Truncated Identity Indicator for Early User Equipment (UE) Capability Retrieval

Abstract

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may truncate or remove a number of bits from its UE identity based on identity truncation information to generate a truncated UE identity. The truncated UE identity may be transmitted by an eMTC device to a base station in an RRC connection request and may be used by the base station to determine which core network entity stores UE capabilities. In some implementations, the UE may truncate or remove a number of bits from a 48-bit 5G-S-TMSI based on identity truncation information to generate a 40-bit 5G-S-TMSI, which may be transmitted by the eMTC device to the base station in an RRC connection request and still provide the base station with sufficient information to determine which AMF stores the UE context.

Description

[0001] Cross-reference

[0002] This patent application claims priority to U.S. Patent Application No. 17 / 154,921, filed Jan. 21, 2021, by KADIRI et al. and entitled “TRUNCATED IDENTIFICATION INDICATORS FOR EARLY USER EQUIPMENT (UE) CAPABILITY RETRIEVAL”, and to U.S. Provisional Patent Application No. 62 / 975,939, filed Feb. 13, 2020, by KADIRI et al. and entitled “TRUNCATED IDENTIFICATION INDICATORS FOR EARLY USER EQUIPMENT (UE) CAPABILITY RETRIEVAL”, each of which is assigned to the assignee of the present application. Technical Field

[0003] This disclosure generally relates to wireless communications and, more particularly, to truncated identification indicators.

[0004] Description of the Related Art

[0005] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and the like. These systems may be capable of supporting communication with multiple users by sharing available system resources such as time, frequency, and power. Examples of such multi-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems (such as long term evolution (LTE) systems or fifth generation (5G) new radio (NR) systems). A wireless multi-access communication system may include several base stations or access network nodes, each of which simultaneously supports communication of multiple communication devices, which may also be referred to as user equipment (UE).

[0006] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global levels. An example telecommunication standard is 5G New Radio (NR), which is part of the ongoing evolution of mobile broadband promulgated by the 3rd Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability, and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low latency communication (URLLC). There is a need for further improvement in 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies.

[0007] Overview

[0008] Describes a method for a user equipment (UE) with a UE identity to perform wireless communication. The method may include: receiving identity truncation information; generating a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information; and transmitting the truncated UE identity to a base station (BS) during establishment of a radio resource control (RRC) connection with the BS.

[0009] Describes an apparatus for a UE with a UE identity to perform wireless communication. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: receive identity truncation information; generate a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information; and transmit the truncated UE identity to the BS during establishment of an RRC connection with the BS.

[0010] Describes another device for a UE with a UE identity to perform wireless communication. The device may include: means for receiving identity truncation information; means for generating a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information; and means for transmitting the truncated UE identity to the BS during establishment of an RRC connection with the BS.

[0011] Describes a non-transitory computer-readable medium storing code for a UE with a UE identity to perform wireless communication. The code may include instructions executable by a processor to perform the following operations: receive identity truncation information; generate a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information; and transmit the truncated UE identity to the BS during establishment of an RRC connection with the BS.

[0012] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the identity truncation information indicates the number of least significant bits (LSBs) to be retained during generation of the truncated UE identity in at least one of the one or more fields of the UE identity.

[0013] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a first value indicates the number of LSBs of an access and mobility management function (AMF) set identifier of the UE identity, and a second value indicates the number of LSBs of an AMF pointer of the UE identity.

[0014] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, generating the truncated UE identity may include operations, features, apparatuses, or instructions for the following actions: retaining only a number of LSBs of the AMF set identifier of the UE identity according to the first value; and retaining only a number of LSBs of the AMF pointer of the UE identity according to the second value.

[0015] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, generating the truncated UE identity may include operations, features, apparatuses, or instructions for the following actions: retaining only (40 – n – m) LSBs of a temporary mobile station identifier (TMSI) of the UE identity, where n represents the first value and m represents the second value.

[0016] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the UE includes an enhanced machine type communication (eMTC) device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

[0017] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the truncated UE identity may be transmitted to the BS in an RRC connection request message.

[0018] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: receiving, from the BS, an RRC connection setup message indicating a signaling radio bearer (SRB) configuration, the SRB configuration being based on UE capabilities retrieved from an access and mobility management function (AMF) of a core network.

[0019] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, retrieving the UE capabilities from the AMF may be based on the truncated UE identity.

[0020] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, receiving the identity truncation information may include operations, features, apparatuses, or instructions for the following actions: receiving the identity truncation information from the BS in a system information block (SIB).

[0021] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: transmitting a non-access stratum (NAS) registration request message to an access and mobility management function (AMF) of a core network; and receiving a NAS registration acceptance message containing the identity truncation information from the AMF.

[0022] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: receiving, in a SIB broadcast by the BS, an indication to include the truncated UE identity in an RRC connection request message.

[0023] A method for performing wireless communication by a base station (BS) is described. The method may include: indicating to a UE identity truncation information for one or more fields for truncating a UE identity, the identity truncation information indicating a number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; and receiving, in an RRC connection request message, a truncated UE identity from the UE, the truncated UE identity being generated according to the identity truncation information.

[0024] An apparatus for performing wireless communication by a base station (BS) is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus: to indicate to a UE identity truncation information for one or more fields for truncating a UE identity, the identity truncation information indicating a number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; and to receive, in an RRC connection request message, a truncated UE identity from the UE, the truncated UE identity being generated according to the identity truncation information.

[0025] Another device for performing wireless communication by a base station (BS) is described. The device may include: means for indicating to a UE identity truncation information for one or more fields for truncating a UE identity, the identity truncation information indicating a number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; and means for receiving, in an RRC connection request message, a truncated UE identity from the UE, the truncated UE identity being generated according to the identity truncation information.

[0026] A non-transitory computer-readable medium storing code for performing wireless communication by a base station (BS) is described. The code may include instructions executable by a processor to perform the following operations: indicating to a UE identity truncation information for one or more fields of a truncated UE identity, the identity truncation information indicating the number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; and receiving from the UE a truncated UE identity in an RRC connection request message, the truncated UE identity being generated based on the identity truncation information.

[0027] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, indicating the identity truncation information may include operations, features, apparatuses, or instructions for the following action: transmitting the identity truncation information to the UE in a SIB.

[0028] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the presence of the identity truncation information in the SIB includes causing the UE to transmit an indication of the truncated UE identity to the BS in the RRC connection request message.

[0029] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, indicating the identity truncation information may include operations, features, apparatuses, or instructions for the following action: broadcasting an indication for the UE to use a truncated UE identity during an RRC connection procedure.

[0030] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following action: receiving the identity truncation information from an access and mobility management function (AMF) of a core network.

[0031] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a first value indicates the number of LSBs of an AMF set identifier of the UE identity, and a second value indicates the number of LSBs of an AMF pointer of the UE identity.

[0032] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following action: determining a difference (40–n–m) indicating the number of LSBs to be retained in a temporary mobile station identifier (TMSI) indicating the UE identity when generating the truncated UE identity, where n represents the first value and m represents the second value.

[0033] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, at least one of the first value or the second value may be based on the number of AMFs assigned to the core network.

[0034] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: constructing an AMF identifier based on the truncated UE identity; and identifying which AMF among a plurality of AMFs stores the UE's capability information based on the constructed AMF identifier.

[0035] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, constructing the AMF identifier in a given AMF area identified by the AMF area ID may be further based on the AMF set identifier and the number of most significant bits (MSBs) of the AMF pointer and the LSB of the AMF set identifier and the AMF pointer.

[0036] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the MSBs of the AMF set identifier and the AMF pointer may be received from the identified AMF.

[0037] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: retrieving the UE capability information and UE inter-service quality of service (QoS) information from the identified AMF; determining a signaling radio bearer (SRB) configuration for the UE based on the retrieved UE capability information; and transmitting the SRB configuration to the UE in an RRC connection setup message.

[0038] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: transmitting an RRC connection rejection message to the UE based on the UE inter-QoS information and the traffic load of the BS.

[0039] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the UE includes an enhanced machine type communication (eMTC) device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

[0040] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: receiving the identity truncation information from a core network entity. Brief Description of the Drawings

[0042] Figure 1 A diagram illustrating an example wireless communication system is shown.

[0043] Figure 2A An example of a first 5G NR frame is shown.

[0044] Figure 2B Shows an example downlink (DL) channel within a 5G NR time slot.

[0045] Figure 2C Shows an example of a second 5G NR frame.

[0046] Figure 2D Shows an example uplink (UL) channel within a 5G NR time slot.

[0047] Figure 3 Shows a diagram illustrating an example base station and user equipment (UE) in an access network.

[0048] Figure 4 Shows a sequence diagram for wireless communication to support the RRC connection procedure.

[0049] Figure 5 Shows example fields of a UE identity and a truncated UE identity.

[0050] Figure 6 Depicts the generation of an example truncated UE identity.

[0051] Figure 7A Shows a sequence diagram for wireless communication to support early retrieval of UE capabilities.

[0052] Figure 7B Shows another sequence diagram for wireless communication to support early retrieval of UE capabilities.

[0053] Figure 8 Shows a diagram illustrating an example UE supporting a truncated UE identity.

[0054] Figure 9 Shows a diagram illustrating an example base station supporting a truncated UE identity.

[0055] Figure 10A –10C shows a flowchart depicting example operations of wireless communication to support early retrieval of UE capabilities.

[0056] Figure 11A –11C shows a flowchart depicting example operations of wireless communication to support early retrieval of UE capabilities.

[0057] Figure 12A –12C shows a flowchart depicting example operations of wireless communication to support early retrieval of UE capabilities.

[0058] Like reference numerals and names in the various figures indicate like elements.

[0059] Detailed Description

[0060] The following description is directed to some particular implementations with the aim of describing innovative aspects of the present disclosure. However, those of ordinary skill in the art will readily recognize that the teachings herein can be applied in numerous different ways. The described implementations can be realized in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to one or more of the following: Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)) standards released by the 3rd Generation Partnership Project (3GPP), Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, IEEE 802.15 standards, or as defined by the Bluetooth Special Interest Group (SIG) standards, and so on. The described implementations can be realized in any device, system, or network capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Single User (SU) Multiple-Input Multiple-Output (MIMO), and Multi-User (MU) MIMO. The described implementations can also be realized using other wireless communication protocols or RF signals suitable for use in one or more of Wireless Wide Area Networks (WWANs), Wireless Personal Area Networks (WPANs), Wireless Local Area Networks (WLANs), or Internet of Things (IoT) networks.

