CN111031587A - User equipment and wireless communication method thereof - Google Patents

Abstract

A method of wireless communication includes determining a set of RATs available to a user equipment based on a first subscriber identity associated with a first network and a second subscriber identity associated with a second network. Further comprising when the set of RATs includes a first RAT for accessing base stations in the first network, a second RAT for accessing base stations in the second network, and a third RAT for accessing access points to WLAN, the UE selecting the first RAT in a first performance configuration to establish a first call under the first subscriber identity; the UE further communicates with a first IMS server of the first network under the first subscriber identity over the first RAT to establish the first call; and when the first call is active, the UE maintains a connection with a second IMS server of the second network through the first RAT or the third RAT in the second subscriber identity. By utilizing the invention, the user equipment can better carry out wireless communication.

Description

User equipment and wireless communication method thereof

Technical Field

The present invention relates generally to communication systems, and more particularly to techniques for selecting a Radio Access Technology (RAT) at a Dual SIM Dual Standby (DSDS) User Equipment (UE).

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. A typical wireless communication system may employ multiple-access (multiple-access) techniques that are capable of supporting communication with multiple users by sharing the available system resources. Examples of Multiple Access techniques include 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.

The above-described multiple access techniques have been employed in various telecommunications standards to provide common protocols that may enable different wireless devices to communicate at a city level, a country level, a region level, or even a global level. One example of a telecommunications standard is the fifth Generation (5th Generation, 5G) New Radio (NR). The 5G NR is part of the continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3 GPP) to meet new requirements associated with latency, reliability, security, scalability (scalability), such as with the Internet of Things (IoT), among other requirements. Some aspects of 5G NR may be based on the fourth Generation (4th Generation, 4G) Long Term Evolution (LTE) standard. The 5G NR technique requires further improvements which may also be applicable to other multiple access techniques and telecommunications standards employing these techniques.

Disclosure of Invention

An aspect of the invention provides a method of wireless communication for a user equipment, the method comprising determining a set of radio access technologies available to the user equipment from a first subscriber identity associated with a first network and a second subscriber identity associated with a second network. The method also includes selecting the first radio access technology in a first performance configuration to establish a first call under the first subscriber identity when the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network; communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

One aspect of the present invention provides user equipment for wireless communication, comprising a processing system including a memory; and at least one processor coupled with the memory. The processing system is configured to determine a set of radio access technologies available to the user equipment based on a first subscriber identity associated with a first network and a second subscriber identity associated with a second network. Selecting the first radio access technology in a first capability configuration to establish a first call under the first subscriber identity when the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network; communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

One aspect of the present invention provides a user equipment for wireless communication, comprising a decision component configured to: determining a set of radio access technologies available to the user equipment from a first subscriber identity associated with a first network and a second subscriber identity associated with a second network; and determining whether the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network. The user equipment further comprises a communication management component configured to, when the set of radio access technologies includes the first radio access technology accessing the base station in the first network, the second radio access technology accessing the base station in the second network, and the third radio access technology accessing the access point of the wireless local area network: selecting the first radio access technology in a first performance configuration to establish a first call under the first subscriber identity; communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

An aspect of the invention provides a computer-readable medium storing computer-executable code for wireless communication of a user equipment, the code, when executed by the user equipment, causing the user equipment to perform the following. A set of radio access technologies available to the user equipment is determined from a first subscriber identity associated with a first network and a second subscriber identity associated with a second network. Selecting the first radio access technology in a first capability configuration to establish a first call under the first subscriber identity when the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network; communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

By utilizing the invention, the user equipment can better carry out wireless communication.

Drawings

Fig. 1 is a schematic diagram illustrating an exemplary wireless communication system and access network.

Fig. 2 is a schematic diagram illustrating a BS and a UE communicating in an access network.

Fig. 3 illustrates an exemplary logical architecture (local architecture) of a distributed access network.

Fig. 4 illustrates an exemplary physical architecture of a distributed access network.

Fig. 5 is a diagram illustrating an exemplary subframe (subframe) centered on DL.

Fig. 6 is a diagram illustrating an exemplary subframe centered on the UL.

Fig. 7 is a diagram 700 illustrating communication between a UE and another UE over different RATs.

Fig. 8 is a schematic diagram illustrating an exemplary Enhanced IMS service availability Maintenance Mechanism (eisam).

Fig. 9 is a schematic diagram illustrating an eisam technique and an Intelligent Traffic control mechanism (ITSM).

FIG. 10 is a schematic diagram of exemplary EISAMM and ITSM.

Fig. 11 is a diagram illustrating a wireless communication technique of a UE.

Fig. 12 is another diagram illustrating a wireless communication technique of a UE.

Fig. 13 is yet another diagram illustrating a wireless communication technique of a UE.

Fig. 14 is also a diagram illustrating a wireless communication technique of a UE.

Fig. 15 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 16 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 17 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 18 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 19 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 20 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 21 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 22 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 23 is a flowchart illustrating a wireless communication method (process) of the UE.

Fig. 24 is a flowchart illustrating a wireless communication method (process) of the UE.

FIG. 25 is a conceptual data flow diagram illustrating the flow of data between different components/means in an exemplary device.

FIG. 26 is a schematic diagram illustrating an exemplary hardware implementation of an apparatus employing a processing system.

Detailed Description

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description section includes specific details for the purpose of providing a thorough understanding of various concepts. It will be apparent, however, to one skilled in the art that the concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of a telecommunications system will now be presented with reference to various apparatus and methods. The above described apparatus and methods are described in particular embodiments and are illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). The above elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

For example, an element, any portion of an element, or any combination of elements may be implemented as a "processing system," which may include one or more processors. Examples of processors include microprocessors, microcontrollers, Graphics Processing Units (GPUs), Central Processing Units (CPUs), application processors, Digital Signal Processors (DSPs), Reduced Instruction Set Computing (RISC) processors, Systems On a Chip (SoC), baseband processors, Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), state machines (state machines), gated Logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described herein. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subprograms, software components, applications, software packages, routines (routines), subroutines, objects, executables, threads of execution, processes, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Thus, in one or more exemplary embodiments, the functions described above may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer readable media includes computer storage media. A storage media may be any available media that can be accessed by a computer. The computer-readable medium may include, by way of example Only, and not by way of limitation, Random-Access Memory (RAM), Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, a combination of the above-described types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of computer-accessible instructions or data structures.

Fig. 1 is a schematic diagram illustrating an exemplary wireless communication system and access network 100. A Wireless communication system (also referred to as a Wireless Wide Area Network (WWAN)) includes a Base Station (BS) 102, a UE104, and a Core Network (e.g., Evolved Packet Core (EPC), 5G Core Network) 160. BS 102 may include macro cells (high power cellular base stations) and/or small cells (small cells) (low power cellular base stations). The macro cell includes a BS, and the small cell includes a femto cell (femtocell), a pico cell (picocell), and a micro cell (microcell).

The BS 102 (collectively referred to as evolved universal Mobile Telecommunications System Terrestrial Radio Access Network, E-UTRAN)) interfaces with the core Network 160 via a backhaul link 132 (e.g., S1 interface). Among other functions, BS 102 may perform one or more of the following functions: transfer of user data (transfer), Radio channel encryption (cipher) and decryption, integrity protection (integrity protection), header compression (header compression), mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment (setup) and release (release), load balancing (load balancing), allocation of Non-Access Stratum (NAS) messages, NAS node selection, synchronization (synchronization), Radio Access Network (RAN) sharing, Multimedia Broadcast Multicast Service (MBMS), user and device tracking (subscription and identity processing), RAN information management (RAN information, RIM), paging (paging), positioning, and delivery of alert messages (delivery). BSs 102 can communicate with each other directly or indirectly (e.g., via core network 160) via backhaul links 134 (e.g., an X2 interface). The backhaul link 134 may be wired or wireless.

The BS 102 may communicate wirelessly with the UE 104. Each BS 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110, for example, a small cell 102 'may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network containing both small cells and macro cells may be called a heterogeneous network (heterogeneous network). The heterogeneous network may also include Home Evolved Node bs (enbs) (Home enbs, henbs), where the henbs may provide services to a restricted Group called a Closed Subscriber Group (CSG). The communication link 120 between the BS 102 and the UE104 may include Uplink (UL) transmissions from the UE104 to the BS 102, which may also be referred to as reverse link (reverse link), and/or Downlink (DL) transmissions from the BS 102 to the UE104, which may also be referred to as forward link (forward link). The communication link 120 may use Multiple-Input Multiple-Output (MIMO) antenna techniques including spatial multiplexing, beamforming, And/or transmit diversity. The communication link may be through one or more carriers. BS 102/UE 104 may use a spectrum up to a Y MHz (say 5, 10, 15, 20, 100MHz) bandwidth per carrier, with carriers being allocated (allocated) in carrier aggregation (carrier aggregation) for transmission in various directions, with carrier aggregation amounting to Yx MHz (x component carriers). The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL than to UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The Primary component carrier may be referred to as a Primary Cell (PCell), and the secondary component carrier may be referred to as a secondary Cell (SCell).

The wireless communication system may also include a Wi-Fi Access Point (AP) 150, where the Wi-Fi AP150 communicates with a Wi-Fi Station (STA) 152 via a communication link 154 in a 5GHz unlicensed frequency spectrum (unlicensed spectrum). When communicating in the unlicensed spectrum, the STA 152/AP150 may perform a Clear Channel Assessment (CCA) prior to communicating to determine whether the Channel is available.

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

The enode B (gNB) may operate in a Millimeter Wave (mmW) frequency and/or a near mmW frequency when communicating with the UE 104. When the gNB operates in mmW or near mmW frequencies, the gNB may be referred to as an mmW BS. An Extremely High Frequency (EHF) is a portion of the Radio Frequency (RF) in the electromagnetic spectrum. The EHF has a range of 30GHz to 300GHz and a wavelength of 1mm to 10 mm. The radio waves in this band may be referred to as mmW. Near mmW can be extended down to frequencies of 3GHz with a wavelength of 100 mm. The ultra high frequency (SHF) band extends between 3GHz to 30GHz, also known as a centimeter wave. Communications using the mmW/near mmW radio band have extremely high path loss and extremely short range. The mmW BS may utilize beamforming with the UE104 to compensate for the extremely high path loss and the extremely short range.

