CN117998683A - Method and user equipment for processing process conflict associated with EPS bearing - Google Patents

Abstract

The invention provides a method, user equipment and a storage medium for processing process conflict associated with EPS bearing. One of the methods for handling process conflicts associated with an EPS bearer includes: initiating a mobile initiated MO process for modifying an Evolved Packet System (EPS) bearer to release all traffic flows associated with the EPS bearer; receiving a request to initiate a mobile terminated MT procedure for modifying the EPS bearer; in response to receiving the request, suspending the MO process; and locally deactivating the EPS bearer. By utilizing the invention, the process conflict can be better processed.

Description

Method and user equipment for processing process conflict associated with EPS bearing

Technical Field

The present invention relates generally to communication systems, and more particularly to techniques for handling process collisions (procedure collision) associated with Evolved Packet System (EPS) bearers.

Background

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

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. A typical wireless communication system may employ multiple access techniques capable of supporting communication with multiple users by sharing the available system resources. Examples of such multiple-access techniques include code division multiple access (code division multiple access, CDMA) systems, time division multiple access (time division multiple access, TDMA) systems, frequency division multiple access (frequency division multiple access, FDMA) systems, orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) systems, single-carrier frequency division multiple access (single-carrier frequency division multiple access, SC-FDMA) systems, and time division synchronous code division multiple access (time division synchronous code division multiple access, TD-SCDMA) systems.

Disclosure of Invention

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

An embodiment of the present invention provides a method for processing a process conflict associated with an EPS bearer, including: initiating a mobile initiated MO process for modifying an Evolved Packet System (EPS) bearer to release all traffic flows associated with the EPS bearer; receiving a request to initiate a mobile terminated MT procedure for modifying the EPS bearer; in response to receiving the request, suspending the MO process; and locally deactivating the EPS bearer.

An embodiment of the present invention provides a user equipment for processing a process conflict associated with an EPS bearer, including: a memory; and at least one processor, coupled to the memory, for: initiating a mobile initiated MO process for modifying an Evolved Packet System (EPS) bearer to release all traffic flows associated with the EPS bearer; receiving a request to initiate a mobile terminated MT procedure for modifying the EPS bearer; in response to receiving the request, suspending the MO process; and locally deactivating the EPS bearer.

An embodiment of the present invention provides a storage medium storing a program that, when executed, causes an apparatus to perform the steps of the method for handling a process conflict associated with an EPS bearer set forth in the present invention.

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

Drawings

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

Fig. 2 is a block diagram illustrating a base station in an access network in communication with a UE.

Fig. 3 is a schematic diagram illustrating EPS bearers.

Fig. 4 is a sequence diagram illustrating a dedicated bearer establishment procedure.

FIG. 5 is a schematic diagram illustrating a process conflict handling mechanism.

Fig. 6 is a flowchart illustrating a method (procedure) of handling a process conflict associated with an EPS bearer.

Detailed Description

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

Aspects of a telecommunications system will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the figures by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). 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.

As an example, an element, any portion of an element, or any combination of elements may be implemented as a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (graphics processing unit, GPU), central processing units (central processing unit, CPU), application processors, digital signal processors (DIGITAL SIGNAL processor, DSP), reduced instruction set computing (reduced instruction set computing, RISC) processors, system on chip (systems on a chip, soC), baseband processors, field programmable gate arrays (field programmable GATE ARRAY, FPGA), programmable logic devices (programmable logic device, PLD), state machines, gate logic (gated logic), discrete hardware circuits, and other suitable hardware configured to perform the various functions described herein. One or more processors in the processing system may execute the software. Software should be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software components, applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, and the like, whether referred to as software, firmware, middleware, microcode, hardware description language, or the like.

Accordingly, in one or more examples, the described functionality may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer readable media includes computer storage media. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise random-access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (ELECTRICALLY ERASABLE PROGRAMMABLE ROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the foregoing types of computer-readable media, or any other media that can be used to store computer-executable code in the form of computer-accessible instructions or data structures.

Fig. 1 is a schematic diagram illustrating a wireless communication system and an access network 100. A wireless communication system, also referred to as a Wireless Wide Area Network (WWAN), includes a base station 102, a User Equipment (UE) 104, an evolved packet core (evolved packet core, EPC) 160, and another core network 190 (e.g., a 5G core (5 gc)). Base station 102 may include a macrocell (high power cellular base station) and/or a small cell (SMALL CELL, low power cellular base station). The macrocell includes a base station. The small cells include femto cells (femtocells), pico cells (picocell), and micro cells (microcell).