[0061] Implementations of the subject matter described in the present disclosure can allow for early retrieval of UE capabilities when a UE seeking to establish a connection with a radio access network cannot transmit its UE identity in a single RRC message. An RRC connection request for a base station associated with a 5G core network typically includes a 48-bit 5G-S-TMSI that uniquely identifies the UE and also uniquely identifies the core network entity that stores the UE context (such as UE capabilities). Some UEs (such as eMTC devices) cannot send the full 48-bit 5G-S-TMSI to the base station in a single RRC message and instead send the 40 least significant bits (LSBs) of the 5G-S-TMSI in the RRC connection request and then send the remaining 8 bits of the 5G-S-TMSI to the base station in the RRC connection setup complete message. However, the 8 most significant bits (MSBs) of the 5G-S-TMSI correspond to an 8-bit AMF set ID, which is necessary for the base station to determine which AMF stores the UE context. Thus, the base station may not be able to identify the AMF and retrieve the UE capabilities until it receives the RRC connection setup complete message (which occurs after the base station selects a signaling radio bearer (SRB) configuration and transmits that SRB configuration to the UE).

[0062] Selecting an SRB configuration without knowledge of the UE radio capabilities limits the ability of the base station to customize or optimize the SRB configuration for the UE. This can be particularly problematic for cellular IoT (CIoT) devices such as eMTC or NB-IoT devices, as they use control plane optimization for small data transmissions and these CIoT devices may have different radio capabilities for different radio enhancements. Accordingly, it is desirable for the base station to obtain the UE radio capabilities of such devices before selecting an SRB configuration and transmitting that SRB configuration in the RRC connection setup message.

[0063] According to various aspects of the present disclosure, a UE may truncate or remove a number of bits from its UE identity based on identity truncation information to generate a truncated UE identity. The truncated UE identity may be transmitted by an eMTC device to a base station in an RRC connection request and may be used by the base station to determine which core network entity (such as an AMF) stores the UE capabilities. In some implementations, the UE may truncate or remove a number of bits from a 48-bit 5G-S-TMSI based on the identity truncation information to generate a 40-bit truncated 5G-S-TMSI, which may be transmitted by the eMTC device to the base station in an RRC connection request and still provide the base station with sufficient information to determine which AMF stores the UE context. This allows the base station to retrieve the UE capabilities from the AMF before selecting an SRB configuration for the UE. In this way, even for UEs (such as eMTC devices) that may not be able to transmit the 48-bit 5G-S-TMSI in an RRC message, the base station may select or determine an SRB configuration for these UEs based on the capabilities of the UE.

[0064] Certain aspects of a telecommunications system will now be presented with reference to various apparatuses and methods. These apparatuses and methods will be described in detail below and illustrated by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements") in the drawings. These 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.

[0065] By way of example, an element, or any portion of an element, or any combination of elements can be implemented as a "processing system" that includes 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, system on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in the processing system can execute software. Software should be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to in software, firmware, middleware, microcode, hardware description language, or otherwise.

[0066] Accordingly, in one or more example implementations, the described functions can be implemented in hardware, software, or any combination thereof. If implemented in software, the functions can be stored or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include random access memory (RAM), read only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other media capable of storing computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0067] Figure 1 A diagram of an example wireless communication system 100 is shown. The wireless communication system 100, which can be a next-generation RAN (NG-RAN), includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190. The base station 102 can include a macro cell (high-power cellular base station) or a small cell (low-power cellular base station). Macro cells include base stations. Small cells include femtocells, picocells, and microcells.

[0068] The base station 102 configured for 4G LTE (collectively referred to as the evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via the S1 interface through the backhaul link 132, and the base station 102 configured for 5G NR can interface with the core network 190 via the N2 and N3 interfaces through the backhaul link 184. The base stations 102 can communicate with each other via the X2 interface through one or more backhaul links 134. The base station 102 can perform several functions, including (but not limited to) the transfer of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (such as handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, radio access network information management (RIM), paging, positioning, and delivery of alert messages.

[0069] Each base station 102 can provide communication coverage for its respective geographical coverage area 110. There may be overlapping geographical coverage areas 110. For example, the 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 including both small cells and macro cells can be referred to as a heterogeneous network. The heterogeneous network may also include a home evolved Node B (eNB) (HeNB) that can serve a restricted group called a closed subscriber group (CSG).

[0070] The wireless communication system 100 can utilize both licensed and unlicensed radio frequency bands. For example, the wireless communication system 100 can adopt licensed-assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (such as the 5 GHz industrial, scientific, and medical (ISM) band). When operating in an unlicensed radio frequency band, devices (such as the base station 105 and the UE 404) can use carrier sensing for collision detection and avoidance. In some cases, the operation in the unlicensed band can be based on a carrier aggregation configuration (e.g., LAA) in coordination with the component carriers operating in the licensed band. The operation in the unlicensed spectrum can include downlink transmission, uplink transmission, peer-to-peer (P2P) transmission, device-to-device (D2D) transmission, etc.

[0071] The wireless communication system may further include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in the 2.4 GHz unlicensed spectrum, the 5 GHz unlicensed spectrum, or both. When communicating in the unlicensed spectrum, the STA 152 and the AP 150 may perform a Clear Channel Assessment (CCA) before communication to determine whether the channel is available.

[0072] A given base station 102 may also be referred to as a gNB, Node B, evolved Node B (eNB), access point, base transceiver station, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), transmission reception point (TRP), or some other suitable term. The base station 102 provides an access point for the UE 104 to the EPC 160 or the core network 190. Examples of the UE 104 include a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop device, 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, a tablet device, a smart device, a wearable device, a vehicle, a meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similar functional device. Some UEs 104 may be referred to as IoT devices (such as parking meters, fuel pumps, ovens, vehicles, heart monitors, etc.). Other UEs 104 may be referred to as cellular IoT (CIoT) devices (such as smart phones capable of narrowband communication based on one or more designed for IoT devices). The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable term.

[0073] Whether it is a small cell 102' or a large cell (such as a macro base station), the base station 102 can include an eNB, a gNB node (gNB), or another type of base station. Some base stations (such as gNB 180) can operate in the traditional sub-6GHz spectrum, millimeter wave (mmW) frequencies, or near mmW frequencies to communicate with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 can be referred to as a millimeter wave or mmW base station. Extremely high frequency (EHF) is a part of RF in the electromagnetic spectrum. EHF has a range of 30GHz to 300GHz and a wavelength between 1 millimeter and 10 millimeters. The radio waves in this frequency band can be referred to as millimeter waves. Near mmW can extend down to 3GHz frequencies with a 100 millimeter wavelength. The super high frequency (SHF) band extends between 3GHz and 30GHz, which is also referred to as centimeter waves.

[0074] Communication using mmW / near mmW radio frequency bands (such as between 3GHz–300GHz) has extremely high path loss and short range. The mmW base station 180 can utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. Beamforming (which can also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (such as the base station 102 or the UE 104) to shape or steer an antenna beam along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals communicated via the antenna elements of an antenna array such that some signals propagating in a particular orientation relative to the antenna array experience constructive interference while other signals experience destructive interference. The adjustment of the signals communicated via the antenna elements can include the transmitting device or the receiving device applying certain amplitude offsets, phase offsets, or both to the signals carried via the antenna elements associated with the device. The adjustment associated with each antenna element can be defined by a set of beamforming weights associated with a particular orientation (such as relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0075] For example, the base station 180 can transmit beamformed signals to the UE 104 in one or more transmission directions 182'. The UE 104 can receive beamformed signals from the base station 180 in one or more reception directions 182". The UE 104 can also transmit beamformed signals to the base station 180 in one or more transmission directions. The base station 180 can receive beamformed signals from the UE 104 in one or more reception directions. The base station 180 and the UE 104 can perform beam training to determine the optimal reception and transmission directions for each of the base station 180 and the UE 104. The transmission direction and the reception direction of the base station 180 can be the same or can be different. The transmission direction and the reception direction of the UE 104 can be the same or can be different.

[0076] Base station 102 and UE 104 may communicate wirelessly with each other via one or more communication links 120 using one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communication link 120. For example, a carrier for communication link 120 may include a portion of a radio frequency spectrum band (such as a bandwidth part (BWP)) that operates according to the physical layer channels for a given radio access technology. Each physical layer channel may carry acquisition signaling (such as synchronization signals, system information), control signaling for coordinating carrier operation, user data, or other signaling. Wireless communication system 100 may support communication between base station 102 and UE 104 using carrier aggregation or multi-carrier operation. Carrier aggregation may be used in conjunction with both frequency division duplex (FDD) and time division duplex (TDD) component carriers. The allocation of carriers may be asymmetric with respect to DL and UL channels, such that the UL and DL channels may include different numbers of carriers. Component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as the primary cell (PCell), and the secondary component carriers may be referred to as secondary cells (SCells).

[0077] In some examples, a carrier may support multiple cells and may be configured with different cell types according to different protocol types (such as MTC, NB-IoT, enhanced mobile broadband (eMBB), or others) that may provide access for different types of devices.

[0078] Communication link 120 may include an uplink (UL) transmission from UE 104 to base station 102 or a downlink (DL) transmission from base station 102 to UE 104. Communication link 120 may use multiple-input multiple-output (MIMO) antenna technology, for example, to provide spatial multiplexing, beamforming, or transmit diversity. For each carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) for transmission in each direction, base station 102 and UE 104 may use a spectrum with a bandwidth of up to Y MHz (such as 5 MHz, 10 MHz, 15 MHz, 20 MHz, 100 MHz, 400 MHz, etc.). These carriers may or may not be adjacent to each other.

