the UE 104 may be equipped with

antennas

552 and 553. In the MIMO communication system 500, the base station 102 may be able to send data over multiple communication links at the same time. Each communication link may be called a “layer” and the “rank” of the communication link may indicate the number of layers used for communication. For example, in a 2x2 MIMO communication system where base station 102 transmits two “layers, ” the rank of the communication link between the base station 102 and the UE 104 is two.

At the base station 102, a transmit (Tx) processor 520 may receive data from a data source. The transmit processor 520 may process the data. The transmit processor 520 may also generate control symbols or reference symbols. A transmit MIMO processor 530 may perform spatial processing (e.g., precoding) on data symbols, control symbols, or reference symbols, if applicable, and may provide output symbol streams to the transmit modulator/

demodulators

532 and 533. Each modulator/demodulator 532 through 533 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator/demodulator 532 through 533 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a DL signal. In one example, DL signals from modulator/

demodulators

532 and 533 may be transmitted via the

antennas

534 and 535, respectively.

The UE 104 may be an example of aspects of the UEs 104 described with reference to FIGS. 1-2. At the UE 104, the

UE antennas

552 and 553 may receive the DL signals from the base station 102 and may provide the received signals to the modulator/

demodulators

554 and 555, respectively. Each modulator/demodulator 554 through 555 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each modulator/demodulator 554 through 555 may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. A MIMO detector 556 may obtain received symbols from the modulator/

demodulators

554 and 555, perform MIMO detection on the received symbols, if applicable, and provide detected symbols. A receive (Rx) processor 558 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, providing decoded data for the UE 104 to a data output, and provide decoded control information to a processor 580, or memory 582.

The processor 580 may in some cases execute stored instructions to instantiate a communicating component 242 (see e.g., FIGS. 1 and 2) .

On the uplink (UL) , at the UE 104, a transmit processor 564 may receive and process data from a data source. The transmit processor 564 may also generate reference symbols for a reference signal. The symbols from the transmit processor 564 may be precoded by a transmit MIMO processor 566 if applicable, further processed by the modulator/demodulators 554 and 555 (e.g., for SC-FDMA, etc. ) , and be transmitted to the base station 102 in accordance with the communication parameters received from the base station 102. At the base station 102, the UL signals from the UE 104 may be received by the

antennas

534 and 535, processed by the modulator/

demodulators

532 and 533, detected by a MIMO detector 536 if applicable, and further processed by a receive processor 538. The receive processor 538 may provide decoded data to a data output and to the processor 540 or memory 542.

The components of the UE 104 may, individually or collectively, be implemented with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the noted modules may be a means for performing one or more functions related to operation of the MIMO communication system 500. Similarly, the components of the base station 102 may, individually or collectively, be implemented with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the noted components may be a means for performing one or more functions related to operation of the MIMO communication system 500.

The above detailed description set forth above in connection with the appended drawings describes examples and does not represent the only examples that may be implemented or that are within the scope of the claims. The term “example, ” when used in this description, means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and apparatuses are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

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, computer-executable code or instructions stored on a computer-readable medium, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a specially-programmed device, such as but not limited to a processor, a digital signal processor (DSP) , an ASIC, a FPGA or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination thereof designed to perform the functions described herein. A specially-programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A specially-programmed processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a non-transitory computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a specially programmed processor, hardware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or. ” That is, unless specified otherwise, or clear from the context, the phrase, for example, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, for example the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (A and B and C) .

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 medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, 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 means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. 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, include 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 are also included within the scope of computer-readable media.

The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the common principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Furthermore, although elements of the described aspects and/or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or embodiment may be utilized with all or a portion of any other aspect and/or embodiment, unless stated otherwise. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication, comprising:

detecting a channel release from a circuit-switched (CS) call; and

prioritizing, based on detecting the channel release, cell selection for a cell that supports fifth generation (5G) radio access technology (RAT) communications over a cell that supports fourth generation (4G) RAT communications.
The method of claim 1, wherein prioritizing the cell selection for the cell that supports 5G communications includes:

performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications;

where the first cell that supports 5G RAT communications is detected within the period of time, connecting to the first cell; and

where the first cell that supports 5G RAT communications is not detected within the period of time, performing the second search for the second cell that supports 4G RAT communications.
The method of claim 2, wherein performing the first search includes attempting to detect one or more signals from the first cell based on an acquisition procedure defined for the 5G RAT communications.
The method of claim 3, wherein the one or more signals include a synchronization signal block (SSB) .
The method of claim 2, wherein connecting to the first cell includes establishing idle mode communications with the first cell.
The method of claim 2, further comprising, where the second cell that supports 4G communications is detected, connecting to the second cell.
The method of claim 6, wherein connecting to the second cell includes establishing idle mode communications with the second cell.
The method of claim 6, further comprising:

obtaining, from the second cell, a list of one or more neighboring cells that support 5G RAT communications; and

measuring the one or more neighboring cells for reselection based on 5G RAT communications.
An apparatus for wireless communication, comprising:

a transceiver;

a memory configured to store instructions; and

one or more processors communicatively coupled with the transceiver and the memory, wherein the one or more processors are configured to:

detect a channel release from a circuit-switched (CS) call; and

prioritize, based on detecting the channel release, cell selection for a cell that supports fifth generation (5G) radio access technology (RAT) communications over a cell that supports fourth generation (4G) RAT communications.
The apparatus of claim 9, wherein the one or more processors are configured to prioritize the cell selection for the cell that supports 5G communications at least in part by:

performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications;

where the first cell that supports 5G RAT communications is detected within the period of time, connecting to the first cell; and

where the first cell that supports 5G RAT communications is not detected within the period of time, performing the second search for the second cell that supports 4G RAT communications.
The apparatus of claim 10, wherein performing the first search includes attempting to detect one or more signals from the first cell based on an acquisition procedure defined for the 5G RAT communications.
The apparatus of claim 11, wherein the one or more signals include a synchronization signal block (SSB) .
The apparatus of claim 10, wherein the one or more processors are configured to connect to the first cell at least in part by establishing idle mode communications with the first cell.
The apparatus of claim 10, wherein the one or more processors are configured to, where the second cell that supports 4G communications is detected, connect to the second cell.
The apparatus of claim 14, wherein the one or more processors are configured to connect to the second cell at least in part by establishing idle mode communications with the second cell.
The apparatus of claim 14, wherein the one or more processors are further configured to:

obtain, from the second cell, a list of one or more neighboring cells that support 5G RAT communications; and

measure the one or more neighboring cells for reselection based on 5G RAT communications.
An apparatus for wireless communication, comprising:

means for detecting a channel release from a circuit-switched (CS) call; and

means for prioritizing, based on detecting the channel release, cell selection for a cell that supports fifth generation (5G) radio access technology (RAT) communications over a cell that supports fourth generation (4G) RAT communications.
The apparatus of claim 17, wherein the means for prioritizing the cell selection for the cell that supports 5G communications includes:

means for performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications;

where the first cell that supports 5G RAT communications is detected within the period of time, means for connecting to the first cell; and

where the first cell that supports 5G RAT communications is not detected within the period of time, means for performing the second search for the second cell that supports 4G RAT communications.
The apparatus of claim 18, wherein the means for performing the first search attempts to detect one or more signals from the first cell based on an acquisition procedure defined for the 5G RAT communications.
The apparatus of claim 19, wherein the one or more signals include a synchronization signal block (SSB) .
The apparatus of claim 18, wherein the means for connecting to the first cell establishes idle mode communications with the first cell.
The apparatus of claim 18, further comprising, where the second cell that supports 4G communications is detected, means for connecting to the second cell.
The apparatus of claim 22, wherein the means for connecting to the second cell establishes idle mode communications with the second cell.
The apparatus of claim 22, further comprising:

means for obtaining, from the second cell, a list of one or more neighboring cells that support 5G RAT communications; and

means for measuring the one or more neighboring cells for reselection based on 5G RAT communications.
A computer-readable medium, comprising code executable by one or more processors for wireless communications, the code comprising code for:

detecting a channel release from a circuit-switched (CS) call; and

prioritizing, based on detecting the channel release, cell selection for a cell that supports fifth generation (5G) radio access technology (RAT) communications over a cell that supports fourth generation (4G) RAT communications.
The computer-readable medium of claim 25, wherein the code for prioritizing the cell selection for the cell that supports 5G communications includes:

code for performing, for a period of time, a first search for the first cell that supports 5G RAT communications without first performing a second search for the second cell that supports 4G RAT communications;

where the first cell that supports 5G RAT communications is detected within the period of time, code for connecting to the first cell; and

where the first cell that supports 5G RAT communications is not detected within the period of time, code for performing the second search for the second cell that supports 4G RAT communications.
The computer-readable medium of claim 26, wherein the code for performing the first search attempts to detect one or more signals from the first cell based on an acquisition procedure defined for the 5G RAT communications.
The computer-readable medium of claim 27, wherein the one or more signals include a synchronization signal block (SSB) .
The computer-readable medium of claim 26, wherein the code for connecting to the first cell establishes idle mode communications with the first cell.
The computer-readable medium of claim 26, further comprising, where the second cell that supports 4G communications is detected, code for connecting to the second cell.
The computer-readable medium of claim 30, wherein the code for connecting to the second cell establishes idle mode communications with the second cell.
The computer-readable medium of claim 30, further comprising:

code for obtaining, from the second cell, a list of one or more neighboring cells that support 5G RAT communications; and

code for measuring the one or more neighboring cells for reselection based on 5G RAT communications.