The core Network 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, serving gateways 166, MBMS gateways 168, broadcast multicast Service centers (BM-SCs) 170, and Packet Data Networks (PDN) gateways 172. The MME 162 may communicate with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that handles signaling between the UE104 and the core network 160. Generally, the MME 162 provides bearer (bearer) and connection management. All user Internet Protocol (IP) packets are transferred through the serving gateway 166, where the serving gateway 166 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 BM-SC 170 are connected to the PDN 176. The PDN 176 may contain the internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet-switched streaming Service (PSS), and/or other IP services. The BM-SC 170 may provide functionality for provisioning (provisioning) and delivery of MBMS user services. The BM-SC 170 may serve as an entry point for content provider MBMS delivery, may be used to authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and may be used to schedule MBMS delivery. The MBMS gateway 168 may be used to allocate MBMS services (traffic) to the BS 102 and may be responsible for session management (start/end) and collecting evolved MBMS (eMBMS) -related charging information (charging information), wherein the BS 102 belongs to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a specific service.

A BS may also be referred to as a gNB, a Node B (NB), an eNB, an AP, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a Basic Service Set (BSs), an Extended Service Set (ESS), or some other suitable terminology. The BS 102 provides an AP to the core network 160 for the UE 104. Examples of UEs 104 include a cellular phone (cellular phone), a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a Personal Digital Assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (such as an MP3 player), a camera, a game console (game console), a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, an oven, or any other similarly functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, ovens, vehicles, etc.). UE104 may also be referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, or some other suitable terminology.

In a particular aspect, the UE104 includes a decision component (decision component)192, a communication management component 194, and a handover component 198, among other components. The decision component 192 determines a set of RATs available to the UE104 based on a first subscriber identity (subscriber identity) associated with a first network and a second subscriber identity associated with a second network. Decision component 192 determines whether the set of RATs includes a first RAT to access a BS in a first Network, a second RAT to access a BS in a second Network, and a third RAT to access an AP of a Wireless Local Area Network (WLAN). When the set of RATs includes a first RAT to access a BS in the first network, a second RAT to access the BS in the second network, and a third RAT to access an AP of the WLAN, the communication management component 194 communicates with a first IMS server of the first network via the first RAT under the first subscriber identity to establish a first call (call). When the first call is active, the communication management component 194 maintains (maintain) a connection with a second IMS server of the second network under the second user identity over the first RAT or a third RAT.

Fig. 2 is a block diagram of BS 210 communicating with UE 250 in an access network. In the DL, IP packets from the core network 160 may be provided to the controller/processor 275. The controller/processor 275 performs layer 3 and layer 2 functions. Layer 3 includes a Radio Resource Control (RRC) layer, and layer 2 includes a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Medium Access Control (MAC) layer. The controller/processor 275 provides: RRC layer functions associated with the broadcast of system Information such as Master Information Block (MIB), System Information Block (SIB), RRC connection control such as RRC connection paging, RRC connection establishment, RRC connection modification and RRC connection release, inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functions, wherein the PDCP layer functions are associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support (handover support) functions; an RLC layer function, wherein the RLC layer function is associated with transfer of higher layer Packet Data Units (PDUs), error correction by Automatic Repeat Request (ARQ), concatenation (concatenation), segmentation (segmentation), and reassembly (reordering) of RLC Service Data Units (SDUs), re-segmentation of RLC Data PDUs, and re-ordering of RLC Data PDUs; and a MAC layer function, wherein the MAC layer function is associated with mapping between logical channels and Transport channels, multiplexing of MAC SDUs onto Transport Blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction by Hybrid Automatic Repeat Request (HARQ), priority handling, and logical channel prioritization.

A Transmit (TX) processor 216 and a Receive (RX) processor 270 implement layer 1 functions associated with various signal processing functions. Layer 1 (including the Physical (PHY) layer) may include error detection on transport channels, Forward Error Correction (FEC) coding/decoding of transport channels, interleaving (interleaving), rate matching, mapping onto Physical channels, modulation/demodulation of Physical channels, and MIMO antenna processing. TX processor 216 processes a mapping to a signal constellation (signal constellation) based on various Modulation schemes such as Binary Phase-Shift Keying (BPSK), Quadrature Phase-Shift Keying (QPSK), M-Phase-Shift Keying (M-PSK), M-Quadrature Amplitude Modulation (M-QAM). The coded and modulated symbols may then be divided into parallel streams, and each stream may then be mapped onto Orthogonal Frequency Division Multiplexing (OFDM) subcarriers, multiplexed with Reference Signals (RSs), such as pilots (pilots), in the time and/or Frequency domain, and then combined together using Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM streams are spatially precoded to produce a plurality of spatial streams. The channel estimates from channel estimator 274 may be used to determine the codec and modulation scheme, as well as for spatial processing. The channel estimates may be derived (drive) from the RS and/or channel state feedback transmitted by the UE 250. Each spatial stream may then be provided to a different antenna 220 via a separate transmitter 218 TX. Each transmitter 218TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 250, each receiver 254RX may receive a signal through a respective antenna 252. Each receiver 254RX recovers information modulated onto an RF carrier and provides the information to an RX processor 256. The TX processor 268 and the RX processor 256 implement layer 1 functions associated with various signal processing functions. The RX processor 256 may perform spatial processing on the information to recover any spatial streams destined for the UE 250. If multiple spatial streams are destined for the UE 250, the multiple spatial streams may be combined into a single OFDM symbol stream by the RX processor 256. The RX processor 256 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and RSs on each subcarrier are recovered and demodulated by determining the most likely signal constellation points transmitted by BS 210. These soft decisions (soft decisions) may be based on the channel estimates computed by the channel estimator 258. These soft decisions may then be decoded and deinterleaved to recover the data and control signals that were originally transmitted by BS 210 on the physical channel. The data and control signals described above may then be provided to controller/processor 259, where controller/processor 259 performs layer 3 and layer 2 functions.

Controller/processor 259 may be associated with a memory 260 that stores program codes and data. Memory 260 may be referred to as a computer-readable medium. In the UL, the controller/processor 259 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression and control signal processing to recover IP packets from the core network 160. The controller/processor 259 is also responsible for error detection using an Acknowledgement (ACK) and/or Negative Acknowledgement (NACK) protocol to support HARQ operations.

Similar to the functionality described in connection with the DL transmission of BS 210, controller/processor 259 provides: RRC layer functions, wherein the RRC layer functions are associated with acquisition of system information (such as MIB, SIB), RRC connection, and measurement reporting; PDCP layer functions, wherein PDCP layer functions are associated with header compression/decompression and security (ciphering, deciphering, integrity protection, integrity verification); an RLC layer function, wherein the RLC layer function is associated with transfer of higher layer PDUs, error correction by ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs and re-ordering of RLC data PDUs; and a MAC layer function, wherein the MAC layer function is associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction by HARQ, priority handling, and logical channel prioritization.

Channel estimates, derived by channel estimator 258 from the RS or feedback transmitted by BS 210, may be used by TX processor 268 to select appropriate codecs and modulation schemes, as well as to facilitate spatial processing. The spatial streams generated by the TX processor 268 may be provided to different antennas 252 via separate transmitters 254 TX. Each transmitter 254TX may modulate an RF carrier with a respective spatial stream for transmission. UL transmissions are handled in a similar manner at BS 210, similar to that described in connection with the receiver function at UE 250. Each receiver 218RX receives a signal through a respective antenna 220. Each receiver 218RX recovers information modulated onto an RF carrier and provides the information to an RX processor 270.

The controller/processor 275 can be associated with a memory 276 that stores program codes and data. Memory 276 may be referred to as a computer-readable medium. In the UL, the controller/processor 275 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 250. IP packets from the controller/processor 275 may be provided to the core network 160. The controller/processor 275 is also responsible for error detection using ACK and/or NACK protocols to support HARQ operations.

NR may refer to a radio configured to operate according to a new air interface (such as in addition to an OFDMA-based air interface) or a fixed transport layer (such as in addition to IP). NR may utilize OFDM with Cyclic Prefix (CP) on UL and DL and may contain support for half duplex operation using Time Division Duplexing (TDD). NRs may include critical tasks of Enhanced Mobile Broadband (eMBB) service targeting wide bandwidths (e.g., above 80 MHz), mmW targeting high carrier frequencies (e.g., 60GHz), Massive Machine Type Communication (MTC) targeting non-backward compatible (non-backward compatible) MTC technology, and/or Ultra-Reliable Low Latency Communication (URLLC) service.

A single component carrier bandwidth of 100MHz may be supported. In an example, a NR Resource Block (RB) may span (span)12 subcarriers, where the 12 subcarriers have a subcarrier bandwidth of 60KHz over a 0.125ms duration or a bandwidth of 15KHz over a 0.5ms duration. Each radio frame may include 20 or 80 subframes (or NR slots) having a length of 10 ms. Each subframe may indicate a link direction (i.e., DL or UL) for data transmission and a link direction for each subframe may be dynamically switched (switch). Each subframe may contain DL/UL data as well as DL/UL control data. UL and DL subframes for NR may be described in more detail with reference to fig. 5 and 6 as follows.

The NR RAN may include a Central Unit (CU) and a Distributed Unit (DU). An NR BS (such as a gNB, 5G NB, Transmission Reception Point (TRP), AP) may correspond to one or more BSs. The NR Cell may be configured as an Access Cell (ACell) or a Data Only Cell (DCell). For example, the RAN (such as a CU or DU) may configure the above-described cells. The DCell may be a cell for carrier aggregation or dual connectivity and may not be used for initial access, cell selection/reselection, or handover. In some cases, the DCell may not transmit a Synchronization Signal (SS), and in some cases, the DCell may transmit the SS. The NR BS may transmit a DL signal to the UE to indicate the cell type. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine an NR BS based on the indicated cell type to account for cell selection, access, handover, and/or measurements.

Fig. 3 illustrates an exemplary logical architecture 300 of a distributed RAN in accordance with aspects of the present invention. The 5G Access Node (AN) 306 may include AN Access Node Controller (ANC) 302. ANC may be a CU of the distributed RAN 300. A backhaul interface (ANC) to a Next Generation Core Network (NG-CN) 304 may terminate at the ANC. The backhaul interface to the neighboring next generation Access Node (NG-AN) may terminate at the ANC. An ANC may contain one or more TRPs 308 (a TRP may also be referred to as a BS, NR BS, NB, 5G NB, AP, or some other terminology). As described above, TRP may be used interchangeably with "cell".