Base stations 102 configured for 4G LTE (collectively referred to as evolved universal mobile telecommunications system (universal mobile telecommunications system, UMTS) terrestrial radio access network (evolved UMTS terrestrial radio access network, E-UTRAN)) may interact with EPC 160 through backhaul link 132 (e.g., S1 interface). A base station 102 configured for 5G NR (collectively referred to as next generation RAN (NG-RAN)) may interact with a core network 190 through a backhaul link 184. Among other functions, the base station 102 may perform one or more of the following functions: transport user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast services (multimedia broadcast multicast service, MBMS), subscriber and device tracking, RAN information management (RAN information management, RIM), paging, positioning, and delivery of alert messages. Base stations 102 may communicate with each other directly or indirectly (e.g., through EPC 160 or core network 190) over backhaul link 134 (e.g., an X2 interface). The backhaul link 134 may be wired or wireless.

The base station 102 may communicate wirelessly with the UE 104. Each base station 102 may provide communication coverage for a corresponding geographic coverage area 110. The geographic coverage areas 110 may overlap. 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 comprising small cells and macro cells may be referred to as a heterogeneous network. The heterogeneous network may also include home enbs (henbs) that may provide services to a restricted group called a closed subscriber group (closed subscriber group, CSG). The communication link 120 between the base station 102 and the UE 104 may include Uplink (UL) (also referred to as reverse link) transmissions from the UE 104 to the base station 102 and/or Downlink (DL) (also referred to as forward link) transmissions from the base station 102 to the UE 104. Communication link 120 may use multiple-input multiple-output (MIMO) antenna techniques including spatial multiplexing, beamforming, and/or transmit diversity. The communication link may be through one or more carriers. Each carrier of the base station 102/UE 104 may use a spectrum up to X MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz), where each carrier is allocated in carrier aggregation (X component carriers) up to yxmhz in total for transmission in each direction. The carriers may or may not be adjacent to each other. The carrier allocation on DL and UL may be asymmetric (e.g., DL may be allocated more or less carriers than UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PRIMARY CELL, PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more side link channels, such as a physical side link broadcast channel (PHYSICAL SIDELINK broadcast channel, PSBCH), a physical side link discovery channel (PHYSICAL SIDELINK discovery channel, PSDCH), a physical side link shared channel (PHYSICAL SIDELINK SHARED CHANNEL, PSSCH), and a physical side link control channel (PHYSICAL SIDELINK control channel, PSCCH). D2D communication may be through various wireless D2D communication systems, such as FLASHLINQ, WIMEDIA, BLUETOOTH, ZIGBEE, wi-Fi, LTE, or NR based on the IEEE 802.11 standard.

The wireless communication system may also include a Wi-Fi Access Point (AP) 150 in communication with a Wi-Fi Station (STA) 152 via a communication link 154 in the 5GHz unlicensed spectrum. When communicating in the unlicensed spectrum, STA 152/AP 150 may perform clear channel assessment (CLEAR CHANNEL ASSESSMENT, CCA) prior to communication to determine whether a channel is available.

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

Base station 102 (whether small cell 102' or a large cell (e.g., macro base station)) may include an eNB, a gNB, or other type of base station. Some base stations, such as the gNB 180, may operate in the traditional sub 6GHz frequency spectrum, millimeter wave (MILLIMETER WAVE, mmW) frequencies, and/or frequencies near mmW, in communication with the UE 104. When the gNB 180 operates at or near mmW frequencies, the gNB 180 may be referred to as a mmW base station. The extremely high frequency (extremely high frequency, EHF) is a portion of the Radio Frequency (RF) in the electromagnetic spectrum. EHF has a wavelength in the range of 30GHz to 300GHz, between 1mm and 10 mm. The radio waves in the frequency band may be referred to as millimeter waves. Frequencies close to mmW may extend down to frequencies of 3GHz with a wavelength of 100 mm. The ultra-high frequency (super high frequency, SHF) band lies between 3GHz and 30GHz, also known as centimetre waves. Communications using mmW/near mmW radio frequency bands (e.g., 3GHz to 300 GHz) have extremely high path loss and short distances. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for extremely high path loss and short distances.

The base station 180 may transmit the beamformed signals to the UE 104 in one or more transmit directions 108 a. The UE 104 may receive the beamformed signals from the base station 180 in one or more receive directions 108 b. The UE 104 may also transmit the beamformed signals in one or more transmit directions to the base station 180. The base station 180 may receive the beamformed signals from the UEs 104 in one or more directions. The base station 180/UE 104 may perform beam training to determine the best reception and transmission direction of the base station 180/UE 104. The transmission and reception directions of the base station 180 may be the same or different. The transmit and receive directions of the UE 104 may be the same or different.