[0079] Some UEs 104 may communicate with each other using device-to-device (D2D) communication links 158. The D2D communication links 158 may use DL / UL WWAN spectrum. The D2D communication links 158 may use one or more sidelink channels, such as the Physical Sidelink Broadcast Channel (PSBCH), the Physical Sidelink Discovery Channel (PSDCH), the Physical Sidelink Shared Channel (PSSCH), and the Physical Sidelink Control Channel (PSCCH). D2D communication may be through various wireless D2D communication systems, such as, for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0080] Some UEs 104 (such as MTC or IoT devices) may be low-cost or low-complexity devices and may provide automated communication between machines (such as by using machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with each other or with a base station 102 without human intervention. In some examples, M2M communication or MTC may include communication from devices integrated with sensors or meters to measure or capture information and relay such information to a central server or application that utilizes the information or presents the information to a person interacting with the application. Some UEs 104 may be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wilderness survival monitoring, weather and geographical event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0081] The wireless communication system 100 may be a packet-based network that operates according to a hierarchical protocol stack. On the user plane, the communication of the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. The Radio Link Control (RLC) layer may perform packet segmentation and reassembly for communication on logical channels. The Media Access Control (MAC) layer may perform priority handling and multiplex logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmission at the MAC layer to improve link efficiency. On the control plane, the RRC protocol layer may provide the establishment, configuration, and maintenance of the RRC connection that supports the radio bearers for user plane data between the UE 104 and the base station 102 or the EPC 160. At the physical layer, the transport channels may be mapped to physical channels.

[0082] The EPC 160 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. In some implementations, the EPC 160 can include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 is a control plane entity that manages access and mobility and can communicate with a Home Subscriber Server (HSS) 174. The MME 162 can manage Non-Access Stratum (NAS) functions such as the mobility, authentication, and bearer management of the UE 104 served by the base station 104 associated with the EPC 160, and can handle the signaling between the UE 104 and the EPC 160. All user IP packets are passed through the Serving Gateway 166, which is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation and other functions. The PDN Gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 can include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS streaming service, or other IP services. The BM-SC 170 can provide functions for MBMS user service provisioning and delivery. The BM-SC 170 can serve as an entry point for content provider MBMS transmissions, can be used to authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and can be used to schedule MBMS transmissions. The MBMS Gateway 168 can be used to distribute MBMS traffic to base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area for a particular broadcast service, and can be responsible for session management (start / stop) and for collecting MBMS-related charging information.

[0083] The core network 190 can include an Access and Mobility Management Function (AMF) 192, one or more other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 can be in communication with a Unified Data Management (UDM) 196. The AMF 192 is a control node that processes the signaling between the UE 104 and the core network 190. Generally, the AMF 192 provides Quality of Service (QoS) flow and session management. User IP packets are passed through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to IP services 197. The IP services 197 can include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS streaming service, or other IP services.

[0084] Figure 2A An example of a first time slot 200 within the 5G NR frame structure is shown.Figure 2B An example of the DL channel 230 within a 5G NR time slot is shown. Figure 2C An example of the second time slot 250 within a 5G NR frame structure is shown. Figure 2D An example of the UL channel 280 within a 5G NR time slot is shown. In some instances, the 5G NR frame structure can be FDD, where for a particular set of subcarriers (carrier system bandwidth), the time slots within that set of subcarriers are dedicated to either DL or UL transmission. In some other instances, the 5G NR frame structure can be TDD, where for a particular set of subcarriers (carrier system bandwidth), the time slots within that set of subcarriers are dedicated to both DL and UL transmission. In Figure 2A and 2C the example shown, the 5G NR frame structure is based on TDD, where time slot 4 is configured with time slot format 28 (mostly DL) and time slot 3 is configured with time slot format 34 (mostly UL), where D indicates DL, U indicates UL, and X indicates that the time slot can be flexibly used between DL and UL. Although time slots 3 and 4 are shown as having time slot formats 34 and 28 respectively, any particular time slot can be configured with any one of the various available time slot formats 0 - 61. Time slot formats 0 and 1 are all-DL and all-UL respectively. The other time slot formats 2 - 61 include a mixture of DL, UL, and flexible symbols. The UE can be configured with a time slot format (dynamically configured via downlink control information (DCI) or semi-statically configured via radio resource control (RRC) signaling) via a time slot format indicator (SFI). The configured time slot format can also be applied to an FDD-based 5G NR frame structure.

[0085] Other wireless communication technologies can have different frame structures or different channels. A frame can be divided into several equally sized subframes. For example, a frame having a duration of 10 milliseconds (ms) can be divided into 10 equally sized subframes, each having a duration of 1 ms. Each subframe can include one or more time slots. A subframe can also include mini-slots, which can include 7, 4, or 2 symbols. Each time slot can include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot can include 14 symbols, while for time slot configuration 1, each time slot can include 7 symbols. The symbols on the DL can be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on the UL can be CP-OFDM symbols (such as for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also known as single carrier frequency division multiple access (SC-FDMA) symbols) (such as for power-constrained scenarios).

[0086] The number of time slots within a subframe is based on the time slot configuration and the parameter design. For time slot configuration 0, different parameter designs (μ) from 0 to 5 allow 1, 2, 4, 8, 16, and 32 time slots per subframe respectively. For time slot configuration 1, different parameter designs from 0 to 2 allow 2, 4, and 8 time slots per subframe respectively. Correspondingly, for time slot configuration 0 and parameter design μ, there are 14 symbols per time slot and 2^μ time slots per subframe. The subcarrier spacing and symbol length / duration are dependent on the parameter design. The subcarrier spacing can be equal to 2^μ * 15 kHz, where μ is the parameter design from 0 to 5. Thus, parameter design μ = 0 has a subcarrier spacing of 15 kHz, while parameter design μ = 5 has a subcarrier spacing of 480 kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A - 2D An example is provided with time slot configuration 0 having 14 symbols per time slot and parameter design μ = 0 having 1 time slot per subframe. The subcarrier spacing is 15 kHz and the symbol duration is approximately 66.7 microseconds (μs).

[0087] The resource grid can be used to represent the frame structure. Each time slot includes resource blocks (RBs) (also known as physical RBs (PRBs)) that span 12 consecutive subcarriers and extend across several symbols. The intersection of subcarriers spans 14 symbols. The intersection of subcarriers and RBs defines multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0088] As Figure 2A explained, some REs carry reference signals (RSs) for the UE. In some configurations, one or more REs can carry demodulation reference signals (DM-RSs) (denoted as Rx for a specific configuration, where 100x is the port number, but other DM-RS configurations are possible). In some configurations, one or more REs can carry channel state information reference signals (CSI-RSs) for channel measurements at the UE. REs can also include beam measurement reference signals (BRSs), beam refinement reference signals (BRRSs), and phase tracking reference signals (PT-RSs).

[0089] Figure 2BExamples of various DL channels within a subframe of a frame are explained. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including 9 resource element groups (REGs), each REG including 4 consecutive resource elements (REs) in an OFDM symbol. The primary synchronization signal (PSS) may be in symbol 2 of a specific subframe of a frame. The PSS is used by the UE 104 to determine subframe or symbol timing and the physical layer identity. The secondary synchronization signal (SSS) may be in symbol 4 of a specific subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the location of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) may be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides the number of resource blocks (RBs) in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH (such as system information blocks (SIBs)), and paging messages.

[0090] As Figure 2C explained, some resource elements carry DM-RS for channel estimation at the base station (indicated as R for one particular configuration, but other DM-RS configurations are possible). The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the previous one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether a short PUCCH or a long PUCCH is transmitted and depending on the particular PUCCH format used. Although not shown, the UE may transmit sounding reference signals (SRS). The SRS may be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0091] Figure 2D Examples of various UL channels within a subframe of a frame are explained. The PUCCH may be located at the position indicated in one configuration. The PUCCH carries uplink control information (UCI), such as a scheduling request, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), or UCI.

[0092] Figure 3A block diagram of an example base station 310 and a UE 350 in an access network is shown. In the DL, IP packets from the EPC 160 may be provided to the controller / processor 375. The controller / processor 375 implements layer-3 and layer-2 functionality. Layer-3 includes the radio resource control (RRC) layer, and layer-2 includes the service data adaptation protocol (SDAP) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, and the media access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with the broadcast of system information (such as MIB and SIB), RRC connection control (such as RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration of UE measurement reports; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction via ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and re-ordering of RLC data PDUs; and MAC layer functionality associated with the mapping between logical channels and transport channels, multiplexing of MAC service data units (MAC SDUs) onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel priority differentiation.

[0093] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer-1 functionality associated with various signal processing functions. Layer-1, which includes the physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding / decoding of the transport channels, interleaving, rate matching, mapping to physical channels, modulation / demodulation of the physical channels, and MIMO antenna processing. The TX processor 316 handles the mapping to the 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), and M-quadrature amplitude modulation (M-QAM). The decoded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to OFDM subcarriers, multiplexed with a reference signal such as a pilot signal in the time domain or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a stream of time-domain OFDM symbols. The OFDM stream is space precoded to generate multiple spatial streams. Channel estimates from the channel estimator 374 may be used to determine the coding and modulation schemes and for spatial processing. The channel estimates may be derived from reference signals transmitted by the UE 350 or channel status feedback. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX modulates an RF carrier with the corresponding spatial stream for transmission.

[0094] At the UE 350, each receiver 354RX receives signals via its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer-1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If there are multiple spatial streams destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then uses a fast Fourier transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency-domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the signal constellation point most likely transmitted by the base station 310. These soft decisions may be based on the channel estimates computed by the channel estimator 358. These soft decisions are then decoded and deinterleaved to recover the original data and control signals transmitted by the base station 310 on the physical channel. These data and control signals are then provided to the controller / processor 359 that implements layer-3 and layer-2 functionality.

[0095] The controller / processor 359 may be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport channels and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using the ACK or NACK protocol to support HARQ operations.

[0096] The memory 360 may include a random access memory (RAM) and a read-only memory (ROM). The memory 360 may store computer-readable, computer-executable software / firmware including instructions that, when executed, cause the processor 369 to perform the various functions described herein (e.g., early UE capability retrieval, etc.), including the functions described with reference to the UE truncation manager 815. Alternatively, the software / firmware code may not be directly executable by the processor 359 but (e.g., when compiled and executed) causes a computer to perform the functions described herein. The processor 359 may include an intelligent hardware device (e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc.).