TRP 308 may be a DU. A TRP may be linked to one ANC (ANC 302) or more than one ANC (not illustrated). For example, for RAN sharing, Radio as a Service (RaaS) and Service specific ANC deployments, a TRP may be connected to more than one ANC. The TRP may contain one or more antenna ports. The TRP may be configured to provision services to the UE independently (such as dynamic selection) or jointly (such as joint transmission).

The logical architecture of the distributed RAN 300 may be used to instantiate the fronthaul (frontaul) definition. An architecture may be defined to support a fronthaul solution across different deployment types. For example, the architecture may be based on transport network performance such as bandwidth, latency, and/or jitter (jitter). The architecture may share features and/or components with LTE. According to AN aspect, the NG-AN 310 may support dual connectivity with NRs. The NG-ANs may share a common fronthaul for LTE and NR.

The architecture may enable collaboration between TRPs 308. For example, cooperation may be preset within and/or across the TRP via ANC 302. According to aspects, an inter-TRP (inter-TRP) interface may not be required/present.

According to an aspect, dynamic configuration of the split logical function may exist within the architecture of the distributed RAN 300. PDCP, RLC, MAC protocols may be adaptively located at ANC or TRP.

Fig. 4 illustrates an exemplary physical architecture 400 of a distributed RAN in accordance with aspects of the present invention. A Centralized Core Network Unit (C-CU) 402 may host (host) Core Network functions. The C-CU can be deployed centrally. To handle peak capacity, the C-CU functions may be offloaded (offload), such as to Advanced Wireless Service (AWS). A Centralized RAN Unit (C-RU) 404 may host one or more ANC functions. Alternatively, the C-RU may host the core network functions locally. The C-RU may have a distributed deployment. The C-RU may be closer to the network edge. DU 406 may host one or more TRPs. The DUs may be located at the edge of the RF-enabled network.

Fig. 5 is a diagram 500 of an exemplary subframe centered on DL. The DL-centric subframe may contain a control portion (control portion) 502. The control portion 502 may exist in an initial or starting portion of a subframe centered on the DL. Control portion 502 may contain various scheduling information and/or control information corresponding to various portions of a DL-centric subframe. In some configurations, as shown in fig. 5, the Control portion 502 may be a Physical Downlink Control Channel (PDCCH). The DL-centric sub-frame may also contain a DL data portion 504. The DL data portion 504 may sometimes be referred to as a payload (payload) of a DL-centric subframe. The DL data section 504 may contain communication resources for communicating DL data from a scheduling entity (scheduling entity), such as a UE or BS, to a subordinate entity (subordinate), such as a UE. In some configurations, the DL data portion 504 may be a Physical Downlink Shared Channel (PDSCH).

The DL-centric sub-frame may also contain a common UL portion 506. Common UL portion 506 may sometimes be referred to as a UL burst (burst), a common UL burst, and/or various other suitable terms. The common UL portion 506 may contain feedback information corresponding to various other portions of the DL-centric sub-frame. For example, common UL portion 506 may contain feedback information corresponding to control portion 502. Non-limiting examples of feedback information may include ACK signals, NACK signals, HARQ indicators, and/or various other suitable types of information. The common UL section 506 may contain additional or additional information such as information about Random Access Channel (RACH) processes, scheduling requests, and various other suitable types of information.

As shown in fig. 5, the end of the DL data portion 504 may be separated in time from the beginning of the common UL portion 506. This time separation may sometimes be referred to as a gap (gap), guard period (guard period), guard interval (guard interval), and/or various other suitable terms. This separation provides time for transition (switch-over) from DL communications (such as receive operations by subordinate entities (such as UEs)) to UL communications (such as transmissions by subordinate entities (such as UEs)). One skilled in the art will appreciate that the foregoing is merely one example of a DL-centric sub-frame and that alternative structures having similar features may exist without necessarily departing from the described aspects of the invention.

Fig. 6 is a diagram 600 of an exemplary UL-centric subframe. The UL centric sub-frame may contain a control portion 602. The control portion 602 may exist in an initial or starting portion of a UL-centric sub-frame. The control portion 602 in fig. 6 may be similar to the control portion 502 described above with reference to fig. 5. The UL-centric sub-frame may also contain a UL data portion 604. The UL data portion 604 may sometimes be referred to as the payload of a UL-centric sub-frame. The UL portion may refer to communication resources for communicating UL data from a subordinate entity (such as a UE) to a scheduling entity (such as a UE or a BS). In some configurations, the control portion 602 may be the PUCCH.

As shown in fig. 6, the end of control portion 602 may be separated in time from the beginning of UL data portion 604. The time separation may sometimes be referred to as a gap, guard period, guard interval, and/or various other suitable terms. This separation provides time for the transition from UL communications (such as a receive operation by the scheduling entity) to DL communications (such as a transmission by the scheduling entity). The UL centric sub-frame may also contain a common UL portion 606. The common UL portion 606 in fig. 6 may be similar to the common UL portion 506 described above with reference to fig. 5. The common UL portion 606 may additionally or alternatively contain information regarding Channel Quality Indicators (CQIs), Sounding Reference Signals (SRSs), and various other suitable types of information. One of ordinary skill in the art will appreciate that the foregoing is merely one example of a UL-centric sub-frame and that alternative structures having similar features may exist without necessarily departing from the described aspects of the invention.

In some cases, two or more subordinate entities, such as UEs, may communicate with each other using sidelink (sidelink) signals. Practical applications of such sidelink communications may include public safety, proximity services (proximity), UE-To-network relay (relay), Vehicle-To-Vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical mesh (mission-critical), and/or various other suitable applications. In general, sidelink signals may refer to signals communicated from one subordinate entity (such as UE1) to another subordinate entity (such as UE2) that are not relayed through a scheduling entity (such as a UE or BS), even though the scheduling entity may be used for scheduling and/or control purposes. In some examples, sidelink signals may be communicated using licensed spectrum (as opposed to wireless local area networks that typically use unlicensed spectrum).

Recently, calls made using the Voice over Long Term Evolution (VoLTE) Voice over Long Term Evolution (lte) standard have been propagated. In conjunction with the continued growth in cellular network telecommunications traffic, some service providers have been incentivized to provide calls over Wi-Fi connections that conform to the various Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. Such Wi-Fi offloading, as its name implies, may enable telecommunication calls and data from the UE to be offloaded from the cellular network to the internet for transmission from the UE to a terminal destination point (termination point) and vice versa. Such Wi-Fi networks may be generally secure, operator-controlled networks, referred to as trusted networks, or generally unsecure, publicly accessible Wi-Fi networks through public hotspots, or the like, referred to as untrusted networks.

Furthermore, IMS is a technology that merges (merge) the internet and the cellular network. IMS makes internet technologies such as the world wide web (web), email, instant messaging, user presence (user presence), video conferencing, etc. available almost anywhere. IMS is a key element in the third Generation (3G) (and beyond) architecture, which makes it possible for IMS to provide ubiquitous access to all services offered by the internet. For example, wherever, IMS enables people to access their favorite web pages, read their emails, watch movies, or participate in video conferences by simply using a mobile device and accessing the required services.

Generally, IMS combines the latest trends of packet switching technology and circuit switching technology to make mobile internet available. IMS also creates a common platform for developing various multimedia services, creating a mechanism for service providers to expand their profit due to the additional use of mobile packet-switched networks. Various protocols are used in IMS, including session control (sessioncontrol) protocol, SIP, and other protocols known to those of ordinary skill in the art for providing multimedia services. The IMS architecture is a collection of functions linked by standardized interfaces. Most vendors focus closely on the IMS architecture and implement the functions in a single node, although other nodes may be used.

Fig. 7 is a diagram 700 illustrating communication between a UE702 and another UE703 over different mobile networks using respective RATs. A Subscriber Identity Module (SIM), a widely known SIM card, is an Integrated Circuit (IC) intended to securely store an International Mobile Subscriber Identity (IMSI) code and its associated key (key), which may be used by the network to identify and authenticate (authenticated) users on UEs (e.g., UE702 and UE 703). One device may have multiple SIMs. In this example, the UE702, as one multi-SIM device, may have two SIMs: SIM1702-1 and SIM 2702-2. Typically, different SIMs correspond to different cellular network operators. In this example, SIM1702-1 corresponds to mobile network 791, and SIM2702-2 corresponds to mobile network 792. In other words, the UE702 may operate as a subscriber of the mobile network 791 using the identity information provided by the SIM1702-1, or the UE702 may operate as a subscriber of the mobile network 792 using the identity information provided by the SIM 2702-2. The mobile network 791 may include, among other components, a BS 704-1, a serving gateway 706-1, a PDN gateway 708-1, an MME 710-1, and a Policy and Charging Rules Function (PCRF) 712-1. The mobile network 791 is associated with IMS service 714-1. The PDN gateway 708-1 connects to IMS services 714-1 and PDN 720. Similarly, the mobile network 792 may include the BS 704-2, the serving gateway 706-2, the PDN gateway 708-2, the MME 710-2, and the PCRF 712-2, among other components. Mobile network 792 is associated with IMS service 714-2. The PDN gateway 708-2 connects to IMS services 714-2 and PDN 720. On the other hand, the UE703 is connected to the IMS service 714-3 and the PDN720 in the same manner. IMS service 714-1, IMS service 714-2, and IMS service 714-3 may communicate with each other.

Accordingly, the UE702 and the UE703 may communicate with each other via various paths. For example, the UE702 may communicate with the UE703 in an IMS call via the mobile network 791 corresponding to the SIM 1702-1. More specifically, the signaling path may begin at the UE702, through the BS 704-1, the serving gateway 706-1, the PDN gateway 708-1, the IMS service 714-3, and finally to the UE703, and vice versa. The data traffic path may begin at the UE702, through the BS 704-1, the serving gateway 706-1, the PDN gateway 708-1, the PDN720, and eventually to the UE703, and vice versa.

In another example, the UE702 may communicate with the UE703 via a mobile network 792 corresponding to the SIM2702-2 in an IMS call. More specifically, the signaling path may begin at the UE702, through the BS 704-2, the serving gateway 706-2, the PDN gateway 708-2, the IMS service 714-3, and finally to the UE703, and vice versa. The data traffic path may begin at the UE702, through the BS 704-2, the serving gateway 706-2, the PDN gateway 708-2, the PDN720, and eventually to the UE703, and vice versa.