EPC 160 may include Mobility Management Entity (MME) 162, other MMEs 164, serving gateway (SERVING GATEWAY, SGW) 166, MBMS gateway 168, broadcast multicast service center (broadcast multicast SERVICE CENTER, BM-SC) 170, and Packet Data Network (PDN) gateway 172.MME 162 may communicate with home subscriber server (home subscriber server, HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. In general, MME 162 provides bearer and connection management. All user internet protocol (Internet protocol, IP) packets are transmitted through the serving gateway 166, which serving gateway 166 itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation as well as other functions. The PDN gateway 172 and BM-SC 170 are connected to an IP service 176.IP services 176 may include the internet, intranets, IP multimedia subsystem (IP multimedia subsystem, IMS), PS streaming services, and/or other IP services. The BM-SC 170 may provide functionality for MBMS user service provision and delivery. The BM-SC 170 may be used as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (public land mobile network, PLMN), and may be used to schedule MBMS transmissions. The MBMS gateway 168 may be used to distribute MBMS traffic to base stations 102 belonging to a multicast broadcast single frequency network (multicast broadcast single frequency network, MBSFN) area broadcasting a particular service and may be responsible for session management (start/stop) and collecting eMBMS related charging information.

The core network 190 may include access and mobility management functions (ACCESS AND mobility management function, AMF) 192, other AMFs 193, location management functions (location management function, LMF) 198, session management functions (session management function, SMF) 194, and user plane functions (user plane function, UPF) 195. The AMF 192 may communicate with a unified data management (unified DATA MANAGEMENT, UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. In general, SMF194 provides quality of service (quality of service, qoS) flows and session management. All user IP packets may be transmitted through UPF 195. The UPF 195 provides UE IP address assignment as well as other functions. The UPF 195 is connected to an IP service 197. The IP services 197 may include the internet, intranets, IMS, PS streaming services, and/or other IP services.

A base station may also be called a gNB, a node B, eNB, an access point, a base station transceiver, a radio base station, a radio transceiver, a transceiver function, a Basic Service Set (BSS), an Extended SERVICE SET (ESS), a transmit receive point (transmit reception point, TRP), or some other suitable terminology. The base station 102 provides an access point for the UE 104 to the EPC 160 or core network 190. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (session initiation protocol) phone, a laptop computer, a Personal Digital Assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a car, an ammeter, an air 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 (e.g., parking timers, air pumps, ovens, carts, heart monitors, etc.). The UE 104 may also be referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, or some other suitable terminology.

Although the application may refer to 5G NR, the application may be applicable to other similar fields, such as LTE, LTE-advanced (LTE-a), CDMA, global system for mobile communications (global system for mobile communications, GSM) or other wireless/radio access technologies.

Fig. 2 is a block diagram of a UE 250 in an access network in communication with a base station 210. In DL, IP packets from EPC 160 may be provided to controller/processor 275. Controller/processor 275 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (radio resource control, RRC) layer, and layer 2 includes a packet data convergence protocol (PACKET DATA convergence protocol, PDCP) layer, a radio link control (radio link control, RLC) layer, and a medium access control (medium access control, MAC) layer. Controller/processor 275 provides RRC layer functions associated with broadcast of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT (inter-RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification) and handover support functions; RLC layer functions associated with transmission of upper layer (upper layer) packet data units (PACKET DATA units, PDUs), error correction by ARQ, concatenation/segmentation and reassembly of RLC service data units (SERVICE DATA units, SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto Transport Blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction by HARQ, priority handling and logical channel ordering.

A Transmit (TX) processor 216 and a Receive (RX) processor 270 implement layer 1 functions associated with various signal processing functions. Layer 1, which includes a Physical (PHY) layer, may include error detection on a transport channel, forward error correction (forward error correction, FEC) encoding/decoding of a transport channel, interleaving, rate matching, mapping onto a physical channel, modulation/demodulation of a physical channel, and MIMO antenna processing. TX processor 216 processes the mapping to signal constellations 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-quadrature amplitude modulation, M-QAM). The encoded and modulated symbols may then be separated into parallel streams, and the individual streams may then be mapped to OFDM subcarriers, multiplexed with reference signals (e.g., pilots) in the time and/or frequency domain, and combined together using an inverse fast fourier transform (INVERSE FAST Fourier transform, IFFT) to produce a physical channel carrying the time-domain OFDM symbol stream. The OFDM streams are spatially precoded to produce a plurality of spatial streams. Channel estimates from channel estimator 274 may be used to determine coding and modulation schemes, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 250. Each spatial stream may be provided to a different antenna 220 via a separate transmitter 218 TX. Each transmitter 218TX may modulate an RF carrier with a corresponding spatial stream for transmission.

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

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

Similar to the functionality described in connection with DL transmission by base station 210, controller/processor 259 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression/decompression and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction by ARQ, concatenation/segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto TBs, demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction by HARQ, priority handling and logical channel ordering.