[0097] Similar to the functionality described in connection with DL transmissions by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (such as MIB and SIB) capture, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and re-ordering of RLC data PDUs; and MAC layer functionality associated with the mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel prioritization.

[0098] Channel estimates derived by the channel estimator 358 from reference signals or feedback transmitted by the base station 310 may be used by the TX processor 368 to select an appropriate coding and modulation scheme and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0099] UL transmissions are processed at the base station 310 in a manner similar to that described in connection with the receiver functionality at the UE 350. Each receiver 318RX receives signals via its respective corresponding antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides this information to the RX processor 370.

[0100] The controller / processor 375 may be associated with a memory 376 that stores program code and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between the transport channel and the logical channel, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using the ACK or NACK protocol to support HARQ operations. Information to be wirelessly conveyed (such as LTE- or NR-based communication) is encoded at the PHY layer and mapped to one or more radio channels for transmission.

[0101] The memory 376 may include random access memory (RAM) and read-only memory (ROM). The memory 376 may store computer-readable, computer-executable software / firmware including instructions that, when executed, cause the processor 375 to perform the various functions described herein (e.g., early UE capability retrieval, etc.), including the functions described with reference to the base station decoding manager 915. Alternatively, the software / firmware code may not be directly executable by the processor 375 but (e.g., when compiled and executed) causes a computer to perform the functions described herein. The processor 375 may include intelligent hardware devices (e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc.).

[0102] In Figure 3 the example, each antenna 352 of the UE 350 is coupled to a respective transmitter 354TX. However, in some other implementations, the UE 350 may include fewer transmitters (or transmit chains) than receive (RX) antennas. Although not shown for simplicity, each transmitter may be coupled to a respective power amplifier (PA) that amplifies the signal to be transmitted. The combination of the transmitter and the PA may be referred to herein as a "transmit chain" or "TX chain" herein. To save cost or die area, the same PA may be reused to transmit signals via multiple RX antennas. In other words, one or more TX chains of the UE may be selectively coupled to multiple RX antenna ports.

[0103] Figure 4 A sequence diagram 400 is shown depicting an example message exchange that supports the establishment of an RRC connection between a base station 402 and a UE 404. The base station 402 may beFigure 1 a base station 102 or Figure 3 an example of base station 310, and the UE 404 may be Figure 1 a UE 104 or Figure 3 an example of UE 350. The UE 404 may use a random access procedure to establish layer-1 (physical layer) and layer-2 (MAC layer) connections with the base station 402, and then use the RRC procedure to establish a layer-3 connection (such as an RRC connection) with the base station 402.

[0104] The UE 404 may transmit a random access preamble (Msg1) to the base station 402 on the random access channel (RACH) of the radio access network. The transmit power may be used on the indicated RACH resources to transmit the random access preamble with a selected preamble sequence. The base station 402 receives the random access preamble in Msg1 and transmits a random access response (Msg2) to the UE 404. When the random access response contains a random access preamble identifier that matches the preamble sequence of the random access preamble, the UE404 may stop monitoring the RACH and may initiate an RRC connection establishment procedure.

[0105] The UE 404 may transmit an RRC connection request (Msg3) to the base station 402. The RRC connection request may include a UE identity (UEID) that uniquely identifies the UE 404. The UE identity may indicate a core network entity that stores the UE context (such as UE capabilities and UE-to-UE QoS information). In some instances, the UE identity may indicate a specific AMF (such as Figure 1 AMF 192), and may be used by the base station 402 to retrieve the UE 404's capability information from that specific AMF.

[0106] The base station 402 receives Msg3 and may use the UE identity to identify the core network entity that stores the UE context. The base station 402 may retrieve the UE context from the identified core network entity and may use the UE's radio capability information to determine an initial signaling radio bearer (SRB1) configuration for the UE 404.

[0107] The base station 402 may transmit the SBR1 configuration to the UE 404 in an RRC connection setup message (Msg4). The UE 404 receives Msg4, determines its SRB1 configuration, and transmits an RRC connection setup complete message (Msg5) to the base station 402. The base station 402 receiving Msg5 may end the RRC connection establishment procedure.

[0108] In some instances, the number of bits available in a given RRC message for transmitting UE identity information may be less than the number of bits in the UE identity, and thus the UE may not be able to transmit the complete UE identity to the base station 402 in the RRC connection request (Msg3). For example, physical layer transport block size constraints may prevent an eMTC device from embedding an identifier of more than 40 bits in a given RRC message, and thus the eMTC device may not be able to transmit the complete 48-bit UE identity to the base station 402 in the RRC connection request (Msg3).

[0109] The RRC connection request for a base station associated with a 5G core network typically includes a 48-bit 5G-S-TMSI as the UE identity. The 5G-S-TMSI includes a 10-bit AMF set ID, a 6-bit AMF pointer, and a 32-bit 5G-TMSI. A UE (such as an eMTC device) that cannot send the complete 48-bit 5G-S-TMSI in a given RRC message typically sends the 40 least significant bits (LSB) of the 5G-S-TMSI in the RRC connection request (Msg3) and then sends the remaining 8 bits of the 5G-S-TMSI to the base station 402 in the RRC connection setup complete message (Msg5). However, the 8 most significant bits (MSB) of the 5G-S-TMSI correspond to the 8-bit AMF set ID, which is necessary for the base station 402 to determine which AMF stores the UE context. As a result, the base station 402 may not be able to identify the AMF and retrieve the UE capabilities until it receives Msg5, and thus typically configures SRB1 for the UE 404 before determining the UE capabilities.

[0110] Selecting the SRB1 configuration without knowing the UE capabilities limits the ability of the base station to customize or optimize the SRB1 configuration for the UE. This may be particularly problematic for cellular IoT (CIoT) devices (such as eMTC or NB-IoT devices) because these CIoT devices use control plane optimization for small data transmissions and have various capabilities for different radio enhancements. Thus, it is desirable for the base station 402 to obtain the UE radio capabilities of such devices before selecting the SRB1 configuration and transmitting the SRB1 configuration in the RRC connection setup message (Msg4).

[0111] According to various aspects of the present disclosure, a UE may truncate or remove a number of bits from its UE identity based on identity truncation information to generate a truncated UE identity. The truncated UE identity may be transmitted by an eMTC device to a base station in an RRC connection request and may be used by the base station to determine which core network entity (such as an AMF) stores the UE capabilities. In some implementations, the UE may truncate or remove a number of bits from a 48-bit 5G-S-TMSI based on identity truncation information to generate a 40-bit truncated 5G-S-TMSI, which may be transmitted by the eMTC device to the base station in an RRC connection request and still provide the base station with sufficient information to determine which AMF stores the UE context. This allows the base station to retrieve the UE capabilities from the AMF before selecting an SRB configuration for the UE. In this way, even for UEs (such as eMTC devices) that may not be able to transmit the 48-bit 5G-S-TMSI in an RRC message, the base station may select or determine an SRB configuration for these UEs based on the UE capabilities.

[0112] Figure 5 An example UE identity 510 and an example truncated UE identity 520 are shown. The UE identity 510 (which may be a 48-bit 5G-S-TMSI in some instances) includes an AMF set identifier 512, an AMF pointer 514, and a TMSI 516. The AMF set identifier 512 may uniquely identify an AMF set within an AMF area, the AMF pointer 514 may identify one or more AMFs within the AMF set, and the TMSI 516 may uniquely identify a particular UE. The truncated UE identity 520 (which includes a truncated AMF set identifier 522, a truncated AMF pointer 524, and a truncated TMSI 526) may be generated by removing a number of bits from one or more of the AMF set identifier 512, the AMF pointer 514, or the TMSI 516 of the UE identity 510 based on identity truncation information.

[0113] In some network implementations, within a given AMF region, there may be a relatively small number of AMF sets that can be uniquely identified by the AMF set identifier 512, and thus one or more MSBs of the AMF set identifier 512 can be the same for multiple different AMF sets. Similarly, within a given AMF set, there may be a relatively small number of AMFs that can be uniquely identified by the AMF pointer 514, and thus one or more MSBs of the AMF pointer 514 can be the same for multiple different AMFs. In other words, several MSBs that are common to all AMF sets within a given AMF region in the AMF set identifier 512 are not used to uniquely identify the AMF sets within the given AMF region, and thus can be removed or truncated from the UE identity 510 to generate the truncated UE identity 520. Similarly, several MSBs that are common to all AMFs within a given AMF set in the AMF pointer 514 are not used to uniquely identify the AMFs within the given AMF set, and thus can be removed or truncated from the UE identity 510 to generate the truncated UE identity 520.

[0114] The several LSBs of the AMF set identifier 512 that are not common to the AMF sets within a given AMF region can uniquely identify the AMF sets, and thus can be retained when generating the truncated UE identity 520. Similarly, the several LSBs of the AMF pointer 514 that are not common to the AMFs within a given AMF set can uniquely identify the AMFs within the given AMF set, and thus can be retained when generating the truncated UE identity 520. In some implementations, the identity truncation information can indicate a first number (n) of LSBs of the AMF set identifier 512 to be retained when generating the truncated UE identity 520, and can indicate a second number (m) of LSBs of the AMF pointer 514 to be retained when generating the truncated UE identity 520. In some aspects, the truncated AMF set identifier 522 can be generated by retaining n LSBs of the AMF set identifier 512 (and removing the remaining MSBs of the AMF set identifier 512), and the truncated AMF pointer 524 can be generated by retaining m LSBs of the AMF pointer 514 (and removing the remaining MSBs of the AMF pointer 514).

[0115] In some implementations, the first number n and the second number m may also be used to determine the number of LSBs M to be retained in the truncated UE identity 520 when generating the truncated UE identity 520 from the TMSI 516. The number M may be expressed as M = N – n – m, where N is the number of bits in the truncated UE identity 520. In some aspects, the truncated TMSI 526 may be generated by retaining only the N – n – m LSBs of the TMSI 516. For example, in an instance where the truncated UE identity 520 comprises 40 bits, the number of common MSBs of the AMF set identifier 512 is 6 bits, and the number of common MSBs of the AMF pointer 514 is 4, the truncated AMF set identifier 522 may be generated by retaining only the n = 6 LSBs of the AMF set identifier 512, the truncated AMF pointer 524 may be generated by retaining only the m = 4 LSBs of the AMF pointer 514, and the truncated TMSI 526 may be generated by retaining only the 40 – 6 – 4 LSBs of the TMSI 516. In some other implementations, the identity truncation information may explicitly indicate the number of LSBs to be retained in the TMSI 516 when generating the truncated UE identity 520. For example, the identity truncation information may also include a value z indicating the number of LSBs to be retained in the TMSI 516 when generating the truncated UE identity 520.