In yet another example, the UE702 may communicate with the PDN Gateway 708-2 of the mobile network 792 through a security Gateway (such as an Enhanced Packet Data Gateway (EPDGVI)) 718 using an untrusted access network (such as WLAN network 716, where the WLAN network 716 may be a Wi-Fi network). The ePDG 718 is one of the elements of the core network. The ePDG 718 can act as a security node for untrusted access networks, such as the WLAN network 716. In various configurations, the UE702 may establish a secure tunnel (tunnel) with the ePDG 718 over the WLAN network 716. With the aid of the ePDG 718 and WLAN network 716, the UE702 may communicate with the UE703 via both the WLAN network 716 and a PDN gateway 708-2 of the mobile network 792 corresponding to the SIM 2702-2. More specifically, the signaling path may begin at the UE702, through the WLAN network 716, ePDG 718, PDN gateway 708-2, IMS services 714-3, and finally to the UE703, and vice versa. The data traffic path may start from the UE702, through the WLAN network 716, ePDG 718, PDN gateway 708-2, PDN720, and finally to the UE703, and vice versa. Thus, calls with the UE702 over the mobile network 791 or the mobile network 792 may be offloaded to IMS calls over the WLAN network 716.

FIG. 8 is a schematic diagram 800 illustrating an exemplary EISAMM. An application layer (application layer)802 uses EISAMM804 for IMS calls. The UE702 may use three RATs: RAT-1826, RAT-2822, and RAT-3824. Under the user identity of the SIM2702-2, the UE702 can access the mobile network 792 using RAT-2822 and thus connect to IMS service 714-2 or PDN 720. More specifically, EISAMM804 may establish an IMS call through a Non Access Stratum (NAS) 806, an Access Stratum (AS) 808, and a cellular modem and radio (cellular modem and radio)810 of UE702, where UE702 may Access mobile network 792. The NAS 806 is a functional layer in a wireless telecommunications protocol stack (protocol stack) between the core network (including, among other things, the serving gateway 706-2, the PDN gateway 708-2, the MME 710-2, and the PCRF 712-2) and the UE 702. The AS 808 is a functional layer in a wireless telecommunications protocol stack between the radio network (including BS 704-2, among other things) and the UE 702. The cellular modem and radio 810 is a module that contains, among other things, a modem (modem), radio frequency components such as an antenna, power amplifier (power amplifier). Although RAT-1826 is owned by mobile network 791 and RAT-2822 is owned by mobile network 792, RAT-1 and RAT-2 may be the same "radio access technology" (e.g., E-UTRA, NR … …, etc.).

Under the user identity of the SIM1702-1, the UE702 may also access the mobile network 791 using RAT-1826 and thus connect to IMS services 714-1 or PDN 720. More specifically, EISAMM804 may establish an IMS call through NAS818, AS820 and cellular modem and radio 810 of UE702, where UE702 may access mobile network 791. The NAS818 is a functional layer in the wireless telecommunications protocol stack between the core network (including, among other things, the serving gateway 706-1, the PDN gateway 708-1, the MME 710-1, and the PCRF712-1) and the UE 702. The AS820 is a functional layer in the wireless telecommunications protocol stack between the radio network (including BS 704-1, among other things) and the UE 702. The cellular modem and radio 810 is a module that contains, among other things, a modem, radio frequency components (such as antennas, power amplifiers).

Further, in this example, under the user identity of the SIM2702-2, the UE702 may access the mobile network 792 through the WLAN network 716 using RAT-3824 and thus connect to the IMS service 714-2 or the PDN 720. More specifically, EISAMM804 may establish an IMS call through a WLAN driver (driver)812, WLAN firmware 814, and a Wi-Fi modem and radio 816 of UE702, where UE702 may access WLAN network 716. The Wi-Fi modem and radio 816 is a module that contains, among other things, a modem, radio frequency components (such as an antenna, power amplifier). Thus, eismam 804 may select an available RAT to establish an IMS call on UE 702.

Fig. 9 is a schematic diagram 900 illustrating eisam and ITSM techniques. One or more UEs may be connected to one or more of the mobile network 791, the mobile network 792, and the WLAN network 716. In addition, mobile network 791 has coverage 908, mobile network 792 has coverage 910, and WLAN network 716 has coverage 912. The area may be divided into 7 sub-areas depending on the coverage of these three networks. In other words, there are 7 scenarios depending on the location of the UE 702.

In a first scenario 914, a UE (such as UE 702) is only within coverage 908 of the mobile network 791. Similarly, in the third scenario 918, the UE is only within coverage 910 of the mobile network 792. In a second scenario 916, the UE is within the coverage 908 and 910 of the mobile network 791 and the mobile network 792. In each of the three scenarios (i.e., the first scenario 914, the second scenario 916, and the third scenario 918), only a mobile network (such as the mobile network 791 and/or the mobile network 792) is available to the UE, and the WLAN network 716 is not available. Thus, the UE may only connect to IMS services 714-1 and/or 714-2 via the mobile network.

In a fourth scenario 920, the UE is within coverage 908 of the mobile network 791 and coverage 912 of the WLAN network 716. Similarly, in a sixth scenario 924, the UE is within coverage 910 of the mobile network 792 and coverage 912 of the WLAN network 716. While in a fifth scenario 922, the UE is within coverage 908 of mobile network 791, coverage 910 of mobile network 792, and coverage 912 of WLAN network 716. In each of these three scenarios (i.e., the fourth scenario 920, the fifth scenario 922, and the sixth scenario 924), at least one of the mobile networks 791 and/or 792 and the WLAN network 716 is available. Thus, the UE may connect to IMS services 714-1 and/or 714-2 via the mobile network 791 and/or 792 or the WLAN network 716.

Finally, in a seventh scenario 926, the UE is only within coverage 912 of the WLAN network 716. In other words, no cellular network (such as the mobile network 791 and/or the mobile network 792) is available to the UE. Thus, the UE may only connect to IMS services 714-1 and/or 714-2 via WLAN network 716.

Eisam is a mechanism by which a suitable RAT may be selected to access a particular network for establishing or maintaining IMS. In each of the 7 scenarios in this example, eismam may select an appropriate RAT to access mobile network 791, mobile network 792, and WLAN network 716.

On the other hand, ITSM may enhance the performance of active calls through handover. For example, in a second scenario 916, where the UE702 is within the coverage 908 of the mobile network 791 and the coverage 910 of the mobile network 792, the ITSM may transition (transfer) the connection with the IMS service, such as IMS service 714-1, from one RAT to another. More specifically, under the subscriber identity of the SIM2702-2, the ITSM may transition the connection with the IMS service from via the mobile network 792 to via the mobile network 791. In another example, in a fifth scenario 922, the UE702 is within coverage 908, 910, and 912. Thus, under the subscriber identity of the SIM2702-2, the ITSM can transition the connection with the IMS service 714-2 from via the mobile network 792 to via the mobile network 791 or via the WLAN network 716. The selection of the IMS service connection may be according to a selection scheme to be described below.

Fig. 10 is a schematic diagram 1000 illustrating exemplary eisam and ITSM. "a" denotes option a in which the SIM is used to access its own network (own network). "C" denotes an option C in which the SIM is used to access a peer-to-peer network (SIM). "B" denotes option B, in which the SIM is used to access the network through the WLAN.

In a first scenario 914, a UE (such as UE 702) is only within coverage 908 of the mobile network 791. Thus, SIM1702-1 is used in option A and SIM2702-2 is used in option C. In other words, the SIM1702-1 is used to access its own network (mobile network 791), and the SIM2 is used to access the peer-to-peer network of the SIM2 (mobile network 791).

Similarly, in the third scenario 918, the UE is only within coverage 910 of the mobile network 792. Thus, SIM1702-1 is used in option C and SIM2702-2 is used in option A. In other words, SIM1702-1 is used to access the peer-to-peer network (mobile network 792), while SIM2702-2 is used to access its own network (mobile network 792).

In a second scenario 916, the UE is within coverage 908 and 910. Thus, SIM1702-1 is used in options A and C, as is SIM 2702-2. In other words, the SIM1702-1 and the SIM2702-2 can be used to access their respective own networks or peer-to-peer networks. If the SIM1702-1 is used to make a voice call, EISAMM804 may select option A for SIM1702-1 because using its own network (mobile network 791) may provide better voice call performance. Accordingly, the SIM2702-2 may eventually use option C. In other words, the SIM2702-2 is used to access a peer-to-peer network (mobile network 791). In other words, both SIM1702-1 and SIM2702-2 are available to access the mobile network 791.

In a fourth scenario 920, the UE is within coverage 908 and 912. Thus, SIM1702-1 is used in options A and B, while SIM2702-2 is used in options B and C. In other words, the SIM1702-1 can be used to access its own network or a WLAN network, while the SIM2 can be used to access a peer-to-peer network or a WLAN network. If the SIM1702-1 is used to make a voice call, EISAMM804 may select option A for SIM1702-1 because using the own network (mobile network 791) may provide better voice call performance. Accordingly, the SIM2702-2 can be used in option B or option C. In other words, the SIM2702-2 is used to access the WLAN network 716 or a peer-to-peer network (Mobile network 791). In other words, both SIM1702-1 and SIM2702-2 are available to access the mobile network 791. Since there are two options available for the SIM2702-2, ITSM can be employed to enhance the performance of active calls through handover.

Similarly, in a sixth scenario 924, the UE is within coverage 910 and 912. Thus, SIM1702-1 is used in options C and B, while SIM2702-2 is used in options A and B. In other words, the SIM1702-1 can be used to access a peer-to-peer network or a WLAN network, while the SIM2702-2 can be used to access its own network or a WLAN network. If SIM1702-1 is used to make a voice call, EISAMM804 may select either option B or option C for SIM1702-1 because it is not available here using its own network. Accordingly, the SIM2702-2 may be used in option a or option B. In other words, the SIM2702-2 is used to access the WLAN network 716 or its own network (i.e., the mobile network 792). Since there are two options available for SIM1702-1 and SIM2702-2, ITSM can be employed to enhance the performance of active calls through handover.