Channel estimator 258 derives channel estimates from reference signals or feedback transmitted by base station 210 that can be used by TX processor 268 to select the appropriate coding and modulation scheme and for spatial processing. The spatial streams generated by TX processor 268 may be provided to different antennas 252 via separate transmitters 254 TX. Each transmitter 254TX may modulate an RF carrier with a corresponding spatial stream for transmission. UL transmissions are processed at base station 210 in a manner similar to that described in connection with the receiver function at UE 250. Each receiver 218RX receives a signal via its respective antenna 220. Each receiver 218RX recovers information modulated onto an RF carrier and provides the information to the RX processor 270.

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

NR may refer to a radio configured to operate according to a new air interface (e.g., other than an orthogonal frequency division multiple access (orthogonal frequency divisional multiple access, OFDMA) -based air interface) or a fixed transport layer (e.g., other than IP). NR may utilize OFDM with Cyclic Prefix (CP) on uplink and downlink and may include support for half-duplex (half-duplex) operation using time division duplex (time division duplexing, TDD). NR may include critical tasks for enhanced mobile broadband (enhanced mobile broadband, eMBB) services with wide bandwidth (e.g., above 80 MHz), millimeter waves (MILLIMETER WAVE, mmW) for high carrier frequencies (e.g., 60 GHz), large-scale MTC (MASSIVE MTC, MMTC) for non-backward compatible MTC technologies, and/or for ultra-reliable low-latency communication (ultra-reliable low latency communications, URLLC) services.

A single component carrier bandwidth of 100MHz may be supported. In one example, an NR Resource Block (RB) may span 12 subcarriers, with the subcarrier bandwidth being 60kHz over 0.25ms duration, or the bandwidth being 30kHz over 0.5ms duration (similarly, 50MHz BW is used for 15kHz SCS over 1ms duration). Each radio frame may include 10 subframes (10, 20, 40 or 80 NR slots) of length 10 ms. Each time slot may indicate a link direction (i.e., DL or UL) for data transmission, and the link direction of each time slot may be dynamically switched. Each slot may include DL/UL data and DL/UL control data.

The NR RAN may include a Central Unit (CU) and a Distributed Unit (DU). An NR BS (e.g., gNB, 5G node B, TRP, AP) can correspond to one or more BSs. The NR unit may be configured as an access cell (ACCESS CELL, ACell) or a data only cell (DCell). For example, the RAN (e.g., a central unit or a distributed unit) may configure the cells. The DCell may be a cell for carrier aggregation or dual connectivity and may not be used for initial access, cell selection/reselection or handover. In some cases, the DCell may not transmit synchronization signals (synchronization signal, SS); in some cases, the DCell may transmit the SS. The NR BS may indicate the cell type to the UE by sending a downlink signal. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine that the NR BS is cell-selected, accessed, handed over, and/or measured based on the indicated cell type.

EPS includes E-UTRAN and EPC. The EPC includes MME, SGW and packet data network gateway (PGW), and is mainly responsible for mobility management, NAS signaling processing, EPS bearer resource control, and so on.

An EPS bearer is a logical pipe (logical pipe) of one or more service data flows (SERVICE DATA flows, SDFs) between the UE and the PGW. After the UE attaches (attach) to the core network, when initiating data service, the bearer resources required by the service can be obtained by initiating a bearer resource allocation procedure. Based on QoS parameters and traffic flow templates (traffic flow template, TFT) carried in the request message sent by the UE in this process, the EPC allocates bearer resources matching the current service.

In the current network, there is still a frequent cross radio access technology (inter radio access technology, inter-RAT) Tracking Area Update (TAU) procedure for handover from GSM/EDGE radio access network (GSM/EDGEradio access network, GERAN) and UTRAN to LTE. Accordingly, this may also result in the QoS change of the UE triggering the bearer modification procedure after the cross-RAT TAU is completed. The modification procedure includes a mobile originated (mobile originated, MO) modification in the uplink and a mobile terminated (mobile terminated, MT) modification in the downlink.

In addition, to ensure efficient utilization of resources, the base station may initiate a UE context release request to the core network, such as in the following cases: 1) The base station determines that the UE does not send any data transmission request within a certain time; 2) The base station does not receive an initial context establishment request sent by the core network within a certain time; 3) The base station determines that resources do not need to be configured for the UE; or 4) the base station cannot provide resources for the UE due to its own failure. And after receiving the UE context release command sent by the core network, the base station releases all resources configured for the UE.

In LTE, the UE may utilize a modification procedure to release bearer resources. To release the bearer resources, the UE includes all packet filters (PACKET FILTER, PF) belonging to the above mentioned bearers. In an EPS bearer context modification procedure, a priority conflict (PRECEDENCE CONFLICT) occurs if there are two or more packet filters with the same packet filter priority value in all TFTs associated with the PDN connection (if the old PF belongs to a dedicated EPS bearer context). At this time, the UE needs to: 1) Deleting old PFs having the same priority value; 2) And executing a bearer resource modification process requested by the UE to deactivate (deactivate) the corresponding dedicated EPS bearer context.