[0116] Figure 6 Illustrates the generation of an example truncated UE identity by truncating certain bits of the UE identity and retaining certain other bits of the UE identity. As shown, the UE identity includes a 10-bit AMF set identifier 610, a 6-bit AMF pointer 620, and a TMSI 630. The truncated AMF set identifier may be generated by truncating several MSBs or a subset of MSBs 610 of the AMF set identifier 610 and thereby retaining only several LSBs or a subset of LSBs 614 of the AMF set identifier 610. Similarly, the truncated AMF pointer may be generated by truncating several MSBs or a subset of MSBs 622 of the AMF pointer 620 and thereby retaining only several LSBs or a subset of LSBs 624 of the AMF pointer 620. The truncated TMSI may be generated by truncating several MSBs or a subset of MSBs 632 of the TMSI 630 and thereby retaining only several LSBs or a subset of LSBs 634 of the TMSI 630.

[0117] In some implementations, the value of n may be equal to or less than the total length of the AMF set identifier 610, and the value of m may be equal to or less than the total length of the AMF pointer 620. For example, n may not be greater than 10 and m may not be greater than 6. The total of n + m + z may be equal to the number of bits allocated for transmitting the identification indicator (e.g., 40 bits).

[0118] The UE may receive identity truncation information and may generate a truncated UE identity by removing several bits from one or more fields of the UE identity according to the value included in the identity truncation information. For Figure 6 example, the identity truncation information may indicate 6, 4, and 30 as the values of n, m, and z, respectively. For example, the UE may remove 4 MSBs 612 from the AMF set identifier 610, remove 2 MSBs from the AMF pointer 620, and remove 2 MSBs from the TMSI 630 to generate a truncated UE identity.

[0119] Figure 7A A sequence diagram 700 of wireless communication between a base station 704, a UE 702, and an AMF 706 for early retrieval of UE capabilities in an access network is shown. The base station 704 may be Figure 1 an example of the base station 102 of Figure 3 the base station 310 of Figure 4 or an example of the base station 402 of Figure 1 the UE 104 of Figure 3 the UE 350 of Figure 4 or an example of the UE 404 of Figure 1 In some implementations, the AMF 706 may be an example of the AMF 192 of

[0120] In some implementations, the UE 702 may be an enhanced machine type communication (eMTC) device capable of embedding an identity of no more than 40 bits in an RRC message, and the core network associated with the AMF 706 may be a 5G core network that uses a 48-bit 5G-S-TMSI to uniquely identify the UE and its corresponding AMF. In some aspects, the UE 702 may generate a 40-bit truncated UE identity from the 48-bit 5G-S-TMSI such that the truncated UE identity can be transmitted to the base station 704 in a single RRC message and can be used by the base station to identify the AMF that stores the capabilities and other information of the UE.

[0121] For Figure 7AAs an example, the AMF 706 stores the UE context for the UE 702, and can determine or obtain the values of n and m based on the number of AMF sets assigned to the associated AMF region and the number of AMFs assigned to the associated AMF set. The AMF 706 can provide the identity truncation information containing the values of n and m to the base station 704 via the N2 connection between the base station 704 and the core network associated with the AMF 706. The base station 704 can broadcast the identity truncation information in one or more SIBS for reception by UEs within the coverage area of the base station 704.

[0122] The UE 702 receives the identity truncation information and can use the identity truncation information to generate a truncated UE identity, for example, by truncating one or more fields of the UE identity. In some implementations, the identity truncation information includes a first value n that indicates the number of LSBs to be retained in the AMF set identifier portion of the UE identity when generating the truncated UE identity; and includes a second value m that indicates the number of LSBs to be retained in the AMF pointer portion of the UE identity when generating the truncated UE identity.

[0123] The UE 702 can use the random access procedure to establish an access stratum connection with the base station 704. In some aspects, the UE transmits a random access preamble (Msg1) to the base station 704. The random access preamble can be transmitted on the random access channel (RACH) and can include a selected preamble sequence. The base station 704 can receive the random access preamble in Msg1 and transmit a random access response (Msg2) to the UE 702. The random access response contains a random access preamble identifier that matches the preamble sequence of the random access preamble, and the UE 702 can initiate the RRC connection procedure by transmitting an RRC connection request (Msg3) to the base station 704.

[0124] The RRC connection request (Msg3) contains the truncated UE identity generated according to the identity truncation information. In some aspects, the truncated UE identity contains 40 bits and can be embedded in the RRC connection request (Msg3) by an eMTC device. The base station 704 receives the truncated UE identity in Msg3 and constructs an AMF identifier at least partially based on the truncated UE identity.

[0125] In some implementations, the base station 704 obtains the identity truncation information from the AMF 706 and uses the values of n and m to reconstruct the 5G-S-TMSI (or at least parts of the 5G-S-TMSI), from which the base station 704 can identify the AMF that stores the capability information of the UE 702. In some aspects, constructing the AMF set identifier can be based on the number of MSBs of the AMF set identifier and the AMF pointer. In other aspects, constructing the AMF set identifier can be based on the AMF set identifier and the LSB of the AMF pointer.

[0126] The base station 704 sends a request for the UE context to the identified AMF 706 via the N2 connection. The AMF 706 responds by sending the UE context to the base station 704 via the N2 connection. In some implementations, the UE context includes at least UE capabilities and UE - to - UE QoS information. The base station 704 uses the UE capabilities to select or determine the SRB1 configuration for the UE 702, for example, such that the SRB configuration can be customized or optimized based on the specific capabilities and / or constraints of the UE 702.

[0127] The base station 704 transmits the SRB1 configuration to the UE 702 in the RRC connection setup message (Msg4). The UE 702 receives Msg4, determines its SRB1 configuration, and transmits an RRC connection setup complete message (Msg5) to the base station 704. The base station 704 receiving Msg5 can end the RRC connection establishment procedure.

[0128] Figure 7B A sequence diagram 710 of the wireless communication between the base station 704, the UE 702, and the AMF 706 for early retrieval of UE capabilities in the access network is shown. The base station 704 can be Figure 1 an example of the base station 102, Figure 3 an example of the base station 310, or Figure 4 an example of the base station 402. The UE 702 can be Figure 1 an example of the UE 104, Figure 3 an example of the UE 350, or Figure 4 an example of the UE 404. In some implementations, the AMF 706 can be Figure 1 an example of the AMF 192. In some other implementations, the AMF 796 can be any suitable network entity or network function capable of establishing a connection between the UE 702 and the core network (not shown for simplicity).

[0129] The sequence diagram 710 is similar to Figure 7B the sequence diagram 700 in some aspects and different from Figure 7B the sequence diagram 700 in other aspects. One difference is that in the sequence diagram 710, the UE 702 receives identity truncation information from the AMF 706 via NAS signaling. In some implementations, the UE 702 may transmit a NAS registration request message to the AMF 706, and the AMF 706 may respond by sending a NAS registration accept message containing the identity truncation information. The base station 704 may broadcast one or more SIBS containing an indicator to cause the UE702 to embed, for example, a 40 - bit truncated UE identity instead of a part of the 48 - bit 5G - S - TMSI in the RRC connection request (Msg3).

[0130] Figure 8 A block diagram of a UE 800 (which may be referred to as device 800) supporting a truncated UE identity in accordance with aspects of the present disclosure is shown. The UE 800 may be a Figure 1 UE 104 of Figure 3 UE 350 of Figure 4 UE 404 of Figure 7A –7B or an example of the UE 702 of –7B. The device 800 may include a receiver 810, a UE truncation manager 815, and a transmitter 835. The device 800 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0131] The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to truncated identifier indicators, etc.). The information may be passed to other components of the device 800. The receiver 810 may utilize a single antenna or an antenna array.

[0132] The UE truncation manager 815 may include a control signaling receiver 820, a truncated identity generator 825, and a truncated UE identity transmitter 830. The control signaling receiver 820 may receive control signaling that indicates identity truncation information for truncating one or more fields of the UE identity to generate a truncated UE identity. The truncated identity generator 825 may generate a truncated UE identity based on the identity truncation information. The truncated UE identity transmitter 830 may transmit the truncated UE identity to a base station.

[0133] Actions performed by the UE truncation manager 815 as described herein may be implemented to achieve one or more potential advantages. Using the truncated UE identity may allow the base station 102 to retrieve UE capabilities after receiving Msg3 in the RACH procedure and use the retrieved UE capabilities to optimally provide SRB configuration to the UE 104 in Msg4. This technique may allow the UE 104 to provide improved quality of service and reliability at the UE 115, as latency may be reduced due to identifying the UE before the RRC connection setup complete message. Other benefits may include efficient radio transmission, reduced UE power transmission, and the like.

[0134] The transmitter 835 may transmit signals generated by other components of the device 800. In some instances, the transmitter 835 may be co-located with the receiver 810 in a transceiver module. The transmitter 835 may utilize a single antenna or an antenna array.

[0135] Figure 9 A block diagram of a base station 900 supporting a truncated UE identity in accordance with aspects of the present disclosure is shown. The base station 900 may be a Figure 1base station 102, Figure 3 base station 310, Figure 4 base station 402, or Figure 7A – an example of base station 704 of 7B. Base station 900 includes a receiver 910, a base station decoding manager 915, and a transmitter 935. Although not shown for simplicity, base station 900 may also include one or more processors and other suitable components, such as those described with reference to Figure 3 as described. Each of these components may be in communication with each other (e.g., via one or more buses).

[0136] Receiver 910 may utilize any number of antennas or antenna arrays and may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to truncated identification indicators, etc.). The information received via one or more antennas may be passed to other components of base station 900. Receiver 910 may be an example of aspects of the receiver described with reference to Figure 3 as described.