In a fifth scenario 922, the UE is within coverage 908, 910, and 912. Thus, SIM1702-1 and SIM2702-2 have option A, option B, and option C. In other words, the SIM1702-1 and the SIM2702-2 can be used to access their respective own networks, peer-to-peer networks, or WLAN networks. If SIM1702-1 is used to make a voice call, EISAMM804 may select option A for SIM1702-1 because better voice call performance may be provided using the own network. Accordingly, the SIM2702-2 can be used in option B or option C. In other words, the SIM2 is used to access the WLAN network 716 or a peer-to-peer network (i.e., the mobile network 791). In other words, both the SIM1702-1 and the SIM2702-2 can be used to access the mobile network 791. Since there are two options available for the SIM2702-2, ITSM can be employed to enhance the performance of active calls through handover.

In a seventh scenario 926, the UE is within coverage 912. Thus, SIM1702-1 and SIM2702-2 can be used in option B. In other words, both SIM1702-1 and SIM2702-2 can be used to access their networks via the WLAN network 716.

Fig. 11 is a diagram 1100 illustrating wireless communication techniques for a UE 702. SIM 11102 has two available RATs: SIM1RAT option a (RAT-OPT-a)1106 (denoted SIM1RAT a in fig. 11) and SIM1RAT option B (RAT-OPT-B)1108 (denoted SIM1RAT B in fig. 11), where SIM1RAT-OPT-a 1106 refers to the RAT accessing the SIM's own network (i.e., mobile network 791) and SIM1 RAT-OPT-B1108 refers to the RAT accessing WLAN network 716. SIM21104 has three RATs available: SIM2 RAT-OPT-a 1110 (represented by SIM2RAT a in fig. 11), SIM2 RAT-OPT-B1112 (represented by SIM2RAT B in fig. 11), and SIM2 RAT-OPT-C1114 (represented by SIM2RAT C in fig. 11), where SIM2 RAT-OPT-a 1110 refers to the RAT of the SIM's own network (i.e., mobile network 792), SIM2 RAT-OPT-B1112 refers to the RAT of WLAN network 716, and SIM2 RAT-OPT-C1114 refers to the RAT of the peer-to-peer network (i.e., mobile network 791) accessing the SIM.

At start 1116, the IMS service is initially idle (idle). More specifically, at 1118, SIM 11102 is connected via SIM1 RAT-OPT-A1106, and at 1120, SIM21104 is connected via SIM2 RAT-OPT-A1110. In other words, both SIM 11102 and SIM21104 use their own network in initial phase 1116, where the IMS services are idle in initial phase 1116.

SIM 11102 then becomes active for the call at 1122. Since using its own network may provide better voice call performance than using the WLAN network 716, eismam may select the SIM1RAT-OPT-a 1106 at 1124 to establish the call. For SIM21104, there are two options: select one 1126 and select two 1132.

In selection one 1126, only the mobile network is available 1128. In other words, SIM2 RAT-OPT-A1110 and SIM2 RAT-OPT-C1114 are available and SIM2 RAT-OPT-B1112 is not available. In this case, the SIM21104 is connected (at 1130) via the SIM2 RAT-OPT-C1114. Put another way, the SIM21104 may use a peer-to-peer network, i.e. the mobile network 791.

In option two 1132, both the mobile network and the WLAN network 716 are available at 1134. The SIM21104 may access the ePDG 718 at 1136 via a peer-to-peer network (mobile network 791). In this case, the SIM21104 is connected via the SIM2 RAT-OPT-C1114 at 1138.

At 1140, the SIM21104 may also access the ePDG 718 via the WLAN network 716. More specifically, at 1142, the connection of the SIM21104 is switched to the SIM2 RAT-OPT-B1112. More specifically, at 1144, the devices first authenticate each other and establish a Security association using a Protocol called Internet Key Exchange version 2 (IKEv 2), and then perform encryption (encryption) and integrity protection (integrity protection) using Internet Security Protocol (IPsec) encapsulating Security payload (encryption Security payload). At 1146, IPsec tunnel establishment is complete. At 1148, the SIM21104 is connected via the ePDG 718. Then, at 1150, the 3GPP bearer (bearer) is released. In summary, the UE702 may switch the connection of the SIM21104 to the WLAN network 716 according to the 3GPP TS 23.402 procedure.

Under different conditions, IMS services may have different characteristics. For example, an IMS service (corresponding to option a) connected via an own mobile network of the SIM has stable radio resources with Quality of service (QoS) guaranteed characteristics. The IMS service connected via the peer mobile network of the SIM (corresponding to option C) has stable radio resources but does not have the feature of QoS guarantee. IMS services connected via WLAN network 716 (corresponding to option B) have lower power consumption and lower cost from unlicensed band (2.4GHz/5GHz), contention-based wireless resources, and do not have the features of QoS guarantees.

For DSDS UEs under the second scenario 916, the fourth scenario 920, the fifth scenario 922, and the sixth scenario 924, as described above and shown in fig. 9, the ITSM selects an appropriate RAT based on at least one of the following set of requirements: call quality, cost of making the first call, power consumption of the UE702, and handover rate. In an embodiment, the performance configuration is associated with at least one of a call quality, a cost of making the first call, a power consumption of the user equipment and a handover rate requirement. More specifically, in a performance-centric scenario, the best voice/video quality is required, and IMS services that typically have active calls (such as IMS service 714-1 or 714-2) may typically remain on the mobile network. In the cost-centric case, there is a need to reduce the data plan cost of voice/video calls, and IMS services that typically have active calls (such as IMS service 714-1 or 714-2) may remain on WLAN network 716. In the power-centric case, there is a need to reduce the power consumption of the UE 702. In the mobility-centric case, the rate at which handovers occur needs to be reduced. In the hybrid case, the ITSM may combine all of the above requirements or performance indicators (performance indicators) with different weights (weights) to select a preferred RAT. The assignment of weights may be flexible as desired. Note that other requirements or performance metrics may be employed based on the needs of the consumer.

Fig. 12 is a diagram 1200 illustrating wireless communication techniques for a UE 702. The SIM 11202 has two RATs available: SIM1RAT-OPT-a 1206 (represented in fig. 12 by SIM1RAT a) and SIM1 RAT-OPT-C1208 (represented in fig. 12 by SIM1RAT C), where SIM1RAT-OPT-a 1206 refers to the RAT accessing the SIM's own network (i.e., mobile network 791) and SIM1 RAT-OPT-C1208 refers to the RAT accessing the SIM's peer-to-peer network (i.e., mobile network 792). SIM 21204 has two available RATs: SIM2 RAT-OPT-A1210 (represented by SIM2RAT A in FIG. 12) and SIM2 RAT-OPT-C1212 (represented by SIM2RAT C in FIG. 12), where SIM2 RAT-OPT-A1210 refers to the RAT that accesses the SIM's own network (i.e., mobile network 792) and SIM2 RAT-OPT-C1212 refers to the RAT that accesses the SIM's peer-to-peer network (i.e., mobile network 791).

At start 1214, a SIM1VoLTE call is active. More specifically, at 1216, the call is active on SIM1 via mobile network 791, while at 1218, SIM2 is connected via SIM2 RAT-OPT-C1212. In other words, both SIM 11202 and SIM 21204 use the mobile network 791 in the initial phase 1214, where the SIM1VoLTE call is active in the initial phase 1214.

The SIM2 Mobile Terminating (MT) call then occurs at 1220. More specifically, at 1222, a SIP invite (invite) is sent via SIM1 internet PDN.

The UE702 may then hold the SIM1 call and answer the SIM2 call at 1224, so that the SIM2 call may become an active call. More specifically, a performance-centric mechanism may be applied at 1226, and at 1244, the SIM2 call is made active via SIM2 RAT-OPT-a 1210. In other words, the SIM2 call may be via the mobile network 792. Note that the order between 1226 and 1244 may be changed. In other words, the SIM2 call may first become active via the SIM2 RAT-OPT-a 1210 at 1244, and then apply the performance-centric mechanism at 1226.

More specifically, application performance-centric mechanism 1226 involves SIM2 IMS services being transitioned to IMS service 714-2 at 1228. In other words, the SIM2 call may use its own network (i.e., the mobile network 792) and thus may achieve better voice/video quality. More specifically, at 1230, a PDN handover request is sent to the mobile network 792. Since the SIM1 call is being held, the UE702 may reserve sufficient radio resources to serve the SIM2PDN handover request over the mobile network 792. The IMS PDN is then connected, i.e., SIM 21204 is connected to IMS service 714-2, at 1232. The 3GPP bearer is then released at 1234.

Optionally, the connection of the SIM 11202 is switched to the SIM1 RAT-OPT-C1208 (at 1236). In other words, the SIM 11202 may use a peer-to-peer network (i.e., the mobile network 792). More specifically, at 1238, a PDN handover request is sent to the mobile network 792. The IMS PDN is then connected, at 1240, i.e., SIM 11202 is connected to IMS service 714-2. The 3GPP bearer is then released 1242.

Fig. 13 is a diagram 1300 illustrating wireless communication techniques for a UE 702. The SIM 11302 has three RATs available: SIM1RAT-OPT-a 1306 (denoted SIM1RAT a in fig. 13), SIM1 RAT-OPT-B1308 (denoted SIM1RAT B in fig. 13) and SIM1 RAT-OPT-C1310 (denoted SIM1RAT C in fig. 13), where SIM1RAT-OPT-a 1306 refers to the RAT of the own network (i.e., mobile network 791) accessing the SIM, SIM1 RAT-OPT-B1308 refers to the RAT of WLAN network 716 accessing, and SIM1 RAT-OPT-C1310 refers to the RAT of the peer-to-peer network (i.e., mobile network 792) accessing the SIM. SIM 21304 has two RATs available: SIM2 RAT-OPT-a 1312 (denoted SIM2RAT a in fig. 13) and SIM2 RAT-OPT-B1314 (denoted SIM2RAT B in fig. 13), where SIM2 RAT-OPT-a 1312 refers to the RAT accessing the SIM's own network (i.e., mobile network 792) and SIM2 RAT-OPT-B1314 refers to the RAT accessing WLAN network 716.

At start 1316, a SIM1 call is active. More specifically, at 1318, the SIM1 call is active via SIM1RAT-OPT-a 1306, while at 1320, SIM2 is connected via SIM2 RAT-OPT-B1313. In other words, the SIM 11302 may use its own network (mobile network 791), while the SIM 21304 may use the WLAN network 716.

Then, a SIM2WiFi Voice over WiFi (VoWifi) MT call occurs at 1322. More specifically, at 1324, a SIP invite is sent.