When the bearer resource modification procedure requested by the UE collides with the EPS bearer context modification procedure, the UE will suspend the bearer resource modification procedure requested by the UE and enter into the state bearer context active (BEARER CONTEXT ACTIVE).

However, if the goal is to release the bearer, suspending the UE-requested procedure and entering state BEARER CONTEXT ACTIVE will keep the bearer active, which is not as intended by the UE. Furthermore, if the corresponding dedicated EPS bearer has no PF in its TFT, such bearer cannot be maintained, nor is it possible to enter state BEARER CONTEXT ACTIVE. Therefore, it is necessary to solve these problems.

In EPS of a radio evolution network, a core network mainly includes three logical functional entities, namely MME, SGW and PGW. The MME is mainly responsible for NAS signaling encryption, allocates temporary identity labels for UEs, selects core network elements (e.g., SGW, PGW), and provides roaming, tracking, security, and other functions. In addition, the MME may save bearer context information when the UE is in an idle state. PGW is a gateway providing connection services, and is responsible for forwarding, filtering, etc. of UE data flows. The SGW is mainly responsible for relaying UE service flows between the UE and the PGW, and serves as an anchor point (anchor point) at the time of inter-base station handover.

Those skilled in the art will appreciate that a PDN connection is a logical data path between a UE and a PDN, while an EPS bearer is a smaller logical data path contained in the PDN connection. The PDN connection is used for ensuring the connectivity between the UE and the PDN and transmitting SDF between the UE and the PDN; while EPS bearers function to achieve finer QoS control. EPS bearers are one of the bearers in LTE.

Fig. 3 is a schematic diagram 300 illustrating an EPS bearer. A bearer is a logical path from the core network to the UE. Nodes between two, three or more network elements may form various types of bearers.

EPS bearers can be divided into two types: default bearers (default bearers) and dedicated bearers (DEDICATED BEARER). The default bearer is a user bearer for data and signaling that satisfies the default QoS. When a UE attaches to the core network, the UE requests the EPS to establish a PDN connection between the UE and the PDN. At the same time, a default bearer may be established. Both have the same lifecycle. The default bearer context remains active during the presence of the PDN connection, providing permanent online IP transport services for the user. When the UE has a small amount of data to transmit, it may transmit directly on the default bearer. Such data transmitted on the so-called default bearer may be understood as, in essence, a small amount of data sent directly on the common channel. Generally, the RRC is released after a certain time (inactivity timer) expires even though there is no data on the default bearer.

The dedicated bearer can only be initiated by the EPS, provided that the default bearer is established. The dedicated bearer provides specific QoS requirements for additional transmission requirements between the UE and the PGW. When the dedicated bearer is released, the default bearer is not affected. And when the UE has a larger data volume to be transmitted and a special wireless channel needs to be established for transmission, establishing a special bearing.

The UE may create multiple PDN connections with multiple EPS bearers, where the EPS bearers are identified by EPS bearer identities (EPS bearer identity, EBI). EBI is allocated to EPS bearers by MME, which is unique for each UE, and is used to distinguish multiple EPS bearers in the same UE. The EBI may be repeated among different UEs. All SDFs on the same EPS bearer have the same QoS guarantees (e.g., rate, delay, and bit error rate). Different QoS guarantees need different types of EPS bearers to provide.

Each EPS bearer has an associated QoS class identifier (QoS CLASS IDENTIFIER, QCI) and allocation and retention priority (allocation and retention priority, ARP). Each qci+arp combination corresponds to a unique EPS bearer.

The UE selects a PDN connection based on the service requirements of an Application (APP). After selecting the PDN connection, the EPS bearer with finer granularity may continue to be selected for transmitting data. That is, the user's IP data packets need to be mapped onto different EPS bearers to obtain corresponding QoS guarantees. This mapping is achieved by the TFT and its included PF. A TFT is a set of all PFs mapped to a corresponding EPS bearer. The PF indicates mapping the SDF of the user onto the corresponding EPS bearer to allow/reject SDF to pass, thereby implementing SDF filtering. If the SDF matches the PF set conditions, the PDN connection may use EPS bearers corresponding to the PF to transfer the SDF. The PF typically contains a source/destination IP address, a source/destination port (port) number, a protocol number, etc. The dedicated bearer must have a corresponding TFT. In contrast, default bearers are typically not configured with specific TFTs, or wild card (wildcard) TFTs, so that data packets that cannot be mapped to dedicated bearers can be mapped to default bearers. TFTs are created by PGW and forwarded to UEs through SGW and MME, which are divided into uplink TFT (UL TFT) and downlink TFT (DL TFT). In the uplink data direction, the UE maps SDFs over UL TFTs onto corresponding EPS bearers. In the downlink data direction, the PGW maps SDFs to corresponding EPS bearers via DL TFTs.