[0137] Base station decoding manager 915 may determine identity truncation information for generating a truncated UE identity. In some implementations, base station decoding manager 915 may include a truncation configuration manager 920, a control signaling transmitter 925, and a truncated UE identity receiver 930. Truncation configuration manager 920 may determine identity truncation information for one or more fields of the UE identity to be truncated. Control signaling transmitter 925 may transmit control signaling indicating the identity truncation information. Truncated UE identity receiver 930 may receive the truncated UE identity generated based on the identity truncation information.

[0138] The actions performed by base station decoding manager 915 as described herein may be implemented to achieve one or more potential advantages. Using the truncated UE identity may allow base station 102 to retrieve UE capabilities after receiving Msg3 in the RACH procedure and optimally provide SRB configuration to UE 104 using the retrieved UE capabilities in Msg4. This technique may allow base station 102 to provide improved quality of service and reliability at base station 102 because identifying the UE before the RRC connection setup complete message may reduce latency. Other benefits may include efficient radio transmission, reduced UE power transmission, and so on.

[0139] The base station decoding manager 915 or its sub-components can be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the base station decoding manager 915 or its sub-components can be performed by a general-purpose processor, DSP, application specific integrated circuit (ASIC), FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure.

[0140] The base station decoding manager 915 or its sub-components can be physically located at various positions, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, the base station decoding manager 915 or its sub-components can be separate and distinct components in accordance with various aspects of this disclosure. In some examples, in accordance with various aspects of this disclosure, the base station decoding manager 915 or its sub-components can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, transceivers, network servers, another computing device, one or more other components described in this disclosure, or combinations thereof.

[0141] The transmitter 935 can utilize any number of antennas or antenna arrays and can transmit signals generated by other components of the base station 900 to other wireless communication devices, network entities, and so on. In some instances, the transmitter 935 can be co-located with the receiver 910 in a transceiver module.

[0142] Figure 10A A flowchart depicting an example operation 1000 for supporting early retrieval of UE capabilities in wireless communication is shown. Operation 1000 can be performed by a wireless communication device such as Figure 1 UE 104, Figure 3 UE 350, Figure 4 UE 404, Figure 7A UE 702 of FIG. 7B, or Figure 8 UE 800). Although described with reference to Figure 7A BS 704, UE 702, and AMF 706 of FIG. 7B, the example operation 1000 can be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities.

[0143] At block 1002, the UE receives identity truncation information. In some implementations, the UE may receive the identity truncation information from the BS 704. In some instances, the BS 704 may include the identity truncation information in one or more broadcasted SIBS, and the UE may receive at least one SIB and obtain the identity truncation information. In other implementations, the UE may receive the identity truncation information from the AMF 706 (which may be part of a core network such as a 5G core network). In some instances, the UE may transmit a NAS registration request message to the AMF 706, and the AMF 706 may respond by sending a NAS registration acceptance message to the UE that includes the identity truncation information (such as a first value n and a second value m). Additionally, the UE may receive an indication to use its truncated UE identity (instead of its initial or original UE identity) when establishing a connection with the BS 704. In some instances, the UE may receive the indication in one or more SIBS broadcasted by the BS704.

[0144] At block 1004, the UE generates a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information. In some implementations, the UE may generate the truncated UE identity by retaining only the n least significant bits (LSBs) of the AMF set identifier of the UE identity, only the m LSBs of the AMF pointer of the UE identity, and only the (L - n - m) LSBs of the 5G-TMSI of the UE identity, where L indicates the number of bits in the truncated UE identity.

[0145] At block 1006, the UE transmits the truncated UE identity to the BS during an RRC connection establishment with the BS. In some implementations, the truncated UE identity may be transmitted in an RRC connection request message. In some instances, the UE is an eMTC device, the truncated UE identity includes 40 bits, and the UE identity is a 48-bit 5G-S-TMSI.

[0146] Figure 10B A flowchart depicting example operations 1010 for supporting early retrieval of UE capabilities in wireless communication is shown. Operations 1010 may be performed by a wireless communication device such as Figure 1 UE 104, Figure 3 UE 350, Figure 4 UE 404, Figure 7A UE 702 of –7B, or Figure 8 UE 800). Although described with reference to Figure 7A BS 704, UE 702, and AMF 706 of –7B, example operations 1010 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities. In some implementations, operations 1010 may be performed in Figure 10AThe operation in box 1006 of operation 1000 is performed after the UE transmits the truncated UE identity.

[0147] In box 1012, the UE receives an RRC connection setup message from the BS indicating an SRB configuration, which is based on the UE capabilities retrieved from the AMF of the core network. In some implementations, the identity truncation information indicates the number of least significant bits (LSBs) to be retained during generation of the truncated UE identity in at least one of one or more fields of the UE identity.

[0148] Figure 10C A flowchart illustrating an example operation 1020 of wireless communication for supporting early retrieval of UE capabilities is shown. Operation 1020 may be performed by a wireless communication device (such as Figure 1 UE 104 of Figure 3 UE 350 of Figure 4 UE 404 of Figure 7A –UE 702 of 7B, or Figure 8 UE 800 of Figure 7A –Although described with reference to BS 704, UE 702, and AMF 706 of 7B, example operation 1020 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities. In some implementations, operation 1010 may be an example of receiving the truncated UE identity in box 1002 of operation 1000 of Figure 10A

[0149] In box 1022, the UE transmits a non-access stratum (NAS) registration request message to the access and mobility management function (AMF) of the core network. In some implementations, the AMF may determine the identity truncation information as described herein.

[0150] In box 1024, the UE receives a NAS registration accept message from the AMF containing the identity truncation information.

[0151] In box 1026, the UE receives an indication in a system information block (SIB) broadcast by the BS to include the truncated UE identity in an RRC connection request message.

[0152] Figure 11A A flowchart illustrating an example operation 1100 of wireless communication for supporting early retrieval of UE capabilities is shown. Operation 1100 may be performed by a wireless communication device (such as Figure 1 BS102 of Figure 3 BS 310 of Figure 4 BS 402 of Figure 7A BS704 of Figure 9 BS 900 of Although described with reference toFigure 7A described in terms of BS 704, UE 702, and AMF 706, but example operation 1100 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities.

[0153] In block 1102, the BS receives identity truncation information for one or more fields of a truncated user equipment (UE) identity, the identity truncation information indicating the number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity.

[0154] In block 1104, the BS indicates the identity truncation information to the UE. In some implementations, the identity truncation information may be included in one or more system information blocks (SIBs) broadcast by the BS.

[0155] In block 1106, the BS receives from the UE a truncated UE identity in a radio resource control (RRC) connection request message, the truncated UE identity being generated according to the identity truncation information. In some implementations, the truncated UE identity is generated by retaining only the n LSBs of the AMF set identifier of the UE identity, only the m LSBs of the AMF pointer of the UE identity, and only the (L - n - m) LSBs of the 5G-TMSI of the UE identity, where L indicates the number of bits in the truncated UE identity. In some instances, the UE is an eMTC device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

[0156] Figure 11B A flowchart depicting an example operation 1110 for supporting early retrieval of UE capabilities in wireless communication is shown. Operation 1110 may be performed by a wireless communication device such as Figure 1 BS102, Figure 3 BS 310, Figure 4 BS 402, Figure 7A BS704, or Figure 9 BS 900). Although described in terms of Figure 7A BS 704, UE 702, and AMF 706, example operation 1100 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities. In some implementations, operation 1110 may be performed after receiving the truncated UE identity in block 1106 of operation 1100. Figure 11A

[0157] In block 1112, the BS constructs an AMF identifier at least partially based on the truncated UE identity.

[0158] ​At block 1114, the BS identifies which one of several AMFs stores the UE's capability information based on the constructed AMF identifier.

[0159] Figure 11C A flowchart depicting an example operation 1120 of wireless communication for supporting early retrieval of UE capabilities is shown. Operation 1120 may be performed by a wireless communication device (such as Figure 1 BS 102 of Figure 3 BS 310 of Figure 4 BS 402 of Figure 7A BS704 of, or Figure 9 BS 900 of). Although described with reference to Figure 7A BS 704, UE 702, and AMF 706 of, example operation 1120 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities. In some implementations, operation 1120 may be performed after identifying the AMF in block 1114 of operation 1110 of Figure 11B ).

[0160] At block 1122, the BS retrieves the UE capability information and the inter-UE QoS information from the identified AMF.

[0161] At block 1124, the BS determines a signaling radio bearer (SRB) configuration for the UE based at least in part on the retrieved UE capability information.

[0162] At block 1126, the BS transmits the SRB configuration to the UE in an RRC connection setup message.

[0163] At block 1128, the BS transmits an RRC connection rejection message to the UE based at least in part on the inter-UE QoS information and the traffic load of the BS.

[0164] Figure 12A A flowchart depicting an example operation 1200 of wireless communication for supporting early retrieval of UE capabilities is shown. Operation 1200 may be performed by a wireless communication device (such as Figure 1 BS 102 of Figure 3 BS 310 of Figure 4 BS 402 of Figure 7B BS704 of, or Figure 9 BS 900 of). Although described with reference to Figure 7B BS 704, UE 702, and AMF 706 of, example operation 1200 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities.

[0165] At block 1202, the BS receives identity truncation information for one or more fields of a truncated user equipment (UE) identity, the identity truncation information indicating the number of least significant bits (LSBs) to retain in at least one of the one or more fields of the UE identity.

[0166] At block 1204, the BS broadcasts an indication for the UE to use the truncated UE identity instead of the 48-bit 5G-S-TMSI, for example, during a radio resource control (RRC) connection procedure.

[0167] At block 1206, the BS receives the truncated UE identity from the UE in an RRC connection request message, the truncated UE identity being generated according to the identity truncation information. In some implementations, the truncated UE identity is generated by retaining only the n LSBs of the AMF set identifier of the UE identity, only the m LSBs of the AMF pointer of the UE identity, and only the (L - n - m) LSBs of the 5G-TMSI of the UE identity, where L indicates the number of bits in the truncated UE identity. In some instances, the UE is an eMTC device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

[0168] Figure 12B A flowchart depicting example operation 1210 for supporting early retrieval of UE capabilities in wireless communication is shown. Operation 1210 may be performed by a wireless communication device such as Figure 1 BS 102 of Figure 3 BS 310 of Figure 4 BS 402 of Figure 7B BS704 of Figure 9 BS 900 of Figure 7B Although described with reference to Figure 12A BS 704, UE 702, and AMF 706, example operation 1210 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities. In some implementations, operation 1210 may be performed after receiving the truncated UE identity in block 1206 of operation 1200 of

[0169] At block 1212, the BS constructs an AMF identifier at least partially based on the truncated UE identity.