Then at 1326, the UE may hold the SIM1 call and answer the SIM2 call so that the SIM2 call may become an active call. More specifically, a performance-centric mechanism may be applied at 1328, and at 1354, the SIM2 call becomes active via the SIM2 RAT-OPT-a 1312. Note that the order between 1328 and 1354 may be altered. In other words, the SIM2 call may first become active via the SIM2 RAT-OPT-a 1312 at 1354, and then apply a performance-centric mechanism at 1328.

More specifically, applying the performance-centric mechanism 1328 involves switching the connection of the SIM 11302 to the SIM1 RAT-OPT-B1308 at 1330. In other words, the SIM1 call may use the WLAN network 716 and thus mobile network resources are released. More specifically, at 1332, the devices first authenticate each other and establish a security association using a protocol known as IKEv2, and then perform encryption and integrity protection using IPsec encapsulated security payload. At 1334, IPsec tunnel establishment is complete. Then, at 1336, the 3GPP bearer is released.

To maintain the performance of active calls, SIM2 calls need to be transitioned to the mobile network (i.e., mobile network 792). Thus, at 1338, the connection of the SIM 21304 is switched to the SIM2 RAT-OPT-a 1312. More specifically, at 1340, a PDN handover request is sent. The IMS PDN is then connected, i.e., SIM 21304 is connected to IMS service 714-2 at 1342. The non-3 GPP bearer is then released at 1344.

Optionally, the connection of the SIM 11302 is switched to SIM1 RAT-OPT-C1310 (at 1346). In other words, the SIM 11302 may use a peer-to-peer network (i.e., the mobile network 792). More specifically, at 1348, a PDN handover request is sent to the mobile network 792. The IMS PDN is then connected, i.e., SIM 11302 is connected to IMS service 714-2 at 1350. The non-3 GPP bearer is then released 1352.

Fig. 14 is a diagram 1400 illustrating wireless communication techniques for a UE 702. The SIM 11402 has two available RATs: SIM1 RAT-OPT-A1406 (represented by SIM1RAT A in FIG. 14) and SIM1 RAT-OPT-B1408 (represented by SIM1RAT B in FIG. 14), where SIM1 RAT-OPT-A1406 refers to the RAT that accesses the SIM's own network (i.e., mobile network 791) and SIM1 RAT-OPT-B1408 refers to the RAT that accesses WLAN network 716. SIM 21404 has two RATs available: SIM2 RAT-OPT-a 1410 (represented in fig. 14 by SIM2RAT a) and SIM2 RAT-OPT-B1412 (represented in fig. 14 by SIM2RAT B), where SIM2 RAT-OPT-a 1410 refers to the RAT accessing the SIM's own network (i.e., mobile network 792) and SIM2 RAT-OPT-B1412 refers to the RAT accessing WLAN network 716.

At start 1414, the initial phase is idle for IMS services. More specifically, at 1416, the SIM 11402 is connected via the SIM1 RAT-OPT-A1406, while at 1418, the SIM 21404 is connected via the SIM2 RAT-OPT-A1410. In other words, both SIM 11402 and SIM 21404 use their own network in initial stage 1414, where IMS services are idle in initial stage 1414.

Then at 1420, the SIM1 call becomes active. More specifically, at 1422, a SIP invite is sent.

Then at 1424, a cost-centric mechanism is applied. Also at 1436, the SIM1 call becomes active via SIM1 RAT-OPT-B1408. For example, in the case of a video call, WLAN is generally preferred to save costs. In one embodiment, applying the cost-centric mechanism 1424 involves switching the connection of the SIM 11402 to the SIM1 RAT-OPT-B1408 at 1426. In other words, the SIM1 call may use the WLAN network 716. More specifically, at 1428, the devices first authenticate each other and establish a security association using a protocol known as IKEv2, and then perform encryption and integrity protection using IPsec encapsulated security payload. At 1430, IPsec tunnel establishment is complete. At 1432, the SIM 11402 connects to the IMS service 714-1 via an ePDG (similar to ePDG 718). The 3GPP bearer is then released at 1434. In summary, the UE702 may switch the SIM1 call to the WLAN network 716 according to a cost-centric mechanism.

In addition, in the case of hybrid RAT selection, each available RAT is evaluated (evaluate) by weighting each relevant demand or performance metric and calculating a respective total score for each RAT. The active call may then be transitioned to the RAT with the highest aggregate score, which may be referred to as the preferred RAT. The performance-centric mechanisms and cost-centric mechanisms described above may be considered as typical examples of general hybrid RAT selection scenarios. In other words, a general hybrid RAT selection may flexibly select the requirements or performance indicators of interest and assign their weights as needed.

More specifically, an average of each performance indicator over time is first calculated. Then, each performance indicator that is required may be assigned the number 1 and the other performance indicators may be assigned the number 0. Finally, the average of each performance indicator over time is multiplied by the assigned number (0 or 1, representing whether the particular performance indicator needs to be used for evaluation) and its weight, and the results are added. In this way, each RAT may get a weighted average score (weighted mean score) with respect to time and different performance indicators. This is an intelligent, adaptive mechanism.

Fig. 15 is a flowchart 1500 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 1502, the UE702 determines a set of RATs available to the UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792).

At operation 1504, the UE702 determines whether the set of RATs includes a first RAT (e.g., RAT-1826) to access a BS in a first network (e.g., BS 704-1), a second RAT (e.g., RAT-2822) to access a BS in a second network (e.g., BS 704-2), and a third RAT (e.g., RAT-3824) to access an access point for a WLAN (e.g., WLAN network 716). The method (process) may proceed to operation 1506 if the set of RATs includes a first RAT to access the BS in the first network, a second RAT to access the BS in the second network, and a third RAT to access an access point of the WLAN, otherwise the method (process) may end.

At operation 1506, the UE702 selects a first RAT in a first capability configuration to establish the first call under a first subscriber identity (such as SIM 1702-1). In a particular configuration, the first RAT is selected based on at least one of call quality, cost of making the first call, power consumption of the UE, and handover rate.

At operation 1508, the UE702 maintains a connection with a first IMS server (such as IMS service 714-1) over the first RAT under the first subscriber identity.

At operation 1510, the UE702 maintains a connection with a second IMS server (such as IMS service 714-2) over a second RAT (such as RAT-2822) under a second user identity.

At operation 1512, the UE702 communicates with a first IMS server of the first network (such as IMS service 714-1) over the first RAT under the first subscriber identity to establish the first call.

At operation 1514, the UE702 switches the connection with the second IMS server (such as IMS service 714-2) from the second RAT to the first RAT or the third RAT.

Operation 1514 is followed by operation 1602 in fig. 16, below.

Fig. 16 is a flowchart 1600 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 1602, the UE702 maintains a connection with a second IMS server of a second network (such as IMS service 714-2) over the first RAT (such as RAT-1826) or a third RAT (such as RAT-3824) under a second user identity while the first call is active.

In operation 1604, the UE702 receives a call invitation under a first subscriber identity over a first RAT to establish a first call.

In operation 1606, the UE702 selects a third RAT in the second performance configuration to establish the first call under the first subscriber identity.

At operation 1608, the UE702 switches the connection with the first IMS server under the first user identity from the first RAT to a third RAT (such as RAT-3824).

At operation 1610, the UE702 communicates with the first IMS server over a third RAT (such as RAT-3824) under the first subscriber identity to establish the first call.

At operation 1612, the UE702 determines whether the connection with the second IMS server under the second user identity is maintained over a third RAT (such as RAT-3824). If the connection with the second IMS server under the second subscriber identity is maintained over a third RAT, such as RAT-3824, operation 1614 may proceed, otherwise the method (process) may end.

At operation 1614, the UE702 receives a call invitation to establish a second call over a third RAT (such as RAT-3824) in a second subscriber identity.

Operation 1614 is followed by operation 1702 in fig. 17 below.

Fig. 17 is a flowchart 1700 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). In operation 1702, the UE702 maintains the first call.

In operation 1704, the UE702 switches the connection with the second IMS server under the second user identity from the third RAT (such as RAT-3824) to the second RAT (such as RAT-2822).

At operation 1706, the UE702 communicates with a second IMS server over a second RAT (such as RAT-2822) under a second subscriber identity to establish the second call.

In operation 1708, the UE702 switches the holding of the first call from the third RAT to the first RAT.

Fig. 18 is a flowchart 1800 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 1802, the UE702 determines a set of RATs available to the UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792).

In operation 1804, the UE702 determines whether the set of RATs includes a first RAT. If the set of RATs includes the first RAT, the method (process) may proceed to operation 1806, otherwise the method (process) may end.

In operation 1806, the UE702 communicates with a first IMS server over a first RAT in a first subscriber identity to establish a first call.

At operation 1808, the UE702 maintains a connection with a second IMS server over the first RAT (such as RAT-1826) in the second subscriber identity while the first call is active.

Fig. 19 is a flowchart 1900 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 1902, the UE702 determines a set of RATs available to the UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792).

In operation 1904, the UE702 determines whether the set of RATs includes the first RAT and the second RAT. If the set of RATs includes the first RAT and the second RAT, the method (process) may proceed to operation 1906, otherwise the method (process) may end.

In operation 1906, the UE702 communicates with a first IMS server over a first RAT under a first subscriber identity to establish a first call.

In operation 1908, while the first call is active, the UE702 maintains a connection with a second IMS server over the first RAT (such as RAT-1826) in the second subscriber identity.

At operation 1910, the UE702 receives a call invitation to establish a second call over a first RAT (such as RAT-1826) in a second subscriber identity.

In operation 1912, the UE702 holds the first call.

At operation 1914, the UE702 switches the connection with the second IMS server under the second user identity from the first RAT (such as RAT-1826) to the second RAT (such as RAT-2822).

Operation 1914 is followed by operation 2002 in FIG. 20, below.

Fig. 20 is a flowchart 2000 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). In operation 2002, the UE702 communicates with a second IMS server under a second subscriber identity over a second RAT to establish a second call.

In operation 2004, the UE702 switches the hold of the first call from the first RAT to the second RAT.

Fig. 21 is a flowchart 2100 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 2102, the UE702 determines a set of RATs available to the UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792).

At operation 2104, the UE702 determines whether the set of RATs includes a second RAT. If the set of RATs includes a second RAT, the method (process) may proceed to operation 2106, otherwise the method (process) may end.

In operation 2106, the UE702 communicates with the first IMS server over the second RAT under the first user identity to establish the first call.