Each PF has a priority. The priority of each PF is unique in the same PDN connection. When the UE transmits uplink data, it searches all TFTs owned by itself for the PF with the highest priority, and maps the SDF to the TFT containing the PF. If no match is successful, the priority is decremented until successful. Finally, the UE maps the SDF to the corresponding EPS bearer via the TFT. If all PFs do not match, the UE maps the SDF onto EPS bearers not associated with any UL TFTs, which is typically the default bearer.

The establishment of the EPS dedicated bearer may be initiated by the network side or by the terminal side. In the dedicated bearer establishment procedure initiated by the network side, the dedicated bearer establishment signaling procedure is initiated by the network side. In this scenario, the application layer of the UE does not need to know specific QoS information of the EPS bearer layer. The application layer of the UE may negotiate QoS related information with the network through application layer signaling. In an EPS dedicated bearer establishment procedure (also referred to as a bearer resource allocation procedure) initiated by the UE side, the application layer of the UE directly requests the network side for a bearer layer QoS. If the network side accepts the request of the UE, signaling is further sent to the UE to establish the EPS special bearing.

Fig. 4 is a sequence diagram 400 illustrating a dedicated bearer establishment procedure. The above-described process includes the following operations. In operation 402, the connected UE 464 transmits a bearer resource allocation request or a bearer resource modification request message to the base station 462 through a UL information transmission (UL INFORMATION TRANSFER) message. In operation 404, the base station 462 sends a bearer resource allocation request or a bearer resource modification request message to the EPC 460 via an uplink NAS transport (UPLINK NAS TRANSPORT) message. In operation 406, EPC 460 processes the bearer resource allocation request or the bearer resource modification request.

In operation 408, EPC 460 sends an activate dedicated EPS bearer context request message to base station 462 via an EUTRAN radio access bearer (EUTRAN radio access bearer, E-RAB) setup request (E-RAB SETUP REQUEST) message. The E-RAB is the RAB in EPS. The E-RAB is identified by an E-RAB ID, which is assigned by the MME. As part of the EPS bearer, the E-RAB corresponds one-to-one with the EPS bearer. In operation 410, the base station 462 transmits a NAS message activate dedicated EPS bearer context request to the UE 464 via an RRC connection reconfiguration (RRC Connection Reconfiguration) message. In operation 412, the UE 464 successfully establishes a dedicated bearer and returns an RRC connection reconfiguration complete (RRC Connection Reconfiguration Complete) message to indicate that the bearer establishment was successful.

In operation 414, the base station 462 sends an E-RAB setup response (E-RAB SETUP RESPONSE) message to the EPC 460 indicating that a Radio Bearer (RB) was successfully established. After sending the RRC reconfiguration complete message in operation 412, the UE 464 notifies the base station 462 of the activate dedicated EPS bearer context accept message through a UL information transfer (UL INFORMATION TRANSFER) message in operation 416.

In operation 418, the base station 462 sends an activate dedicated EPS bearer context accept message to the EPC 460 via UPLINK NAS TRANSPORT message. Subsequently, in operation 420, the UE 464 and EPC 460 may transmit data via the base station 462.

The EPS bearer context-related procedure includes: default EPS bearer context activation, dedicated EPS bearer context activation, EPS bearer context modification, EPS bearer context deactivation.

FIG. 5 is a schematic diagram 500 illustrating a process conflict handling mechanism. UE 464 communicates with EPC 460 via base station 462. In operation 502, the UE 464 detects a semantic/grammatical error, such as a priority conflict. For example, priority conflicts may occur in the following scenarios: when a TFT operates as "create new TFT", "add packet filter to existing TFT" or "replace packet filter in existing TFT", there are two or more PFs in all TFTs associated with the PDN connection that have the same PF priority value and result in a bearer having an empty TFT. These errors trigger the UE 464 to initiate the UE requested modification procedure 504. The modification process 504 requested by the UE is an MO process.

In the above case, if the old PF does not belong to the default bearer context, the UE 464 will not diagnose it as an error, but will further process the new activation request. If successful, the old PF with the same filter priority value is deleted. Further, through point-to-point signaling between the network and the UE 464, the UE 464 may perform a bearer resource modification procedure requested by the UE to delete the PF in the network corresponding to the PF that has been deleted in the UE 464.