[0170] At block 1214, the BS identifies which of several AMFs stores the UE's capability information based on the constructed AMF identifier.

[0171] Figure 12C A flowchart depicting example operation 1220 for supporting early retrieval of UE capabilities in wireless communication is shown. Operation 1220 may be performed by a wireless communication device such asFigure 1 BS102 of Figure 3 BS 310 of Figure 4 BS 402 of Figure 7B BS704 of, or Figure 9 BS 900) to perform. Although described with reference to Figure 7B BS 704, UE 702, and AMF 706 of, example operation 1220 may be performed in conjunction with other suitable base stations, access nodes, TRPs, network functions, or network entities. In some implementations, operation 1220 may be performed after identifying the AMF in block 1214 of operation 1210 of Figure 12B

[0172] In block 1222, the BS retrieves UE capability information and inter-UE QoS information from the identified AMF.

[0173] In block 1224, the BS determines a signaling radio bearer (SRB) configuration for the UE based at least in part on the retrieved UE capability information.

[0174] In block 1226, the BS transmits the SRB configuration to the UE in an RRC connection setup message.

[0175] In block 1228, the BS transmits an RRC connection rejection message to the UE based at least in part on the inter-UE QoS information and the traffic load of the BS.

[0176] Thus, operations 1000, 1010, 1020, 1110, 1120, 1200, 1210, and 1220 may provide early UE capability retrieval. It should be noted that methods 1000, 1010, 1020, 1110, 1120, 1200, 1210, and 1220 describe possible implementations, and the operations and steps may be rearranged or otherwise modified such that other implementations are also possible. In some examples, aspects from two or more of methods 1000, 1010, 1020, 1110, 1120, 1200, 1210, and 1220 may be combined.

[0177] Aspect 1: A method for a UE having a UE identity to perform wireless communication, the method comprising: receiving identity truncation information; generating a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information; and transmitting the truncated UE identity to a base station (BS) during establishment of an RRC connection with the BS.

[0178] Aspect 2: The method according to aspect 1, wherein the identity truncation information indicates the number of least significant bits (LSBs) to be retained during generation of the truncated UE identity in at least one of the one or more fields of the UE identity.

[0179] Aspect 3: The method according to aspect 2, wherein the identity truncation information includes: a first value indicating the number of LSBs of the access and mobility management function (AMF) set identifier of the UE identity; and a second value indicating the number of LSBs of the AMF pointer of the UE identity.

[0180] Aspect 4: The method according to aspect 3, wherein generating the truncated UE identity further includes: retaining only the number of LSBs of the AMF set identifier of the UE identity according to the first value; and retaining only the number of LSBs of the AMF pointer of the UE identity according to the second value.

[0181] Aspect 5: The method according to aspect 4, wherein generating the truncated UE identity further includes: retaining only (40–n–m) LSBs of the temporary mobile station identifier (TMSI) of the UE identity, where n represents the first value and m represents the second value.

[0182] Aspect 6: The method according to any one of aspects 1 to 5, wherein the UE includes an enhanced machine type communication (eMTC) device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

[0183] Aspect 7: The method according to any one of aspects 1 to 6, wherein the truncated UE identity is transmitted to the BS in an RRC connection request message.

[0184] Aspect 8: The method according to aspect 7, further comprising: receiving an RRC connection setup message from the BS indicating a signaling radio bearer (SRB) configuration, the SRB configuration being based on UE capabilities retrieved from an access and mobility management function (AMF) of the core network.

[0185] Aspect 9: The method according to aspect 8, wherein retrieving the UE capabilities from the AMF is based on the truncated UE identity.

[0186] Aspect 10: The method according to any one of aspects 1 to 9, wherein receiving the identity truncation information further includes: receiving the identity truncation information from the BS in a system information block (SIB).

[0187] Aspect 11: The method according to any one of aspects 1 to 10, further comprising: transmitting a non-access stratum (NAS) registration request message to an access and mobility management function (AMF) of the core network; and receiving a NAS registration acceptance message from the AMF containing the identity truncation information.

[0188] Aspect 12: The method according to aspect 11, further comprising: receiving, in a system information block (SIB) broadcast by the BS, an indication to include the truncated UE identity in an RRC connection request message.

[0189] Aspect 13: A method for wireless communication performed by a base station (BS), the method comprising: indicating to a UE identity truncation information for one or more fields for truncating a UE identity, the identity truncation information indicating a number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; and receiving, from the UE in an RRC connection request message, a truncated UE identity generated according to the identity truncation information.

[0190] Aspect 14: The method according to aspect 13, wherein indicating the identity truncation information further comprises: transmitting the identity truncation information to the UE in an SIB.

[0191] Aspect 15: The method according to aspect 14, wherein the presence of the identity truncation information in the SIB causes the UE to transmit an indication of the truncated UE identity to the BS in the RRC connection request message.

[0192] Aspect 16: The method according to any one of aspects 13 to 15, wherein indicating the identity truncation information further comprises: broadcasting an indication for the UE to use the truncated UE identity during an RRC connection procedure.

[0193] Aspect 17: The method according to any one of aspects 13 to 16, further comprising: receiving the identity truncation information from an access and mobility management function (AMF) of a core network.

[0194] Aspect 18: The method according to aspect 17, wherein the identity truncation information comprises: a first value indicating a number of LSBs of an AMF set identifier of the UE identity; and a second value indicating a number of LSBs of an AMF pointer of the UE identity.

[0195] Aspect 19: The method according to aspect 18, further comprising: determining a difference (40–n–m) indicating a number of LSBs to be retained in a temporary mobile station identifier (TMSI) of the UE identity when generating the truncated UE identity, where n represents the first value and m represents the second value.

[0196] Aspect 20: The method according to any one of aspects 19 to 19, wherein at least one of the first value or the second value is based on a number of AMFs assigned to the core network.

[0197] Aspect 21: The method as described in any one of Aspects 18 to 20 further includes: constructing an AMF identifier at least partially based on the truncated UE identity; and identifying which AMF among a plurality of AMFs stores the UE's capability information based on the constructed AMF identifier.

[0198] Aspect 22: The method as described in Aspect 21, wherein constructing the AMF identifier in a given AMF area identified by the AMF area ID is further based on the AMF set identifier, the number of most significant bits (MSBs) of the AMF pointer, and the least significant bits (LSBs) of the AMF set identifier and the AMF pointer.

[0199] Aspect 23: The method as described in Aspect 22, wherein the MSBs of the AMF set identifier and the AMF pointer are received from the identified AMF.

[0200] Aspect 24: The method as described in Aspect 23 further includes: retrieving the UE capability information and UE - to - UE QoS information from the identified AMF; determining a signaling radio bearer (SRB) configuration for the UE at least partially based on the retrieved UE capability information; and transmitting the SRB configuration to the UE in an RRC connection setup message.

[0201] Aspect 25: The method as described in Aspect 24 further includes: transmitting an RRC connection rejection message to the UE at least partially based on the UE - to - UE QoS information and the traffic load of the BS.

[0202] Aspect 26: The method as described in any one of Aspects 13 to 25, wherein the UE includes an enhanced machine - type communication (eMTC) device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

[0203] Aspect 27: The method as described in any one of Aspects 13 to 26 further includes: receiving the identity truncation information from a core network entity.

[0204] Aspect 28: An apparatus for a UE with a UE identity to perform wireless communication includes: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method as described in any one of Aspects 1 to 12.

[0205] Aspect 29: A device for a UE with a UE identity to perform wireless communication includes at least one means for performing the method as described in any one of Aspects 1 to 12.

[0206] Aspect 30: A non-transitory computer-readable medium storing code for use by a UE having a UE identity to perform wireless communication, the code including instructions executable by a processor to perform the method described in any one of Aspects 1 to 12.

[0207] Aspect 31: An apparatus for use by a base station (BS) to perform wireless communication, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method described in any one of Aspects 13 to 27.

[0208] Aspect 32: An apparatus for use by a base station (BS) to perform wireless communication, comprising at least one means for performing the method described in any one of Aspects 13 to 27.

[0209] Aspect 33: A non-transitory computer-readable medium storing code for use by a base station (BS) to perform wireless communication, the code including instructions executable by a processor to perform the method described in any one of Aspects 13 to 27.

[0210] As used herein, a phrase that recites "at least one of" a list of items refers to any combination of those items, including a single member. By way of example, "at least one of a, b, or c" is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

[0211] The various illustrative logical, logical blocks, modules, circuits, and algorithmic processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. This interchangeability of hardware and software has been described generally in terms of its functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented as hardware or software depends upon the particular application and the design constraints imposed on the overall system.

[0212] Hardware and data processing apparatus for implementing the various illustrative logics, logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented using a general-purpose single-chip or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (such as a combination of a DSP and a microprocessor), multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration. In some implementations, specific processes and methods may be performed by circuitry dedicated to a given function.

[0213] In one or more aspects, the described functionality may be implemented in hardware, digital electronic circuitry, computer software, firmware (including the structures disclosed in this specification and structural equivalents thereof), or in any combination thereof. Implementations of the subject matter described in this specification may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by, or to control the operation of, a data processing apparatus.

[0214] If implemented in software, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. The processes of the methods or algorithms disclosed herein may be implemented in a processor-executable software module that may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be implemented to transfer a computer program from one place to another. The storage media may be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection may also be properly termed a computer-readable medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically and discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or more codes and instructions, or any combination or set thereof, on a machine-readable medium and a computer-readable medium that may be incorporated into a computer program product.

[0215] Various modifications to the implementations described in this disclosure may be apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with the disclosure, the principles disclosed herein, and the novel features.