At operation 2108, while the first call is active, the UE702 maintains a connection with a second IMS server over a second RAT (such as RAT-2822) under a second subscriber identity.

Fig. 22 is a flowchart 2200 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 2202, the UE702 determines a set of RATs available to the UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792).

In operation 2204, the UE702 determines whether the set of RATs includes the first RAT and the third RAT. If the set of RATs includes the first RAT and the third RAT, the method (process) may proceed to operation 2206, otherwise the method (process) may end.

In operation 2206, the UE702 communicates with a first IMS server over a first RAT in a first user identity to establish a first call.

At operation 2208, the UE702 maintains a connection with the second IMS server over the first RAT (such as RAT-1826) or the third RAT (such as RAT-3824) in the second subscriber identity while the first call is active.

Fig. 23 is a flowchart 2300 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 2302, the UE702 determines a set of RATs available to the UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792).

In operation 2304, the UE702 determines whether the set of RATs includes the second RAT and the third RAT. If the set of RATs includes the second RAT and the third RAT, the method (process) may proceed to operation 2306, otherwise the method (process) may end.

At operation 2306, the UE702 communicates with the first IMS server under the first user identity over the second RAT or a third RAT (such as RAT-3824) to establish the first call.

At operation 2308, the UE702 maintains a connection with a second IMS server over a second RAT (such as RAT-2822) or a third RAT (such as RAT-3824) in a second subscriber identity while the first call is active.

Fig. 24 is a flowchart 2400 illustrating a wireless communication method (process) of the UE 702. The method may be performed by a UE (e.g., UE702, device 2502/2502'). At operation 2402, the UE702 determines a set of RATs available to the UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792).

In operation 2404, the UE702 determines whether the set of RATs includes a third RAT. If the set of RATs includes a third RAT, the method (process) may proceed to operation 2406, otherwise the method (process) may end.

In operation 2406, the UE702 communicates with the first IMS server under the first user identity over a third RAT (e.g., RAT-3824) to establish the first call.

In operation 2408, the UE702 maintains a connection with a second IMS server over a third RAT (such as RAT-3824) in a second subscriber identity while the first call is active.

FIG. 25 is a conceptual data flow diagram 2500 illustrating the flow of data between different components/means in an exemplary apparatus 2502. The apparatus 2502 may be a UE. The apparatus 2502 includes a receiving component 2504, a decision component 2506, a communication management component 2508, a switching component 2512, and a transmitting component 2510. The apparatus 2502 may communicate with the BS2550 through a transmitting component 2510 and a receiving component 2504.

Decision component 2506 determines a set of RATs available to UE702 based on a first subscriber identity (e.g., SIM 1702-1) associated with a first network (e.g., mobile network 791) and a second subscriber identity (e.g., SIM 2702-2) associated with a second network (e.g., mobile network 792). In a particular configuration, the first RAT is selected based on at least one of call quality, cost of making the first call, power consumption of the UE, and handover rate.

Decision component 2506 determines whether the set of RATs includes a first RAT to access a BS in a first network (e.g., BS 704-1), a second RAT to access a BS in a second network (e.g., BS 704-2), and a third RAT to access an access point of a WLAN (e.g., WLAN network 716).

The method (process) may proceed when the set of RATs includes a first RAT to access the BS in the first network, a second RAT to access the BS in the second network, and a third RAT to access the access point of the WLAN, otherwise the method (process) may end.

The communication management component 2508 selects a first RAT in a first performance configuration to establish a first call under a first subscriber identity, such as the SIM 1702-1.

Communication management component 2508 maintains a connection with a first IMS server (such as IMS service 714-1) under a first subscriber identity over a first RAT.

Communication management component 2508 maintains a connection with a second IMS server, such as IMS service 714-2, under a second user identity over a second RAT, such as RAT-2822.

Communication management component 2508 communicates with a first IMS server of the first network (such as IMS service 714-1) under the first subscriber identity over the first RAT to establish the first call.

A handover component 2512 switches the connection with the second IMS server, such as IMS service 714-2, from the second RAT to the first RAT or the third RAT.

While the first call is active, communication management component 2508 maintains a connection with a second IMS server of the second network (such as IMS service 714-2) over the first RAT (such as RAT-1826) or a third RAT (such as RAT-3824) under the second user identity.

The communication management component 2508 receives a call invitation under a first subscriber identity over a first RAT to establish a first call.

The communication management component 2508 selects a third RAT in the second performance configuration to establish the first call under the first subscriber identity.

A switching component 2512 switches the connection with the first IMS server under the first subscriber identity from the first RAT to a third RAT (such as RAT-3824).

The communication management component 2508 communicates with the first IMS server under the first subscriber identity over a third RAT (such as RAT-3824) to establish the first call.

Decision component 2506 determines whether a connection with a second IMS server under a second subscriber identity is maintained over a third RAT (such as RAT-3824). This may be done if the connection with the second IMS server under the second subscriber identity is maintained over a third RAT, such as RAT-3824, otherwise the method (process) may end.

The communication management component 2508 receives a call invitation to establish a second call over a third RAT (such as RAT-3824) under a second subscriber identity.

The communication management component 2508 maintains the first call.

A handover component 2512 switches the connection with the second IMS server under the second subscriber identity from the third RAT (such as RAT-3824) to the second RAT (such as RAT-2822).

Communication management component 2508 communicates with a second IMS server over a second RAT (such as RAT-2822) under a second subscriber identity to establish a second call.

A handover component 2512 hands over the holding of the first call from the third RAT to the first RAT.

Decision component 2506 determines whether the set of RATs contains a first RAT. The method (process) may proceed if the set of RATs includes the first RAT, otherwise the method (process) may end.

The communication management component 2508 communicates with the first IMS server under the first subscriber identity over the first RAT to establish the first call.

While the first call is active, communication management component 2508 maintains a connection with a second IMS server under a second subscriber identity over a first RAT (such as RAT-1826).

Decision component 2506 determines whether the set of RATs includes a first RAT and a second RAT. The method (process) may proceed if the set of RATs includes the first RAT and the second RAT, otherwise the method (process) may end.

The communication management component 2508 communicates with the first IMS server under the first subscriber identity over the first RAT to establish the first call.

While the first call is active, communication management component 2508 maintains a connection with a second IMS server under a second subscriber identity over a first RAT (such as RAT-1826).

The communication management component 2508 receives a call invitation to establish a second call over a first RAT (such as RAT-1826) under a second subscriber identity.

The communication management component 2508 maintains the first call.

A handover component 2512 switches the connection with the second IMS server under the second subscriber identity from the first RAT (such as RAT-1826) to the second RAT (such as RAT-2822).

Communication management component 2508 communicates with a second IMS server under a second subscriber identity over a second RAT to establish a second call.

A handover component 2512 hands over the holding of the first call from the first RAT to the second RAT.

Decision component 2506 determines whether the set of RATs contains a second RAT. The method (process) may proceed if the set of RATs includes a second RAT, otherwise the method (process) may end.

The communication management component 2508 communicates with the first IMS server under the first subscriber identity over the second RAT to establish the first call.

While the first call is active, the communication management component 2508 maintains a connection with a second IMS server over a second RAT (such as RAT-2822) under a second subscriber identity.

Decision component 2506 determines whether the set of RATs includes the first RAT and the third RAT. The method (process) may proceed if the set of RATs includes the first RAT and the third RAT, otherwise the method (process) may end.

The communication management component 2508 communicates with the first IMS server under the first subscriber identity over the first RAT to establish the first call.

When the first call is active, communication management component 2508 maintains a connection with the second IMS server under the second subscriber identity over the first RAT (such as RAT-1826) or a third RAT (such as RAT-3824).

Decision component 2506 determines whether the set of RATs includes the second RAT and the third RAT. The method (process) may proceed if the set of RATs includes the second RAT and the third RAT, otherwise the method (process) may end.

The communication management component 2508 communicates with the first IMS server under the first subscriber identity over the second RAT or a third RAT (such as RAT-3824) to establish the first call.

While the first call is active, communication management component 2508 maintains a connection with the second IMS server over the second RAT (such as RAT-2822) or a third RAT (such as RAT-3824) under the second subscriber identity.

Decision component 2506 determines whether the set of RATs contains a third RAT. The method (process) may proceed if the set of RATs includes a third RAT, otherwise the method (process) may end.

The communication management component 2508 communicates with the first IMS server under the first subscriber identity over a third RAT (such as RAT-3824) to establish the first call.

While the first call is active, the communication management component 2508 maintains a connection with a second IMS server under a second subscriber identity over a third RAT (such as RAT-3824).

Fig. 26 is a schematic 2600 illustrating an exemplary hardware implementation of an apparatus 2502' employing a processing system 2614. The apparatus 2502' may be a UE. The processing system 2614 may be implemented with a bus (bus) architecture, represented generally by the bus 2624. The bus 2624 may contain any number of interconnecting buses and bridges depending on the specific application of the processing system 2614 and the overall design constraints. The bus 2624 links together various circuits including one or more processors and/or hardware components, as represented by the one or more processors 2604, the receiving component 2504, the decision-making component 2506, the communication management component 2508, the transmitting component 2510, the switching component 2512, and the computer-readable medium/memory 2606. The bus 2624 may also link various other circuits such as a timing source (timing source), peripheral (peripheral), voltage regulator (voltage regulator), and power management circuits.

The processing system 2614 may be coupled to a transceiver 2610, where the transceiver 2610 may be one or more transceivers 254. The transceiver 2610 is coupled to one or more antennas 2620, where the antennas 2620 may be the communication antennas 252.

The transceiver 2610 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 2610 receives signals from one or more antennas 2620, extracts (extract) information from the received signals, and provides the extracted information to the processing system 2614, particularly the receive component 2504. In addition, the transceiver 2610 receives information from the processing system 2614 (and particularly the transmit component 2510) and generates signals that are applied to one or more antennas 2620 based on the received information.

The processing system 2614 includes one or more processors 2604 coupled to a computer-readable medium/memory 2606. The one or more processors 2604 are responsible for overall processing, including the execution of software stored on the computer-readable medium/memory 2606, which when executed by the one or more processors 2604, causes the processing system 2614 to perform the various functions of any particular apparatus described above. The computer-readable medium/memory 2606 may also be used for storing data, where the data is operated on by the one or more processors 2604 when executing software. The processing system 2614 also includes at least one of a receive component 2504, a decision component 2506, a communication management component 2508, a transmit component 2510, and a switch component 2512. The above-described components may be software components running in one or more processors 2604, resident/stored in the computer readable medium/memory 2606, one or more hardware components coupled to the one or more processors 2604, or some combination thereof. Processing system 2614 may be a component of UE 250 and may include memory 260 and/or at least one of TX processor 268, RX processor 256, and controller/processor 259.