In the UE requested modification procedure 504, the UE 464 receives a modify EPS bearer context request (MODIFY EPS BEARER CONTEXT REQUEST) message 506 from the EPC 460. The UE 464 determines MODIFY EPS BEARER CONTEXT REQUEST that the process transaction identity (procedure transaction identity, PTI) information element (information element, IE) of message 506 is set to "no process transaction identity allocated" and the EPS bearer indicated in MODIFY EPS BEARER CONTEXT REQUEST message 506 is the EPS bearer that the UE requested to be modified in the modification procedure 504 requested by the UE. In other words, the modification requested by UE 464 is for the same bearer/session as the modification requested by EPC 460.

In a first method, the UE may abort the UE-requested modification procedure 504 in operation 508. Subsequently, the UE 464 initiates an EPS bearer context modification procedure 510. The EPS bearer context modifying process 510 is an MT process. Next, the UE 464 enters state BEARER CONTEXT ACTIVE.

However, in the UE requested modification procedure 504, all PFs may have been deleted, for example, due to all existing PFs colliding with newly added PFs, wherein both bearers/TFTs are associated with the same PDN connection. In this case, the UE 464 cannot maintain such a context, and the modifications are sent to the network to synchronize with the network. The dedicated bearer will be deleted because there are no more TFTs associated with the aforementioned old PF specifying the dedicated EPS bearer.

In a second method, after operation 508, the UE 464 determines whether the bearer still needs to be released. When the UE 464 still needs to release the bearer, for example because the TFT may still be empty, the UE 464 initiates an internal procedure 580 in parallel with the EPS bearer context modification procedure 510.

The UE 464 may proceed with the EPS bearer context modification procedure 510 and send a modification accept/reject message 512 to cause the network to complete the modification procedure. Where other problems occur during the MT modification procedure, a reject message may be used. The modify accept/reject message 512 may be a modify EPS bearer context accept (MODIFY EPS BEARER CONTEXT ACCEPT) message or a modify EPS bearer context reject (MODIFY EPS BEARER CONTEXT REJECT) message.

Further, in internal process 580, UE 464 may deactivate the EPS bearer context locally (locally) in operation 511 without peer-to-peer signaling between the UE and MME. To synchronize the EPS bearer context state with the MME, the UE 464 may send a tracking area UPDATE REQUEST (TRACKING AREA UPDATE REQUEST) message 514 to the MME of the EPC 460 that includes the EPS bearer context state IE.

After operation 508, when the UE 464 determines that no bearer release is required, the UE 464 may proceed with the EPS bearer context modification procedure 510 and enter state BEARER CONTEXT ACTIVE.

In general, when a UE initiated modification procedure triggers a bearer release, if the UE requested modification is triggered due to a priority conflict, the UE may: 1) When a process conflict occurs, locally releasing the bearer and/or sending the TAU to synchronize with the network; or 2) reinitiating the modification when a process conflict occurs, for example indicating that the TAU of the bearer is inactive.

Fig. 6 is a flow chart 600 of a method (procedure) for handling a process conflict associated with an EPS bearer. The above-described methods may be performed by a UE (e.g., UE 404, UE 250). In operation 602, the UE initiates an MO procedure for modifying an EPS bearer to release all traffic flows associated with the EPS bearer. In some configurations, to initiate the MO procedure, the UE may send a bearer resource modification request message. The bearer resource modification request message contains an EPS bearer identifier of the EPS bearer. In some configurations, MO processes are initiated in response to semantic or grammatical errors. Semantic or grammatical errors indicate that there is a priority conflict between packet filters. Priority collision occurs when there are two or more packet filters in all TFTs of the EPS bearer associated with the PDN connection that have the same packet filter priority value.

In operation 604, the UE receives a request to initiate an MT procedure for modifying an EPS bearer. In operation 606, in response to receiving the request, the UE suspends the MO process. In some configurations, the request includes a modify EPS bearer context request message. The PTI IE in the modify EPS bearer context request message indicates that no PTI is allocated.

In operation 612, the UE locally deactivates the EPS bearer. In some examples, operation 608 may optionally be performed prior to operation 612. In operation 608, the UE determines whether the EPS bearer needs to be released. For example, if the EPS bearer has an empty TFT, the UE may determine that the EPS bearer needs to be released. If the UE determines that the EPS bearer does not need to be released, the UE enters a live context state (e.g., state BEARER CONTEXT ACTIVE) and proceeds with the EPS bearer context modification procedure in operation 610. Note that in some examples, operation 608 may be skipped.

In operation 614, the UE continues the MT procedure by sending a modify EPS bearer context accept message or a modify EPS bearer context reject message. In operation 616, after locally deactivating the EPS bearer, the UE sends a TAU request to the core network to synchronize the EPS bearer context state. The TAU request indicates that the EPS bearer is in an inactive state.