Claims

1. A method for a User Equipment (UE) with a UE identity to perform wireless communication, the method comprising: Receiving identity truncation information; Generating a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information; Transmitting the truncated UE identity during establishment of a Radio Resource Control (RRC) connection with a network entity, wherein the truncated UE identity is transmitted to the network entity in an RRC connection request message; And Receiving an RRC connection setup message from the network entity indicating a Signaling Radio Bearer (SRB) configuration, the SRB configuration being based on UE capabilities retrieved from an Access and Mobility Management Function (AMF) of a core network, wherein retrieving the UE capabilities from the AMF is based on the truncated UE identity.

2. The method according to claim 1, wherein The identity truncation information indicates the number of Least Significant Bits (LSBs) to be retained in at least one of the one or more fields of the UE identity during generation of the truncated UE identity.

3. The method according to claim 2, wherein, The identity truncation information includes: A first value indicating the number of LSBs of an Access and Mobility Management Function (AMF) set identifier of the UE identity; and A second value indicating the number of LSBs of an AMF pointer of the UE identity.

4. The method according to claim 3, wherein Generating the truncated UE identity further includes: Retaining only a number of LSBs of the AMF set identifier of the UE identity according to the first value; and Retaining only a number of LSBs of the AMF pointer of the UE identity according to the second value.

5. The method according to claim 4, wherein, Generating the truncated UE identity further includes: Retaining only (40–n–m) LSBs of a Temporary Mobile Station Identifier (TMSI) of the UE identity, where n represents the first value and m represents the second value.

6. The method according to claim 1, wherein, The UE includes an enhanced Machine Type Communication (eMTC) device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

7. The method according to claim 1, wherein Receiving the identity truncation information further includes: Receiving the identity truncation information from the network entity in a System Information Block (SIB).

8. The method according to claim 1, further comprising: Transmitting a Non-Access Stratum (NAS) registration request message to an Access and Mobility Management Function (AMF) of a core network; And Receiving a NAS registration acceptance message from the AMF containing the identity truncation information.

9. The method according to claim 8, further comprising: Receiving an indication in a System Information Block (SIB) broadcast by the network entity to include the truncated UE identity in an RRC connection request message.

10. A method for a network entity to perform wireless communication, the method comprising: Indicating to a User Equipment (UE) identity truncation information for truncating one or more fields of the UE identity, the identity truncation information indicating the number of Least Significant Bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; Receiving a truncated UE identity from the UE in a Radio Resource Control (RRC) connection request message, the truncated UE identity being generated according to the identity truncation information; Constructing an AMF identifier at least in part based on the truncated UE identity; Identifying, based on the constructed AMF identifier, which one of several AMFs stores UE capability information; Retrieving the UE capability information and UE - to - UE Quality of Service (QoS) information from the identified AMF; Determining a Signaling Radio Bearer (SRB) configuration for the UE at least in part based on the retrieved UE capability information; and Transmitting the SRB configuration to the UE in an RRC connection setup message.

11. The method according to claim 10, wherein, Indicating that the identity truncation information further includes: Transmitting the identity truncation information to the UE in a System Information Block (SIB).

12. The method according to claim 10, wherein, Indicating that the identity truncation information further includes: Broadcasting an indication for the UE to use the truncated UE identity during the RRC connection procedure.

13. The method according to claim 10, wherein, The presence of the identity truncation information in the System Information Block (SIB) includes an indication for the UE to transmit the truncated UE identity to the network entity in the RRC connection request message.

14. The method according to claim 10, further comprising: Receiving the identity truncation information from an Access and Mobility Management Function (AMF) of the core network.

15. The method according to claim 14, wherein, The identity truncation information includes: A first value indicating the number of least - significant bits (LSBs) of an AMF set identifier of the UE identity; and A second value indicating the number of least - significant bits (LSBs) of an AMF pointer of the UE identity.

16. The method according to claim 15, further comprising: Determining a difference (40–n–m) in the number of least - significant bits to be retained in a Temporary Mobile Station Identifier (TMSI) indicating the UE identity when generating the truncated UE identity, where n represents the first value and m represents the second value.

17. The method according to claim 15, wherein, At least one of the first value or the second value is based on the number of AMFs allocated to the core network.

18. The method according to claim 15, wherein, Constructing the AMF identifier in a given AMF area identified by an AMF area ID is further based on the number of most - significant bits (MSBs) of the AMF set identifier and the AMF pointer and the number of least - significant bits (LSBs) of the AMF set identifier and the AMF pointer.

19. The method according to claim 18, wherein, The number of most - significant bits (MSBs) of the AMF set identifier and the AMF pointer is received from the identified AMF.

20. The method according to claim 19, further comprising: Transmitting an RRC connection rejection message to the UE at least in part based on the UE - to - UE QoS information and the traffic load of the network entity.

21. The method according to claim 10, wherein, The UE includes an enhanced machine - type communication (eMTC) device, the UE identity includes 48 bits, and the truncated UE identity includes 40 bits.

22. The method according to claim 10, further comprising: Receiving the identity truncation information from a core network entity.

23. A device for wireless communication, comprising: Means for receiving identity truncation information; Apparatus for generating a truncated UE identity by truncating one or more fields of a UE identity based on the identity truncation information; Apparatus for transmitting the truncated UE identity during establishment of a Radio Resource Control (RRC) connection with a network entity, wherein the truncated UE identity is transmitted to the network entity in an RRC connection request message; And Apparatus for receiving, from the network entity, an RRC connection setup message indicating a Signaling Radio Bearer (SRB) configuration, the SRB configuration being based on UE capabilities retrieved from an Access and Mobility Management Function (AMF) of a core network, wherein retrieving the UE capabilities from the AMF is based on the truncated UE identity.

24. The apparatus according to claim 23, further comprising apparatus for performing the method according to any one of claims 2 - 9.

25. An apparatus for wireless communication, comprising: Apparatus for indicating to a User Equipment (UE) identity truncation information for truncating one or more fields of a UE identity, the identity truncation information indicating the number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; And Apparatus for receiving, in a Radio Resource Control (RRC) connection request message, a truncated UE identity from the UE, the truncated UE identity being generated according to the identity truncation information; Apparatus for constructing an AMF identifier based at least in part on the truncated UE identity; Apparatus for identifying, based on the constructed AMF identifier, which one of a plurality of AMFs stores UE capability information; Apparatus for retrieving the UE capability information and UE - to - UE Quality of Service (QoS) information from the identified AMF; Apparatus for determining, based at least in part on the retrieved UE capability information, a Signaling Radio Bearer (SRB) configuration for the UE; And Apparatus for transmitting the SRB configuration to the UE in an RRC connection setup message.

26. The apparatus according to claim 25, further comprising apparatus for performing the method according to any one of claims 11 - 22.

27. A device for wireless communication, comprising: A processor; A memory coupled to the processor; And Instructions stored in the memory, the instructions being executable by the processor to cause the device to: Receive identity truncation information; Generate a truncated UE identity by truncating one or more fields of a UE identity based on the identity truncation information; Transmit the truncated UE identity during establishment of a Radio Resource Control (RRC) connection with a network entity, wherein the truncated UE identity is transmitted to the network entity in an RRC connection request message; And Receive, from the network entity, an RRC connection setup message indicating a Signaling Radio Bearer (SRB) configuration, the SRB configuration being based on UE capabilities retrieved from an Access and Mobility Management Function (AMF) of a core network, wherein retrieving the UE capabilities from the AMF is based on the truncated UE identity.

28. The device according to claim 27, wherein The instruction can further be executed by the processor to cause the device to perform the method according to any one of claims 2-9.

29. A device for wireless communication, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory, the instructions being executable by the processor to cause the device to: indicate to a user equipment (UE) identity truncation information for truncating one or more fields of the UE identity, the identity truncation information indicating the number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; receive, in a radio resource control (RRC) connection request message, a truncated UE identity from the UE, the truncated UE identity being generated according to the identity truncation information; construct an AMF identifier at least in part based on the truncated UE identity; identify, based on the constructed AMF identifier, which of a plurality of AMFs stores UE capability information; retrieve the UE capability information and UE inter-service quality of service (QoS) information from the identified AMF; determine a signaling radio bearer (SRB) configuration for the UE at least in part based on the retrieved UE capability information; and transmit the SRB configuration to the UE in an RRC connection setup message.

30. The apparatus according to claim 29, wherein, The instruction can further be executed by the processor to cause the device to perform the method according to any one of claims 11-22.

31. A non-transitory computer-readable medium storing code for performing wireless communication by a user equipment (UE) having a UE identity, the code including instructions executable by a processor to perform the following operations: receive identity truncation information; generate a truncated UE identity by truncating one or more fields of the UE identity based on the identity truncation information; transmit the truncated UE identity during establishment of a radio resource control (RRC) connection with a network entity, wherein the truncated UE identity is transmitted to the network entity in an RRC connection request message; and receive, from the network entity, an RRC connection setup message indicating a signaling radio bearer (SRB) configuration, the SRB configuration being based on UE capabilities retrieved from an access and mobility management function (AMF) of a core network, wherein the UE capabilities are retrieved from the AMF based on the truncated UE identity.

32. The non-transitory computer-readable medium according to claim 31, wherein, The code further includes instructions executable by the processor to perform the method according to any one of claims 2-9.

33. A non-transitory computer-readable medium storing code for performing wireless communication by a network entity, the code including instructions executable by a processor to perform the following operations: indicate to a user equipment (UE) identity truncation information for truncating one or more fields of the UE identity, the identity truncation information indicating the number of least significant bits (LSBs) to be retained in at least one of the one or more fields of the UE identity; Receive a truncated UE identity from the UE in a Radio Resource Control (RRC) connection request message, the truncated UE identity being generated according to the identity truncation information; Construct an AMF identifier at least partially based on the truncated UE identity; Identify which of several AMFs stores UE capability information based on the constructed AMF identifier; Retrieve the UE capability information and UE inter-service quality of service (QoS) information from the identified AMF; Determine a signaling radio bearer (SRB) configuration for the UE at least partially based on the retrieved UE capability information; and Transmit the SRB configuration to the UE in an RRC connection setup message.

34. The non-transitory computer-readable medium according to claim 33, wherein, The code further includes instructions executable by the processor to perform the method according to any one of claims 11-22.

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