In one configuration, the means 2502/means 2502' for wireless communication comprise means for performing the operations of fig. 13 and 14. The aforementioned means may be one or more of the aforementioned components of the apparatus 2502 and/or the processing system 2614 of the apparatus 2502', wherein the aforementioned components are configured to perform the functions recited by the aforementioned means.

As described supra, the processing system 2614 may include the TX processor 268, the RX processor 256, and the controller/processor 259. Thus, in one configuration, the aforementioned means may be the TX processor 268, the RX processor 256, and the controller/processor 259 configured to perform the functions recited by the aforementioned means.

Note that the particular order or hierarchy of blocks in the processes/flow diagrams of the present invention are examples of exemplary approaches. It will thus be appreciated that the particular order or hierarchy of blocks in the processes/flow diagrams can be rearranged based upon design preferences, and that some blocks may be further combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to limit the invention to the specific order or hierarchy presented.

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. Accordingly, the claims are not intended to be limited to the aspects shown, but are to be accorded the full scope consistent with the language 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. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any aspect of the invention described as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. The term "some" means one or more unless specifically stated otherwise. Combinations such as "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C", and "A, B, C or any combination thereof" include any combination of A, B and/or C, and may include a plurality of a, B plurality, or C plurality. In particular, combinations such as "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C", and "A, B, C or any combination thereof" may be a only, B only, C only, a and B inclusive, a and C inclusive, B and C inclusive, or a and B and C inclusive, where any such combination may include A, B or one or more of C. All structural and functional equivalents to the elements of the various aspects described herein 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. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words "module," mechanism, "" element, "" device, "and the like may not be alternatives to the word" means. Thus, unless the phrase "means for …" is used to specifically state an element in a claim, that element should not be construed as a functional limitation.

Claims (23)

1. A method of wireless communication of a user equipment, comprising:

determining a set of radio access technologies available to the user equipment from a first subscriber identity associated with a first network and a second subscriber identity associated with a second network;

when the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network:

selecting the first radio access technology in a first performance configuration to establish a first call under the first subscriber identity;

communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and

maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

2. The method of wireless communication of a user equipment according to claim 1, wherein the performance configuration is associated with at least one requirement of call quality, a cost of making the first call, power consumption of the user equipment and handover rate, the first radio access technology being selected based on at least one of the call quality, the cost of making the first call, the power consumption of the user equipment and the handover rate.

3. The method of wireless communication of a user equipment according to claim 2, characterized by selecting at least one of the set of radio access technologies available to the user equipment by giving weight to the at least one requirement.

4. The method of wireless communication of a user equipment of claim 1, further comprising:

prior to communicating with the first internet protocol multimedia subsystem server to establish the first call:

maintaining a connection with the first internet protocol multimedia subsystem server over the first radio access technology under the first subscriber identity; and

maintaining the connection with the second internet protocol multimedia subsystem server under the second subscriber identity over the second radio access technology or the third radio access technology.

5. The method of wireless communication of a user equipment of claim 1, further comprising:

after communicating with the first internet protocol multimedia subsystem server to establish the first call:

switching the connection with the second internet protocol multimedia subsystem server from the second radio access technology to the first radio access technology or the third radio access technology.

6. The method of wireless communication of a user equipment of claim 4, further comprising:

receiving a call invitation over the first radio access technology under the first subscriber identity to establish the first call;

selecting the third radio access technology in a second capability configuration to establish the first call under the first subscriber identity;

switching the connection with the first internet protocol multimedia subsystem server under the first subscriber identity from the first radio access technology to the third radio access technology; and

communicating with the first internet protocol multimedia subsystem server over the third radio access technology under the first subscriber identity to establish the first call.

7. The method of wireless communication of a user equipment of claim 1, wherein the connection is maintained with the second internet protocol multimedia subsystem server under the second subscriber identity over the first radio access technology or the third radio access technology, the method further comprising:

receiving a call invitation to establish a second call over the third radio access technology under the second subscriber identity;

maintaining the first call;

switching the connection with the second internet protocol multimedia subsystem server under the second subscriber identity from the first radio access technology or the third radio access technology to the second radio access technology; and

communicating with the second internet protocol multimedia subsystem server over the second radio access technology under the second subscriber identity to establish the second call.

8. The wireless communication method of the user equipment according to claim 7, further comprising:

switching the holding of the first call from the first radio access technology to the second radio access technology or the third radio access technology.

9. The method of wireless communication of a user equipment of claim 1, further comprising, when the set of radio access technologies includes the first radio access technology:

communicating with the first internet protocol multimedia subsystem server over the first radio access technology under the first subscriber identity to establish the first call; and

maintaining the connection with the second internet protocol multimedia subsystem server over the first radio access technology or the third radio access technology in the second subscriber identity when the first call is active.

10. The method of wireless communication of a user equipment of claim 1, further comprising, when the set of radio access technologies includes the first radio access technology and the second radio access technology:

communicating with the first internet protocol multimedia subsystem server over the first radio access technology under the first subscriber identity to establish the first call; and

maintaining the connection with the second internet protocol multimedia subsystem server over the first radio access technology in the second subscriber identity when the first call is active.

11. The wireless communication method of the user equipment according to claim 10, further comprising:

receiving a call invitation to establish a second call over the first radio access technology under the second subscriber identity;

maintaining the first call;

switching the connection with the second internet protocol multimedia subsystem server under the second subscriber identity from the first radio access technology to the second radio access technology; and

communicating with the second internet protocol multimedia subsystem server over the second radio access technology under the second subscriber identity to establish the second call.

12. The method of wireless communication of a user equipment of claim 11, further comprising:

switching the maintaining of the first call from the first radio access technology to the second radio access technology.

13. The method of wireless communication of a user equipment according to claim 1, wherein when the set of radio access technologies includes the second radio access technology:

communicating with the first internet protocol multimedia subsystem server over the second radio access technology under the first subscriber identity to establish the first call; and

maintaining the connection with the second internet protocol multimedia subsystem server over the second radio access technology in the second subscriber identity when the first call is active.

14. The method of wireless communication of a user equipment according to claim 1, wherein when the set of radio access technologies includes the first radio access technology and the third radio access technology:

communicating with the first internet protocol multimedia subsystem server over the first radio access technology under the first subscriber identity to establish the first call; and

maintaining the connection with the second internet protocol multimedia subsystem server over the first radio access technology or the third radio access technology in the second subscriber identity when the first call is active.

15. The method of wireless communication of a user equipment according to claim 1, wherein when the set of radio access technologies includes the second radio access technology and the third radio access technology:

communicating with the first internet protocol multimedia subsystem server over the second radio access technology or the third radio access technology under the first subscriber identity to establish the first call; and

maintaining the connection with the second internet protocol multimedia subsystem server over the second radio access technology or the third radio access technology in the second subscriber identity when the first call is active.

16. The method of wireless communication of a user equipment according to claim 1, wherein when the set of radio access technologies includes the third radio access technology:

communicating with the first internet protocol multimedia subsystem server over the third radio access technology under the first subscriber identity to establish the first call; and

maintaining the connection with the second internet protocol multimedia subsystem server over the third radio access technology in the second subscriber identity when the first call is active.

17. A user equipment for wireless communication, comprising a processing system, the processing system comprising:

a memory; and

at least one processor coupled with the memory;

the processing system is configured to:

determining a set of radio access technologies available to the user equipment from a first subscriber identity associated with a first network and a second subscriber identity associated with a second network;

when the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network:

selecting the first radio access technology in a first performance configuration to establish a first call under the first subscriber identity;

communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and

maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

18. The user equipment of claim 17, wherein the first radio access technology is selected based on at least one of call quality, cost of making the first call, power consumption of the user equipment, and handover rate.

19. The user device of claim 17, wherein the processing system is further configured to:

prior to communicating with the first internet protocol multimedia subsystem server to establish the first call:

maintaining a connection with the first internet protocol multimedia subsystem server over the first radio access technology under the first subscriber identity; and

maintaining the connection with the second internet protocol multimedia subsystem server under the second subscriber identity over the second radio access technology or the third radio access technology.

20. The user device of claim 19, wherein the processing system is further configured to:

receiving a call invitation over the first radio access technology under the first subscriber identity to establish the first call;

selecting the third radio access technology in a second capability configuration to establish the first call under the first subscriber identity;

switching the connection with the first internet protocol multimedia subsystem server under the first subscriber identity from the first radio access technology to the third radio access technology; and

communicating with the first internet protocol multimedia subsystem server over the third radio access technology under the first subscriber identity to establish the first call.

21. A user equipment for wireless communication, comprising:

a decision component configured to:

determining a set of radio access technologies available to the user equipment from a first subscriber identity associated with a first network and a second subscriber identity associated with a second network; and

determining whether the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network; and

a communication management component configured to, when the set of radio access technologies includes the first radio access technology accessing the base station in the first network, the second radio access technology accessing the base station in the second network, and the third radio access technology accessing the access point of the wireless local area network:

selecting the first radio access technology in a first performance configuration to establish a first call under the first subscriber identity;

communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and

maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

22. The user equipment of claim 21, further comprising a switching component that switches the connection with the second internet protocol multimedia subsystem server from the second radio access technology to the first radio access technology or the third radio access technology after communicating with the first internet protocol multimedia subsystem server to establish the first call.

23. A computer-readable medium storing computer-executable code for wireless communication of a user device, the code, when executed by the user device, causing the user device to:

determining a set of radio access technologies available to the user equipment from a first subscriber identity associated with a first network and a second subscriber identity associated with a second network;

when the set of radio access technologies includes a first radio access technology accessing a base station in the first network, a second radio access technology accessing a base station in the second network, and a third radio access technology accessing an access point of a wireless local area network:

selecting the first radio access technology in a first performance configuration to establish a first call under the first subscriber identity;

communicating with a first internet protocol multimedia subsystem server of the first network over the first radio access technology under the first subscriber identity to establish the first call; and

maintaining a connection with a second internet protocol multimedia subsystem server of the second network under the second subscriber identity over the first radio access technology or the third radio access technology when the first call is active.

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