It should be understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is only for exemplary illustration. The particular order or hierarchy of blocks in the processes/flow diagrams may be rearranged based on design preferences. Furthermore, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The above description may enable one of ordinary skill in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein but are to be accorded the full scope of the language claims. Where elements are referred to in the singular, unless explicitly stated to the contrary, it is not intended to mean "one and only one" but rather "one or more". The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. The term "some" means one or more unless specifically stated otherwise. Combinations such as "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C", and "A, B, C or any combination thereof" include any combination of A, B and/or C, and may include a plurality of a, a plurality of B, or a plurality of C. Specifically, for example, a combination of "at least one of A, B or C", "one or more of A, B or C", "at least one of A, B and C", "one or more of A, B and C" and "A, B, C or any combination thereof" may be a alone, B alone, C, A and B, A and C, B and C, or a and B and C, wherein any such combination may comprise one or more members of A, B or C. All structural and functional equivalents to the elements of the various aspects described throughout this document (that are known to those of ordinary skill in the art or that later become known) are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words "module," mechanism, "" element, "" means, "and the like may not be substitutes for the word" means. Thus, unless the phrase "means for …" is used to expressly state the element, the claim elements should not be construed as device-plus-function.

Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of the various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.

Claims (20)

1. A method of handling process conflicts associated with EPS bearers, comprising:

Initiating a mobile initiated MO process for modifying an Evolved Packet System (EPS) bearer to release all traffic flows associated with the EPS bearer;

receiving a request to initiate a mobile terminated MT procedure for modifying the EPS bearer;

in response to receiving the request, suspending the MO process; and

The EPS bearer is locally deactivated.

2. The method of handling process conflicts associated with EPS bearers according to claim 1 wherein the EPS bearers are deactivated locally in response to determining that the EPS bearers need to be released.

3. The method of handling process conflicts associated with EPS bearers according to claim 2 wherein determining that the EPS bearers need to be released comprises: and determining that the EPS bearing has an empty traffic flow template TFT.

4. The method of processing a process conflict associated with an EPS bearer according to claim 1 wherein the MT procedure is continued.

5. The method of processing a process conflict associated with an EPS bearer according to claim 4 wherein the MT procedure is executed in response to determining that release of an EPS bearer is not required, the method of processing a process conflict associated with an EPS bearer further comprising: a live context state is entered.

6. The method of processing a process conflict associated with an EPS bearer of claim 1, further comprising:

And sending a modified EPS bearing context acceptance message or a modified EPS bearing context rejection message.

7. The method of claim 1, wherein initiating the MO procedure comprises sending a bearer resource modification request message.

8. The method of claim 7, wherein the bearer resource modification request message includes an EPS bearer identification of the EPS bearer.

9. The method of processing a process conflict associated with an EPS bearer of claim 1 wherein the MO process is initiated in response to a semantic or grammatical error.

10. The method of processing a process conflict associated with an EPS bearer according to claim 9 wherein the semantic or grammatical error indicates that a priority conflict exists between packet filters.

11. The method of processing a process conflict associated with an EPS bearer according to claim 10 wherein the priority conflict occurs when there are two or more packet filters in all TFTs of the EPS bearer associated with a packet data network connection that have the same packet filter priority value.

12. The method of processing a process conflict associated with an EPS bearer according to claim 1 wherein the request comprises a modify EPS bearer context request message.

13. The method of processing a process conflict associated with an EPS bearer according to claim 12 wherein the process transaction identification, PTI, information element in the modify EPS bearer context request message indicates that no PTI is allocated.

14. The method of processing a process conflict associated with an EPS bearer of claim 1, further comprising:

after locally deactivating the EPS bearer, sending a tracking area update TAU request to a core network to synchronize an EPS bearer context state, wherein the TAU request indicates that the EPS bearer is in an inactive state.

15. A user equipment for handling process conflicts associated with an EPS bearer, comprising:

A memory; and

At least one processor, coupled to the memory, for:

Initiating a mobile initiated MO process for modifying an Evolved Packet System (EPS) bearer to release all traffic flows associated with the EPS bearer;

receiving a request to initiate a mobile terminated MT procedure for modifying the EPS bearer;

in response to receiving the request, suspending the MO process; and

The EPS bearer is locally deactivated.

16. The user device of claim 15, wherein the at least one processor is further configured to: the EPS bearer is locally deactivated in response to determining that release of the EPS bearer is required.

17. The user device of claim 15, wherein the at least one processor is further configured to: and sending a modified EPS bearing context acceptance message or a modified EPS bearing context rejection message.

18. The user equipment of claim 15, wherein initiating the MO procedure comprises sending a bearer resource modification request message.

19. The user device of claim 15, wherein the MO process is initiated in response to a semantic or grammatical error.

20. A storage medium storing a program which, when executed, causes an apparatus to perform the steps of the method of handling process conflicts associated with EPS bearers of any of claims 1 to 14.